/* ==========================================================================
   SignalGuessr - CSS Design System
   Modern SDR-inspired dark theme with glowing accents
   ========================================================================== */

/* CSS Custom Properties (Design Tokens) */
:root {
    /* Colors - SDR/Radio inspired palette */
    --color-bg-primary: #0a0e14;
    --color-bg-secondary: #121820;
    --color-bg-elevated: #1a2230;
    --color-bg-card: rgba(26, 34, 48, 0.8);

    --color-accent-primary: #00d9ff;
    /* Cyan - spectrum analyzer */
    --color-accent-secondary: #39ff14;
    /* Green - signal strength */
    --color-accent-tertiary: #ff6b35;
    /* Orange - warnings */
    --color-accent-gold: #ffd700;
    /* Gold - achievements */

    --color-text-primary: #e8eaed;
    --color-text-secondary: #9aa5b1;
    --color-text-muted: #5d6875;

    --color-success: #39ff14;
    --color-error: #ff4757;
    --color-warning: #ffb347;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #00d9ff 0%, #0066ff 100%);
    --gradient-success: linear-gradient(135deg, #39ff14 0%, #00c853 100%);
    --gradient-card: linear-gradient(180deg, rgba(26, 34, 48, 0.9) 0%, rgba(18, 24, 32, 0.95) 100%);
    --gradient-waterfall: linear-gradient(180deg, #000428 0%, #004e92 100%);

    /* Shadows & Glows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
    --glow-cyan: 0 0 20px rgba(0, 217, 255, 0.3);
    --glow-green: 0 0 20px rgba(57, 255, 20, 0.3);

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 2rem;
    --text-4xl: 2.5rem;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;

    /* Accessibility */
    --tap-target: 44px;
}

/* ==========================================================================
   Base Styles
   ========================================================================== */

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--color-text-primary);
    background: var(--color-bg-primary);
    min-height: 100vh;

    /* Subtle animated background */
    background-image:
        radial-gradient(ellipse at top, rgba(0, 217, 255, 0.05) 0%, transparent 50%),
        radial-gradient(ellipse at bottom right, rgba(57, 255, 20, 0.03) 0%, transparent 50%);
}

a {
    color: var(--color-accent-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-text-primary);
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* ==========================================================================
   Layout
   ========================================================================== */

.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--space-4);
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* ==========================================================================
   Header
   ========================================================================== */

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-4) var(--space-6);
    margin-bottom: var(--space-8);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    cursor: pointer;
    transition: opacity var(--transition-base);
}

.logo:hover {
    opacity: 0.8;
}

.logo:focus {
    outline: 2px solid var(--cyan-400);
    outline-offset: 4px;
    border-radius: var(--radius-sm);
}

.logo-icon {
    font-size: var(--text-3xl);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.7;
    }
}

.logo h1 {
    font-size: var(--text-2xl);
    font-weight: 700;
    letter-spacing: -0.5px;
}

.logo .accent {
    color: var(--color-accent-primary);
    text-shadow: var(--glow-cyan);
}

.nav {
    display: flex;
    gap: var(--space-2);
}

.nav-btn {
    padding: var(--space-2) var(--space-4);
    min-height: var(--tap-target);
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-btn:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-elevated);
}

/* Mobile Navigation Menu */
.nav-mobile {
    display: none;
    position: relative;
}

.nav-menu-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: var(--tap-target);
    height: var(--tap-target);
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-menu-btn:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-elevated);
}

.nav-menu-btn:focus {
    outline: 2px solid var(--cyan-400);
    outline-offset: 2px;
}

.nav-menu-dropdown {
    display: none;
    position: absolute;
    top: calc(100% + var(--space-2));
    right: 0;
    min-width: 160px;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    z-index: 100;
    overflow: hidden;
}

.nav-menu-dropdown.open {
    display: block;
}

.nav-menu-item {
    display: block;
    width: 100%;
    padding: var(--space-3) var(--space-4);
    text-align: left;
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.nav-menu-item:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-surface);
}

.nav-menu-item:focus {
    outline: none;
    color: var(--color-text-primary);
    background: var(--color-bg-surface);
}

/* Hide settings menu */
#btn-settings,
#btn-menu-settings {
    display: none !important;
}

.level-indicator {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: var(--tap-target);
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-full);
    border: 1px solid rgba(0, 217, 255, 0.35);
    background: var(--color-bg-elevated);
    box-shadow: var(--shadow-sm);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-text-primary);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    white-space: nowrap;
}

/* ==========================================================================
   Screens
   ========================================================================== */

.screen {
    display: none;
    animation: fadeIn var(--transition-base);
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==========================================================================
   Start Screen
   ========================================================================== */

.hero {
    text-align: center;
    margin-bottom: var(--space-12);
}

.hero-title {
    font-size: var(--text-4xl);
    font-weight: 700;
    margin-bottom: var(--space-4);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Mode Selector */
.mode-selector {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--space-6);
    max-width: 900px;
    margin: 0 auto;
}

.mode-card {
    position: relative;
    padding: var(--space-8);
    background: var(--gradient-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-xl);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    backdrop-filter: blur(10px);
}

.mode-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-accent-primary);
    box-shadow: var(--glow-cyan);
}

.mode-icon {
    font-size: 3rem;
    margin-bottom: var(--space-4);
}

.mode-card h3 {
    font-size: var(--text-xl);
    font-weight: 600;
    margin-bottom: var(--space-2);
}

.mode-card p {
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
}

.mode-badge {
    position: absolute;
    top: var(--space-3);
    right: var(--space-3);
    padding: var(--space-1) var(--space-3);
    background: var(--gradient-success);
    color: var(--color-bg-primary);
    font-size: var(--text-xs);
    font-weight: 600;
    border-radius: var(--radius-full);
}

.mode-progress {
    display: block;
    margin-top: var(--space-2);
    font-size: var(--text-xs);
    color: var(--color-accent-primary);
    font-weight: 500;
}

/* Daily Challenge Card Styles */
.daily-date {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-accent-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin: var(--space-2) 0;
}

.daily-completion-indicator {
    position: absolute;
    top: var(--space-3);
    right: var(--space-3);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-full);
    background: var(--color-bg-secondary);
    opacity: 0;
    transition: all var(--transition-base);
}

.completion-check {
    font-size: var(--text-lg);
    font-weight: 700;
}

/* Daily card not completed - emphasized with glow */
.mode-card[data-mode="daily"]:not(.daily-completed) {
    border-color: var(--color-accent-primary);
    box-shadow: var(--glow-cyan);
}

/* Daily card completed - muted colors */
.mode-card[data-mode="daily"].daily-completed {
    opacity: 0.7;
    border-color: rgba(255, 255, 255, 0.05);
}

.mode-card[data-mode="daily"].daily-completed:hover {
    opacity: 0.9;
    transform: translateY(-2px);
    border-color: var(--color-accent-primary);
    box-shadow: var(--glow-cyan);
}

.mode-card[data-mode="daily"].daily-completed .daily-completion-indicator {
    opacity: 1;
    background: var(--gradient-success);
    box-shadow: var(--glow-green);
}

.mode-card[data-mode="daily"].daily-completed .completion-check {
    color: var(--color-bg-primary);
}

/* ==========================================================================
   Story Mode Overview Screen
   ========================================================================== */

.hero-compact {
    margin-bottom: var(--space-8);
}

/* Tier Grid */
.story-tier-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-6);
    max-width: 900px;
    margin: 0 auto;
}

/* Tier Cards */
.story-tier-card {
    padding: var(--space-6);
    background: var(--gradient-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition: all var(--transition-base);
    backdrop-filter: blur(10px);
}

.story-tier-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-accent-primary);
    box-shadow: var(--glow-cyan);
}

/* Locked State */
.story-tier-card.locked {
    opacity: 0.5;
    cursor: not-allowed;
    filter: grayscale(30%);
}

.story-tier-card.locked:hover {
    transform: none;
    border-color: rgba(255, 255, 255, 0.05);
    box-shadow: none;
}

.story-tier-top {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--space-4);
}

.story-tier-title {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--color-text-primary);
    margin: 0;
    flex: 1;
}

.story-tier-lock {
    font-size: var(--text-xl);
    line-height: 1;
}

.story-tier-description {
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    line-height: 1.6;
    margin: 0 0 var(--space-4);
}

.story-tier-meta {
    display: flex;
    gap: var(--space-4);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
}

.story-tier-lessons {
    padding: var(--space-1) var(--space-3);
    background: rgba(0, 217, 255, 0.1);
    border-radius: var(--radius-sm);
}

.story-tier-actions {
    display: flex;
    gap: var(--space-3);
    margin-top: var(--space-4);
}

.story-tier-btn-tutorial,
.story-tier-btn-test {
    flex: 1;
    text-align: center;
}

/* Visual hierarchy: tutorials completed - swap primary/secondary */
.story-tier-card.tutorials-complete .story-tier-btn-tutorial {
    background: var(--color-bg-elevated);
    color: var(--color-text-secondary);
}

.story-tier-card.tutorials-complete .story-tier-btn-tutorial:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-secondary);
}

.story-tier-card.tutorials-complete .story-tier-btn-test {
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    font-size: var(--text-lg);
}

.story-tier-card.tutorials-complete .story-tier-btn-test:hover {
    transform: scale(1.02);
    box-shadow: var(--glow-cyan);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .story-tier-grid {
        grid-template-columns: 1fr;
        gap: var(--space-4);
    }
}

/* ==========================================================================
   Story Test Screen
   ========================================================================== */

.story-test-header-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.story-test-progress {
    margin: 0;
    font-size: var(--text-xs);
    color: var(--color-text-muted);
}

/* Test Progress Bar */
.test-progress-bar {
    display: flex;
    gap: var(--space-2);
    margin: 0 auto var(--space-8);
    padding: var(--space-2);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-full);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.test-progress-segment {
    flex: 1;
    height: 8px;
    background: var(--color-bg-elevated);
    border-radius: var(--radius-full);
    transition: background-color var(--transition-base);
}

.test-progress-segment.segment-correct {
    background: var(--color-success);
}

.test-progress-segment.segment-incorrect {
    background: var(--color-error);
}

#story-test-signal-host {
    max-width: 900px;
    margin: 0 auto;
}

#story-test-complete {
    max-width: 900px;
    margin: var(--space-8) auto 0;
}

.story-test-complete-score {
    margin: var(--space-4) 0 0;
    font-size: var(--text-lg);
    font-weight: 700;
    text-align: center;
}

.story-test-complete-note {
    margin: var(--space-2) 0 var(--space-6);
    color: var(--color-text-secondary);
    text-align: center;
}

/* Fixed Bottom Bar for Story Test Choices */
.story-test-bottom-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: var(--space-4) var(--space-6);
    background: rgba(10, 15, 28, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 -4px 30px rgba(0, 0, 0, 0.3);
    /* Hidden by default, shown when story test screen is active */
    display: none;
}

/* Show story test bottom bar when screen is active */
.screen-story-test.active .story-test-bottom-bar {
    display: block;
}

/* Hide bottom bar when reveal or complete panels are shown */
.screen-story-test.active .story-test-bottom-bar.is-hidden {
    display: none;
}

/* Add padding to story test screen to prevent content from hiding behind fixed bar */
.screen-story-test.active {
    padding-bottom: 140px;
}

@media (max-width: 768px) {
    .story-test-bottom-bar {
        padding: var(--space-3) var(--space-4);
    }

    .screen-story-test.active {
        padding-bottom: 180px;
    }
}

/* Story test reveal padding for fixed bottom bar */
#story-test-reveal:not([hidden]) {
    padding-bottom: 80px;
}

@media (max-width: 768px) {
    #story-test-reveal:not([hidden]) {
        padding-bottom: 70px;
    }
}

/* Story Test Result Bar - fixed bottom bar for result/continue */
.story-test-result-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: var(--space-3) var(--space-6);
    background: rgba(10, 15, 28, 0.95);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 -4px 30px rgba(0, 0, 0, 0.3);
}

.story-test-result-bar .result-bottom-bar-content {
    max-width: 720px;
    margin: 0 auto;
}

.story-test-result-bar .result-action-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
}

.story-test-result-bar .result-header {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    margin-bottom: 0;
}

.story-test-result-bar .result-icon {
    font-size: 1.2em;
    line-height: 1;
}

.story-test-result-bar .result-title {
    font-size: var(--text-lg);
    font-weight: 600;
}

.story-test-result-bar .result-header.correct .result-title {
    color: var(--color-success);
}

.story-test-result-bar .result-header.incorrect .result-title {
    color: var(--color-error);
}

.story-test-result-bar .btn-next {
    padding: var(--space-3) var(--space-6);
    min-height: var(--tap-target);
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    font-size: var(--text-base);
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.story-test-result-bar .btn-next:hover {
    transform: scale(1.02);
    box-shadow: var(--glow-cyan);
}

@media (max-width: 768px) {
    .story-test-result-bar {
        padding: var(--space-2) var(--space-4);
    }

    .story-test-result-bar .result-title {
        font-size: var(--text-base);
    }

    .story-test-result-bar .btn-next {
        padding: var(--space-2) var(--space-4);
        font-size: var(--text-sm);
    }
}

/* ==========================================================================
   Game Screen
   ========================================================================== */

/* Game HUD */
.game-hud {
    display: flex;
    justify-content: center;
    gap: var(--space-8);
    margin-bottom: var(--space-8);
    padding: var(--space-4);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
}

.hud-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-1);
}

.hud-label {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.hud-value {
    font-family: var(--font-mono);
    font-size: var(--text-xl);
    font-weight: 600;
    color: var(--color-accent-primary);
}

.hud-timer .hud-value {
    color: var(--color-accent-tertiary);
}

/* Signal Display */
.signal-display {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-6);
    margin-bottom: var(--space-8);
}

@media (max-width: 768px) {
    .signal-display {
        grid-template-columns: 1fr;
    }
}

/* Audio Player */
.audio-player-container {
    background: var(--color-bg-elevated);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.player-visual {
    margin-bottom: var(--space-4);
    background: var(--color-bg-primary);
    border-radius: var(--radius-md);
    overflow: hidden;
}

#audio-visualizer {
    width: 100%;
    height: 80px;
    display: block;
}

.player-controls {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.player-btn {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-full);
    color: var(--color-text-primary);
    font-size: var(--text-lg);
    transition: all var(--transition-fast);
}

.player-btn.loop-inactive {
    opacity: 0.55;
}

.player-btn.loop-active {
    background: var(--color-accent-secondary);
    color: var(--color-bg-primary);
    box-shadow: var(--glow-green);
}

.player-btn:hover {
    background: var(--color-accent-primary);
    color: var(--color-bg-primary);
    box-shadow: var(--glow-cyan);
}

.player-btn.loop-active:hover {
    background: var(--color-accent-secondary);
    color: var(--color-bg-primary);
    box-shadow: var(--glow-green);
}

.progress-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.progress-bar {
    height: 6px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-full);
    overflow: hidden;
    cursor: pointer;
}

.progress-fill {
    height: 100%;
    width: 0%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    transition: width 100ms linear;
}

.time-display {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
}

/* Waterfall Display */
.waterfall-container {
    background: var(--color-bg-elevated);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    border: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 200px;
    overflow: hidden;
}

#waterfall-image {
    max-width: 100%;
    width: 100%;
    max-height: min(300px, 45vh);
    object-fit: contain;
    border-radius: var(--radius-md);
    display: none;
}

#waterfall-image.loaded {
    display: block;
}

.waterfall-placeholder {
    color: var(--color-text-muted);
    font-size: var(--text-lg);
}

/* Signal Info Bar (Frequency & Location) */
.signal-info-bar {
    grid-column: 1 / -1;
    display: flex;
    justify-content: center;
    gap: var(--space-6);
    flex-wrap: wrap;
    padding: var(--space-4);
    background: var(--color-bg-elevated);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.signal-info-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-1);
}

.signal-info-label {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.signal-info-value {
    font-size: var(--text-sm);
    color: var(--color-accent-primary);
    font-family: var(--font-mono);
}

/* Dev mode only elements - hidden by default */
.dev-mode-only {
    display: none !important;
}

body.dev-mode .dev-mode-only {
    display: flex !important;
}

/* Hide dev-mode items with missing values (more specific than dev-mode rule) */
body.dev-mode .dev-mode-only.is-hidden,
.signal-info-item.is-hidden {
    display: none !important;
}

@media (max-width: 768px) {
    .signal-info-bar {
        gap: var(--space-4);
        padding: var(--space-3);
    }
}

/* Hints */
.hints-container {
    margin-bottom: var(--space-6);
    text-align: center;
}

.hint-tags {
    display: flex;
    justify-content: center;
    gap: var(--space-3);
    flex-wrap: wrap;
}

.hint-tag {
    padding: var(--space-2) var(--space-4);
    background: rgba(0, 217, 255, 0.1);
    border: 1px solid rgba(0, 217, 255, 0.3);
    color: var(--color-accent-primary);
    font-size: var(--text-sm);
    border-radius: var(--radius-full);
}

/* Fixed Bottom Bar for Answer Input */
.game-bottom-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: var(--space-4) var(--space-6);
    background: rgba(10, 15, 28, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 -4px 30px rgba(0, 0, 0, 0.3);
    /* Hidden by default, shown when game screen is active */
    display: none;
}

/* Show bottom bar only when game screen is active */
.screen-game.active .game-bottom-bar {
    display: block;
}

/* Add padding to game screen to prevent content from hiding behind fixed bar */
.screen-game.active {
    padding-bottom: 140px;
}

@media (max-width: 768px) {
    .game-bottom-bar {
        padding: var(--space-3) var(--space-4);
    }

    .screen-game.active {
        padding-bottom: 180px;
    }
}

/* Guess Input */
.guess-container {
    display: flex;
    gap: var(--space-4);
    justify-content: center;
    align-items: center;
    margin-bottom: 0;
}

.guess-input-wrapper {
    position: relative;
    flex: 1;
    max-width: 400px;
}

.guess-input {
    width: 100%;
    padding: var(--space-4) var(--space-5);
    background: var(--color-bg-elevated);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    color: var(--color-text-primary);
    font-size: var(--text-lg);
    font-family: var(--font-primary);
    transition: all var(--transition-fast);
}

.guess-input:focus {
    outline: none;
    border-color: var(--color-accent-primary);
    box-shadow: var(--glow-cyan);
}

.guess-input::placeholder {
    color: var(--color-text-muted);
}

/* Autocomplete Dropdown - opens upward since input is fixed at bottom */
.autocomplete-dropdown {
    position: absolute;
    bottom: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg-elevated);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-2);
    max-height: 300px;
    overflow-y: auto;
    z-index: 100;
    display: none;
    box-shadow: var(--shadow-lg);
}

.autocomplete-dropdown.active {
    display: block;
}

.autocomplete-item {
    padding: var(--space-3) var(--space-4);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.autocomplete-item:hover,
.autocomplete-item.selected {
    background: rgba(0, 217, 255, 0.1);
}

.autocomplete-item .signal-name {
    font-weight: 500;
}

.autocomplete-item .signal-category {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
}

.autocomplete-item .signal-match-reason {
    font-size: var(--text-xs);
    color: var(--color-accent-primary);
}

/* Submit and Skip Buttons */
.btn-submit {
    padding: var(--space-4) var(--space-8);
    min-height: var(--tap-target);
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    font-size: var(--text-lg);
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}

.btn-submit:hover {
    transform: scale(1.02);
    box-shadow: var(--glow-cyan);
}

.btn-input-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-3) auto;
    padding: var(--space-2) var(--space-4);
    min-height: 32px;
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    border-radius: var(--radius-full);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    transition: all var(--transition-fast);
}

.btn-input-toggle:hover {
    color: var(--color-text-primary);
    border-color: var(--color-accent-cyan);
    box-shadow: var(--glow-cyan);
}

/* Multiple Choice */
.choices-container[hidden] {
    display: none;
}

.choices-container {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-4);
    max-width: 900px;
    margin: 0 auto;
}

.choice-btn {
    padding: var(--space-4) var(--space-5);
    min-height: var(--tap-target);
    background: var(--color-bg-elevated);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    color: var(--color-text-primary);
    font-size: var(--text-base);
    text-align: left;
    transition: all var(--transition-fast);
}

.choice-btn:hover {
    border-color: var(--color-accent-primary);
    background: rgba(0, 217, 255, 0.05);
}

.choice-btn.correct {
    border-color: var(--color-success);
    background: rgba(57, 255, 20, 0.1);
}

.choice-btn.incorrect {
    border-color: var(--color-error);
    background: rgba(255, 71, 87, 0.1);
}

.choice-btn.correct:disabled,
.choice-btn.incorrect:disabled {
    opacity: 1;
}

.choice-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.choice-btn:disabled:hover {
    border-color: rgba(255, 255, 255, 0.1);
    background: var(--color-bg-elevated);
}

.choice-btn.correct:disabled:hover {
    border-color: var(--color-success);
    background: rgba(57, 255, 20, 0.1);
}

.choice-btn.incorrect:disabled:hover {
    border-color: var(--color-error);
    background: rgba(255, 71, 87, 0.1);
}

/* Dev mode hint for correct answer (dashed border, subtle highlight) */
.choice-btn.dev-hint {
    border-style: dashed;
    border-color: var(--color-success);
    background: rgba(57, 255, 20, 0.05);
}

/* ==========================================================================
   Result Screen
   ========================================================================== */

.result-card {
    max-width: 600px;
    margin: 0 auto;
    padding: var(--space-10);
    background: var(--gradient-card);
    border-radius: var(--radius-xl);
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.05);
    /* Flex layout for vertical stacking */
    display: flex;
    flex-direction: column;
}

.screen-result.active {
    display: flex;
    flex-direction: column;
    flex: 1;
    padding-bottom: 120px;
    /* Space for fixed bottom bar */
}

.screen-result .result-card {
    flex: 1;
    min-height: 0;
    max-width: 720px;
    overflow-y: auto;
}

/* Fixed Bottom Bar for Result Actions */
.result-bottom-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: var(--space-3) var(--space-6);
    background: rgba(10, 15, 28, 0.95);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 -4px 30px rgba(0, 0, 0, 0.3);
    /* Hidden by default, shown when result screen is active */
    display: none;
}

.screen-result.active .result-bottom-bar {
    display: block;
}

.result-bottom-bar-content {
    max-width: 720px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.result-points {
    font-family: var(--font-mono);
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--color-accent-secondary);
    text-shadow: var(--glow-green);
    text-align: center;
}

.result-points.partial {
    color: var(--color-warning);
    text-shadow: 0 0 18px rgba(255, 179, 71, 0.35);
}

.result-points.incorrect {
    color: var(--color-error);
    text-shadow: 0 0 18px rgba(255, 71, 87, 0.35);
}

.result-points.is-hidden {
    display: none;
}

.result-action-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
}

.result-bottom-bar .result-header {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    margin-bottom: 0;
}

.result-bottom-bar .result-icon {
    font-size: 1.2em;
    line-height: 1;
}

.result-bottom-bar .result-title {
    font-size: var(--text-lg);
    font-weight: 600;
}

.result-header.correct .result-title {
    color: var(--color-success);
}

.result-header.partial .result-title {
    color: var(--color-warning);
}

.result-header.incorrect .result-title {
    color: var(--color-error);
}

.result-bottom-bar .btn-next {
    padding: var(--space-3) var(--space-6);
    min-height: var(--tap-target);
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    font-size: var(--text-base);
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
    white-space: nowrap;
    margin-left: auto;
}

.result-bottom-bar .btn-next:hover {
    transform: scale(1.02);
    box-shadow: var(--glow-cyan);
}

@media (max-width: 768px) {
    .screen-result.active {
        padding-bottom: 100px;
    }

    .result-bottom-bar {
        padding: var(--space-2) var(--space-4);
    }

    .result-points {
        font-size: var(--text-lg);
    }

    .result-bottom-bar .result-title {
        font-size: var(--text-base);
    }

    .result-bottom-bar .btn-next {
        padding: var(--space-2) var(--space-4);
        font-size: var(--text-sm);
    }
}

/* Widen result card on desktop when dual columns are visible */
@media (min-width: 768px) {
    .result-card.has-dual-columns {
        max-width: 900px;
    }
}

.result-header {
    margin-bottom: var(--space-4);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-3);
}

.result-icon {
    font-size: 1.1em;
    display: inline-flex;
    align-items: center;
    line-height: 1;
    margin-bottom: 0;
}

.result-title {
    font-size: var(--text-3xl);
    font-weight: 700;
}

.result-header.correct .result-title {
    color: var(--color-success);
}

.result-header.partial .result-title {
    color: var(--color-warning);
}

.result-header.incorrect .result-title {
    color: var(--color-error);
}

.result-feedback {
    margin: 0 0 var(--space-4);
    font-size: var(--text-sm);
    font-weight: 600;
    letter-spacing: 0.5px;
    color: var(--color-text-secondary);
}

.result-feedback.correct {
    color: var(--color-success);
}

.result-feedback.partial {
    color: var(--color-warning);
}

.result-feedback.incorrect {
    color: var(--color-error);
}

.result-feedback.is-hidden {
    display: none;
}

.result-signal-info {
    text-align: left;
    margin-bottom: var(--space-8);
    padding: var(--space-6);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
}

.result-signal-info.is-hidden {
    display: none;
}

.result-score.is-hidden {
    display: none;
}

.btn-next.is-hidden {
    display: none;
}

.dual-signal-comparison {
    display: grid;
    gap: var(--space-6);
    margin-bottom: var(--space-8);
    align-items: stretch;
    min-height: 0;
}

.dual-signal-comparison.is-hidden {
    display: none;
}

.dual-signal-comparison.single-column {
    grid-template-columns: minmax(0, 1fr);
}

.dual-signal-comparison.single-column .signal-column-guess {
    display: none;
}

.dual-signal-comparison.single-column .signal-column-correct {
    justify-self: center;
    width: min(100%, 640px);
}

@media (min-width: 768px) {
    .dual-signal-comparison {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .dual-signal-comparison.single-column {
        grid-template-columns: minmax(0, 1fr);
    }
}

.screen-result .dual-signal-comparison {
    flex: 1;
    margin-bottom: 0;
}

.screen-result .result-signal-info {
    flex: 1;
    min-height: 0;
    margin-bottom: 0;
    display: flex;
    flex-direction: column;
}

.screen-result .result-signal-info.is-hidden {
    display: none;
}

.screen-result .result-signal-info .signal-description {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    margin-bottom: 0;
    padding-right: var(--space-2);
}

.signal-column {
    text-align: left;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    border: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    min-height: 0;
}

.signal-column-header {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-size: var(--text-xl);
    font-weight: 700;
}

.signal-column-header .result-title {
    color: var(--color-text-primary);
}

.signal-column-header .result-points {
    font-size: var(--text-lg);
}

.signal-column-header.correct .result-title {
    color: var(--color-success);
}

.signal-column-header.incorrect .result-title {
    color: var(--color-error);
}

.signal-column-header.partial .result-title {
    color: var(--color-warning);
}

.signal-column-badge {
    align-self: flex-start;
    font-size: var(--text-xs);
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    padding: 4px 10px;
    border-radius: var(--radius-full);
}

.badge-correct {
    color: var(--color-success);
    background: rgba(57, 255, 20, 0.15);
    border: 1px solid rgba(57, 255, 20, 0.4);
}

.badge-guess {
    color: var(--color-warning);
    background: rgba(255, 165, 0, 0.15);
    border: 1px solid rgba(255, 165, 0, 0.4);
}

.signal-column-name {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--color-accent-primary);
}

.signal-column-waterfall {
    background: var(--color-bg-elevated);
    border-radius: var(--radius-lg);
    padding: var(--space-3);
    border: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 160px;
    overflow: hidden;
}

.signal-column-waterfall img {
    max-width: 100%;
    width: 100%;
    max-height: 220px;
    object-fit: contain;
    border-radius: var(--radius-md);
    display: none;
}

.signal-column-waterfall img.loaded {
    display: block;
}

.signal-column-waterfall-placeholder {
    color: var(--color-text-muted);
    font-size: var(--text-sm);
}

.signal-column-listen-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-full);
    border: 1px solid rgba(255, 255, 255, 0.1);
    background: var(--color-bg-elevated);
    color: var(--color-text);
    font-size: var(--text-sm);
    cursor: pointer;
    min-height: var(--tap-target);
    transition: transform 150ms ease, border-color 150ms ease;
}

.signal-column-listen-btn:hover {
    border-color: rgba(255, 255, 255, 0.25);
    transform: translateY(-1px);
}

.signal-column-info {
    display: grid;
    gap: var(--space-2);
}

.signal-column-info-row {
    display: flex;
    justify-content: space-between;
    gap: var(--space-3);
    font-size: var(--text-xs);
}

.signal-column-info-label {
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
}

.signal-column-info-value {
    color: var(--color-text-secondary);
    text-align: right;
}

.signal-column-description {
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    line-height: 1.6;
    margin: 0;
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    padding-right: var(--space-2);
}

.signal-name {
    font-size: var(--text-xl);
    font-weight: 600;
    margin-bottom: var(--space-3);
    color: var(--color-accent-primary);
}

.signal-description {
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    margin-bottom: var(--space-4);
    line-height: 1.7;
}

.signal-meta {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    margin-bottom: var(--space-4);
}

.meta-item {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.meta-label {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.meta-tags {
    display: flex;
    gap: var(--space-2);
    flex-wrap: wrap;
}

.meta-tag {
    padding: var(--space-1) var(--space-3);
    background: var(--color-bg-elevated);
    border-radius: var(--radius-sm);
    font-size: var(--text-xs);
    color: var(--color-text-secondary);
}

.meta-value {
    color: var(--color-text-primary);
}

.wiki-link {
    display: inline-block;
    font-size: var(--text-sm);
    color: var(--color-accent-primary);
    margin-top: var(--space-2);
}

.result-score {
    margin-bottom: var(--space-8);
}

.score-label {
    display: block;
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin-bottom: var(--space-2);
}

.score-value {
    font-family: var(--font-mono);
    font-size: var(--text-3xl);
    font-weight: 700;
    color: var(--color-accent-secondary);
    text-shadow: var(--glow-green);
}

.score-value.partial {
    color: var(--color-warning);
    text-shadow: 0 0 18px rgba(255, 179, 71, 0.35);
}

.score-value.incorrect {
    color: var(--color-error);
    text-shadow: 0 0 18px rgba(255, 71, 87, 0.35);
}

/* Result bottom section for dual-column view (inline Points + Next button) */
.result-bottom-section {
    display: flex;
    justify-content: space-between;
    align-items: center;
    text-align: left;
    margin-top: var(--space-4);
}

.result-bottom-section.is-hidden {
    display: none;
}

.result-score-inline {
    margin-bottom: 0;
}

.result-score-inline .score-label {
    margin-bottom: var(--space-1);
}

.result-score-inline .score-value {
    font-size: var(--text-2xl);
}

.btn-next {
    padding: var(--space-4) var(--space-10);
    min-height: var(--tap-target);
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    font-size: var(--text-lg);
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}

.btn-next:hover {
    transform: scale(1.02);
    box-shadow: var(--glow-cyan);
}



.btn-result-quit,
.btn-result-next {
    padding: var(--space-2) var(--space-4);
    min-height: var(--tap-target);
    font-size: var(--text-sm);
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.btn-result-quit {
    color: var(--color-text-secondary);
    background: var(--color-bg-elevated);
}

.btn-result-quit:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-secondary);
}

.btn-result-next {
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
}

.btn-result-next:hover {
    box-shadow: var(--glow-cyan);
}

/* ==========================================================================
   Final Score Screen
   ========================================================================== */

.final-card {
    max-width: 500px;
    margin: 0 auto;
    padding: var(--space-12);
    background: var(--gradient-card);
    border-radius: var(--radius-xl);
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.final-title {
    font-size: var(--text-3xl);
    font-weight: 700;
    margin-bottom: var(--space-10);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.final-stats {
    display: flex;
    justify-content: center;
    gap: var(--space-10);
    margin-bottom: var(--space-10);
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.stat-value {
    font-family: var(--font-mono);
    font-size: var(--text-3xl);
    font-weight: 700;
    color: var(--color-accent-primary);
}

.stat-label {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
}

.leaderboard-panel {
    margin-bottom: var(--space-8);
    padding: var(--space-6);
    background: rgba(0, 0, 0, 0.18);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-lg);
    text-align: left;
}

.leaderboard-title {
    font-size: var(--text-lg);
    font-weight: 600;
    margin-bottom: var(--space-4);
    color: var(--color-text-primary);
}

.leaderboard-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.leaderboard-label {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

.leaderboard-controls {
    display: flex;
    gap: var(--space-3);
    align-items: center;
}

.leaderboard-input {
    flex: 1;
    min-width: 0;
    padding: var(--space-3) var(--space-4);
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.08);
    outline: none;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.leaderboard-input:focus {
    border-color: rgba(0, 217, 255, 0.55);
    box-shadow: var(--glow-cyan);
}

.leaderboard-note {
    margin-top: var(--space-3);
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    min-height: 1.2em;
}

.leaderboard-status {
    margin-top: var(--space-2);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    min-height: 1.2em;
}

.leaderboard-status.error {
    color: var(--color-error);
}

/* ==========================================================================
   Leaderboard Screen
   ========================================================================== */

.leaderboard-page {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--space-10);
    background: var(--gradient-card);
    border-radius: var(--radius-xl);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.leaderboard-page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    margin-bottom: var(--space-4);
}

.leaderboard-page-title {
    font-size: var(--text-3xl);
    font-weight: 700;
    margin: 0;
}

.leaderboard-page-status {
    margin-bottom: var(--space-8);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    min-height: 1.2em;
}

.leaderboard-page-status.error {
    color: var(--color-error);
}

.leaderboard-section {
    margin-top: var(--space-8);
}

.leaderboard-section-title {
    font-size: var(--text-lg);
    font-weight: 600;
    margin-bottom: var(--space-2);
    color: var(--color-text-primary);
}

.leaderboard-section-status {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    min-height: 1.2em;
    margin-bottom: var(--space-3);
}

.leaderboard-section-status.error {
    color: var(--color-error);
}

.leaderboard-table-wrap {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.leaderboard-table {
    width: 100%;
    border-collapse: collapse;
    background: rgba(0, 0, 0, 0.18);
}

.leaderboard-table th,
.leaderboard-table td {
    padding: var(--space-3) var(--space-4);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    text-align: left;
    white-space: nowrap;
}

.leaderboard-table th {
    font-size: var(--text-xs);
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--color-text-muted);
}

.leaderboard-table td {
    font-size: var(--text-sm);
    color: var(--color-text-primary);
}

.leaderboard-table tbody tr:nth-child(even) td {
    background: rgba(255, 255, 255, 0.02);
}

.leaderboard-table td.leaderboard-rank,
.leaderboard-table td.leaderboard-score,
.leaderboard-table td.leaderboard-date {
    font-family: var(--font-mono);
}

.final-actions {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.btn-primary {
    padding: var(--space-4) var(--space-8);
    min-height: var(--tap-target);
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    font-size: var(--text-lg);
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}

.btn-primary:hover {
    transform: scale(1.02);
    box-shadow: var(--glow-cyan);
}

.btn-secondary {
    padding: var(--space-3) var(--space-6);
    min-height: var(--tap-target);
    background: var(--color-bg-elevated);
    color: var(--color-text-secondary);
    font-size: var(--text-base);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.btn-secondary:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-secondary);
}

#btn-share.copied,
#btn-share.copied:hover {
    background: var(--gradient-success);
    color: var(--color-bg-primary);
}

#btn-share.copy-failed,
#btn-share.copy-failed:hover {
    color: var(--color-error);
}

/* ==========================================================================
   Modal
   ========================================================================== */

.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(10, 14, 20, 0.9);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(4px);
}

.modal.active {
    display: flex;
}

.modal-content {
    position: relative;
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    overflow-x: hidden;
    padding: var(--space-10);
    background: var(--color-bg-elevated);
    border-radius: var(--radius-xl);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-sizing: border-box;
}

.modal-close {
    position: absolute;
    top: var(--space-4);
    right: var(--space-4);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-xl);
    color: var(--color-text-muted);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
}

.modal h2 {
    font-size: var(--text-2xl);
    margin-bottom: var(--space-6);
    text-align: center;
}

.help-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.help-step {
    display: flex;
    align-items: flex-start;
    gap: var(--space-4);
}

.step-number {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    font-weight: 600;
    border-radius: var(--radius-full);
    flex-shrink: 0;
}

.help-step p {
    color: var(--color-text-secondary);
    padding-top: var(--space-1);
}

/* ==========================================================================
   Settings
   ========================================================================== */

.settings-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.settings-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
}

.settings-label {
    font-weight: 600;
    color: var(--color-text-primary);
}

.settings-note {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    text-align: center;
}

.segmented-control {
    display: inline-flex;
    gap: var(--space-1);
    padding: var(--space-1);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-full);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.segmented-control input {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.segmented-control label {
    padding: var(--space-2) var(--space-4);
    min-height: var(--tap-target);
    border-radius: var(--radius-full);
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    user-select: none;
}

.segmented-control label:hover {
    color: var(--color-text-primary);
}

.segmented-control input:checked+label {
    background: var(--color-bg-elevated);
    color: var(--color-text-primary);
    box-shadow: var(--shadow-sm);
}

/* ==========================================================================
   Practice Filters
   ========================================================================== */

.modal-content-wide {
    max-width: 720px;
}

.filters-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
    max-width: 100%;
    overflow-x: hidden;
}

.filter-block {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.filter-label {
    font-weight: 600;
    color: var(--color-text-primary);
}

.filter-note {
    margin-top: calc(var(--space-3) * -1);
    color: var(--color-text-muted);
    font-size: var(--text-sm);
}

.filter-summary {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    text-align: center;
}

.filter-count {
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
}

.filter-error {
    color: var(--color-error);
    font-size: var(--text-sm);
    min-height: 1.25em;
}

.filter-actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-3);
    justify-content: center;
}

.filter-actions .btn-secondary,
.filter-actions .btn-primary {
    flex: 1 1 120px;
    min-width: 0;
}

.btn-primary:disabled {
    opacity: 0.55;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.filter-chips {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

.filter-chips input {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.filter-chips label {
    padding: var(--space-2) var(--space-4);
    min-height: var(--tap-target);
    border-radius: var(--radius-full);
    background: rgba(12, 18, 32, 0.6);
    border: 1px solid rgba(120, 140, 180, 0.25);
    color: var(--color-text-muted);
    font-size: var(--text-sm);
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    transition: all var(--transition-fast);
    user-select: none;
    cursor: pointer;
}

.filter-chips label::before {
    content: "✓";
    font-size: 0.75rem;
    color: var(--color-text-primary);
    opacity: 0;
    transform: scale(0.8);
    transition: all var(--transition-fast);
}

.filter-chips label:hover {
    color: var(--color-text-primary);
    border-color: rgba(72, 219, 251, 0.45);
    box-shadow: 0 0 0 1px rgba(72, 219, 251, 0.2);
}

.filter-chips input:focus-visible+label {
    outline: 2px solid rgba(72, 219, 251, 0.65);
    outline-offset: 2px;
}

.filter-chips input:checked+label {
    background: linear-gradient(135deg, rgba(30, 72, 125, 0.85), rgba(15, 35, 70, 0.85));
    border-color: rgba(72, 219, 251, 0.7);
    color: var(--color-text-primary);
    box-shadow: 0 6px 16px rgba(10, 24, 45, 0.35), 0 0 0 1px rgba(72, 219, 251, 0.35);
}

.filter-chips input:checked+label::before {
    opacity: 1;
    transform: scale(1);
}

.filter-chips-scroll {
    max-height: 220px;
    overflow: auto;
    padding: var(--space-2);
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.footer {
    text-align: center;
    padding: var(--space-8) var(--space-4);
    color: var(--color-text-muted);
    font-size: var(--text-sm);
}

.footer p {
    margin-bottom: var(--space-2);
}

/* ==========================================================================
   Scrollbar
   ========================================================================== */

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--color-text-muted);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-secondary);
}

/* ==========================================================================
   Responsive Adjustments
   ========================================================================== */

@media (max-width: 768px) {
    .nav-desktop {
        display: none;
    }

    .nav-mobile {
        display: block;
    }

    /* Story tutorial/test navigation stays near top on mobile */
    .tutorial-card {
        display: flex;
        flex-direction: column;
    }

    .tutorial-actions {
        order: -1;
        margin-bottom: var(--space-4);
    }

    .screen-story-test .result-card {
        display: flex;
        flex-direction: column;
    }

    .screen-story-test .result-card>.btn-next {
        order: -1;
        margin-bottom: var(--space-4);
    }
}

@media (max-width: 640px) {
    .app-container {
        padding: var(--space-3);
    }

    .header {
        flex-direction: row;
        gap: var(--space-3);
        margin-bottom: var(--space-4);
        padding: var(--space-3) var(--space-4);
    }

    .header-actions {
        gap: var(--space-2);
    }

    /* Compact hero for mobile - Daily Challenge visible without scrolling */
    .hero {
        margin-bottom: var(--space-4);
    }

    .hero-title {
        font-size: var(--text-2xl);
        margin-bottom: var(--space-2);
    }

    .hero-subtitle {
        font-size: var(--text-sm);
        display: none;
    }

    .mode-selector {
        grid-template-columns: 1fr;
        gap: var(--space-3);
    }

    .mode-card {
        padding: var(--space-4) var(--space-5);
    }

    .mode-icon {
        font-size: 2rem;
        margin-bottom: var(--space-2);
    }

    .mode-card h3 {
        font-size: var(--text-lg);
        margin-bottom: var(--space-1);
    }

    .game-hud {
        gap: var(--space-4);
        flex-wrap: wrap;
    }

    .guess-container {
        flex-direction: column;
    }

    .guess-input-wrapper {
        max-width: 100%;
    }

    .choices-container {
        gap: var(--space-3);
    }

    .settings-row {
        flex-direction: column;
        align-items: stretch;
    }

    .segmented-control {
        width: 100%;
        justify-content: center;
    }

    .final-stats {
        flex-direction: column;
        gap: var(--space-6);
    }

    .result-card {
        padding: var(--space-4);
    }

    .result-header {
        margin-bottom: var(--space-4);
        gap: var(--space-2);
    }

    .result-icon {
        font-size: 1.1em;
    }

    .result-title {
        font-size: var(--text-xl);
    }

    .result-signal-info {
        padding: var(--space-4);
        margin-bottom: var(--space-4);
    }

    .signal-name {
        font-size: var(--text-lg);
        margin-bottom: var(--space-2);
    }

    .signal-description {
        font-size: var(--text-xs);
        margin-bottom: var(--space-3);
        display: -webkit-box;
        -webkit-line-clamp: 2;
        line-clamp: 2;
        -webkit-box-orient: vertical;
        overflow: hidden;
    }

    .screen-result .result-signal-info .signal-description {
        display: block;
        -webkit-line-clamp: unset;
        line-clamp: unset;
        -webkit-box-orient: unset;
        overflow-y: auto;
        margin-bottom: 0;
    }

    .signal-meta {
        gap: var(--space-2);
        margin-bottom: var(--space-2);
    }

    .meta-item {
        gap: var(--space-1);
    }

    .meta-tags {
        gap: var(--space-1);
    }

    .meta-tag {
        padding: var(--space-1) var(--space-2);
        font-size: calc(var(--text-xs) - 1px);
    }

    .wiki-link {
        font-size: var(--text-xs);
    }

    .result-score {
        margin-bottom: var(--space-4);
    }

    .score-value {
        font-size: var(--text-xl);
    }

    /* Modal mobile optimizations - fixed action buttons at bottom */
    .modal-content {
        display: flex;
        flex-direction: column;
        padding: var(--space-4);
        padding-bottom: 0;
        /* Remove bottom padding, actions bar handles it */
        max-height: 90vh;
    }

    .modal h2 {
        font-size: var(--text-xl);
        margin-bottom: var(--space-4);
        flex-shrink: 0;
    }

    /* Make filters content scrollable */
    .filters-content {
        flex: 1;
        min-height: 0;
        overflow-y: auto;
        gap: var(--space-4);
        padding-bottom: var(--space-4);
    }

    /* Fixed action buttons at bottom of modal */
    .filter-actions {
        position: sticky;
        bottom: 0;
        left: 0;
        right: 0;
        margin: 0 calc(var(--space-4) * -1);
        /* Extend to modal edges */
        padding: var(--space-4);
        background: rgba(10, 15, 28, 0.95);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        border-top: 1px solid rgba(255, 255, 255, 0.08);
        border-radius: 0 0 var(--radius-xl) var(--radius-xl);
        z-index: 10;
    }

    /* Adjust category chips scroll area */
    .filter-chips-scroll {
        max-height: 160px;
    }
}

@media (min-width: 768px) {
    .choices-container {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }
}

/* ==========================================================================
   Tutorial Screen
   ========================================================================== */

.tutorial-header {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    margin-bottom: var(--space-6);
}

.btn-back {
    padding: var(--space-2) var(--space-4);
    min-height: var(--tap-target);
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.btn-back:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-elevated);
}

.tutorial-stage {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--color-text-secondary);
    margin: 0;
}

.tutorial-card {
    max-width: 700px;
    margin: 0 auto;
    padding: var(--space-8);
    background: var(--gradient-card);
    border-radius: var(--radius-xl);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.tutorial-card-header {
    margin-bottom: var(--space-6);
    padding-bottom: var(--space-4);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.tutorial-modulation-name {
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--color-accent-primary);
    margin: 0;
}

.tutorial-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

.tutorial-description {
    font-size: var(--text-base);
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin: 0;
}

.tutorial-section {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.tutorial-section-title {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-text-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin: 0;
}

.tutorial-characteristics {
    margin: 0;
    padding-left: var(--space-5);
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.tutorial-characteristics li {
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    line-height: 1.6;
}

.tutorial-characteristics li::marker {
    color: var(--color-accent-primary);
}

.tutorial-audio-hints {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin: 0;
    padding: var(--space-4);
    background: rgba(0, 217, 255, 0.05);
    border-left: 3px solid var(--color-accent-primary);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.tutorial-waterfall-container {
    background: var(--color-bg-elevated);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    border: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 180px;
    overflow: hidden;
}

#tutorial-waterfall-image {
    max-width: 100%;
    width: 100%;
    max-height: min(250px, 40vh);
    object-fit: contain;
    border-radius: var(--radius-md);
    display: none;
}

#tutorial-waterfall-image.loaded {
    display: block;
}

.tutorial-waterfall-placeholder {
    color: var(--color-text-muted);
    font-size: var(--text-base);
}

.tutorial-example-name {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    text-align: center;
    margin: var(--space-2) 0 0 0;
    font-style: italic;
}

.tutorial-audio-player {
    background: var(--color-bg-elevated);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.tutorial-audio-placeholder {
    padding: var(--space-4);
    text-align: center;
    color: var(--color-text-muted);
    font-size: var(--text-sm);
}

.tutorial-actions {
    margin-top: var(--space-8);
    display: flex;
    gap: var(--space-3);
    justify-content: center;
}

.tutorial-actions .btn-secondary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.tutorial-actions .btn-primary:disabled {
    background: var(--color-bg-elevated);
    color: var(--color-text-muted);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

@media (max-width: 360px) {
    .app-container {
        padding: var(--space-3);
    }

    .header {
        padding: var(--space-3) var(--space-4);
    }

    .nav-btn {
        padding: var(--space-2) var(--space-3);
    }
}

/* Hide all leaderboard elements */
[id*="leaderboard"],
[class*="leaderboard"],
#btn-leaderboard,
#btn-menu-leaderboard,
#screen-leaderboard {
    display: none !important;
}

/* Hide story mode from main page */
[data-mode="story"],
#screen-story,
#screen-story-tutorial,
#screen-story-test {
    display: none !important;
}