/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Gold Theme Only */
:root {
    --main-bg: #111112;
    --card-bg: #18181b;
    --sidebar-bg: #18181b;
    --accent: #FFD700;
    --accent-hover: #FFE44D;
    --text: #fff;
    --slider-bg: #222226;
    --slider-thumb: #FFD700;
    --slider-thumb-border: #fff;
    --primary-color: #FFD700;
    --secondary-color: #FFE44D;
    --accent-color: #FFD700;
    --text-color: #222;
    --background-color: #f7f7fa;
    --wave-color: #FFD700;
    --svg-wave-stroke: #FFD700;
    --svg-wave-bg: transparent;
    --card-background: #ffffff;
    --wave-color-2: rgba(255, 215, 0, 0.1);
    --wave-color-3: rgba(255, 215, 0, 0.05);
    --dark-bg: #0f2027;
    --dark-card: rgba(35, 36, 58, 0.7);
    --dark-text: #f7f7fa;
    --dark-accent: #FFD700;
    --light-bg: #f7f7fa;
    --light-card: #fffbe6;
    --light-text: #23242a;
    --light-accent: #FFD700;
    --bg-color: #000000;
    --gold: #FFD700;
    --gold-light: #FFE44D;
    --gold-dark: #B8860B;
}

[data-theme="dark"], [data-theme="light"] {
    --main-bg: #111112;
    --card-bg: #18181b;
    --sidebar-bg: #18181b;
    --accent: #FFD700;
    --accent-hover: #FFE44D;
    --text: #fff;
    --slider-bg: #222226;
    --slider-thumb: #FFD700;
    --slider-thumb-border: #fff;
    --primary-color: #FFD700;
    --secondary-color: #FFE44D;
    --accent-color: var(--dark-accent);
    --text-color: var(--dark-text);
    --background-color: #181a20;
    --wave-color: #FFD700;
    --svg-wave-stroke: #FFD700;
    --svg-wave-bg: transparent;
    --card-background: #1e1e1e;
    --wave-color-2: rgba(100, 181, 246, 0.1);
    --wave-color-3: rgba(100, 181, 246, 0.05);
    --bg-color: var(--dark-bg);
    --accent-color: var(--dark-accent);
}

html, body {
    height: 100%;
    width: 100%;
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #18181a 0%, #1a1a1d 100%);
    color: #fff;
    min-height: 100vh;
    overflow-x: hidden;
    font-family: 'Inter', 'Segoe UI', Arial, sans-serif;
    transition: background 0.4s, color 0.4s;
}

body::before {
    content: '';
    position: fixed;
    top: 0; left: 0; width: 100vw; height: 100vh;
    z-index: 0;
    pointer-events: none;
    background: url('data:image/svg+xml;utf8,<svg width="1000" height="120" xmlns="http://www.w3.org/2000/svg"><path d="M0,60 Q125,0 250,60 T500,60 T750,60 T1000,60" stroke="%23e50914" stroke-width="6" fill="none"/></svg>');
    background-repeat: repeat-x;
    background-size: 1000px 120px;
    opacity: 0.10;
    animation: moveRedWave 18s linear infinite;
}
@keyframes moveRedWave {
    0% { background-position-x: 0; }
    100% { background-position-x: 1000px; }
}

body {
    background: linear-gradient(135deg, #18181a 0%, #1a1a1d 100%);
    color: #fff;
    font-family: 'Inter', 'Segoe UI', Arial, sans-serif;
    min-height: 100vh;
    overflow-x: hidden;
}

[data-theme="dark"] body, body:not([data-theme="light"]) {
    background: linear-gradient(135deg, #18181a 0%, #1a1a1d 100%);
    color: #fff;
}
[data-theme="light"] body {
    background: linear-gradient(135deg, #fff 0%, #fafafa 100%);
    color: #18181a;
}
[data-theme="light"] .tab-content,
[data-theme="light"] .card,
[data-theme="light"] .controls,
[data-theme="light"] .quiz-container,
[data-theme="light"] .comparison-section,
[data-theme="light"] .medium-card,
[data-theme="light"] .team-list,
[data-theme="light"] .info-grid,
[data-theme="light"] .row,
[data-theme="light"] .graph-col {
    background: rgba(255, 255, 255, 0.95);
    color: #18181a;
    box-shadow: 0 8px 32px 0 rgba(255, 215, 0, 0.2), 0 1.5px 8px rgba(0, 0, 0, 0.1);
    border: 2.5px solid var(--gold);
    backdrop-filter: blur(12px);
    border-radius: 1.5rem;
}
[data-theme="light"] .tab-description,
[data-theme="light"] h1, [data-theme="light"] h2, [data-theme="light"] h3 {
    color: #18181a;
    text-shadow: 0 2px 12px rgba(255, 215, 0, 0.4);
}
[data-theme="light"] .svg-wave path {
    stroke: var(--gold) !important;
    filter: drop-shadow(0 0 8px rgba(255, 215, 0, 0.4));
}
[data-theme="light"] .control-btn,
[data-theme="light"] .start-btn {
    background: linear-gradient(90deg, var(--gold) 0%, var(--gold-light) 100%) !important;
    color: #18181a !important;
    border: 2px solid var(--gold) !important;
    box-shadow: 0 4px 24px rgba(255, 215, 0, 0.3) !important;
}
[data-theme="light"] .control-btn:hover,
[data-theme="light"] .start-btn:hover {
    background: linear-gradient(90deg, var(--gold-light) 0%, var(--gold) 100%) !important;
    color: #18181a !important;
    border: 2px solid var(--gold-dark) !important;
}
[data-theme="light"] input[type="range"] {
    background: rgba(255, 215, 0, 0.2) !important;
    border: 2px solid var(--gold) !important;
}
[data-theme="light"] input[type="range"]::-webkit-slider-thumb {
    background: var(--gold) !important;
    border: 3px solid #fff !important;
    box-shadow: 0 2px 8px rgba(255, 215, 0, 0.4) !important;
}
[data-theme="light"] .sidebar {
    background: #fff !important;
    color: #18181a !important;
    border-right: none !important;
    border-bottom: 2px solid var(--gold) !important;
    box-shadow: 0 2px 32px rgba(255,215,0,0.15) !important;
}
[data-theme="light"] .tab-btn {
    color: #18181a;
    background: rgba(255,255,255,0.5);
}
[data-theme="light"] .tab-btn.active, [data-theme="light"] .tab-btn:focus {
    color: var(--gold-dark) !important;
    background: rgba(255, 215, 0, 0.12) !important;
    border-left: none !important;
    border-bottom: 4px solid var(--gold) !important;
}
#themeToggle, .side-toggle {
    transition: background 0.4s, color 0.4s, border 0.4s;
}
[data-theme="light"] #themeToggle, [data-theme="light"] .side-toggle {
    background: rgba(255, 255, 255, 0.92);
    color: var(--gold-dark);
    border: 2.5px solid var(--gold);
}
[data-theme="dark"] #themeToggle, [data-theme="dark"] .side-toggle {
    background: rgba(24,24,27,0.85);
    color: #fff;
    border: 2.5px solid #e50914;
}

/* Theme toggle */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(24, 24, 26, 0.92);
    border: 2px solid #e50914;
    color: #fff;
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 24px #e5091444;
    transition: all 0.3s ease;
    z-index: 1000;
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: 0 8px 32px #e50914cc;
}

[data-theme="light"] .theme-toggle {
    background: rgba(255, 255, 255, 0.92);
    border: 2px solid var(--gold);
    color: var(--gold-dark);
}

/* Cool animated background */
.background-animation {
    display: none;
}

/* Wave Container */
.wave-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.wave {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 200%;
    height: 100px;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%234a90e2" fill-opacity="0.2" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,112C672,96,768,96,864,112C960,128,1056,160,1152,160C1248,160,1344,128,1392,112L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
    background-size: 1440px 100px;
    animation: wave 10s linear infinite;
}

.wave1 {
    bottom: 0;
    opacity: 0.3;
    animation: wave 10s linear infinite;
}

.wave2 {
    bottom: 10px;
    opacity: 0.2;
    animation: wave 15s linear infinite;
}

.wave3 {
    bottom: 20px;
    opacity: 0.1;
    animation: wave 20s linear infinite;
}

@keyframes wave {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-50%);
    }
}

/* Container and layout */
.container, header, main, .tabs, .tab-content, .card, .wave-demo, .svg-wave {
    position: relative;
    z-index: 1;
}

/* Remove any wave movement animation from .svg-wave or .wave-demo */
.svg-wave, .wave-demo {
    animation: none !important;
}

header {
    text-align: center;
    margin-bottom: 2rem;
    position: relative;
}

h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.subtitle {
    font-size: 1.2rem;
    color: var(--secondary-color);
}

/* Modern tab bar styles */
.modern-tabs {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    background: linear-gradient(90deg, #23242a 0%, #3a86ff 100%);
    border-radius: 1.5rem;
    box-shadow: 0 2px 12px #3a86ff22;
    padding: 0.7rem 1.5rem;
}

.tab-btn {
    padding: 0.8rem 1.5rem;
    border: none;
    background: transparent;
    color: #fff;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.7rem;
    transition: background 0.3s, color 0.3s, box-shadow 0.3s;
    position: relative;
}

.tab-btn.active, .tab-btn:focus {
    background: linear-gradient(90deg, #FFD700 0%, #FFE44D 100%);
    color: #fff;
    box-shadow: 0 0 10px #FFD70055;
    border-bottom: 4px solid #FFD700;
}

.tab-btn i {
    font-size: 1.2em;
}

/* Content sections */
.tab-content {
    display: none;
    padding: 2rem;
    background: rgba(24, 24, 26, 0.85);
    border-radius: 1.5rem;
    border: 2.5px solid #e50914;
    backdrop-filter: blur(12px);
    margin: 2rem auto;
    width: 100%;
    max-width: 1000px;
    box-shadow: 0 0 30px rgba(229, 9, 20, 0.1);
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Cards */
.card {
    background: rgba(24, 24, 26, 0.85);
    border-radius: 1.5rem;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 8px 32px 0 #e5091422, 0 1.5px 8px #0008;
    color: #fff;
    transition: box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-5px);
}

.card h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Info Grid */
.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.info-item {
    padding: 1.5rem;
    background-color: var(--card-background);
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.info-item:hover {
    transform: translateY(-5px);
}

.info-item i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Sound controls in speed section */
.sound-controls {
    display: flex;
    align-items: center;
    gap: 1.2rem;
    margin-top: 1.2rem;
    justify-content: center;
}

.play-btn {
    background: linear-gradient(90deg, #3a86ff 0%, #ff006e 100%);
    color: #fff;
    border: none;
    padding: 0.7rem 1.5rem;
    border-radius: 0.7rem;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 600;
    box-shadow: 0 0 10px #3a86ff55;
    display: flex;
    align-items: center;
    gap: 0.7rem;
    transition: background 0.3s, box-shadow 0.3s;
}

.play-btn:hover {
    background: linear-gradient(90deg, #ff006e 0%, #3a86ff 100%);
    box-shadow: 0 0 20px #ff006e;
}

.sound-icon {
    color: #ff006e;
    font-size: 1.5rem;
    filter: drop-shadow(0 0 6px #ff006e88);
}

.frequency-display {
    color: #fff;
    font-size: 1.1rem;
    font-weight: 500;
    background: rgba(58,134,255,0.08);
    border-radius: 8px;
    padding: 0.4rem 1rem;
    box-shadow: 0 0 8px #3a86ff33;
}

/* Wave demos */
.wave-demo {
    background: #000000;
    border-radius: 1rem;
    position: relative;
    overflow: hidden;
    margin: 2rem 0;
    border: 1px solid #e50914;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 120px;
    width: 100%;
    box-shadow: 0 0 30px 2px rgba(229, 9, 20, 0.3);
}

.svg-wave {
    width: 100%;
    height: 100%;
    display: block;
}

.svg-wave path {
    stroke: #e50914 !important;
    stroke-width: 3;
    fill: none;
}

/* Remove any conflicting wave styles */
body[data-theme='dark'] .svg-wave path,
body[data-theme='light'] .svg-wave path {
    stroke: #e50914 !important;
}

/* Update wave animation styles */
.svg-wave {
    width: 100%;
    height: 100%;
    display: block;
    filter: drop-shadow(0 0 8px rgba(229, 9, 20, 0.3));
}

.svg-wave path {
    stroke-width: 3;
    fill: none;
    transition: stroke 0.3s ease;
}

/* Ensure sliders are visible in both themes */
input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 6px;
    background: rgba(229, 9, 20, 0.2);
    outline: none;
    border: 2px solid #e50914;
    margin: 1.2rem 0;
}

body[data-theme='light'] input[type="range"] {
    background: rgba(229, 9, 20, 0.1);
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: #e50914;
    border: 3px solid #fff;
    cursor: pointer;
    box-shadow: 0 2px 8px #e50914cc;
}

body[data-theme='light'] input[type="range"]::-webkit-slider-thumb {
    background: #e50914;
    border: 3px solid #fff;
}

/* Control Buttons */
.control-buttons {
    display: flex;
    gap: 10px;
    margin: 10px 0;
}

.control-btn {
    padding: 8px 16px;
    border: none;
    border-radius: 4px;
    background: var(--primary-color);
    color: white;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 5px;
}

.control-btn:hover {
    background: var(--accent-color);
    transform: scale(1.05);
}

.control-btn:active {
    transform: scale(0.95);
}

.control-btn.mute {
    background: var(--secondary-color);
}

.control-btn.mute.active {
    background: var(--accent-color);
}

/* Slider Container */
.slider-container {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin: 1rem 0;
    width: 100%;
    max-width: 800px;
}

.slider-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex: 1;
}

.slider-controls input[type="range"] {
    width: 350px;
    height: 14px;
    -webkit-appearance: none;
    appearance: none;
    background: linear-gradient(90deg, #3a86ff 0%, #ff006e 100%);
    border-radius: 8px;
    outline: none;
    cursor: pointer;
    box-shadow: 0 0 12px #3a86ff55;
    margin: 0 1rem;
    transition: box-shadow 0.3s;
}

.slider-controls input[type="range"]:hover {
    box-shadow: 0 0 24px #ff006e99;
}

.slider-controls input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 28px;
    height: 28px;
    background: #fff;
    border: 3px solid #3a86ff;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 20px #3a86ff88;
    transition: border 0.3s, box-shadow 0.3s;
}

.slider-controls input[type="range"]:hover::-webkit-slider-thumb {
    border: 3px solid #ff006e;
    box-shadow: 0 0 30px #ff006e;
}

.slider-controls input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: var(--accent-color);
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
    border: none;
}

.slider-controls input[type="range"]:hover::-moz-range-thumb {
    transform: scale(1.2);
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.3);
}

/* Existing animations */
@keyframes waveMove {
    0% {
        transform: translateY(-50%) translateX(-100%);
    }
    100% {
        transform: translateY(-50%) translateX(100%);
    }
}

@keyframes amplitudeWave {
    0%, 100% {
        transform: translateY(-50%) scaleY(1);
    }
    50% {
        transform: translateY(-50%) scaleY(var(--amplitude, 1));
    }
}

@keyframes frequencyWave {
    0% {
        transform: translateY(-50%) translateX(-100%);
    }
    100% {
        transform: translateY(-50%) translateX(100%);
    }
}

@keyframes wavelengthWave {
    0% {
        transform: translateY(-50%) translateX(-100%);
    }
    100% {
        transform: translateY(-50%) translateX(100%);
    }
}

/* Speed comparison */
.speed-comparison {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.medium {
    padding: 1.5rem;
    background-color: var(--card-background);
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: transform 0.3s ease;
}

.medium:hover {
    transform: translateY(-5px);
}

.medium i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Quiz styling */
.quiz-container {
    background: rgba(24, 24, 26, 0.85);
    border: 2.5px solid #e50914;
    border-radius: 1.5rem;
    padding: 2rem;
    color: #fff;
}

[data-theme="light"] .quiz-container {
    background: #fff !important;
    color: #18181a !important;
    box-shadow: 0 8px 32px 0 rgba(255, 215, 0, 0.18), 0 1.5px 8px rgba(0,0,0,0.08) !important;
    border-radius: 1.5rem !important;
    border: none !important;
}

.quiz-container h2,
.quiz-container h3,
.quiz-container .question,
.quiz-container .options label,
.quiz-container #quiz-results p,
.quiz-container #quiz-progress {
    color: #fff;
}

[data-theme="light"] .quiz-container h2,
[data-theme="light"] .quiz-container h3,
[data-theme="light"] .quiz-container .question,
[data-theme="light"] .quiz-container .options label,
[data-theme="light"] .quiz-container #quiz-results p,
[data-theme="light"] .quiz-container #quiz-progress {
    color: #18181a !important;
}

.quiz-container .options label {
    display: block;
    padding: 1rem;
    margin: 0.5rem 0;
    background: rgba(229, 9, 20, 0.1);
    border: 2px solid #e50914;
    border-radius: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

[data-theme="light"] .quiz-container .options label {
    background: #fffbe6 !important;
    color: #18181a !important;
    border: none !important;
}

.quiz-container .options label:hover {
    background: rgba(229, 9, 20, 0.2);
    transform: translateY(-2px);
}

[data-theme="light"] .quiz-container .options label:hover {
    background: #fff6cc !important;
}

.quiz-container #quiz-results {
    text-align: center;
    padding: 2rem;
    border-radius: 1.5rem !important;
    border: none !important;
    margin-top: 2rem;
    box-shadow: 0 4px 24px rgba(255, 215, 0, 0.12) !important;
}

[data-theme="dark"] .quiz-container #quiz-results {
    background-color: transparent;
    color: #fff;
}

.quiz-container #retry-quiz {
    background: linear-gradient(90deg, #e50914 0%, #ff2a36 100%);
    color: #fff;
    border: none;
    padding: 1rem 2rem;
    border-radius: 1rem;
    cursor: pointer;
    margin-top: 1rem;
    font-weight: bold;
    transition: all 0.3s ease;
}

.quiz-container #retry-quiz:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 24px #e5091444;
}

/* Team section */
.team-section {
    text-align: center;
    margin-top: 2rem;
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 1rem;
}

.team-member {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 8px;
    text-align: center;
    margin: 10px 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    width: 100%;
}

.team-member:hover {
    transform: translateY(-5px);
}

.team-member i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    h1 {
        font-size: 2rem;
    }

    .tabs {
        gap: 0.5rem;
    }

    .tab-btn {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }

    .card {
        padding: 1.5rem;
    }

    .start-btn {
        padding: 1rem 2rem;
        font-size: 1.1rem;
    }

    .team-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    }

    .slider-controls input[type="range"] {
        width: 90vw;
    }
}

/* Animations */
@keyframes float {
    0% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-10px);
    }
    100% {
        transform: translateY(0px);
    }
}

/* Wavelength Info */
.wavelength-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.info-box {
    padding: 1.5rem;
    background-color: var(--card-background);
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    text-align: center;
}

/* Start Button */
.start-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    padding: 1.2rem 2.5rem;
    border-radius: 50px;
    font-size: 1.2rem;
    cursor: pointer;
    margin: 2rem auto;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    position: relative;
    overflow: hidden;
}

.start-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.2),
        transparent
    );
    transition: 0.5s;
}

.start-btn:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

.start-btn:hover::before {
    left: 100%;
}

.start-btn i {
    transition: transform 0.3s ease;
}

.start-btn:hover i {
    transform: translateX(5px);
}

/* Additional styles */
.subtitle {
    font-size: 1.2rem;
    color: var(--secondary-color);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.info-item {
    padding: 1.5rem;
    background-color: var(--card-background);
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.info-item:hover {
    transform: translateY(-5px);
}

.info-item i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.info-box {
    padding: 1.5rem;
    background-color: var(--card-background);
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    text-align: center;
}

.speed-comparison {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.medium {
    padding: 1.5rem;
    background-color: var(--card-background);
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: transform 0.3s ease;
}

.medium:hover {
    transform: translateY(-5px);
}

.medium i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Wave Controls */
.wave-controls {
    margin: 1.5rem 0;
    padding: 1rem;
    background-color: var(--card-background);
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.slider-container {
    margin: 1rem 0;
}

.slider-container label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-color);
    font-weight: 500;
}

.slider {
    -webkit-appearance: none;
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    outline: none;
    opacity: 0.7;
    transition: opacity 0.2s;
}

.slider:hover {
    opacity: 1;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    transition: border 0.3s, box-shadow 0.3s;
}

.slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    background: var(--secondary-color);
}

.slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
}

.slider::-moz-range-thumb:hover {
    transform: scale(1.2);
    background: var(--secondary-color);
}

/* Quiz Enhancements */
.quiz-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
    background-color: var(--card-background);
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.quiz-question {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background-color: var(--background-color);
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.quiz-question h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.quiz-options {
    display: grid;
    gap: 1rem;
    margin-top: 1.5rem;
}

.quiz-option {
    padding: 1.2rem;
    border: 2px solid var(--primary-color);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    background-color: var(--card-background);
    font-weight: 500;
}

.quiz-option:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.quiz-option.selected {
    background-color: var(--primary-color);
    color: white;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.3);
}

#quiz-results {
    text-align: center;
    padding: 2rem;
    border-radius: 1.5rem !important;
    border: none !important;
    margin-top: 2rem;
    box-shadow: 0 4px 24px rgba(255, 215, 0, 0.12) !important;
}

[data-theme="dark"] .quiz-container #quiz-results {
    background-color: transparent;
    color: #fff;
}

#retry-quiz {
    background: linear-gradient(90deg, #e50914 0%, #ff2a36 100%);
    color: #fff;
    border: none;
    padding: 1rem 2rem;
    border-radius: 1rem;
    cursor: pointer;
    margin-top: 1rem;
    font-weight: bold;
    transition: all 0.3s ease;
}

#retry-quiz:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 24px #e5091444;
}

/* Progress Bar */
#quiz-progress {
    text-align: center;
    margin-bottom: 2rem;
    padding: 1rem;
    background-color: var(--background-color);
    border-radius: 10px;
    font-size: 1.2rem;
    color: var(--primary-color);
    font-weight: 500;
}

/* Sound Controls Enhancement */
.sound-controls {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 1.5rem;
    flex-wrap: wrap;
}

.sound-btn {
    padding: 1rem 2rem;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.8rem;
    font-weight: 500;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.sound-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
}

.sound-btn i {
    font-size: 1.2rem;
    transition: transform 0.3s ease;
}

.sound-btn:hover i {
    transform: scale(1.2);
}

.mute-btn, .reset-btn, .play-btn, .explore-btn {
    background: linear-gradient(90deg, #3a86ff 0%, #ff006e 100%);
    color: #fff;
    border: none;
    padding: 0.7rem 1.5rem;
    border-radius: 0.7rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-left: 0.5rem;
    margin-top: 0.5rem;
    font-size: 1.1rem;
    box-shadow: 0 0 10px #3a86ff55;
    font-weight: 600;
    letter-spacing: 1px;
}

.mute-btn:hover, .reset-btn:hover, .play-btn:hover, .explore-btn:hover, .mute-btn.active {
    background: linear-gradient(90deg, #ff006e 0%, #3a86ff 100%);
    color: #fff;
    box-shadow: 0 0 20px #ff006e;
}

.explore-btn {
    font-size: 1.3rem;
    padding: 1rem 2.5rem;
    margin-top: 2rem;
    box-shadow: 0 0 30px #3a86ff88;
}

.container.fullscreen {
    width: 100vw;
    height: 100vh;
    min-height: 100vh;
    min-width: 100vw;
    max-width: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(0,0,0,0.85);
    border-radius: 32px;
    box-shadow: 0 0 60px 10px #3a86ff88, 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    border: 3px solid #3a86ff;
    transition: box-shadow 0.3s;
}

.center {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.wave-controls.center, .slider-container.center, .slider-controls.center, .wave-demo.center, .sound-controls.center {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.slider-container, .slider-controls, .wave-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.slider-value {
    font-size: 1.2rem;
    color: #3a86ff;
    margin-left: 0.5rem;
    font-weight: bold;
    text-shadow: 0 0 8px #3a86ff88;
}

/* Decorative red sine curve in the background */
.background-animation::after {
    content: '';
    position: absolute;
    left: 0;
    top: 60%;
    width: 100vw;
    height: 120px;
    pointer-events: none;
    z-index: 0;
    background: none;
    background-image: url('data:image/svg+xml;utf8,<svg width="1000" height="120" xmlns="http://www.w3.org/2000/svg"><path d="M0,60 Q125,0 250,60 T500,60 T750,60 T1000,60" stroke="%23e50914" stroke-width="6" fill="none"/></svg>');
    background-repeat: repeat-x;
    background-size: 1000px 120px;
    opacity: 0.10;
    animation: moveRedWave 18s linear infinite;
}
@keyframes moveRedWave {
    0% { background-position-x: 0; }
    100% { background-position-x: 1000px; }
}

/* Main container */
.container {
    max-width: 1200px;
    width: 95%;
    margin: 2rem auto;
    background: rgba(24, 26, 32, 0.95);
    border-radius: 1.5rem;
    box-shadow: 0 0 20px rgba(58, 134, 255, 0.15);
    border: 1px solid rgba(58, 134, 255, 0.1);
    padding: 2rem;
    position: relative;
    overflow: hidden;
}

.theme-toggle.side-toggle {
    position: absolute;
    top: 1.5rem;
    right: 2rem;
    z-index: 2;
    background: linear-gradient(90deg, #3a86ff 0%, #ff006e 100%);
    color: #fff;
    border: none;
    padding: 0.7rem 1.5rem;
    border-radius: 0.7rem;
    cursor: pointer;
    font-size: 1.2rem;
    box-shadow: 0 0 10px #3a86ff55;
    transition: background 0.3s;
}

#themeToggle.side-toggle:hover {
    background: linear-gradient(90deg, #ff006e 0%, #3a86ff 100%);
}

body[data-theme='light'] {
    background: linear-gradient(120deg, #f7faff 0%, #fffbe6 100%);
    color: #18181a;
}

body[data-theme='light'] .container {
    background: rgba(255,255,255,0.95);
    color: #23242a;
    box-shadow: 0 0 60px 10px #ffbe0b88, 0 8px 32px 0 rgba(255, 222, 89, 0.17);
    border: 3px solid #ffbe0b;
}

body[data-theme='light'] .card {
    background: rgba(255,255,255,0.98);
    color: #23242a;
    box-shadow: 0 4px 24px #ffbe0b33;
}

body[data-theme='light'] .slider-controls input[type="range"] {
    background: linear-gradient(90deg, #ffbe0b 0%, #ff006e 100%);
}

body[data-theme='light'] .slider-value {
    color: #ffbe0b;
    text-shadow: 0 0 8px #ffbe0b88;
}

.team-list {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
    margin-top: 1.5rem;
}

.team-member {
    font-size: 1.1rem;
    color: #fff;
    background: rgba(58,134,255,0.08);
    border-radius: 8px;
    padding: 0.7rem 1.2rem;
    box-shadow: 0 0 8px #3a86ff33;
    display: flex;
    align-items: center;
    gap: 0.7rem;
}

@media (max-width: 1400px) {
    .container {
        max-width: 98vw;
        padding: 1rem;
    }
    .slider-controls input[type="range"] {
        width: 90vw;
    }
}

.section-row {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
    gap: 2.5rem;
    width: 100%;
}

.slider-col {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 1rem;
    min-width: 180px;
}

/* Graph container */
.graph-col {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin-bottom: 2rem;
    background: none;
    border: none;
    box-shadow: none;
}

/* SVG wave */
.svg-wave {
    width: 100%;
    max-width: 500px;
    height: 120px;
    display: block;
    filter: drop-shadow(0 0 16px #e50914cc);
    margin: 0 auto 1.5rem auto;
    background: transparent;
}
.svg-wave path {
    stroke: #e50914 !important;
    stroke-width: 4 !important;
    fill: none !important;
    filter: drop-shadow(0 0 8px #e5091444);
    transition: d 0.3s cubic-bezier(.4,0,.2,1);
    animation: waveGlow 2.5s ease-in-out infinite alternate;
}
@keyframes waveGlow {
    0% { filter: drop-shadow(0 0 8px #e50914cc); }
    100% { filter: drop-shadow(0 0 24px #e50914cc); }
}

body[data-theme='light'] {
    background: linear-gradient(120deg, #f7faff 0%, #e3e8f0 100%);
    color: #23242a;
}

body[data-theme='light'] .graph-col {
    background: #fff;
    border: 1px solid #ccc;
}

/* Premium Text Styles */
.premium-text {
    font-size: 1.1em;
    line-height: 1.6;
    color: var(--text-color);
    margin-bottom: 2rem;
    text-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

/* Premium Controls */
.premium-controls {
    background: rgba(255, 255, 255, 0.05);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.1);
}

.slider-container {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-top: 0.5rem;
}

/* Medium Cards */
.medium-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.medium-card {
    background: rgba(255, 255, 255, 0.05);
    padding: 1.5rem;
    border-radius: 12px;
    text-align: center;
    transition: transform 0.3s ease;
    border: 1px solid rgba(255,255,255,0.1);
    backdrop-filter: blur(10px);
}

.medium-card:hover {
    transform: translateY(-5px);
}

.medium-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.speed-value {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--accent-color);
    margin: 0.5rem 0;
}

/* Comparison Section */
.comparison-section {
    background: rgba(255, 255, 255, 0.05);
    padding: 1.5rem;
    border-radius: 12px;
    margin-top: 2rem;
    border: 1px solid rgba(255,255,255,0.1);
}

.comparison-bar {
    display: flex;
    align-items: center;
    margin: 1rem 0;
    gap: 1rem;
}

.bar-label {
    width: 100px;
    font-weight: 500;
    flex-shrink: 0;
}

.bar-container {
    flex: 1;
    height: 20px;
    background: rgba(255,255,255,0.1);
    border-radius: 10px;
    overflow: hidden;
}

.bar {
    height: 100%;
    border-radius: 10px;
    transition: width 0.3s ease;
}

.air-bar {
    background: linear-gradient(90deg, #4facfe 0%, #00f2fe 100%);
}

.water-bar {
    background: linear-gradient(90deg, #43e97b 0%, #38f9d7 100%);
}

.steel-bar {
    background: linear-gradient(90deg, #fa709a 0%, #fee140 100%);
}

.bar-value {
    width: 140px;
    text-align: right;
    font-weight: 500;
    flex-shrink: 0;
}

/* Sound Controls */
.sound-controls {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 1rem;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    border: 1px solid rgba(255,255,255,0.1);
}

.play-btn {
    background: var(--accent-color);
    color: var(--bg-color);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
}

.play-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.frequency-display {
    font-size: 0.9rem;
    color: var(--text-color);
}

/* Update existing styles */
.controls {
    margin: 2rem 0 1rem 0;
    padding: 2rem 1.5rem;
    border-radius: 1.2rem;
    background: rgba(30, 30, 34, 0.75);
    box-shadow: 0 4px 24px #e5091444;
    border: 2px solid #e50914;
}

.controls label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

input[type="range"] {
    width: 90%;
    max-width: 600px;
    height: 16px;
    border-radius: 8px;
    background: var(--slider-bg);
    outline: none;
    margin: 1.5rem 0;
    box-shadow: 0 2px 8px #e5091422;
}

input[type="range"]::-webkit-slider-thumb {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: 3px solid #fff;
}

input[type="range"]::-moz-range-thumb {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: 3px solid #fff;
}

input[type="range"]::-ms-thumb {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: 3px solid #fff;
}

.slider-value {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--accent);
    text-align: center;
    margin-top: 0.5rem;
}

/* Mute and reset buttons */
.control-buttons {
    display: flex;
    gap: 1.2rem;
    justify-content: center;
    margin-top: 1.2rem;
}

.control-btn {
    background: linear-gradient(90deg, #e50914 0%, #ff2a36 100%);
    color: #fff;
    border: none;
    border-radius: 0.7rem;
    font-size: 1.1rem;
    font-weight: 700;
    padding: 1rem 2.2rem;
    box-shadow: 0 4px 24px #e5091444;
    transition: all 0.3s ease;
    outline: none;
    margin: 0.5rem 0.5rem 0.5rem 0;
}
.control-btn:hover, .control-btn:focus {
    background: linear-gradient(90deg, #ff2a36 0%, #e50914 100%);
    color: #fff;
    box-shadow: 0 8px 32px #e50914cc;
    border: 2px solid #fff;
    transform: scale(1.06) translateY(-2px);
}

/* Remove global mute button styles */
#mute-btn, .mute-btn.global, .control-btn.global-mute {
    display: none !important;
}

/* Layout improvements */
.row {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    width: 100%;
    margin: 0 auto;
}
.col {
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

/* Remove blue/yellow accent colors */
:root {
    --primary-color: #e50914;
    --secondary-color: #ff2a36;
    --accent-color: #e50914;
}

/* Tab description */
.tab-description {
    font-size: 1.35rem;
    font-weight: 700;
    color: #fff;
    text-align: center;
    margin-bottom: 2rem;
    letter-spacing: 0.01em;
    text-shadow: 0 2px 12px #e5091422;
}

/* Home section */
#home {
    text-align: center;
    padding: 4rem 2rem;
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
}

.hero {
    max-width: 800px;
    margin: 0 auto;
}

.start-btn {
    padding: 1rem 2rem;
    font-size: 1.2rem;
    background: #e50914;
    color: white;
    border: none;
    border-radius: 0.5rem;
    cursor: pointer;
    margin-top: 2rem;
    transition: all 0.3s ease;
    min-width: 200px;
}

.start-btn:hover {
    background: #ff1a1a;
    transform: translateY(-2px);
}

/* Theme toggle */
.side-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: transparent;
    border: none;
    color: #ffffff;
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0.5rem;
    z-index: 101;
}

/* Value display */
#amplitude-value,
#frequency-value,
#wavelength-value {
    font-size: 1.2rem;
    color: #ffffff;
    font-weight: bold;
    text-align: center;
    width: 100%;
    margin-top: 0.5rem;
}

/* Responsive design */
@media (max-width: 768px) {
    .row {
        flex-direction: column;
        gap: 1rem;
    }
    .col, .graph-col {
        width: 100%;
    }

    .content-area {
        margin-left: 0;
        padding-bottom: 2rem;
    }
    .sidebar-nav span {
        display: none;
    }
    .controls {
        padding: 1rem;
    }
    .control-btn {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }
}

/* Remove any background animations */
.theme-bg-animation {
    display: none;
}

/* Main layout */
.main-layout {
    display: flex;
    position: relative;
    z-index: 2;
    flex-direction: column;
    min-height: 100vh;
}

.sidebar {
    position: sticky;
    top: 0;
    width: 100%;
    background: #18181b;
    padding: 0.5rem 2rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    border-right: none;
    box-shadow: 0 2px 32px #e5091422;
    z-index: 10;
    flex-direction: row;
    border-bottom: 2.5px solid #e50914;
    justify-content: center;
}

.sidebar-nav {
    display: flex;
    width: auto;
    margin-top: 0;
    flex-direction: row;
    gap: 0.5rem;
}

.tab-btn {
    padding: 0.75rem 1rem;
    color: #a0a0a0;
    background: transparent;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
    text-align: left;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    border-left: none;
    border-bottom: 4px solid transparent;
}

.tab-btn.active, .tab-btn:focus {
    color: #fff;
    background: rgba(229, 9, 20, 0.12);
    border-left: none;
    border-bottom: 4px solid #e50914;
}

.tab-btn i {
    font-size: 1.2rem;
}
.content-area {
    flex: 1;
    padding: 2rem;
    position: relative;
    transition: none;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.main-header {
    width: 100%;
    max-width: 1200px;
    text-align: center;
}

.main-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.tab-content {
    display: none;
    background: rgba(30, 30, 34, 0.75);
    border-radius: 2rem;
    border: 2px solid #e50914;
    box-shadow: 0 8px 48px 0 #e5091444, 0 1.5px 8px #e5091422;
    padding: 2.8rem 2.2rem;
    margin: 2.5rem 0;
    width: 100%;
    max-width: 950px;
    font-size: 1.18rem;
    letter-spacing: 0.01em;
    transition: box-shadow 0.3s, background 0.3s;
    text-align: center;
}
.tab-content.active {
    display: block;
    animation: fadeIn 0.7s cubic-bezier(.4,0,.2,1);
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.card, .controls, .quiz-container, .comparison-section, .medium-card, .team-list, .info-grid, .row, .graph-col {
    background: rgba(30, 30, 34, 0.65);
    border-radius: 1.5rem;
    box-shadow: 0 8px 32px #e5091444, 0 1.5px 8px #e5091422;
    border: 2px solid #e50914;
    padding: 2rem 1.5rem;
    margin-bottom: 2.2rem;
    backdrop-filter: blur(12px);
    transition: box-shadow 0.3s, transform 0.3s;
}
.card:hover, .controls:hover, .quiz-container:hover, .comparison-section:hover, .medium-card:hover, .info-item:hover, .row:hover, .graph-col:hover {
    box-shadow: 0 12px 48px #e50914cc, 0 2px 16px #e5091444;
    transform: scale(1.025) translateY(-4px);
}

h1, h2, h3 {
    color: #fff;
    font-weight: 800;
    letter-spacing: 0.01em;
    text-shadow: 0 2px 12px #e5091422;
}

.start-btn, .control-btn, .mute-btn, .reset-btn, .play-btn, .explore-btn {
    background: linear-gradient(90deg, #e50914 0%, #ff2a36 100%);
    color: #fff;
    border: none;
    border-radius: 1rem;
    font-size: 1.18rem;
    font-weight: 700;
    padding: 1.2rem 2.5rem;
    margin: 1.2rem 0.7rem 0 0;
    box-shadow: 0 2px 16px #e5091444;
    transition: background 0.25s, box-shadow 0.25s, color 0.25s, transform 0.2s;
    cursor: pointer;
    outline: none;
    border: 2px solid transparent;
    position: relative;
}
.start-btn:hover, .control-btn:hover, .mute-btn:hover, .reset-btn:hover, .play-btn:hover, .explore-btn:hover {
    background: linear-gradient(90deg, #ff2a36 0%, #e50914 100%);
    color: #fff;
    box-shadow: 0 8px 32px #e50914cc;
    border: 2px solid #fff;
    transform: scale(1.06) translateY(-2px);
}

input[type="range"] {
    width: 100%;
    max-width: 420px;
    height: 10px;
    border-radius: 5px;
    background: rgba(229, 9, 20, 0.18);
    outline: none;
    border: 2px solid #e50914;
    box-shadow: 0 0 12px #e5091444;
    margin: 1.2rem 0;
    transition: box-shadow 0.2s, border 0.2s;
}
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 28px;
    height: 28px;
    background: #e50914;
    border: 3px solid #fff;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 8px #e50914cc;
    transition: border 0.3s, box-shadow 0.3s;
}
input[type="range"]:hover::-webkit-slider-thumb {
    border: 3px solid #e50914;
    box-shadow: 0 0 32px #e50914;
}

/* Floating, glowing theme toggle */
.side-toggle, #themeToggle {
    position: fixed;
    top: 2.2rem;
    right: 2.2rem;
    background: rgba(24,24,27,0.85);
    border: 2.5px solid #e50914;
    color: #fff;
    border-radius: 50%;
    font-size: 2rem;
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 24px #e50914cc, 0 1.5px 8px #e5091422;
    cursor: pointer;
    z-index: 1000;
    transition: background 0.2s, border 0.2s, box-shadow 0.2s, color 0.2s;
    outline: none;
    animation: floatToggle 3s ease-in-out infinite alternate;
}
@keyframes floatToggle {
    0% { transform: translateY(0); }
    100% { transform: translateY(-10px); }
}
.side-toggle:hover, #themeToggle:hover {
    background: #e50914;
    color: #fff;
    border: 2.5px solid #fff;
    box-shadow: 0 8px 32px #e50914cc;
}

/* Accessibility: focus states */
.tab-btn:focus, .start-btn:focus, .control-btn:focus, .mute-btn:focus, .reset-btn:focus, .play-btn:focus, .explore-btn:focus {
    outline: 2.5px solid #fff;
    outline-offset: 2px;
    box-shadow: 0 0 0 4px #e5091444;
}

/* Responsive */
@media (max-width: 900px) {
    .sidebar-nav .tab-btn span {
        display: none;
    }
    .content-area {
        margin-left: 0;
    }
    .tab-content {
        padding: 1.5rem;
    }
    .side-toggle, #themeToggle {
        top: 1rem;
        right: 1rem;
        width: 48px;
        height: 48px;
        font-size: 1.3rem;
    }
}

.next-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.18rem;
    font-weight: 700;
    padding: 1.1rem 2.5rem;
    margin: 2.5rem auto 0 auto;
    border-radius: 1.2rem;
    background: linear-gradient(90deg, #e50914 0%, #ff2a36 100%);
    color: #fff;
    border: none;
    box-shadow: 0 4px 24px #e5091444;
    cursor: pointer;
    transition: background 0.25s, box-shadow 0.25s, color 0.25s, transform 0.2s;
    outline: none;
    gap: 0.8rem;
}
.next-btn:hover, .next-btn:focus {
    background: linear-gradient(90deg, #ff2a36 0%, #e50914 100%);
    color: #fff;
    box-shadow: 0 8px 32px #e50914cc;
    border: 2px solid #fff;
    transform: scale(1.06) translateY(-2px);
}
[data-theme="light"] .next-btn {
    background: linear-gradient(90deg, #e50914 0%, #ff2a36 100%);
    color: #fff;
    border: 2px solid #e50914;
}
[data-theme="light"] .next-btn:hover, [data-theme="light"] .next-btn:focus {
    background: linear-gradient(90deg, #ff2a36 0%, #e50914 100%);
    color: #fff;
    border: 2px solid #fff;
}

/* Quiz and Conclusion Text Colors */
.quiz-container, .conclusion {
    color: #fff;
}

[data-theme="light"] .quiz-container,
[data-theme="light"] .conclusion,
[data-theme="light"] .quiz-container h2,
[data-theme="light"] .quiz-container h3,
[data-theme="light"] .conclusion h2,
[data-theme="light"] .conclusion p {
    color: #18181a;
}

.quiz-container .question,
.quiz-container .options label,
.quiz-container #quiz-results p,
.quiz-container #quiz-progress {
    color: #fff;
}

[data-theme="light"] .quiz-container .question,
[data-theme="light"] .quiz-container .options label,
[data-theme="light"] .quiz-container #quiz-results p,
[data-theme="light"] .quiz-container #quiz-progress {
    color: #18181a;
}

.team-list .team-member {
    color: #fff;
    background: rgba(229, 9, 20, 0.1);
    border: 2px solid #e50914;
}

[data-theme="light"] .team-list .team-member {
    color: #18181a;
    background: rgba(229, 9, 20, 0.05);
    border: 2px solid #e50914;
}

/* Key Points Animation */
.key-points {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.key-point {
    background: rgba(24, 24, 26, 0.85);
    border: 2.5px solid #e50914;
    border-radius: 1.5rem;
    padding: 2rem;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    animation: float 3s ease-in-out infinite;
}

.key-point:nth-child(2) {
    animation-delay: 0.5s;
}

.key-point:nth-child(3) {
    animation-delay: 1s;
}

.key-point:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 32px #e5091444;
}

[data-theme="light"] .key-point {
    background: rgba(255, 255, 255, 0.85);
    color: #18181a;
}

.key-point i {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--gold-dark);
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

[data-theme="light"] .background-animation .red-curve,
html[data-theme="light"] body .red-curve {
    stroke: var(--gold);
    opacity: 0.15;
    filter: drop-shadow(0 0 12px var(--gold));
}

[data-theme="light"] .red-curve path {
    filter: none;
}
.card, .tab-content, .quiz-container, .controls, .comparison-section, .medium-card, .team-list, .info-grid, .row, .graph-col, .premium-card {
    border-radius: 1.5rem;
}
[data-theme="light"] .card, [data-theme="light"] .tab-content, [data-theme="light"] .quiz-container, [data-theme="light"] .controls, [data-theme="light"] .comparison-section, [data-theme="light"] .medium-card, [data-theme="light"] .team-list, [data-theme="light"] .info-grid, [data-theme="light"] .row, [data-theme="light"] .graph-col, [data-theme="light"] .premium-card {
    border: 2px solid var(--gold);
    box-shadow: 0 4px 24px rgba(255, 215, 0, 0.1);
}

[data-theme="light"] .svg-wave path {
    stroke-width: 3;
}
[data-theme="light"] .svg-wave {
    border-radius: 1rem;
}
[data-theme="light"] .quiz-container {
    padding: 2rem;
    border: 2px solid var(--gold);
    border-radius: 1rem;
}
[data-theme="light"] .quiz-container .options label {
    border: 2px solid transparent;
    transition: all 0.3s ease;
}
[data-theme="light"] .quiz-container .options label:hover {
    border-color: var(--gold);
}
[data-theme="light"] .quiz-container #quiz-results {
    margin-top: 1.5rem;
    padding: 1.5rem;
    border-radius: 0.5rem;
}
[data-theme="light"] .quiz-container h2,
[data-theme="light"] .quiz-container h3 {
    color: var(--dark-text);
    text-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

[data-theme="light"] .svg-wave,
[data-theme="light"] .graph-col,
[data-theme="light"] .quiz-container,
[data-theme="light"] .card,
[data-theme="light"] .tab-content {
    background: rgba(255,255,255,0.7);
}

[data-theme="light"] .svg-wave path,
html[data-theme="light"] body .svg-wave path {
    stroke: var(--gold);
}

[data-theme="light"] .quiz-container {
    background: var(--light-card);
    border: 1px solid var(--light-accent);
}
[data-theme="light"] .quiz-container .options label {
    background-color: rgba(0,0,0,0.05);
}
[data-theme="light"] .quiz-container .options label:hover {
    background-color: rgba(0,0,0,0.1);
}
[data-theme="light"] .quiz-container #quiz-results {
    background: rgba(0,0,0,0.05);
}
[data-theme="light"] .quiz-container h2,
[data-theme="light"] .quiz-container h3 {
    color: var(--light-text);
}
[data-theme="light"] .svg-wave,
[data-theme="light"] .graph-col,
[data-theme="light"] .quiz-container,
[data-theme="light"] .card,
[data-theme="light"] .tab-content {
    background: rgba(255,255,255,0.7);
}

[data-theme="light"] .svg-wave path,
html[data-theme="light"] body .svg-wave path {
    stroke: var(--gold);
}

[data-theme="light"] .quiz-container {
    background: var(--light-card);
    border: 1px solid var(--light-accent);
}
[data-theme="light"] .quiz-container .options label {
    background-color: rgba(0,0,0,0.05);
}
[data-theme="light"] .quiz-container .options label:hover {
    background-color: rgba(0,0,0,0.1);
}
[data-theme="light"] .quiz-container #quiz-results {
    background: rgba(0,0,0,0.05);
}
[data-theme="light"] .quiz-container h2,
[data-theme="light"] .quiz-container h3 {
    color: var(--light-text);
}

[data-theme="light"] .quiz-container,
.conclusion-container {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.8), rgba(255, 255, 255, 0.7));
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

[data-theme="light"] .quiz-option {
    background: #f0f0f0;
    color: #333;
    border: 1px solid #ddd;
}
[data-theme="light"] .quiz-option:hover, [data-theme="light"] .quiz-option.selected {
    background: #e0e0e0;
    border-color: #ccc;
}
[data-theme="light"] .quiz-question h3 {
    color: #333;
}
[data-theme="light"] .quiz-container h2 {
    color: #333;
}
[data-theme="light"] .background-animation .red-curve,
html[data-theme="light"] body .red-curve {
    stroke: var(--gold);
}

[data-theme="light"] .svg-wave path {
    stroke-width: 2.5;
}
[data-theme="light"] .slider-value {
    color: #333;
}
[data-theme="light"] .quiz-option {
    background: #fff;
    border: 1px solid #e0e0e0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
[data-theme="light"] .quiz-option:hover, [data-theme="light"] .quiz-option.selected {
    background: #f7f7f7;
    border-color: #d0d0d0;
}
html[data-theme="light"] body .svg-wave path,
html[data-theme="light"] body .red-curve path {
    filter: drop-shadow(0 0 10px rgba(255, 215, 0, 0.5));
}
html[data-theme="light"] body .svg-wave,
html[data-theme="light"] body .graph-col {
    background: linear-gradient(145deg, #f9f9f9, #e6e6e6);
    box-shadow: 8px 8px 16px #d1d1d1, -8px -8px 16px #ffffff;
    border-radius: 1rem;
}
html[data-theme="light"] body .quiz-container,
html[data-theme="light"] body .card,
html[data-theme="light"] body .tab-content {
    background: #f0f0f0;
}
html[data-theme="light"] body .quiz-option {
    background: #e0e0e0;
}
html[data-theme="light"] body .quiz-option:hover,
html[data-theme="light"] body .quiz-option.selected {
    background: #d0d0d0;
}
html[data-theme="light"] body * {
    /* Potential global override */
}

/* Premium card and text styling from various sections */
[data-theme="light"] .slider-value {
    color: #111;
}

[data-theme="light"] .premium-text {
    color: #333;
}

[data-theme="light"] input[type="range"] {
    background: #ddd;
}
[data-theme="light"] input[type="range"]::-webkit-slider-thumb {
    background: #3a86ff;
}
[data-theme="light"] input[type="range"]::-moz-range-thumb {
    background: #3a86ff;
}

[data-theme="light"] .quiz-option:hover, [data-theme="light"] .quiz-option.selected {
    background: #e0e0e0;
    border-color: #ccc;
}
.quiz-option.correct {
    background: #28a745 !important;
    border-color: #28a745 !important;
    color: #fff !important;
}
.quiz-option.wrong {
    background: #dc3545 !important;
    border-color: #dc3545 !important;
    color: #fff !important;
}
#quiz-results {
    color: #fff;
}
[data-theme="light"] .quiz-question h3 {
    color: #333;
}
[data-theme="light"] .quiz-container h2 {
    color: #333;
}

[data-theme="light"] input[type="range"]::-moz-range-thumb {
    background: #3a86ff;
}

/* --- Quiz Text Color Fixes --- */

/* Ensure all text within the quiz container is visible in dark mode */
.quiz-container,
#quiz-progress,
#quiz-results p,
.quiz-question h3,
.quiz-container .quiz-option {
    color: #fff;
}

/* Ensure all text within the quiz container is visible in light mode */
[data-theme="light"] .quiz-container,
[data-theme="light"] #quiz-progress,
[data-theme="light"] #quiz-results p,
[data-theme="light"] .quiz-question h3,
[data-theme="light"] .quiz-container .quiz-option {
    color: #18181a;
}

/* Text color for selected/correct/wrong options should always be white for contrast */
.quiz-option.correct,
.quiz-option.wrong {
    color: #fff !important;
}

#quiz-results h3 {
    color: inherit;
}

/* --- Wave Dot and Enhanced SVG Styling --- */
.wave-dot {
  fill: currentColor;
  stroke: #fff;
  stroke-width: 2px;
  filter: drop-shadow(0 0 8px #e50914cc);
  transition: fill 0.3s, filter 0.3s;
}
[data-theme="light"] .wave-dot {
  filter: drop-shadow(0 0 8px #FFD700cc);
}
.svg-wave path {
  filter: drop-shadow(0 0 16px #e50914cc) drop-shadow(0 4px 16px #0008);
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: filter 0.3s;
}
[data-theme="light"] .svg-wave path {
  filter: drop-shadow(0 0 16px #FFD700cc) drop-shadow(0 4px 16px #0004);
}

/* --- Enhanced Premium Light Mode --- */
[data-theme="light"] body {
  background: linear-gradient(120deg, #f7faff 0%, #fffbe6 100%);
  color: #18181a;
}
[data-theme="light"] .main-layout,
[data-theme="light"] .tab-content,
[data-theme="light"] .card,
[data-theme="light"] .quiz-container,
[data-theme="light"] .controls,
[data-theme="light"] .comparison-section,
[data-theme="light"] .medium-card,
[data-theme="light"] .team-list,
[data-theme="light"] .info-grid,
[data-theme="light"] .row,
[data-theme="light"] .graph-col {
  background: #fffbe6 !important;
  color: #18181a !important;
  box-shadow: 0 8px 32px 0 rgba(255, 215, 0, 0.12), 0 1.5px 8px rgba(0, 0, 0, 0.06);
  border: 2.5px solid var(--gold);
  backdrop-filter: blur(10px);
  border-radius: 1.5rem;
}
[data-theme="light"] .tab-description,
[data-theme="light"] h1, [data-theme="light"] h2, [data-theme="light"] h3,
[data-theme="light"] .quiz-container h2, [data-theme="light"] .quiz-container h3 {
  color: #b8860b !important;
  text-shadow: 0 2px 12px #ffd70033;
}
[data-theme="light"] .quiz-container,
[data-theme="light"] .quiz-question,
[data-theme="light"] .quiz-option,
[data-theme="light"] #quiz-progress,
[data-theme="light"] #quiz-results p {
  color: #18181a !important;
  background: #fffbe6 !important;
}
[data-theme="light"] .quiz-option.correct {
  background: #ffe44d !important;
  color: #18181a !important;
  border-color: #b8860b !important;
}
[data-theme="light"] .quiz-option.wrong {
  background: #ffd6d6 !important;
  color: #b30000 !important;
  border-color: #b30000 !important;
}
[data-theme="light"] .quiz-option.selected {
  background: #fff2b2 !important;
  color: #18181a !important;
  border-color: #ffd700 !important;
}
[data-theme="light"] .control-btn,
[data-theme="light"] .start-btn {
  background: linear-gradient(90deg, #ffd700 0%, #fffbe6 100%) !important;
  color: #18181a !important;
  border: 2px solid #ffd700 !important;
  box-shadow: 0 4px 24px #ffd70033 !important;
}
[data-theme="light"] .control-btn:hover,
[data-theme="light"] .start-btn:hover {
  background: linear-gradient(90deg, #fffbe6 0%, #ffd700 100%) !important;
  color: #18181a !important;
  border: 2px solid #b8860b !important;
}
[data-theme="light"] .sidebar {
  background: #fffbe6 !important;
  color: #18181a !important;
  border-bottom: 2px solid #ffd700 !important;
  box-shadow: 0 2px 32px #ffd70022 !important;
}
[data-theme="light"] .tab-btn {
  color: #b8860b;
  background: #fffbe6;
}
[data-theme="light"] .tab-btn.active, [data-theme="light"] .tab-btn:focus {
  color: #fff;
  background: linear-gradient(90deg, #ffd700 0%, #fffbe6 100%) !important;
  border-bottom: 4px solid #ffd700 !important;
}
[data-theme="light"] .svg-wave path {
  stroke: #ffd700 !important;
  filter: drop-shadow(0 0 16px #ffd700cc) drop-shadow(0 4px 16px #fffbe6);
}
[data-theme="light"] .wave-dot {
  fill: #ffd700;
  stroke: #fffbe6;
  filter: drop-shadow(0 0 8px #ffd700cc);
}
[data-theme="light"] .slider-value {
  color: #b8860b;
}
[data-theme="light"] input[type="range"] {
  background: #ffe44d !important;
  border: 2px solid #ffd700 !important;
}
[data-theme="light"] input[type="range"]::-webkit-slider-thumb {
  background: #ffd700 !important;
  border: 3px solid #fffbe6 !important;
  box-shadow: 0 2px 8px #ffd70044 !important;
}
[data-theme="light"] input[type="range"]::-moz-range-thumb {
  background: #ffd700 !important;
  border: 3px solid #fffbe6 !important;
  box-shadow: 0 2px 8px #ffd70044 !important;
}