/* ============================================
   Focus Room - Custom Focus BGM Mixer
   A calm, immersive, distraction-free experience
   ============================================ */

/* ---------- CSS Variables (World Themes) ---------- */
:root {
    /* Base typography */
    --font-body: 'Outfit', sans-serif;
    --font-accent: 'Cormorant', serif;
    
    /* Sizing */
    --panel-blur: 20px;
    --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: 0.2s ease;
}

/* Cafe Theme - Warm, cozy browns and ambers */
[data-world="cafe"] {
    --bg-primary: #1a1410;
    --bg-secondary: #2a1f18;
    --bg-gradient-start: #1a1410;
    --bg-gradient-mid: #2d1f15;
    --bg-gradient-end: #1a1612;
    --accent: #d4a574;
    --accent-glow: rgba(212, 165, 116, 0.4);
    --text-primary: #f0e6dc;
    --text-secondary: rgba(240, 230, 220, 0.7);
    --text-muted: rgba(232, 221, 212, 0.45);
    --glass-bg: rgba(50, 38, 30, 0.75);
    --glass-border: rgba(212, 165, 116, 0.2);
    --panel-glow: rgba(212, 165, 116, 0.05);
}

/* Rainy Theme - Cool blue-grays, wet atmosphere */
[data-world="rainy"] {
    --bg-primary: #101418;
    --bg-secondary: #1a2028;
    --bg-gradient-start: #101418;
    --bg-gradient-mid: #182028;
    --bg-gradient-end: #0e1216;
    --accent: #7a9bb8;
    --accent-glow: rgba(122, 155, 184, 0.4);
    --text-primary: #e0e6ec;
    --text-secondary: rgba(224, 230, 236, 0.7);
    --text-muted: rgba(200, 210, 220, 0.45);
    --glass-bg: rgba(30, 40, 50, 0.75);
    --glass-border: rgba(122, 155, 184, 0.2);
    --panel-glow: rgba(122, 155, 184, 0.05);
}

/* Night Theme - Deep blues and purples */
[data-world="night"] {
    --bg-primary: #0c0e1a;
    --bg-secondary: #141828;
    --bg-gradient-start: #0c0e1a;
    --bg-gradient-mid: #151a2e;
    --bg-gradient-end: #0e101c;
    --accent: #8b9dc3;
    --accent-glow: rgba(139, 157, 195, 0.4);
    --text-primary: #e0e4f0;
    --text-secondary: rgba(224, 228, 240, 0.7);
    --text-muted: rgba(216, 221, 232, 0.45);
    --glass-bg: rgba(26, 32, 52, 0.75);
    --glass-border: rgba(139, 157, 195, 0.2);
    --panel-glow: rgba(139, 157, 195, 0.05);
}

/* Cozy Theme - Warm oranges, fireplace feel */
[data-world="cozy"] {
    --bg-primary: #1a1412;
    --bg-secondary: #281c16;
    --bg-gradient-start: #1a1412;
    --bg-gradient-mid: #2a1c14;
    --bg-gradient-end: #181210;
    --accent: #e8a862;
    --accent-glow: rgba(232, 168, 98, 0.4);
    --text-primary: #f4ebe0;
    --text-secondary: rgba(244, 235, 224, 0.7);
    --text-muted: rgba(232, 220, 200, 0.45);
    --glass-bg: rgba(50, 36, 28, 0.75);
    --glass-border: rgba(232, 168, 98, 0.2);
    --panel-glow: rgba(232, 168, 98, 0.05);
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    transition: background-color var(--transition-smooth);
}

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

a {
    color: inherit;
    text-decoration: none;
}

/* ---------- Background Layers ---------- */
.bg-layer {
    position: fixed;
    inset: 0;
    pointer-events: none;
}

/* Background image layer - lowest */
.bg-image {
    z-index: -4;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    filter: blur(4px) brightness(0.4);
    transform: scale(1.03); /* Prevent blur edge artifacts */
    transition: background-image 0.6s ease;
}

.bg-gradient {
    z-index: -3;
    background: radial-gradient(
        ellipse 80% 60% at 50% 40%,
        var(--bg-gradient-mid) 0%,
        var(--bg-gradient-start) 50%,
        var(--bg-gradient-end) 100%
    );
    opacity: 0.4;
    transition: background var(--transition-smooth);
}

.bg-noise {
    z-index: -2;
}

.bg-vignette {
    z-index: -1;
}

/* Subtle noise texture overlay */
.bg-noise {
    opacity: 0.03;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
}

/* Soft vignette effect */
.bg-vignette {
    background: radial-gradient(
        ellipse 70% 70% at 50% 50%,
        transparent 0%,
        rgba(0, 0, 0, 0.4) 100%
    );
}

/* ---------- Site Header (Top Center) ---------- */
.site-header {
    position: fixed;
    top: 0.75rem;
    left: 0;
    right: 0;
    display: flex;
    justify-content: center;
    z-index: 101;
    pointer-events: none;
}

.site-name {
    font-family: var(--font-accent);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.12em;
    color: var(--text-secondary);
    opacity: 0.7;
    transition: color var(--transition-smooth);
}

/* ---------- World Selector (Top Zone) ---------- */
.world-selector {
    position: fixed;
    top: 2rem;
    left: 0;
    right: 0;
    display: flex;
    justify-content: center;
    gap: 2rem;
    padding: 1rem 2rem;
    z-index: 100;
}

.world-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.world-btn {
    font-size: 0.75rem;
    font-weight: 400;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--text-muted);
    padding: 0.5rem 0;
    position: relative;
    transition: color var(--transition-fast);
}

.world-btn::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 1px;
    background: var(--accent);
    box-shadow: 0 0 8px var(--accent-glow);
    transform: translateX(-50%);
    transition: width var(--transition-fast);
}

.world-btn:hover {
    color: var(--text-primary);
}

.world-btn.active {
    color: var(--accent);
}

.world-btn.active::after {
    width: 100%;
}

/* ---------- Image Dots (Under Each World) ---------- */
.image-dots {
    display: none;
    gap: 0.4rem;
    height: 6px;
    opacity: 0;
    transition: opacity var(--transition-fast);
}

/* Show dots only for active world with images */
.world-btn.active ~ .image-dots {
    display: flex;
    opacity: 0.5;
}

.world-btn.active ~ .image-dots:hover {
    opacity: 0.9;
}

.image-dot {
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--text-muted);
    border: none;
    padding: 0;
    cursor: pointer;
    transition: 
        background var(--transition-fast),
        transform var(--transition-fast);
}

.image-dot:hover {
    background: var(--text-secondary);
    transform: scale(1.4);
}

.image-dot.active {
    background: var(--accent);
}

/* ---------- Mixer Panel (Center Zone) ---------- */
.mixer-panel {
    display: flex;
    align-items: center;
    justify-content: center;
    flex: 1;
    width: 100%;
    padding: 2rem;
}

.glass-container {
    background: 
        linear-gradient(
            180deg,
            rgba(255, 255, 255, 0.03) 0%,
            transparent 50%
        ),
        var(--glass-bg);
    backdrop-filter: blur(var(--panel-blur));
    -webkit-backdrop-filter: blur(var(--panel-blur));
    border: 1px solid var(--glass-border);
    border-radius: 2rem;
    padding: 2.5rem 4rem 3rem;
    box-shadow: 
        0 8px 32px rgba(0, 0, 0, 0.4),
        0 0 80px var(--panel-glow),
        inset 0 1px 0 rgba(255, 255, 255, 0.06);
    transition: 
        background var(--transition-smooth),
        border-color var(--transition-smooth),
        box-shadow var(--transition-smooth);
}

/* Tagline - subtle, blends with atmosphere */
.tagline {
    text-align: center;
    font-size: 0.75rem;
    font-weight: 300;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-bottom: 2rem;
    opacity: 0.8;
}

.sound-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 1.5rem 2rem;
    align-items: start;
    justify-items: center;
}

/* 4-column layout for worlds with 4 sounds */
.sound-grid.cols-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* ---------- Volume Sliders ---------- */
.volume-slider {
    grid-row: 2;
    width: 4rem;
    height: 3px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--glass-border);
    border-radius: 2px;
    outline: none;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-fast);
    margin-top: -0.5rem;
}

/* Show slider when sound is active */
.sound-btn.active + .volume-slider {
    opacity: 1;
    pointer-events: auto;
}

/* Slider thumb - Webkit (Chrome, Safari) */
.volume-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 10px;
    height: 10px;
    background: var(--accent);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 8px var(--accent-glow);
    transition: transform var(--transition-fast);
}

.volume-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

/* Slider thumb - Firefox */
.volume-slider::-moz-range-thumb {
    width: 10px;
    height: 10px;
    background: var(--accent);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 8px var(--accent-glow);
}

/* Slider track - Firefox */
.volume-slider::-moz-range-track {
    background: var(--glass-border);
    height: 3px;
    border-radius: 2px;
}

/* ---------- Sound Buttons ---------- */
.sound-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    padding: 1.25rem;
    border-radius: 50%;
    width: 5.5rem;
    height: 5.5rem;
    position: relative;
    transition: transform var(--transition-fast);
}

.sound-btn:hover {
    transform: scale(1.05);
}

.sound-btn:active {
    transform: scale(0.98);
}

.sound-icon {
    width: 1.75rem;
    height: 1.75rem;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.sound-icon svg {
    width: 100%;
    height: 100%;
}

.sound-label {
    font-size: 0.65rem;
    font-weight: 400;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

/* Animated ring around sound buttons */
.sound-ring {
    position: absolute;
    inset: 0;
    border-radius: 50%;
    border: 1px solid transparent;
    transition: 
        border-color var(--transition-fast),
        box-shadow var(--transition-fast);
}

/* Hover state */
.sound-btn:hover .sound-icon,
.sound-btn:hover .sound-label {
    color: var(--text-primary);
}

.sound-btn:hover .sound-ring {
    border-color: var(--glass-border);
}

/* Active (playing) state */
.sound-btn.active .sound-icon {
    color: var(--accent);
}

.sound-btn.active .sound-label {
    color: var(--accent);
}

.sound-btn.active .sound-ring {
    border-color: var(--accent);
    box-shadow: 
        0 0 20px var(--accent-glow),
        inset 0 0 20px var(--accent-glow);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.7;
        transform: scale(1.02);
    }
}

/* ---------- Controls (Bottom Zone) ---------- */
.controls {
    position: fixed;
    bottom: 3rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 2rem;
    z-index: 100;
}

.control-btn {
    font-size: 0.7rem;
    font-weight: 400;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--text-muted);
    padding: 0.6rem 1.2rem;
    border-radius: 2rem;
    border: 1px solid transparent;
    transition: 
        color var(--transition-fast),
        border-color var(--transition-fast),
        background var(--transition-fast);
}

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

.reset-btn:hover {
    border-color: rgba(255, 120, 120, 0.3);
    color: #ff9090;
}

.save-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.save-btn.saved {
    color: var(--accent);
    border-color: var(--accent);
}

/* ---------- Brand / Support (Bottom Right) ---------- */
.brand {
    position: fixed;
    bottom: 1.5rem;
    right: 2rem;
    z-index: 100;
}

.brand-link {
    font-size: 0.6rem;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    opacity: 0.5;
    transition: 
        color var(--transition-fast),
        opacity var(--transition-fast);
}

.brand-link:hover {
    color: var(--text-primary);
    opacity: 0.8;
}

/* ---------- Responsive Adjustments ---------- */
@media (max-width: 768px) {
    .site-name {
        font-size: 0.65rem;
    }
    
    .world-selector {
        gap: 1.25rem;
        padding: 1rem;
    }
    
    .world-item {
        gap: 0.35rem;
    }
    
    .world-btn {
        font-size: 0.65rem;
    }
    
    .image-dot {
        width: 4px;
        height: 4px;
    }
    
    .glass-container {
        padding: 2rem 1.5rem 2.5rem;
        border-radius: 1.5rem;
    }
    
    .tagline {
        font-size: 0.65rem;
        margin-bottom: 1.5rem;
    }
    
    .sound-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 1rem 1.5rem;
        max-width: 280px;
    }
    
    .sound-grid.cols-4 {
        grid-template-columns: repeat(2, 1fr);
        max-width: 200px;
    }
    
    .volume-slider {
        width: 3.5rem;
    }
    
    .sound-btn {
        width: 4.5rem;
        height: 4.5rem;
        padding: 1rem;
    }
    
    .sound-icon {
        width: 1.4rem;
        height: 1.4rem;
    }
    
    .sound-label {
        font-size: 0.55rem;
    }
    
    .controls {
        bottom: 2rem;
        gap: 1rem;
    }
    
    .control-btn {
        font-size: 0.6rem;
        padding: 0.5rem 1rem;
    }
    
    .brand {
        bottom: 1rem;
        right: 1rem;
    }
    
    .brand-link {
        font-size: 0.55rem;
    }
}

@media (max-width: 400px) {
    .sound-grid {
        max-width: 240px;
    }
    
    .sound-btn {
        width: 4rem;
        height: 4rem;
    }
}