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

:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #0f1525;
    --glass-bg: rgba(255, 255, 255, 0.04);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-hover: rgba(255, 255, 255, 0.08);
    --text-primary: #e2e8f0;
    --text-secondary: #8892a8;
    --accent: #6c8cff;
    --accent-glow: rgba(108, 140, 255, 0.3);
    --accent-warm: #a78bfa;
    --slider-track: rgba(255, 255, 255, 0.08);
    --slider-fill: var(--accent);
    --radius: 12px;
    --radius-sm: 8px;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(ellipse at 20% 50%, rgba(108, 140, 255, 0.04) 0%, transparent 50%),
                radial-gradient(ellipse at 80% 20%, rgba(167, 139, 250, 0.03) 0%, transparent 50%),
                radial-gradient(ellipse at 50% 80%, rgba(108, 140, 255, 0.02) 0%, transparent 50%);
    z-index: 0;
    pointer-events: none;
    animation: ambient-drift 20s ease-in-out infinite alternate;
}

@keyframes ambient-drift {
    0% { transform: translate(0, 0) rotate(0deg); }
    100% { transform: translate(30px, -20px) rotate(3deg); }
}

/* === Rain Canvas === */
#rain-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    opacity: 0.4;
}

/* === Container === */
.container {
    position: relative;
    z-index: 1;
    max-width: 720px;
    margin: 0 auto;
    padding: 40px 20px 60px;
    animation: fade-in 0.8s ease-out;
}

@keyframes fade-in {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Stagger card entrance */
.sound-card {
    animation: card-enter 0.5s ease-out backwards;
}
.sound-card:nth-child(1) { animation-delay: 0.05s; }
.sound-card:nth-child(2) { animation-delay: 0.1s; }
.sound-card:nth-child(3) { animation-delay: 0.15s; }
.sound-card:nth-child(4) { animation-delay: 0.2s; }
.sound-card:nth-child(5) { animation-delay: 0.25s; }
.sound-card:nth-child(6) { animation-delay: 0.3s; }
.sound-card:nth-child(7) { animation-delay: 0.35s; }
.sound-card:nth-child(8) { animation-delay: 0.4s; }
.sound-card:nth-child(9) { animation-delay: 0.45s; }
.sound-card:nth-child(10) { animation-delay: 0.5s; }

@keyframes card-enter {
    from { opacity: 0; transform: translateY(16px) scale(0.96); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

/* === Header === */
.header {
    text-align: center;
    margin-bottom: 36px;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 8px;
}

.logo-icon {
    color: var(--accent);
    filter: drop-shadow(0 0 8px var(--accent-glow));
}

.logo h1 {
    font-size: 1.6rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tagline {
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 300;
    letter-spacing: 0.04em;
}

/* === Presets === */
.presets {
    display: flex;
    gap: 8px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 32px;
}

.preset-btn {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-secondary);
    padding: 6px 16px;
    border-radius: 20px;
    font-family: inherit;
    font-size: 0.8rem;
    font-weight: 400;
    cursor: pointer;
    transition: all 0.25s ease;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.preset-btn:hover {
    background: var(--glass-hover);
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.15);
}

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

.preset-btn.active {
    background: rgba(108, 140, 255, 0.12);
    border-color: rgba(108, 140, 255, 0.3);
    color: var(--accent);
    box-shadow: 0 0 16px rgba(108, 140, 255, 0.1);
}

/* === Mixer Grid === */
.mixer {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 12px;
    margin-bottom: 32px;
}

/* === Sound Card === */
.sound-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    padding: 20px 16px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    transition: all 0.3s ease;
    cursor: default;
}

.sound-card:hover {
    background: var(--glass-hover);
    border-color: rgba(255, 255, 255, 0.12);
    transform: translateY(-2px);
}

.sound-card.active {
    background: rgba(108, 140, 255, 0.06);
    border-color: rgba(108, 140, 255, 0.2);
    box-shadow: 0 4px 24px rgba(108, 140, 255, 0.08);
    animation: breathe 3s ease-in-out infinite;
}

@keyframes breathe {
    0%, 100% {
        box-shadow: 0 4px 20px rgba(108, 140, 255, 0.08);
        border-color: rgba(108, 140, 255, 0.2);
    }
    50% {
        box-shadow: 0 4px 32px rgba(108, 140, 255, 0.18), 0 0 60px rgba(108, 140, 255, 0.06);
        border-color: rgba(108, 140, 255, 0.35);
    }
}

.sound-icon {
    color: var(--text-secondary);
    transition: color 0.3s, filter 0.3s;
    height: 28px;
}

.sound-card.active .sound-icon {
    color: var(--accent);
    filter: drop-shadow(0 0 6px var(--accent-glow));
    animation: icon-pulse 2.5s ease-in-out infinite;
}

@keyframes icon-pulse {
    0%, 100% { filter: drop-shadow(0 0 4px var(--accent-glow)); transform: scale(1); }
    50% { filter: drop-shadow(0 0 12px var(--accent-glow)); transform: scale(1.08); }
}

.sound-name {
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.3s;
}

.sound-card.active .sound-name {
    color: var(--text-primary);
}

.volume-value {
    font-size: 0.7rem;
    color: var(--text-secondary);
    font-variant-numeric: tabular-nums;
    min-width: 20px;
    text-align: center;
}

/* === Range Slider === */
.volume-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 4px;
    border-radius: 2px;
    background: var(--slider-track);
    outline: none;
    cursor: pointer;
}

.volume-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: radial-gradient(circle at 35% 35%, #9bb5ff, var(--accent));
    cursor: pointer;
    box-shadow: 0 0 8px var(--accent-glow), 0 0 20px rgba(108, 140, 255, 0.15);
    transition: transform 0.15s ease, box-shadow 0.2s ease;
    border: 2px solid rgba(255, 255, 255, 0.15);
}

.volume-slider::-webkit-slider-thumb:hover {
    transform: scale(1.25);
    box-shadow: 0 0 12px var(--accent-glow), 0 0 30px rgba(108, 140, 255, 0.25);
}

.volume-slider:active::-webkit-slider-thumb {
    transform: scale(1.1);
    box-shadow: 0 0 16px var(--accent), 0 0 40px rgba(108, 140, 255, 0.3);
}

.volume-slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: radial-gradient(circle at 35% 35%, #9bb5ff, var(--accent));
    cursor: pointer;
    border: 2px solid rgba(255, 255, 255, 0.15);
    box-shadow: 0 0 8px var(--accent-glow), 0 0 20px rgba(108, 140, 255, 0.15);
}

/* === Timer === */
.timer-section {
    margin-bottom: 28px;
}

.timer-glass {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    padding: 16px 20px;
    display: flex;
    align-items: center;
    gap: 14px;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    flex-wrap: wrap;
}

.timer-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.timer-buttons {
    display: flex;
    gap: 6px;
}

.timer-btn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid transparent;
    color: var(--text-secondary);
    padding: 4px 12px;
    border-radius: 16px;
    font-family: inherit;
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.2s ease;
}

.timer-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
}

.timer-btn.active {
    background: rgba(108, 140, 255, 0.15);
    border-color: rgba(108, 140, 255, 0.3);
    color: var(--accent);
}

.timer-display {
    margin-left: auto;
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--accent);
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.05em;
}

.timer-display.hidden {
    display: none;
}

/* === Master Controls === */
.master-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 40px;
}

.master-btn {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-secondary);
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.25s ease;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.master-btn:hover {
    background: var(--glass-hover);
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.15);
    transform: scale(1.05);
}

.master-btn:active {
    transform: scale(0.95);
    background: rgba(108, 140, 255, 0.15);
}

.master-volume {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
}

.master-slider {
    width: 120px;
}

/* === Saved Mixes === */
.saved-mixes {
    margin-bottom: 28px;
}

.saved-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 10px;
}

.saved-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.save-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-secondary);
    padding: 5px 14px;
    border-radius: 16px;
    font-family: inherit;
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.2s ease;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.save-btn:hover {
    background: rgba(108, 140, 255, 0.1);
    border-color: rgba(108, 140, 255, 0.3);
    color: var(--accent);
}

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

.saved-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.saved-list:empty::after {
    content: 'No saved mixes yet';
    font-size: 0.72rem;
    color: var(--text-secondary);
    opacity: 0.5;
}

.saved-mix-item {
    display: flex;
    align-items: center;
    gap: 6px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 4px 6px 4px 14px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    animation: card-enter 0.3s ease-out;
}

.saved-mix-item:hover {
    background: rgba(108, 140, 255, 0.08);
    border-color: rgba(108, 140, 255, 0.25);
    color: var(--text-primary);
}

.saved-mix-delete {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 2px 4px;
    border-radius: 50%;
    font-size: 0.7rem;
    line-height: 1;
    opacity: 0.4;
    transition: all 0.2s;
}

.saved-mix-delete:hover {
    opacity: 1;
    color: #ff6b6b;
}

/* === Shortcuts Hint === */
.shortcuts-hint {
    text-align: center;
    font-size: 0.68rem;
    color: var(--text-secondary);
    opacity: 0.35;
    margin-bottom: 32px;
    transition: opacity 0.3s;
}

.shortcuts-hint:hover {
    opacity: 0.7;
}

.shortcuts-hint span {
    display: inline-block;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    padding: 1px 6px;
    font-family: inherit;
    font-size: 0.65rem;
}

/* === Fullscreen / Immersive Mode === */
body.immersive .header,
body.immersive .presets,
body.immersive .timer-section,
body.immersive .saved-mixes,
body.immersive .shortcuts-hint,
body.immersive .footer {
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.5s ease;
}

body.immersive .mixer {
    margin-top: 10vh;
}

body.immersive .master-controls {
    margin-bottom: 0;
}

body.immersive #rain-canvas {
    opacity: 0.7 !important;
}

/* === Footer === */
.footer {
    text-align: center;
}

.footer p {
    font-size: 0.72rem;
    color: var(--text-secondary);
    opacity: 0.5;
}

/* === Scrollbar === */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 3px;
}

/* === Responsive === */
@media (max-width: 480px) {
    .container {
        padding: 28px 14px 40px;
    }

    .mixer {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .sound-card {
        padding: 16px 12px;
    }

    .logo h1 {
        font-size: 1.3rem;
    }

    .presets {
        gap: 6px;
    }

    .preset-btn {
        padding: 5px 12px;
        font-size: 0.75rem;
    }

    .timer-glass {
        flex-direction: column;
        align-items: flex-start;
    }

    .timer-display {
        margin-left: 0;
    }
}

@media (min-width: 481px) and (max-width: 600px) {
    .mixer {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 601px) {
    .mixer {
        grid-template-columns: repeat(3, 1fr);
    }
}