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

:root {
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --bg-card: #1f2937;
    --accent: #e94560;
    --accent-hover: #ff6b6b;
    --text-primary: #ffffff;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --border: #374151;
    --success: #10b981;
    --warning: #f59e0b;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    padding: 30px 0;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 8px;
    background: linear-gradient(90deg, var(--accent), var(--accent-hover));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Views */
.view {
    display: none;
    flex: 1;
}

.view.active {
    display: block;
}

/* Sessions Grid */
.sessions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
    padding: 10px 0;
}

.session-card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid var(--border);
}

.session-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 40px rgba(233, 69, 96, 0.2);
    border-color: var(--accent);
}

.session-card h3 {
    font-size: 1.2rem;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.session-card .date {
    color: var(--accent);
    font-size: 0.9rem;
    margin-bottom: 12px;
}

.session-card .track-count {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.loading {
    text-align: center;
    color: var(--text-secondary);
    padding: 40px;
    grid-column: 1 / -1;
}

.error {
    text-align: center;
    color: var(--accent);
    padding: 40px;
    grid-column: 1 / -1;
}

/* Back Button */
.back-button {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.95rem;
    transition: all 0.2s;
    margin-bottom: 20px;
}

.back-button:hover {
    border-color: var(--accent);
    color: var(--text-primary);
}

/* Session Header */
.session-header {
    margin-bottom: 24px;
}

.session-header h2 {
    font-size: 1.8rem;
    margin-bottom: 4px;
}

.session-date {
    color: var(--accent);
    font-size: 1rem;
}

/* Transport Controls */
.transport {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 20px;
    border: 1px solid var(--border);
}

.play-button {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--accent);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s, transform 0.1s;
    flex-shrink: 0;
}

.play-button:hover {
    background: var(--accent-hover);
}

.play-button:active {
    transform: scale(0.95);
}

.play-button .play-icon,
.play-button .pause-icon {
    font-size: 20px;
    color: white;
}

.play-button .pause-icon {
    display: none;
    letter-spacing: -4px;
}

.play-button.playing .play-icon {
    display: none;
}

.play-button.playing .pause-icon {
    display: inline;
}

.time-display {
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
    font-size: 0.95rem;
    color: var(--text-secondary);
    min-width: 100px;
    flex-shrink: 0;
}

.time-separator {
    margin: 0 4px;
    color: var(--text-muted);
}

.seek-container {
    flex: 1;
}

.seek-bar {
    width: 100%;
    height: 8px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--border);
    border-radius: 4px;
    cursor: pointer;
}

.seek-bar::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    transition: transform 0.1s;
}

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

.seek-bar::-moz-range-thumb {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: none;
}

/* Master Volume */
.master-volume {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 16px 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
    border: 1px solid var(--border);
}

.master-volume label {
    font-weight: 600;
    color: var(--text-primary);
    min-width: 60px;
}

.master-volume input[type="range"] {
    flex: 1;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--border);
    border-radius: 3px;
    cursor: pointer;
}

.master-volume input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--success);
    cursor: pointer;
}

.master-volume input[type="range"]::-moz-range-thumb {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--success);
    cursor: pointer;
    border: none;
}

#master-volume-display {
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
    font-size: 0.85rem;
    color: var(--text-secondary);
    min-width: 40px;
    text-align: right;
}

/* Tracks List */
.tracks-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.track {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 16px 20px;
    display: grid;
    grid-template-columns: auto 1fr auto auto;
    align-items: center;
    gap: 16px;
    border: 1px solid var(--border);
    transition: border-color 0.2s;
}

.track.loading {
    opacity: 0.6;
}

.track.error {
    border-color: var(--accent);
}

.track.main-mix {
    background: linear-gradient(135deg, #1f2937 0%, #2d3748 100%);
    border: 2px solid var(--accent);
    padding: 20px 24px;
}

.track.main-mix .track-name {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--accent);
}

.track-name {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 1rem;
}

.track-controls {
    display: flex;
    gap: 8px;
}

.track-btn {
    padding: 6px 14px;
    border-radius: 6px;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 500;
    transition: all 0.2s;
}

.track-btn:hover {
    border-color: var(--text-secondary);
    color: var(--text-primary);
}

.track-btn.solo.active {
    background: var(--warning);
    border-color: var(--warning);
    color: #000;
}

.track-btn.mute.active {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
}

.track-volume {
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 150px;
}

.track-volume input[type="range"] {
    width: 100px;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--border);
    border-radius: 3px;
    cursor: pointer;
}

.track-volume input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--text-secondary);
    cursor: pointer;
}

.track-volume input[type="range"]::-moz-range-thumb {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--text-secondary);
    cursor: pointer;
    border: none;
}

.track-volume-display {
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
    font-size: 0.8rem;
    color: var(--text-muted);
    min-width: 35px;
    text-align: right;
}

/* Footer */
footer {
    text-align: center;
    padding: 30px 0 10px;
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }

    header h1 {
        font-size: 1.8rem;
    }

    .transport {
        flex-wrap: wrap;
        gap: 15px;
    }

    .seek-container {
        order: 3;
        width: 100%;
    }

    .track {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .track-volume {
        justify-content: flex-start;
    }

    .track-controls {
        justify-content: flex-start;
    }

    .sessions-grid {
        grid-template-columns: 1fr;
    }
}

/* Loading spinner */
@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.spinner {
    width: 24px;
    height: 24px;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto;
}