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

:root {
    --bg-primary: #faf8f6;
    --bg-secondary: #ffffff;
    --bg-overlay: rgba(255, 255, 255, 0.7);

    --text-primary: #2d2d2d;
    --text-secondary: #6b6b6b;
    --text-muted: #9a9a9a;

    --accent-primary: #d4a5a5;
    --accent-secondary: #c8b5d4;
    --accent-tertiary: #a5c4d4;

    --border-color: rgba(0, 0, 0, 0.08);
    --shadow-soft: 0 4px 24px rgba(0, 0, 0, 0.06);
    --shadow-medium: 0 8px 32px rgba(0, 0, 0, 0.08);

    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    background: linear-gradient(135deg, #faf8f6 0%, #f0ede9 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    position: relative;
}

/* Subtle texture overlay */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(212, 165, 165, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(200, 181, 212, 0.1) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

nav {
    position: relative;
    z-index: 10;
    padding: 1.5rem 2rem;
}

.back-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.back-link:hover {
    color: var(--accent-primary);
    transform: translateX(-4px);
}

main {
    position: relative;
    z-index: 1;
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 2rem 4rem;
}

.app-header {
    text-align: center;
    margin-bottom: 3rem;
}

.app-header h1 {
    font-size: 3rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 50%, var(--accent-tertiary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.tagline {
    color: var(--text-secondary);
    font-size: 1.1rem;
    font-weight: 300;
    font-style: italic;
}

.container {
    display: grid;
    gap: 2rem;
}

/* Input Section */
.input-section {
    background: var(--bg-secondary);
    border-radius: 24px;
    padding: 2.5rem;
    box-shadow: var(--shadow-soft);
    border: 1px solid var(--border-color);
}

.input-section h2 {
    font-size: 1.5rem;
    font-weight: 400;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.instructions {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 2rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

label {
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

input[type="text"],
input[type="number"],
select,
textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 1.5px solid var(--border-color);
    border-radius: 12px;
    font-size: 1rem;
    font-family: inherit;
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: var(--transition);
}

input:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
    background: var(--bg-secondary);
    box-shadow: 0 0 0 3px rgba(212, 165, 165, 0.1);
}

textarea {
    resize: vertical;
    min-height: 80px;
}

/* Buttons */
.generate-btn {
    width: 100%;
    padding: 1rem 2rem;
    border: none;
    border-radius: 16px;
    font-size: 1.1rem;
    font-weight: 500;
    background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 100%);
    color: white;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 16px rgba(212, 165, 165, 0.3);
    position: relative;
    overflow: hidden;
}

.generate-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(212, 165, 165, 0.4);
}

.generate-btn:active:not(:disabled) {
    transform: translateY(0);
}

.generate-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.generate-btn .btn-loading {
    display: none;
}

.generate-btn.loading .btn-text {
    display: none;
}

.generate-btn.loading .btn-loading {
    display: inline;
}

/* Output Section */
.output-section {
    background: var(--bg-secondary);
    border-radius: 24px;
    padding: 2.5rem;
    box-shadow: var(--shadow-soft);
    border: 1px solid var(--border-color);
    display: none;
}

.output-section.visible {
    display: block;
    animation: fadeInUp 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.output-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.output-header h2 {
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--text-primary);
}

.icon-btn {
    background: var(--bg-primary);
    border: 1.5px solid var(--border-color);
    border-radius: 10px;
    padding: 0.5rem;
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    background: var(--accent-primary);
    color: white;
    border-color: var(--accent-primary);
}

.lyrics-output {
    background: var(--bg-primary);
    border-radius: 16px;
    padding: 2rem;
    min-height: 200px;
    white-space: pre-wrap;
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--text-primary);
    font-family: 'Georgia', serif;
    border: 1px solid var(--border-color);
}

.lyrics-output:empty::before {
    content: 'Your lyrics will appear here...';
    color: var(--text-muted);
    font-style: italic;
}

.regenerate-section {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.regenerate-prompt {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.secondary-btn {
    padding: 0.75rem 1.5rem;
    border: 1.5px solid var(--accent-secondary);
    background: transparent;
    color: var(--accent-secondary);
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.secondary-btn:hover {
    background: var(--accent-secondary);
    color: white;
}

/* Footer */
footer {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
}

.footer-note {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Responsive */
@media (max-width: 768px) {
    .app-header h1 {
        font-size: 2rem;
    }

    .tagline {
        font-size: 1rem;
    }

    .input-section,
    .output-section {
        padding: 1.5rem;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    main {
        padding: 1rem 1rem 3rem;
    }
}

/* Loading animation */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.generate-btn.loading::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% {
        left: -100%;
    }
    100% {
        left: 100%;
    }
}

/* Mode Toggle */
.mode-toggle {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    justify-content: center;
}

.mode-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: 1.5px solid var(--border-color);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

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

.mode-btn.active {
    background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 100%);
    color: white;
    border-color: transparent;
}

.mode-btn svg {
    width: 20px;
    height: 20px;
}

/* Hide inactive modes */
.input-section {
    display: none;
}

.input-section.active {
    display: block;
}

/* Audio Input Options */
.audio-input-options {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 2rem;
    align-items: center;
    margin: 2rem 0;
}

.audio-option {
    display: flex;
    justify-content: center;
}

.file-upload-label,
.record-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    padding: 2rem;
    border: 2px dashed var(--border-color);
    border-radius: 16px;
    background: var(--bg-primary);
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    min-width: 200px;
}

.file-upload-label:hover,
.record-btn:hover {
    border-color: var(--accent-primary);
    background: var(--bg-secondary);
    transform: translateY(-2px);
}

.file-upload-label svg,
.record-btn svg {
    color: var(--accent-primary);
}

.file-upload-label span,
.record-btn span {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 1rem;
}

.file-upload-label small,
.record-btn small {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.audio-divider {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-style: italic;
}

/* Audio Player Section */
.audio-player-section {
    background: var(--bg-primary);
    border-radius: 16px;
    padding: 1.5rem;
    margin: 2rem 0;
    border: 1px solid var(--border-color);
}

.audio-player-section audio {
    width: 100%;
    margin-bottom: 1rem;
}

/* Recording Controls */
.recording-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 12px;
    margin-bottom: 1rem;
}

.recording-indicator {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-primary);
    font-weight: 500;
}

.recording-pulse {
    width: 12px;
    height: 12px;
    background: #ff4444;
    border-radius: 50%;
    animation: pulse-recording 1.5s ease-in-out infinite;
}

@keyframes pulse-recording {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.5;
        transform: scale(1.2);
    }
}

.stop-recording-btn {
    padding: 0.5rem 1.5rem;
    background: #ff4444;
    color: white;
    border: none;
    border-radius: 8px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.stop-recording-btn:hover {
    background: #cc0000;
}

/* Analysis Status & Results */
.analysis-status {
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 12px;
    margin-bottom: 1rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
    text-align: center;
}

.analysis-status.analyzing {
    animation: pulse 2s ease-in-out infinite;
}

.analysis-results {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

.analysis-item {
    background: var(--bg-secondary);
    padding: 1rem;
    border-radius: 12px;
    text-align: center;
    border: 1px solid var(--border-color);
}

.analysis-item label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.25rem;
}

.analysis-item value {
    display: block;
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--accent-primary);
}

/* =============================================================================
   Synchronized Lyrics Display
   ============================================================================= */

.synced-lyrics-section {
    margin-top: 2rem;
    background: var(--bg-secondary);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: var(--shadow-medium);
    border: 1px solid var(--border-color);
}

.synced-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
    flex-wrap: wrap;
    gap: 1rem;
}

.synced-header h3 {
    font-size: 1.25rem;
    font-weight: 400;
    color: var(--text-primary);
    display: flex;
    align-items: center;
}

.sync-controls {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

/* Beat Indicator */
.beat-indicator-wrapper {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.beat-indicator {
    width: 16px;
    height: 16px;
    background: var(--accent-tertiary);
    border-radius: 50%;
    transition: transform 0.1s ease, background 0.1s ease;
}

.beat-indicator.pulse {
    transform: scale(1.3);
    background: var(--accent-primary);
}

.beat-indicator.pulse.downbeat {
    background: var(--accent-secondary);
    transform: scale(1.5);
}

.beat-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* Timing Controls */
.timing-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.timing-controls label {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 500;
    margin-right: 0.25rem;
}

.timing-btn {
    padding: 0.4rem 0.75rem;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.timing-btn:hover {
    background: var(--accent-primary);
    color: white;
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

.timing-btn svg {
    width: 14px;
    height: 14px;
}

/* Synced Lyrics Container */
.synced-lyrics-container {
    max-height: 400px;
    overflow-y: auto;
    padding: 1rem;
    background: linear-gradient(135deg, rgba(212, 165, 165, 0.05) 0%, rgba(200, 181, 212, 0.05) 100%);
    border-radius: 12px;
    scroll-behavior: smooth;
}

/* Synced Lyric Lines */
.synced-lyric-line,
.synced-section-marker {
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
    border-radius: 8px;
    transition: all 0.3s ease;
    cursor: pointer;
    user-select: none;
}

.synced-lyric-line {
    background: white;
    border-left: 3px solid transparent;
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.6;
}

.synced-section-marker {
    background: transparent;
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding-left: 0;
    margin-top: 1rem;
}

/* Active lyric line */
.synced-lyric-line.active {
    background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 100%);
    color: white;
    border-left-color: var(--accent-tertiary);
    transform: scale(1.02);
    box-shadow: 0 4px 12px rgba(212, 165, 165, 0.3);
    font-weight: 500;
}

/* Past lyric lines (already sung) */
.synced-lyric-line.past {
    opacity: 0.5;
    background: #f9f9f9;
}

/* Hover effect */
.synced-lyric-line:hover {
    background: #fafafa;
    border-left-color: var(--accent-primary);
}

.synced-lyric-line.active:hover {
    background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 100%);
}

/* Sync hint */
.sync-hint {
    margin-top: 1rem;
    padding: 1rem;
    background: rgba(165, 196, 212, 0.1);
    border-radius: 8px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    line-height: 1.5;
}

.sync-hint svg {
    flex-shrink: 0;
    margin-top: 0.1rem;
    color: var(--accent-tertiary);
}

/* Scrollbar styling for synced lyrics */
.synced-lyrics-container::-webkit-scrollbar {
    width: 8px;
}

.synced-lyrics-container::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.05);
    border-radius: 4px;
}

.synced-lyrics-container::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: 4px;
}

.synced-lyrics-container::-webkit-scrollbar-thumb:hover {
    background: var(--accent-secondary);
}

/* Responsive adjustments for audio mode */
@media (max-width: 768px) {
    .mode-toggle {
        flex-direction: column;
    }

    .audio-input-options {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .audio-divider {
        text-align: center;
    }

    .file-upload-label,
    .record-btn {
        min-width: 100%;
    }

    .analysis-results {
        grid-template-columns: 1fr 1fr;
    }

    .synced-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .sync-controls {
        width: 100%;
        flex-direction: column;
        align-items: flex-start;
    }

    .timing-controls {
        flex-wrap: wrap;
    }
}