:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #06b6d4;
    --dark: #1e293b;
    --light: #f1f5f9;
    --white: #ffffff;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --box-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --box-shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--gray-900);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem;
    flex: 1;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    animation: fadeInDown 0.6s ease-out;
}

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

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

header h1 {
    font-size: 3rem;
    font-weight: 800;
    color: var(--white);
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    letter-spacing: -0.5px;
}

.subtitle {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.2rem;
    font-weight: 400;
}

main {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow-xl);
    padding: 2.5rem;
    animation: fadeInUp 0.6s ease-out;
    animation-delay: 0.1s;
    animation-fill-mode: backwards;
}

/* Mode Toggle */
.mode-toggle {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    background: var(--gray-100);
    padding: 0.5rem;
    border-radius: var(--border-radius);
}

.mode-btn {
    flex: 1;
    padding: 0.875rem 1.5rem;
    border: none;
    background: transparent;
    color: var(--gray-700);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
    position: relative;
}

.mode-btn.active {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    box-shadow: var(--box-shadow);
    transform: scale(1.02);
}

.mode-btn:hover:not(.active) {
    background: var(--gray-200);
    transform: translateY(-1px);
}

/* File Upload Section */
.upload-section {
    margin-bottom: 2rem;
}

.file-drop-zone {
    border: 3px dashed var(--gray-300);
    border-radius: var(--border-radius);
    padding: 3.5rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    background: var(--gray-50);
    position: relative;
    overflow: hidden;
}

.file-drop-zone::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
    opacity: 0;
    transition: var(--transition);
}

.file-drop-zone:hover::before,
.file-drop-zone.drag-over::before {
    opacity: 1;
}

.file-drop-zone.drag-over {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.05);
    transform: scale(1.01);
}

.file-drop-zone:hover {
    border-color: var(--primary-light);
    transform: translateY(-2px);
}

.upload-icon {
    width: 64px;
    height: 64px;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    filter: drop-shadow(0 2px 4px rgba(99, 102, 241, 0.3));
    position: relative;
    z-index: 1;
}

.drop-text {
    font-size: 1.25rem;
    color: var(--gray-800);
    margin-bottom: 0.75rem;
    font-weight: 600;
    position: relative;
    z-index: 1;
}

.file-info {
    font-size: 0.95rem;
    color: var(--gray-600);
    position: relative;
    z-index: 1;
}

.file-selected {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
    padding: 1.25rem;
    border-radius: var(--border-radius-sm);
    margin-top: 1rem;
    border: 2px solid var(--primary-light);
    animation: fadeInUp 0.3s ease-out;
}

.file-name {
    font-weight: 600;
    color: var(--gray-800);
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.remove-file {
    background: var(--danger-color);
    color: var(--white);
    border: none;
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 700;
    transition: var(--transition);
    box-shadow: 0 2px 4px rgba(239, 68, 68, 0.3);
}

.remove-file:hover {
    background: #dc2626;
    transform: scale(1.05);
    box-shadow: 0 4px 8px rgba(239, 68, 68, 0.4);
}

/* Advanced Options */
.advanced-options {
    background: var(--gray-50);
    padding: 2rem;
    border-radius: var(--border-radius);
    margin-bottom: 2rem;
    border: 2px solid var(--gray-200);
    animation: fadeInUp 0.3s ease-out;
}

.advanced-options h3 {
    margin-bottom: 1.5rem;
    color: var(--gray-800);
    font-size: 1.3rem;
    font-weight: 700;
}

.option-group {
    margin-bottom: 1.25rem;
}

.option-group label {
    display: block;
    margin-bottom: 0.6rem;
    font-weight: 600;
    color: var(--gray-700);
    font-size: 0.95rem;
}

.option-group select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--gray-300);
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    background: var(--white);
    transition: var(--transition);
    color: var(--gray-800);
    font-weight: 500;
    cursor: pointer;
}

.option-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.option-group select:hover {
    border-color: var(--primary-light);
}

.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
}

.checkbox-group label:hover {
    background: var(--gray-100);
}

.checkbox-group input[type="checkbox"] {
    margin-right: 0.75rem;
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--primary-color);
}

.checkbox-group span {
    color: var(--gray-700);
    font-weight: 500;
}

/* Transcribe Button */
.transcribe-btn {
    width: 100%;
    padding: 1.25rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    border: none;
    border-radius: var(--border-radius);
    font-size: 1.2rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
    position: relative;
    overflow: hidden;
}

.transcribe-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: left 0.5s;
}

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

.transcribe-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.5);
}

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

.transcribe-btn:disabled {
    background: var(--gray-400);
    cursor: not-allowed;
    box-shadow: none;
}

.transcribe-btn.loading {
    background: linear-gradient(135deg, var(--primary-hover) 0%, var(--secondary-color) 100%);
}

.spinner {
    width: 24px;
    height: 24px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: var(--white);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Results Section */
.results-section {
    margin-top: 2rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--border-radius);
    overflow: hidden;
    animation: fadeInUp 0.4s ease-out;
    box-shadow: var(--box-shadow);
}

.results-header {
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--gray-100) 100%);
    padding: 1.25rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 2px solid var(--gray-200);
}

.results-header h3 {
    margin: 0;
    color: var(--gray-800);
    font-size: 1.2rem;
    font-weight: 700;
}

.result-actions {
    display: flex;
    gap: 0.75rem;
}

.action-btn {
    background: var(--white);
    border: 2px solid var(--gray-300);
    padding: 0.625rem;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.action-btn:hover {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(99, 102, 241, 0.3);
}

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

.result-content {
    padding: 2rem;
    max-height: 500px;
    overflow-y: auto;
    background: var(--white);
}

.result-content::-webkit-scrollbar {
    width: 10px;
}

.result-content::-webkit-scrollbar-track {
    background: var(--gray-100);
}

.result-content::-webkit-scrollbar-thumb {
    background: var(--gray-400);
    border-radius: 5px;
}

.result-content::-webkit-scrollbar-thumb:hover {
    background: var(--gray-500);
}

.result-content pre {
    white-space: pre-wrap;
    word-wrap: break-word;
    font-family: 'Monaco', 'Consolas', 'Courier New', monospace;
    font-size: 0.95rem;
    line-height: 1.7;
    color: var(--gray-800);
}

/* Utterance styling */
.utterance {
    margin-bottom: 1.25rem;
    padding: 1rem;
    background: var(--gray-50);
    border-radius: var(--border-radius-sm);
    border-left: 4px solid var(--primary-color);
    transition: var(--transition);
}

.utterance:hover {
    background: var(--gray-100);
    transform: translateX(4px);
}

.utterance-header {
    display: flex;
    gap: 1.25rem;
    margin-bottom: 0.75rem;
    font-size: 0.875rem;
    color: var(--gray-600);
}

.speaker {
    font-weight: 700;
    color: var(--primary-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.timestamp {
    color: var(--gray-500);
    font-family: 'Monaco', 'Consolas', monospace;
}

.utterance-text {
    color: var(--gray-800);
    line-height: 1.7;
    font-size: 1rem;
}

/* Error Message */
.error-message {
    background: rgba(239, 68, 68, 0.1);
    border: 2px solid var(--danger-color);
    color: var(--danger-color);
    padding: 1.25rem;
    border-radius: var(--border-radius);
    margin-top: 1rem;
    font-weight: 600;
    animation: fadeInUp 0.3s ease-out;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    color: rgba(255, 255, 255, 0.9);
    font-size: 1rem;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

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

    header h1 {
        font-size: 2.25rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    main {
        padding: 1.75rem;
    }

    .mode-toggle {
        flex-direction: column;
    }

    .advanced-options {
        padding: 1.25rem;
    }

    .file-drop-zone {
        padding: 2.5rem 1.5rem;
    }

    .upload-icon {
        width: 48px;
        height: 48px;
    }

    .drop-text {
        font-size: 1.1rem;
    }
}

/* Speaker Names Section */
.speaker-names-section {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 2px solid var(--gray-200);
    animation: fadeInUp 0.3s ease-out;
}

.speaker-names-section label {
    display: block;
    margin-bottom: 1rem;
    font-weight: 700;
    color: var(--gray-800);
    font-size: 1.05rem;
}

#speakerNamesContainer,
#simpleSpeakerNamesContainer {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.speaker-name-input {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.speaker-name-input input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 2px solid var(--gray-300);
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    background: var(--white);
    transition: var(--transition);
    color: var(--gray-800);
}

.speaker-name-input input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.speaker-name-input input:hover {
    border-color: var(--primary-light);
}

.add-speaker-btn {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--gray-100);
    border: 2px dashed var(--gray-300);
    border-radius: var(--border-radius-sm);
    color: var(--gray-700);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.add-speaker-btn:hover {
    background: var(--gray-200);
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-1px);
}

/* Metadata Display */
.metadata-display {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    padding: 1rem 1.25rem;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05) 0%, rgba(139, 92, 246, 0.05) 100%);
    border-bottom: 2px solid var(--gray-200);
}

.metadata-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--white);
    border-radius: var(--border-radius-sm);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.metadata-label {
    font-weight: 600;
    color: var(--gray-600);
    font-size: 0.875rem;
}

.metadata-value {
    font-weight: 700;
    color: var(--primary-color);
    font-size: 0.95rem;
}

/* Speaker Swap UI */
.speaker-swap-ui {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.08) 0%, rgba(139, 92, 246, 0.08) 100%);
    border: 2px solid var(--primary-light);
    border-radius: var(--border-radius-sm);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    animation: fadeInUp 0.3s ease-out;
}

.swap-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.swap-header strong {
    color: var(--gray-800);
    font-size: 1rem;
}

.swap-hint {
    color: var(--gray-600);
    font-size: 0.875rem;
    font-style: italic;
}

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

.swap-select {
    flex: 1;
    min-width: 150px;
    padding: 0.75rem 1rem;
    border: 2px solid var(--gray-300);
    border-radius: var(--border-radius-sm);
    font-size: 0.95rem;
    background: var(--white);
    color: var(--gray-800);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.swap-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.swap-select:hover {
    border-color: var(--primary-light);
}

.swap-arrow {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 700;
}

.swap-btn {
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 0.95rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 2px 6px rgba(99, 102, 241, 0.3);
}

.swap-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(99, 102, 241, 0.4);
}

.swap-btn:active {
    transform: translateY(0);
}

/* Simple Mode Options */
.simple-options {
    background: var(--gray-50);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin-bottom: 2rem;
    border: 2px solid var(--gray-200);
    animation: fadeInUp 0.3s ease-out;
}

/* Responsive adjustments for swap UI */
@media (max-width: 768px) {
    .swap-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .swap-arrow {
        transform: rotate(90deg);
        align-self: center;
    }

    .swap-select {
        min-width: 100%;
    }
}