/* ========== ROOT & VARIABLES ========== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;700;800&display=swap');

:root {
    --primary-color: #6c7bff;
    --secondary-color: #8b5cf6;
    --accent-color: #22c1c3;
    --danger-color: #ff6b6b;
    --success-color: #51cf66;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --bg-primary: rgba(255,255,255,0.76);
    --bg-secondary: rgba(245,247,250,0.8);
    --card-bg: rgba(255,255,255,0.6);
    --glass-blur: 8px;
    --border-color: rgba(18,20,30,0.06);
    --shadow-sm: 0 4px 14px rgba(16,24,40,0.06);
    --shadow-md: 0 12px 40px rgba(16,24,40,0.08);
    --transition: 250ms cubic-bezier(.4,0,.2,1);
    --radius: 12px;
    --header-height: 76px;

    --font-family: Inter, system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial;
    --font-mono: ui-monospace, SFMono-Regular, 'Courier New', monospace;
    --base-font-size: 15px;
}

body.dark-mode {
    --primary-color: #6c7bff;
    --secondary-color: #7c3aed;
    --accent-color: #06b6d4;
    --text-primary: #e6eef8;
    --text-secondary: #9ca3af;
    --bg-primary: rgba(12,18,34,0.6);
    --bg-secondary: rgba(8,12,24,0.6);
    --card-bg: rgba(10,14,28,0.5);
    --border-color: rgba(255,255,255,0.06);
}

/* ========== RESET & BASE STYLES ========== */

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

html, body {
    height: 100%;
}

body {
    font-family: var(--font-family);
    color: var(--text-primary);
    min-height: 100vh;
    margin: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background: linear-gradient(180deg, #0f172a 0%, #0b1220 100%);
    background-attachment: fixed;
}

html { font-size: var(--base-font-size); }

/* subtle page backdrop to center app */
.page-backdrop {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 28px;
    min-height: 100vh;
}

.app-container {
    max-width: 1400px;
    width: 100%;
    border-radius: calc(var(--radius) + 4px);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    backdrop-filter: blur(var(--glass-blur));
    background: linear-gradient(180deg, rgba(255,255,255,0.08), rgba(255,255,255,0.02));
    border: 1px solid var(--border-color);
}

/* ========== APP LAYOUT ========== */

.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    background: var(--bg-primary);
}

.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: white;
    padding: 22px 32px;
    height: auto;
    gap: 16px;
    background: linear-gradient(90deg, rgba(108,123,255,0.95), rgba(139,92,246,0.95));
    box-shadow: var(--shadow-sm);
    border-bottom: 1px solid rgba(255,255,255,0.06);
    flex-shrink: 0;
}

body.dark-mode .app-header {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    border-bottom-color: rgba(255, 255, 255, 0.1);
}

.header-left h1 {
    font-size: 1.4rem;
    margin-bottom: 2px;
    font-weight: 700;
}

.header-left .subtitle {
    font-size: 0.85rem;
    opacity: 0.95;
}

.header-right {
    display: flex;
    gap: 10px;
}

.icon-btn {
    background: rgba(255,255,255,0.08);
    color: white;
    border: 1px solid rgba(255,255,255,0.08);
    width: 44px;
    height: 44px;
    border-radius: 10px;
    cursor: pointer;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition), box-shadow var(--transition);
}

.icon-btn:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 30px rgba(99,102,241,0.12);
}

/* ========== MAIN LAYOUT ========== */

.main-layout {
    display: grid;
    grid-template-columns: 320px 1fr 340px;
    gap: 16px;
    flex: 1;
    overflow: hidden;
    padding: 16px;
}

@media (max-width: 1400px) {
    .main-layout {
        grid-template-columns: 280px 1fr 280px;
    }
}

@media (max-width: 1024px) {
    .main-layout {
        grid-template-columns: 1fr;
    }

    .left-panel, .right-panel {
        display: none;
    }
}

/* ========== PANELS ========== */

.left-panel, .right-panel {
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    border-radius: 12px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    padding: 0;
}

.right-panel {
    border-right: none;
    border-left: 1px solid var(--border-color);
}

.panel-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    background: var(--bg-secondary);
    z-index: 10;
}

.panel-header h2 {
    font-size: 1.1em;
    color: var(--text-primary);
}

.center-panel {
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--bg-primary);
    border-radius: 12px;
    border-left: 1px solid var(--border-color);
    border-right: 1px solid var(--border-color);
}

/* ========== SECTIONS ========== */

.section {
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
}

.section h3 {
    font-size: 1rem;
    margin-bottom: 18px;
    color: var(--text-primary);
    font-weight: 700;
    letter-spacing: -0.4px;
}

.section:last-child {
    border-bottom: none;
}

/* ========== FORM CONTROLS ========== */

.text-input {
    width: 100%;
    padding: 14px;
    border: 1px solid rgba(16,24,40,0.06);
    border-radius: 12px;
    font-family: var(--font-mono);
    font-size: 0.95rem;
    resize: vertical;
    background: var(--card-bg);
    color: var(--text-primary);
    transition: box-shadow var(--transition), transform var(--transition);
    margin-bottom: 12px;
    min-height: 120px;
}

.text-input:focus,
.text-input:focus-visible {
    outline: none;
    border-color: rgba(108,123,255,0.9);
    box-shadow: 0 8px 30px rgba(99,102,241,0.08);
    transform: translateY(-2px);
}

.setting-group {
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
}

.setting-group label {
    font-size: 0.85em;
    font-weight: 500;
    margin-bottom: 6px;
    color: var(--text-secondary);
}

.setting-group input[type="number"],
.setting-group input[type="range"] {
    padding: 8px;
    border: 1px solid rgba(16,24,40,0.04);
    border-radius: 8px;
    background: var(--card-bg);
    color: var(--text-primary);
}

.setting-group input[type="range"] {
    cursor: pointer;
    padding: 0;
    height: 6px;
}

.input-with-display {
    display: flex;
    gap: 8px;
}

.input-with-display input[type="range"] {
    flex: 1;
}

.input-with-display input[type="number"] {
    width: 60px;
    text-align: center;
}

.setting-group.checkbox {
    flex-direction: row;
    align-items: center;
    margin-bottom: 10px;
}

.setting-group.checkbox input {
    width: 18px;
    height: 18px;
    margin-right: 8px;
    cursor: pointer;
    flex-shrink: 0;
}

.setting-group.checkbox label {
    margin-bottom: 0;
    cursor: pointer;
    font-weight: 400;
}

/* ========== BUTTONS ========== */

.btn {
    padding: 10px 18px;
    border: none;
    border-radius: 10px;
    font-size: 0.94rem;
    font-weight: 700;
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition), opacity var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.btn-primary {
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    color: white;
    box-shadow: 0 8px 30px rgba(99,102,241,0.12);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 18px 60px rgba(99,102,241,0.14);
}

.btn-secondary {
    background: linear-gradient(180deg, rgba(255,255,255,0.6), rgba(255,255,255,0.45));
    color: var(--text-primary);
    border: 1px solid rgba(16,24,40,0.04);
    box-shadow: var(--shadow-sm);
}

.btn-secondary:hover:not(:disabled) {
    border-color: var(--primary-color);
    background: var(--bg-primary);
}

.btn-danger {
    background: #ffe0e0;
    color: var(--danger-color);
}

.btn-danger:hover:not(:disabled) {
    background: #ffd0d0;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

.btn-sm {
    padding: 8px 12px;
    font-size: 0.85em;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.button-group {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

.button-group .btn {
    flex: 1;
    min-width: 100px;
}

/* ========== TABS ========== */

.panel-tabs {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-secondary);
    flex-shrink: 0;
    padding: 0 16px;
}

.tab-btn {
    flex: 1;
    padding: 16px 18px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
    border-bottom: 3px solid transparent;
    font-size: 0.95rem;
    letter-spacing: -0.3px;
}

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.tab-btn:hover {
    background: rgba(102, 126, 234, 0.05);
}

.tab-content {
    display: none;
    flex: 1;
    overflow: hidden;
}

.tab-content.active {
    display: flex;
    flex-direction: column;
}

/* ========== EDITOR ========== */

.editor-toolbar {
    display: flex;
    gap: 12px;
    padding: 16px;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-secondary);
    flex-wrap: wrap;
    align-items: center;
    flex-shrink: 0;
}

.separator {
    width: 1px;
    height: 24px;
    background: var(--border-color);
}

.search-input {
    flex: 1;
    min-width: 150px;
    padding: 8px 12px;
    border: 1px solid rgba(16,24,40,0.04);
    border-radius: 10px;
    font-size: 0.95rem;
    background: var(--card-bg);
    color: var(--text-primary);
}


.search-input:focus,
.search-input:focus-visible {
    outline: none;
    box-shadow: 0 8px 30px rgba(99,102,241,0.06);
    transform: translateY(-2px);
}
.caption-list {
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
    padding: 16px;
}

.caption-item {
    background: linear-gradient(180deg, rgba(255,255,255,0.6), rgba(255,255,255,0.5));
    border: 1px solid rgba(16,24,40,0.04);
    padding: 16px 18px;
    border-radius: 10px;
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.caption-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(16,24,40,0.06);
    border-color: rgba(99,102,241,0.2);
}

.caption-item.selected {
    background: linear-gradient(90deg, rgba(108,123,255,0.12), rgba(139,92,246,0.08));
    border-color: rgba(108,123,255,0.18);
    box-shadow: 0 12px 40px rgba(108,123,255,0.06);
}

.caption-item-time {
    font-size: 0.8em;
    color: var(--text-secondary);
    font-family: var(--font-mono);
    font-weight: 600;
}

.caption-item-text {
    font-size: 0.9em;
    color: var(--text-primary);
    line-height: 1.4;
}

.caption-item-controls {
    display: flex;
    gap: 6px;
    padding-top: 6px;
    border-top: 1px solid var(--border-color);
}

.caption-item-controls button {
    padding: 4px 8px;
    font-size: 0.75em;
    flex: 1;
}

/* ========== TIMELINE ========== */

.timeline-container {
    display: flex;
    flex-direction: column;
    flex: 1;
    overflow: hidden;
    background: var(--bg-secondary);
}

.timeline-ruler {
    height: 30px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    overflow-x: auto;
    overflow-y: hidden;
    display: flex;
    align-items: flex-end;
    padding: 0 10px;
    font-size: 0.75em;
    color: var(--text-secondary);
}

.timeline-tracks {
    flex: 1;
    overflow: auto;
    position: relative;
    background: var(--bg-primary);
}

.timeline-track {
    height: 50px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: relative;
    padding: 4px;
}

.timeline-caption {
    position: absolute;
    height: 46px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 8px;
    padding: 6px 12px;
    color: white;
    font-size: 0.78rem;
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
    cursor: grab;
    transition: transform var(--transition), box-shadow var(--transition);
    border: 1px solid rgba(255,255,255,0.12);
}

.timeline-caption:hover {
    filter: brightness(1.1);
}

.timeline-caption.selected {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 18px 60px rgba(99,102,241,0.12);
}

.timeline-caption-handle {
    position: absolute;
    top: 0;
    width: 4px;
    height: 100%;
    cursor: col-resize;
}

.timeline-caption-handle.start {
    left: 0;
}

.timeline-caption-handle.end {
    right: 0;
}

.timeline-controls {
    display: flex;
    gap: 16px;
    padding: 16px;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    align-items: center;
    flex-shrink: 0;
}

.zoom-slider {
    flex: 1;
    max-width: 200px;
}

#zoomLevel {
    font-size: 0.9em;
    color: var(--text-secondary);
    white-space: nowrap;
}

/* ========== PREVIEW ========== */

.playback-controls {
    display: flex;
    gap: 16px;
    padding: 18px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    align-items: center;
    flex-wrap: wrap;
    flex-shrink: 0;
}

.progress-slider {
    flex: 1;
    min-width: 150px;
}

#playbackTime {
    font-size: 0.85em;
    color: var(--text-secondary);
    font-family: var(--font-mono);
    white-space: nowrap;
}

.preview-display {
    flex: 1;
    overflow-y: auto;
    padding: 48px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: var(--bg-primary);
}

.preview-caption {
    font-size: 2em;
    color: var(--text-primary);
    line-height: 1.5;
    max-width: 600px;
    font-weight: 500;
}

/* ========== EXPORT ========== */

.format-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 18px;
}

.format-btn {
    padding: 10px 12px;
    border: 1px solid rgba(16,24,40,0.04);
    background: var(--card-bg);
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.format-btn.active {
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-color: transparent;
    box-shadow: 0 12px 40px rgba(99,102,241,0.09);
}

.format-btn:hover:not(.active) {
    border-color: var(--primary-color);
}

.export-preview {
    width: 100%;
    height: 200px;
    padding: 10px;
    border: 1px solid rgba(16,24,40,0.04);
    border-radius: 10px;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    resize: none;
    background: var(--card-bg);
    color: var(--text-primary);
    box-shadow: var(--shadow-sm);
}

/* ========== STATISTICS ========== */

.stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.stat-item {
    background: var(--bg-primary);
    padding: 18px 16px;
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    border: 1px solid var(--border-color);
}

.stat-label {
    font-size: 0.75em;
    color: var(--text-secondary);
    text-transform: uppercase;
    font-weight: 600;
}

.stat-value {
    font-size: 1.4em;
    color: var(--primary-color);
    font-weight: 700;
    font-family: var(--font-mono);
}

/* ========== MODAL ========== */

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.modal-content {
    background: linear-gradient(180deg, rgba(255,255,255,0.9), rgba(255,255,255,0.75));
    padding: 26px;
    border-radius: 14px;
    max-width: 680px;
    width: 92%;
    max-height: 86vh;
    overflow-y: auto;
    position: relative;
    box-shadow: 0 30px 80px rgba(2,6,23,0.6);
    border: 1px solid rgba(16,24,40,0.04);
}

.modal-close {
    position: absolute;
    top: 15px;
    right: 15px;
    font-size: 28px;
    cursor: pointer;
    color: var(--text-secondary);
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal h2 {
    margin-bottom: 20px;
}

.shortcuts-table {
    width: 100%;
    border-collapse: collapse;
}

.shortcuts-table tr {
    border-bottom: 1px solid var(--border-color);
}

.shortcuts-table td {
    padding: 10px;
    text-align: left;
}

.shortcuts-table td:first-child {
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--primary-color);
    width: 100px;
}

kbd {
    background: var(--bg-secondary);
    padding: 2px 6px;
    border-radius: 3px;
    border: 1px solid var(--border-color);
    font-family: var(--font-mono);
    font-size: 0.9em;
}

/* Range styling for webkit */
input[type="range"]::-webkit-slider-runnable-track {
    height: 8px;
    background: linear-gradient(90deg, rgba(99,102,241,0.2), rgba(139,92,246,0.2));
    border-radius: 8px;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    background: white;
    border-radius: 50%;
    box-shadow: 0 6px 18px rgba(16,24,40,0.12);
    margin-top: -5px;
}

/* Firefox */
input[type="range"]::-moz-range-track {
    height: 8px;
    background: linear-gradient(90deg, rgba(99,102,241,0.12), rgba(139,92,246,0.12));
    border-radius: 8px;
}

input[type="range"]:focus-visible {
    outline: none;
}

/* Focus-visible for accessibility */
:focus-visible {
    outline: 3px solid rgba(108,123,255,0.16);
    outline-offset: 2px;
}

/* ========== SCROLLBARS ========== */

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-color);
}

/* ========== RESPONSIVENESS ========== */

@media (max-width: 768px) {
    .app-header {
        padding: 15px 15px;
    }

    .app-header h1 {
        font-size: 1.4em;
    }

    .header-left .subtitle {
        display: none;
    }

    .tab-btn {
        font-size: 0.8em;
        padding: 10px 12px;
    }

    .caption-item {
        padding: 10px;
    }

    .preview-caption {
        font-size: 1.5em;
    }
}