/* =============================================
   FrameForge — Premium Video Frame Extractor
   Design System & Styles
   ============================================= */

/* ---------- CSS Custom Properties ---------- */
:root {
    /* Colors */
    --bg-primary: #0a0a0f;
    --bg-secondary: #111118;
    --bg-card: rgba(18, 18, 28, 0.7);
    --bg-card-hover: rgba(24, 24, 38, 0.8);
    --bg-glass: rgba(255, 255, 255, 0.03);

    --text-primary: #f0f0f5;
    --text-secondary: #9898b0;
    --text-muted: #5a5a72;

    --accent-purple: #a78bfa;
    --accent-cyan: #06b6d4;
    --accent-pink: #f472b6;
    --accent-green: #34d399;

    --gradient-primary: linear-gradient(135deg, #a78bfa 0%, #06b6d4 100%);
    --gradient-accent: linear-gradient(135deg, #f472b6 0%, #a78bfa 50%, #06b6d4 100%);
    --gradient-success: linear-gradient(135deg, #34d399 0%, #06b6d4 100%);

    --border-color: rgba(255, 255, 255, 0.06);
    --border-hover: rgba(167, 139, 250, 0.3);

    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 16px 64px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(167, 139, 250, 0.15);

    /* Spacing */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* ---------- Background Particles ---------- */
.bg-particles {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

.particle {
    position: absolute;
    border-radius: 50%;
    opacity: 0;
    animation: particleFloat linear infinite;
}

@keyframes particleFloat {
    0% {
        opacity: 0;
        transform: translateY(100vh) scale(0);
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        opacity: 0;
        transform: translateY(-10vh) scale(1);
    }
}

/* ---------- Header ---------- */
.header {
    position: relative;
    z-index: 10;
    padding: 24px 32px;
    border-bottom: 1px solid var(--border-color);
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.header-inner {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: var(--bg-glass);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: var(--transition-base);
}

.logo-icon:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-glow);
}

.logo-text {
    font-size: 22px;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.header-tagline {
    font-size: 14px;
    color: var(--text-muted);
    font-weight: 400;
}

/* ---------- Main Content ---------- */
.main-content {
    position: relative;
    z-index: 10;
    max-width: 900px;
    margin: 0 auto;
    padding: 40px 24px 80px;
    display: flex;
    flex-direction: column;
    gap: 28px;
}

/* ---------- Cards ---------- */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 36px;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    transition: var(--transition-base);
    animation: cardSlideIn 0.5s ease-out;
}

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

.card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-glow);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 28px;
}

.card-header h1,
.card-header h2 {
    font-size: 22px;
    font-weight: 700;
    letter-spacing: -0.3px;
}

.step-badge {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--gradient-primary);
    color: #fff;
    font-size: 14px;
    font-weight: 700;
    flex-shrink: 0;
}

.step-badge.pulse {
    animation: badgePulse 2s ease-in-out infinite;
}

.step-badge.success {
    background: var(--gradient-success);
}

@keyframes badgePulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(167, 139, 250, 0.4); }
    50% { box-shadow: 0 0 0 12px rgba(167, 139, 250, 0); }
}

/* ---------- Dropzone ---------- */
.dropzone {
    border: 2px dashed rgba(167, 139, 250, 0.25);
    border-radius: var(--radius-lg);
    padding: 56px 32px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition-base);
    position: relative;
    background: var(--bg-glass);
}

.dropzone:hover,
.dropzone.dragover {
    border-color: var(--accent-purple);
    background: rgba(167, 139, 250, 0.05);
    box-shadow: inset 0 0 40px rgba(167, 139, 250, 0.05);
}

.dropzone.dragover {
    transform: scale(1.01);
}

.dropzone-icon {
    margin-bottom: 20px;
    opacity: 0.8;
    transition: var(--transition-base);
}

.dropzone:hover .dropzone-icon {
    opacity: 1;
    transform: translateY(-4px);
}

.dropzone-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text-primary);
}

.dropzone-subtitle {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.dropzone-formats {
    font-size: 12px;
    color: var(--text-muted);
    background: rgba(255, 255, 255, 0.04);
    display: inline-block;
    padding: 4px 14px;
    border-radius: 20px;
}

/* ---------- Video Preview ---------- */
.video-preview {
    margin-top: 24px;
}

.video-wrapper {
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--border-color);
    background: #000;
}

.video-wrapper video {
    width: 100%;
    display: block;
    max-height: 420px;
    object-fit: contain;
    background: #000;
}

.video-info {
    display: flex;
    gap: 24px;
    padding: 16px 0;
    flex-wrap: wrap;
}

.video-info .info-chip {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--text-secondary);
    background: rgba(255, 255, 255, 0.04);
    padding: 6px 14px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
}

.info-chip .chip-label {
    color: var(--text-muted);
    font-weight: 500;
}

.info-chip .chip-value {
    color: var(--text-primary);
    font-weight: 600;
}

/* ---------- Settings ---------- */
.settings-grid {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.setting-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.setting-label {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.8px;
}

/* Format Buttons */
.format-selector {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
}

.format-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 22px 16px;
    border-radius: var(--radius-lg);
    border: 2px solid var(--border-color);
    background: var(--bg-glass);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-base);
    font-family: inherit;
}

.format-btn:hover {
    border-color: rgba(167, 139, 250, 0.3);
    background: rgba(167, 139, 250, 0.05);
    color: var(--text-primary);
}

.format-btn.active {
    border-color: var(--accent-purple);
    background: rgba(167, 139, 250, 0.1);
    color: var(--text-primary);
    box-shadow: 0 0 24px rgba(167, 139, 250, 0.1);
}

.format-icon {
    font-size: 28px;
}

.format-name {
    font-size: 16px;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.format-desc {
    font-size: 11px;
    color: var(--text-muted);
}

.format-btn.active .format-desc {
    color: var(--text-secondary);
}

/* FPS Slider */
.fps-control {
    display: flex;
    align-items: center;
    gap: 20px;
}

.fps-slider {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 6px;
    border-radius: 3px;
    background: rgba(255, 255, 255, 0.08);
    outline: none;
    transition: var(--transition-base);
}

.fps-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--gradient-primary);
    cursor: pointer;
    box-shadow: 0 0 12px rgba(167, 139, 250, 0.4);
    transition: var(--transition-fast);
}

.fps-slider::-webkit-slider-thumb:hover {
    transform: scale(1.15);
    box-shadow: 0 0 20px rgba(167, 139, 250, 0.6);
}

.fps-slider::-moz-range-thumb {
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--gradient-primary);
    cursor: pointer;
    border: none;
    box-shadow: 0 0 12px rgba(167, 139, 250, 0.4);
}

.fps-display {
    display: flex;
    align-items: baseline;
    gap: 4px;
    min-width: 80px;
    justify-content: center;
}

.fps-value {
    font-size: 32px;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.fps-unit {
    font-size: 14px;
    color: var(--text-muted);
    font-weight: 600;
}

/* FPS Presets */
.fps-presets {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.preset-btn {
    padding: 6px 14px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    background: var(--bg-glass);
    color: var(--text-secondary);
    font-size: 12px;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: var(--transition-fast);
}

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

.preset-btn.active {
    border-color: var(--accent-purple);
    background: rgba(167, 139, 250, 0.12);
    color: var(--accent-purple);
}

.frame-estimate {
    font-size: 13px;
    color: var(--text-muted);
    font-weight: 500;
}

.quality-slider::-webkit-slider-thumb {
    background: var(--gradient-accent) !important;
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    border: none;
    font-family: inherit;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-base);
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: var(--gradient-primary);
    color: #fff;
    box-shadow: 0 4px 20px rgba(167, 139, 250, 0.3);
}

.btn-primary:hover {
    box-shadow: 0 6px 30px rgba(167, 139, 250, 0.45);
    transform: translateY(-2px);
}

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

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.btn-ghost:hover {
    border-color: var(--border-hover);
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.03);
}

.btn-convert {
    width: 100%;
    margin-top: 12px;
    padding: 18px 28px;
    font-size: 16px;
    border-radius: var(--radius-lg);
}

.btn-download {
    padding: 18px 36px;
    font-size: 16px;
    border-radius: var(--radius-lg);
    background: var(--gradient-success);
    box-shadow: 0 4px 24px rgba(52, 211, 153, 0.3);
}

.btn-download:hover {
    box-shadow: 0 6px 36px rgba(52, 211, 153, 0.45);
    transform: translateY(-2px);
}

.download-size {
    font-size: 12px;
    opacity: 0.8;
    font-weight: 400;
    margin-left: 4px;
}

/* ---------- Progress ---------- */
.progress-container {
    margin-bottom: 28px;
}

.progress-bar-wrapper {
    height: 8px;
    background: rgba(255, 255, 255, 0.06);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 12px;
}

.progress-bar {
    height: 100%;
    width: 0%;
    background: var(--gradient-primary);
    border-radius: 4px;
    transition: width 0.3s ease;
    position: relative;
}

.progress-bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    animation: progressShine 1.5s ease-in-out infinite;
}

@keyframes progressShine {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.progress-stats {
    display: flex;
    justify-content: space-between;
    font-size: 14px;
    font-weight: 600;
}

.progress-stats span:first-child {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.progress-stats span:last-child {
    color: var(--text-secondary);
}

.progress-status {
    font-size: 13px;
    color: var(--text-muted);
    margin-top: 8px;
}

/* Frame Preview Grid */
.frame-preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 8px;
    margin-bottom: 20px;
    max-height: 300px;
    overflow-y: auto;
    padding-right: 4px;
}

.frame-preview-grid::-webkit-scrollbar {
    width: 6px;
}

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

.frame-thumb {
    border-radius: var(--radius-sm);
    overflow: hidden;
    aspect-ratio: 16/9;
    border: 1px solid var(--border-color);
    animation: thumbFadeIn 0.3s ease;
}

.frame-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

@keyframes thumbFadeIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

/* ---------- Results ---------- */
.results-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 14px;
    margin-bottom: 28px;
}

.stat-card {
    background: var(--bg-glass);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 18px;
    text-align: center;
}

.stat-value {
    font-size: 28px;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.stat-label {
    font-size: 12px;
    color: var(--text-muted);
    font-weight: 500;
    margin-top: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.results-preview {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 10px;
    margin-bottom: 28px;
    max-height: 400px;
    overflow-y: auto;
    padding-right: 4px;
}

.results-preview::-webkit-scrollbar {
    width: 6px;
}

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

.result-thumb {
    border-radius: var(--radius-sm);
    overflow: hidden;
    aspect-ratio: 16/9;
    border: 1px solid var(--border-color);
    position: relative;
    cursor: pointer;
    transition: var(--transition-fast);
}

.result-thumb:hover {
    border-color: var(--border-hover);
    transform: scale(1.03);
}

.result-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.result-thumb .thumb-label {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 4px 8px;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    font-size: 10px;
    color: var(--text-secondary);
    font-weight: 600;
    text-align: center;
}

.results-actions {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

/* ---------- Footer ---------- */
.footer {
    position: relative;
    z-index: 10;
    text-align: center;
    padding: 24px;
    font-size: 13px;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
}

/* ---------- Utilities ---------- */
.hidden {
    display: none !important;
}

/* ---------- Responsive ---------- */
@media (max-width: 640px) {
    .header-inner {
        flex-direction: column;
        gap: 8px;
        text-align: center;
    }

    .card {
        padding: 24px 18px;
        border-radius: var(--radius-lg);
    }

    .card-header h1,
    .card-header h2 {
        font-size: 18px;
    }

    .format-selector {
        grid-template-columns: 1fr;
    }

    .fps-control {
        flex-direction: column;
        align-items: stretch;
    }

    .fps-display {
        justify-content: flex-start;
    }

    .fps-presets {
        justify-content: center;
    }

    .results-actions {
        flex-direction: column;
    }

    .btn-convert,
    .btn-download {
        width: 100%;
    }

    .frame-preview-grid,
    .results-preview {
        grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
    }
}