/* =========================================================
   MASTER CONVERTER — Complete Design System
   ========================================================= */

/* === 1. CSS CUSTOM PROPERTIES (Design Tokens) === */
:root {
    /* Colors */
    --color-bg-base: #080c18;
    --color-bg-card: rgba(15, 22, 40, 0.75);
    --color-bg-card-solid: #0f1628;
    --color-bg-elevated: rgba(25, 35, 65, 0.8);
    --color-bg-input: rgba(10, 16, 35, 0.7);
    --color-bg-hover: rgba(59, 130, 246, 0.07);
    --color-border: rgba(255, 255, 255, 0.07);
    --color-border-hover: rgba(255, 255, 255, 0.14);
    --color-border-focus: rgba(59, 130, 246, 0.55);
    --color-accent-blue: #3b82f6;
    --color-accent-blue-light: #60a5fa;
    --color-accent-cyan: #06b6d4;
    --color-accent-purple: #8b5cf6;
    --color-accent-green: #10b981;
    --color-accent-red: #ef4444;
    --color-accent-amber: #f59e0b;
    --color-text-primary: #f0f4ff;
    --color-text-secondary: #94a3b8;
    --color-text-muted: #4b5a72;
    --color-text-accent: #60a5fa;
    --gradient-accent: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
    --gradient-accent-hover: linear-gradient(135deg, #60a5fa 0%, #a78bfa 100%);
    --gradient-progress: linear-gradient(90deg, #3b82f6, #8b5cf6, #06b6d4, #3b82f6);
    --gradient-glow: linear-gradient(135deg, rgba(59,130,246,0.12), rgba(139,92,246,0.12));

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

    /* Spacing */
    --space-1: 4px;  --space-2: 8px;   --space-3: 12px;
    --space-4: 16px; --space-5: 20px;  --space-6: 24px;
    --space-8: 32px; --space-10: 40px; --space-12: 48px;

    /* Borders */
    --radius-sm: 8px;  --radius-md: 12px;
    --radius-lg: 16px; --radius-xl: 20px; --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4), 0 0 20px rgba(59,130,246,0.04);
    --shadow-lg: 0 10px 30px rgba(0,0,0,0.5), 0 0 40px rgba(59,130,246,0.08);
    --shadow-glow-blue: 0 0 20px rgba(59,130,246,0.35), 0 0 50px rgba(59,130,246,0.12);
    --shadow-glow-green: 0 0 15px rgba(16,185,129,0.3);
    --shadow-glow-red: 0 0 15px rgba(239,68,68,0.3);

    /* Glass */
    --glass-bg: rgba(15, 22, 40, 0.75);
    --glass-blur: blur(20px);
    --glass-border: 1px solid rgba(255,255,255,0.07);

    /* Transitions */
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

    /* Z-Index */
    --z-controls: 10; --z-header: 100; --z-sidebar: 200;
    --z-modal-bg: 300; --z-modal: 400; --z-toast: 500;

    /* Layout */
    --max-width: 1420px;
    --header-height: 70px;
}

/* === 2. RESET & BASE === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-primary);
    background: var(--color-bg-base);
    color: var(--color-text-primary);
    min-height: 100vh;
    line-height: 1.6;
    overflow-x: hidden;
    /* Animated gradient background */
    background-image:
        radial-gradient(ellipse 80% 50% at 20% -10%, rgba(59,130,246,0.08) 0%, transparent 60%),
        radial-gradient(ellipse 60% 40% at 80% 110%, rgba(139,92,246,0.07) 0%, transparent 60%);
    background-attachment: fixed;
}

/* Custom Scrollbar */
::-webkit-scrollbar { width: 7px; height: 7px; }
::-webkit-scrollbar-track { background: rgba(255,255,255,0.02); }
::-webkit-scrollbar-thumb { background: rgba(99,102,241,0.35); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: rgba(99,102,241,0.55); }

/* Focus Visible */
:focus-visible { outline: 2px solid var(--color-accent-blue); outline-offset: 3px; border-radius: 4px; }

/* === 3. TYPOGRAPHY === */
h1, h2, h3, h4 { font-weight: 700; letter-spacing: -0.02em; }
code {
    font-family: var(--font-mono);
    font-size: 0.82em;
    background: rgba(59,130,246,0.12);
    color: var(--color-accent-blue-light);
    padding: 2px 6px;
    border-radius: 4px;
}

/* === 4. HEADER === */
.app-header {
    position: fixed; top: 0; left: 0; right: 0;
    height: var(--header-height);
    z-index: var(--z-header);
    background: rgba(8, 12, 24, 0.85);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-bottom: var(--glass-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--space-6);
}

.header-left {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.logo-circle {
    width: 44px; height: 44px;
    border-radius: 50%;
    background: var(--gradient-accent);
    display: flex; align-items: center; justify-content: center;
    color: white;
    animation: logoPulse 3s ease-in-out infinite;
    flex-shrink: 0;
    box-shadow: var(--shadow-glow-blue);
}

.header-title {
    font-size: 1.4rem;
    font-weight: 800;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.header-subtitle {
    font-size: 0.72rem;
    color: var(--color-text-muted);
    font-weight: 400;
    letter-spacing: 0;
}

.header-right {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.header-btn {
    position: relative;
    width: 40px; height: 40px;
    border-radius: var(--radius-md);
    border: var(--glass-border);
    background: var(--glass-bg);
    color: var(--color-text-secondary);
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    transition: all var(--transition-base);
    backdrop-filter: var(--glass-blur);
}
.header-btn:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-elevated);
    border-color: var(--color-border-hover);
    transform: translateY(-1px);
}

.history-badge {
    position: absolute;
    top: -4px; right: -4px;
    width: 18px; height: 18px;
    border-radius: 50%;
    background: var(--gradient-accent);
    color: white;
    font-size: 0.6rem;
    font-weight: 700;
    display: flex; align-items: center; justify-content: center;
}

/* === 5. MAIN LAYOUT === */
.app-main {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: calc(var(--header-height) + var(--space-8)) var(--space-6) var(--space-8);
    display: flex;
    flex-direction: column;
    gap: var(--space-5);
}

/* === 6. DROP ZONE === */
.drop-zone {
    border: 2px dashed rgba(59,130,246,0.3);
    border-radius: var(--radius-xl);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    min-height: 280px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-base);
    animation: borderGlow 3s ease-in-out infinite;
    position: relative;
    overflow: hidden;
}

.drop-zone::before {
    content: '';
    position: absolute; inset: 0;
    background: var(--gradient-glow);
    opacity: 0;
    transition: opacity var(--transition-base);
    pointer-events: none;
}

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

.drop-zone:hover {
    border-color: rgba(59,130,246,0.6);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.drop-zone.drag-over {
    border-color: var(--color-accent-blue);
    border-style: solid;
    background: rgba(59,130,246,0.06);
    box-shadow: var(--shadow-glow-blue);
    animation: dragPulse 0.6s ease-in-out infinite;
}

.drop-zone.has-files {
    min-height: 130px;
    padding: var(--space-4) var(--space-6);
}

.drop-zone.has-files .drop-zone-formats { display: none; }
.drop-zone.has-files .drop-zone-subtitle { font-size: 0.78rem; }
.drop-zone.has-files .drop-zone-icon svg { width: 32px; height: 32px; }
.drop-zone.has-files .drop-zone-title { font-size: 1rem; }

.drop-zone-content {
    text-align: center;
    padding: var(--space-10) var(--space-6);
    pointer-events: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-3);
}

.drop-zone-icon {
    color: var(--color-accent-blue);
    animation: iconFloat 3.5s ease-in-out infinite;
    filter: drop-shadow(0 0 12px rgba(59,130,246,0.4));
}

.drop-zone-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text-primary);
}

.drop-zone-subtitle {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.drop-zone-formats {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-2);
    margin-top: var(--space-2);
}

.format-badge {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    font-weight: 500;
    padding: 3px 10px;
    border-radius: var(--radius-full);
    background: rgba(59,130,246,0.1);
    border: 1px solid rgba(59,130,246,0.2);
    color: var(--color-accent-blue-light);
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

/* === 7. GLOBAL CONTROLS === */
.global-controls {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-xl);
    padding: var(--space-5) var(--space-6);
    display: none;
    flex-direction: column;
    gap: var(--space-4);
    box-shadow: var(--shadow-md);
    animation: slideDown 0.4s ease forwards;
}

.global-controls.visible { display: flex; }

.controls-row {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    flex-wrap: wrap;
}

.controls-row-top { flex-wrap: wrap; }
.controls-row-presets {
    gap: var(--space-2);
    padding-top: var(--space-3);
    border-top: var(--glass-border);
}
.controls-row-actions {
    justify-content: space-between;
    padding-top: var(--space-3);
    border-top: var(--glass-border);
    flex-wrap: wrap;
    gap: var(--space-3);
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    min-width: 150px;
    flex: 1;
}

.control-label {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

/* Select wrapper + custom arrow */
.select-wrapper { position: relative; }
.select-wrapper::after {
    content: '';
    position: absolute; right: 12px; top: 50%;
    transform: translateY(-50%);
    width: 0; height: 0;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-top: 5px solid var(--color-text-secondary);
    pointer-events: none;
}

.control-select {
    width: 100%;
    padding: 8px 32px 8px 12px;
    background: var(--color-bg-input);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-primary);
    font-family: var(--font-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    appearance: none;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.control-select:hover { border-color: var(--color-border-hover); }
.control-select:focus { border-color: var(--color-border-focus); box-shadow: 0 0 0 3px rgba(59,130,246,0.15); outline: none; }
.control-select option { background: var(--color-bg-card-solid); }

/* Slider */
.slider-wrapper {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.control-slider {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 5px;
    border-radius: var(--radius-full);
    background: rgba(59,130,246,0.2);
    outline: none;
    cursor: pointer;
}
.control-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px; height: 18px;
    border-radius: 50%;
    background: var(--gradient-accent);
    box-shadow: 0 0 8px rgba(59,130,246,0.5);
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}
.control-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: var(--shadow-glow-blue);
}
.control-slider::-moz-range-thumb {
    width: 18px; height: 18px;
    border-radius: 50%;
    background: var(--gradient-accent);
    border: none;
    cursor: pointer;
}

.slider-value {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--color-accent-blue-light);
    min-width: 36px;
    text-align: right;
}

/* Resize Inputs */
.resize-inputs {
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.control-input-sm {
    width: 64px;
    padding: 7px 8px;
    background: var(--color-bg-input);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-primary);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    text-align: center;
    transition: border-color var(--transition-fast);
    outline: none;
}
.control-input-sm:hover { border-color: var(--color-border-hover); }
.control-input-sm:focus { border-color: var(--color-border-focus); box-shadow: 0 0 0 3px rgba(59,130,246,0.15); }
.control-input-sm::-webkit-inner-spin-button,
.control-input-sm::-webkit-outer-spin-button { opacity: 0.4; }

.control-input {
    width: 100%;
    padding: 9px 12px;
    background: var(--color-bg-input);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-primary);
    font-family: var(--font-primary);
    font-size: 0.875rem;
    outline: none;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.control-input:focus { border-color: var(--color-border-focus); box-shadow: 0 0 0 3px rgba(59,130,246,0.15); }

.resize-x {
    color: var(--color-text-muted);
    font-size: 0.75rem;
    flex-shrink: 0;
}

.btn-lock {
    width: 32px; height: 32px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
    background: var(--color-bg-input);
    color: var(--color-text-muted);
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}
.btn-lock:hover { border-color: var(--color-border-hover); color: var(--color-text-secondary); }
.btn-lock.active { border-color: var(--color-accent-blue); color: var(--color-accent-blue); background: rgba(59,130,246,0.1); }

/* Preset buttons */
.preset-label {
    font-size: 0.72rem;
    color: var(--color-text-muted);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    flex-shrink: 0;
}

.presets-scroll {
    display: flex;
    gap: var(--space-2);
    overflow-x: auto;
    padding-bottom: 4px;
    flex: 1;
}
.presets-scroll::-webkit-scrollbar { height: 3px; }

.btn-preset {
    padding: 5px 12px;
    border-radius: var(--radius-full);
    border: 1px solid var(--color-border);
    background: transparent;
    color: var(--color-text-secondary);
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
    white-space: nowrap;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}
.btn-preset:hover { border-color: var(--color-accent-blue); color: var(--color-accent-blue-light); }
.btn-preset.active {
    background: var(--gradient-accent);
    border-color: transparent;
    color: white;
    box-shadow: var(--shadow-glow-blue);
}

/* File counter */
.file-counter {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--color-text-secondary);
}

/* === 8. BUTTONS === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: 10px 20px;
    border-radius: var(--radius-md);
    border: none;
    font-family: var(--font-primary);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    white-space: nowrap;
}
.btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none !important; box-shadow: none !important; }

.btn-primary {
    background: var(--gradient-accent);
    color: white;
    box-shadow: var(--shadow-md);
}
.btn-primary:not(:disabled):hover {
    background: var(--gradient-accent-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow-blue);
}

.btn-glow { animation: btnGlow 2.5s ease-in-out infinite; }

.btn-secondary {
    background: var(--glass-bg);
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    backdrop-filter: var(--glass-blur);
}
.btn-secondary:not(:disabled):hover {
    border-color: var(--color-accent-blue);
    color: var(--color-accent-blue-light);
    transform: translateY(-1px);
}

.btn-danger {
    background: transparent;
    border: 1px solid rgba(239,68,68,0.3);
    color: var(--color-accent-red);
}
.btn-danger:not(:disabled):hover {
    background: rgba(239,68,68,0.1);
    border-color: var(--color-accent-red);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    font-size: 0.8rem;
    padding: 7px 14px;
}
.btn-outline:not(:disabled):hover {
    border-color: var(--color-accent-blue);
    color: var(--color-accent-blue-light);
}

.btn-sm { padding: 6px 14px; font-size: 0.8rem; }

.action-buttons {
    display: flex;
    gap: var(--space-2);
    flex-wrap: wrap;
}

/* === 9. FILE CARDS GRID === */
.file-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--space-4);
}

/* === 10. FILE CARD === */
.file-card {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: var(--glass-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
    animation: fadeInUp 0.4s ease forwards;
    opacity: 0;
}
.file-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-border-hover);
}

.card-header {
    position: relative;
    height: 175px;
    overflow: hidden;
    background: rgba(0,0,0,0.2);
}

.thumb-img {
    width: 100%; height: 100%;
    object-fit: cover;
    display: block;
    transition: transform var(--transition-slow);
}
.file-card:hover .thumb-img { transform: scale(1.04); }

.thumb-skeleton {
    position: absolute; inset: 0;
    background: linear-gradient(90deg, rgba(255,255,255,0.03) 25%, rgba(255,255,255,0.07) 37%, rgba(255,255,255,0.03) 63%);
    background-size: 400% 100%;
    animation: shimmer 1.5s infinite;
}
.thumb-skeleton.hidden { display: none; }

.card-remove {
    position: absolute; top: 8px; right: 8px;
    width: 28px; height: 28px;
    border-radius: 50%;
    border: none;
    background: rgba(0,0,0,0.6);
    color: rgba(255,255,255,0.7);
    font-size: 16px;
    font-weight: 400;
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    transition: all var(--transition-fast);
    backdrop-filter: blur(4px);
    line-height: 1;
}
.card-remove:hover {
    background: var(--color-accent-red);
    color: white;
    transform: scale(1.1);
}

.card-body { padding: var(--space-3) var(--space-4) var(--space-4); }

.card-filename {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-bottom: var(--space-1);
}

.card-meta {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--color-text-muted);
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: var(--space-3);
    flex-wrap: wrap;
}

.format-badge-sm {
    font-size: 0.62rem;
    padding: 2px 7px;
}

.meta-sep { opacity: 0.4; }

.card-controls {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    margin-bottom: var(--space-3);
}

.card-control-group {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.card-label {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    min-width: 62px;
    flex-shrink: 0;
}

.card-quality-group .slider-wrapper { flex: 1; }
.card-quality-group .control-slider { height: 4px; }
.card-quality-group .slider-value { font-size: 0.72rem; min-width: 30px; }

.control-select-sm {
    flex: 1;
    padding: 6px 28px 6px 10px;
    font-size: 0.8rem;
}

.resize-inputs-sm .control-input-sm { width: 52px; padding: 5px 6px; font-size: 0.75rem; }
.resize-inputs-sm .resize-x { font-size: 0.7rem; }

.card-actions {
    display: flex;
    gap: var(--space-2);
    margin-bottom: var(--space-3);
}
.card-actions .btn-outline { flex: 1; justify-content: center; }

/* Card Status */
.card-status {
    font-size: 0.78rem;
    font-weight: 500;
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-sm);
    background: rgba(255,255,255,0.03);
    border: var(--glass-border);
}

.status-row {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.status-icon { font-size: 0.9rem; }
.status-icon.spinning { display: inline-block; animation: spin 1s linear infinite; }

.status-text { color: var(--color-text-secondary); }
.card-status[data-status="done"] .status-text { color: var(--color-accent-green); }
.card-status[data-status="error"] .status-text { color: var(--color-accent-red); }
.card-status[data-status="converting"] .status-text { color: var(--color-accent-blue-light); }

.status-detail {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    color: var(--color-text-muted);
    padding-left: 24px;
}

.progress-bar {
    height: 4px;
    border-radius: var(--radius-full);
    background: rgba(255,255,255,0.06);
    overflow: hidden;
    margin-top: 4px;
}

.progress-fill {
    height: 100%;
    border-radius: var(--radius-full);
    background: var(--gradient-progress);
    background-size: 200% 100%;
    animation: progressShimmer 2s linear infinite;
    transition: width 0.3s ease;
    width: 0%;
}

/* === 11. FOOTER === */
.app-footer {
    text-align: center;
    padding: var(--space-8) var(--space-6);
    color: var(--color-text-muted);
    font-size: 0.82rem;
    border-top: var(--glass-border);
}
.footer-small { font-size: 0.72rem; margin-top: var(--space-1); opacity: 0.6; }

/* === 12. MODALS === */
.modal-overlay {
    position: fixed; inset: 0;
    background: rgba(4, 7, 18, 0.8);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: var(--z-modal-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-4);
    animation: backdropFadeIn 0.2s ease;
}

.modal-content {
    background: var(--color-bg-card-solid);
    border: var(--glass-border);
    border-radius: var(--radius-xl);
    width: 100%;
    max-height: 92vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg), 0 0 60px rgba(59,130,246,0.1);
    position: relative;
    z-index: var(--z-modal);
    animation: modalAppear 0.25s ease;
}

.modal-preview { max-width: 820px; padding: var(--space-6); }
.modal-settings { max-width: 480px; padding: var(--space-6); }

.modal-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--space-5);
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.modal-close {
    position: absolute; top: var(--space-4); right: var(--space-4);
    width: 32px; height: 32px;
    border-radius: 50%;
    border: var(--glass-border);
    background: rgba(255,255,255,0.05);
    color: var(--color-text-secondary);
    font-size: 20px;
    font-weight: 300;
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    line-height: 1;
    transition: all var(--transition-fast);
}
.modal-close:hover { background: rgba(239,68,68,0.15); color: var(--color-accent-red); border-color: var(--color-accent-red); }

/* === 13. COMPARISON SLIDER === */
.comparison-wrapper {
    position: relative;
    border-radius: var(--radius-md);
    overflow: hidden;
    user-select: none;
    background: rgba(0,0,0,0.4);
    margin-bottom: var(--space-4);
    cursor: ew-resize;
}

.comparison-img {
    display: block;
    width: 100%;
    max-height: 55vh;
    object-fit: contain;
}

.comparison-after-wrapper {
    position: absolute;
    top: 0; left: 0;
    height: 100%;
    width: 50%;
    overflow: hidden;
}

.comparison-after {
    position: absolute;
    top: 0; left: 0;
    height: 100%;
    object-fit: contain;
}

.comparison-slider {
    position: absolute;
    top: 0;
    left: 50%;
    height: 100%;
    width: 44px;
    transform: translateX(-50%);
    cursor: ew-resize;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: center;
}

.comparison-slider-line {
    position: absolute;
    left: 50%; top: 0;
    transform: translateX(-50%);
    width: 2px;
    height: 100%;
    background: rgba(255,255,255,0.9);
    box-shadow: 0 0 8px rgba(0,0,0,0.6);
}

.comparison-slider-handle {
    position: relative;
    z-index: 1;
    width: 40px; height: 40px;
    border-radius: 50%;
    background: var(--gradient-accent);
    display: flex; align-items: center; justify-content: center;
    color: white;
    box-shadow: var(--shadow-glow-blue);
    flex-shrink: 0;
    transition: transform var(--transition-fast);
}
.comparison-slider:hover .comparison-slider-handle,
.comparison-slider:active .comparison-slider-handle { transform: scale(1.1); }

.comparison-info {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.comparison-info-card {
    flex: 1;
    background: rgba(255,255,255,0.03);
    border: var(--glass-border);
    border-radius: var(--radius-md);
    padding: var(--space-3) var(--space-4);
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.comparison-info-card-right { align-items: flex-end; text-align: right; }
.comparison-arrow { font-size: 1.2rem; color: var(--color-text-muted); flex-shrink: 0; }

.info-label {
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
    font-weight: 600;
}
.info-format {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--color-accent-blue-light);
}
.info-dims {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-text-secondary);
}
.info-size {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-text-primary);
}

/* === 14. SETTINGS MODAL === */
.settings-group {
    margin-bottom: var(--space-5);
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}
.settings-group-row { flex-direction: row; align-items: center; justify-content: space-between; gap: var(--space-4); }
.settings-group-row > div { flex: 1; }

.settings-label {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--color-text-primary);
}
.settings-hint {
    font-size: 0.72rem;
    color: var(--color-text-muted);
    line-height: 1.5;
}

/* Toggle Switch */
.toggle-switch {
    position: relative;
    width: 48px; height: 26px;
    cursor: pointer;
    flex-shrink: 0;
}
.toggle-switch input { opacity: 0; width: 0; height: 0; position: absolute; }
.toggle-slider {
    position: absolute; inset: 0;
    background: rgba(255,255,255,0.1);
    border-radius: var(--radius-full);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
}
.toggle-slider::before {
    content: '';
    position: absolute;
    width: 18px; height: 18px;
    border-radius: 50%;
    background: var(--color-text-muted);
    left: 3px; top: 50%;
    transform: translateY(-50%);
    transition: all var(--transition-base);
}
.toggle-switch input:checked + .toggle-slider { background: rgba(59,130,246,0.3); border-color: var(--color-accent-blue); }
.toggle-switch input:checked + .toggle-slider::before { transform: translateX(22px) translateY(-50%); background: var(--color-accent-blue); }

/* === 15. HISTORY PANEL === */
.history-panel {
    position: fixed;
    top: 0; right: 0;
    height: 100vh;
    width: 360px;
    max-width: 100vw;
    background: var(--color-bg-card-solid);
    border-left: var(--glass-border);
    z-index: var(--z-sidebar);
    display: flex;
    flex-direction: column;
    transform: translateX(100%);
    transition: transform var(--transition-slow);
    box-shadow: -8px 0 40px rgba(0,0,0,0.4);
}
.history-panel.open { transform: translateX(0); }

.history-backdrop {
    position: fixed; inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: calc(var(--z-sidebar) - 1);
    backdrop-filter: blur(2px);
}

.history-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-5) var(--space-5) var(--space-4);
    border-bottom: var(--glass-border);
    flex-shrink: 0;
}
.history-title {
    font-size: 1rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: var(--space-2);
    color: var(--color-text-primary);
}
.history-title svg { color: var(--color-accent-blue); }

.history-list {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-4) var(--space-5);
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.history-empty {
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.85rem;
    margin-top: var(--space-8);
}

.history-item {
    background: rgba(255,255,255,0.03);
    border: var(--glass-border);
    border-radius: var(--radius-md);
    padding: var(--space-3) var(--space-4);
    display: flex;
    flex-direction: column;
    gap: 4px;
    transition: border-color var(--transition-fast);
}
.history-item:hover { border-color: var(--color-border-hover); }

.history-date {
    font-size: 0.68rem;
    color: var(--color-text-muted);
    font-family: var(--font-mono);
}
.history-detail {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}
.history-saved {
    font-size: 0.75rem;
    color: var(--color-accent-green);
    font-family: var(--font-mono);
    font-weight: 600;
}

.history-footer {
    padding: var(--space-4) var(--space-5);
    border-top: var(--glass-border);
    flex-shrink: 0;
}
.history-footer .btn { width: 100%; justify-content: center; }

/* === 16. TOAST NOTIFICATIONS === */
.toast-container {
    position: fixed;
    top: calc(var(--header-height) + 12px);
    right: var(--space-5);
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    max-width: 360px;
    width: calc(100vw - 40px);
}

.toast {
    display: flex;
    align-items: flex-start;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-4);
    background: var(--color-bg-card-solid);
    border: var(--glass-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    animation: toastSlideIn 0.3s ease;
    border-left: 3px solid var(--color-accent-blue);
    position: relative;
}

.toast-success { border-left-color: var(--color-accent-green); }
.toast-error { border-left-color: var(--color-accent-red); }
.toast-warning { border-left-color: var(--color-accent-amber); }
.toast-info { border-left-color: var(--color-accent-blue); }

.toast-icon { font-size: 1rem; flex-shrink: 0; margin-top: 1px; }
.toast-message { font-size: 0.82rem; color: var(--color-text-secondary); line-height: 1.5; flex: 1; }

.toast-close {
    background: none; border: none;
    color: var(--color-text-muted);
    cursor: pointer;
    font-size: 16px;
    padding: 0 2px;
    line-height: 1;
    flex-shrink: 0;
    transition: color var(--transition-fast);
}
.toast-close:hover { color: var(--color-text-primary); }

/* === 17. KEYFRAME ANIMATIONS === */
@keyframes borderGlow {
    0%, 100% { box-shadow: 0 0 15px rgba(59,130,246,0.06); }
    50% { box-shadow: 0 0 30px rgba(59,130,246,0.18), 0 0 60px rgba(139,92,246,0.08); }
}
@keyframes iconFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
@keyframes progressShimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}
@keyframes shimmer {
    0% { background-position: -468px 0; }
    100% { background-position: 468px 0; }
}
@keyframes modalAppear {
    from { opacity: 0; transform: scale(0.94) translateY(-10px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}
@keyframes backdropFadeIn {
    from { opacity: 0; } to { opacity: 1; }
}
@keyframes btnGlow {
    0%, 100% { box-shadow: 0 0 15px rgba(59,130,246,0.2), 0 4px 12px rgba(0,0,0,0.3); }
    50% { box-shadow: 0 0 35px rgba(59,130,246,0.45), 0 0 70px rgba(139,92,246,0.2), 0 4px 12px rgba(0,0,0,0.3); }
}
@keyframes toastSlideIn {
    from { opacity: 0; transform: translateX(80px); }
    to { opacity: 1; transform: translateX(0); }
}
@keyframes toastFadeOut {
    from { opacity: 1; transform: translateX(0); }
    to { opacity: 0; transform: translateX(80px); }
}
@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}
@keyframes slideDown {
    from { opacity: 0; transform: translateY(-12px); }
    to { opacity: 1; transform: translateY(0); }
}
@keyframes dragPulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.01); }
}
@keyframes logoPulse {
    0%, 100% { box-shadow: 0 0 16px rgba(59,130,246,0.4); }
    50% { box-shadow: 0 0 30px rgba(59,130,246,0.7), 0 0 60px rgba(139,92,246,0.25); }
}
@keyframes statusPop {
    0% { transform: scale(1); }
    50% { transform: scale(1.15); }
    100% { transform: scale(1); }
}

/* === 18. RESPONSIVE BREAKPOINTS === */
@media (max-width: 1199px) {
    .file-cards-grid { grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); }
}

@media (max-width: 767px) {
    :root { --header-height: 60px; }
    .app-main { padding: calc(var(--header-height) + 20px) var(--space-3) var(--space-8); gap: var(--space-3); }
    .file-cards-grid { grid-template-columns: 1fr; }
    .controls-row-top { flex-direction: column; align-items: stretch; }
    .controls-row-actions { flex-direction: column; }
    .action-buttons { flex-direction: column; }
    .action-buttons .btn { width: 100%; justify-content: center; }
    .drop-zone { min-height: 200px; }
    .card-header { height: 145px; }
    .history-panel { width: 100%; }
    .modal-preview { padding: var(--space-4); }
    .comparison-info { flex-direction: column; }
    .comparison-arrow { transform: rotate(90deg); }
    .header-subtitle { display: none; }
    .header-title { font-size: 1.1rem; }
    .logo-circle { width: 36px; height: 36px; }
    .logo-circle svg { width: 20px; height: 20px; }
    .control-group { min-width: 100%; }
}

@media (max-width: 479px) {
    .modal-content { border-radius: var(--radius-lg); }
    .drop-zone-title { font-size: 1.15rem; }
    .drop-zone-formats { gap: var(--space-1); }
    .format-badge { font-size: 0.62rem; padding: 2px 7px; }
}

/* === 19. PRINT STYLES === */
@media print {
    .app-header, .global-controls, .drop-zone,
    .toast-container, .modal-overlay, .history-panel,
    .history-backdrop, .card-actions, .card-controls,
    .card-remove { display: none !important; }
    .file-card { break-inside: avoid; }
    body { background: white; color: black; }
}

/* === 20. TAB NAVIGATION SYSTEM === */
.tab-nav {
    display: flex;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-6);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-bottom: var(--glass-border);
    position: sticky;
    top: var(--header-height);
    z-index: var(--z-controls);
    margin-top: var(--header-height);
}

.tab-btn {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: transparent;
    border: 1px solid transparent;
    border-radius: var(--radius-full);
    color: var(--color-text-secondary);
    font-family: var(--font-primary);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
}

.tab-btn:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-hover);
}

.tab-btn.active {
    color: var(--color-text-primary);
    background: var(--gradient-glow);
    border-color: var(--color-border-focus);
    box-shadow: var(--shadow-glow-blue);
}

.tab-panel {
    display: none;
    animation: fadeIn 0.4s ease both;
}

.tab-panel.active {
    display: block;
}

.app-main {
    padding-top: var(--space-5) !important;
}

@media (max-width: 767px) {
    .tab-nav {
        padding: var(--space-2) var(--space-3);
    }
    .app-main {
        padding-top: var(--space-3) !important;
    }
}