/* ========================================
   RESET & BASE STYLES
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --success-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --dark-bg: #1a1a2e;
    --card-bg: #16213e;
    --card-hover: #1e2d4d;
    --text-primary: #ffffff;
    --text-secondary: #a0a0c0;
    --border-color: #2d3561;
    --accent-purple: #667eea;
    --accent-pink: #f5576c;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 20px rgba(102, 126, 234, 0.3);

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--dark-bg);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    padding: var(--spacing-md);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

/* ========================================
   HEADER
   ======================================== */
.header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-lg) 0;
}

.title {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

.icon {
    font-size: 2.5rem;
    filter: drop-shadow(0 0 10px rgba(102, 126, 234, 0.5));
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-weight: 400;
}

/* ========================================
   UPLOAD ZONE
   ======================================== */
.upload-section {
    margin-bottom: var(--spacing-lg);
}

.drop-zone {
    background: var(--card-bg);
    border: 3px dashed var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.drop-zone::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--primary-gradient);
    opacity: 0;
    transition: opacity var(--transition-normal);
    z-index: 0;
}

.drop-zone:hover {
    border-color: var(--accent-purple);
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.drop-zone:hover::before {
    opacity: 0.05;
}

.drop-zone.drag-over {
    border-color: var(--accent-purple);
    background: rgba(102, 126, 234, 0.1);
    transform: scale(1.02);
}

.drop-zone.drag-over::before {
    opacity: 0.1;
}

.drop-zone-content {
    position: relative;
    z-index: 1;
}

.upload-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-md);
    color: var(--accent-purple);
    filter: drop-shadow(0 0 10px rgba(102, 126, 234, 0.3));
}

.drop-zone h2 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
}

.drop-zone p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.formats {
    font-size: 0.9rem;
    color: var(--accent-purple);
    font-weight: 500;
}

/* ========================================
   SETTINGS PANEL
   ======================================== */
.settings-section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.section-title {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-md);
    font-weight: 600;
}

.settings-grid {
    display: grid;
    gap: var(--spacing-lg);
}

.setting-item label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
}

.setting-value {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
    font-size: 1.1rem;
}

/* Custom Range Slider */
.slider {
    -webkit-appearance: none;
    width: 100%;
    height: 8px;
    border-radius: 5px;
    background: var(--border-color);
    outline: none;
    transition: background var(--transition-normal);
}

.slider:hover {
    background: #3d4575;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--primary-gradient);
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.5);
    transition: transform var(--transition-fast);
}

.slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 4px 16px rgba(102, 126, 234, 0.7);
}

.slider::-moz-range-thumb {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--primary-gradient);
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.5);
    transition: transform var(--transition-fast);
}

.slider::-moz-range-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 4px 16px rgba(102, 126, 234, 0.7);
}

.slider-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
}

/* Checkbox */
.checkbox-item {
    margin-top: var(--spacing-sm);
}

.checkbox-item label {
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.checkbox-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--accent-purple);
}

/* Text Input */
.text-input {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--dark-bg);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    transition: all var(--transition-normal);
    margin-top: var(--spacing-xs);
}

.text-input:focus {
    outline: none;
    border-color: var(--accent-purple);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.text-input::placeholder {
    color: var(--text-secondary);
    opacity: 0.6;
}

.input-hint {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
    font-style: italic;
}

/* ========================================
   PREVIEW & RESULTS SECTIONS
   ======================================== */
.preview-section,
.results-section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.preview-grid,
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

/* Image Cards */
.image-card {
    background: var(--dark-bg);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.image-card:hover {
    border-color: var(--accent-purple);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.image-preview {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: var(--radius-sm);
    margin-bottom: var(--spacing-sm);
    background: var(--card-bg);
}

.image-info {
    font-size: 0.9rem;
}

.image-name {
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.image-size {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.image-stats {
    display: flex;
    justify-content: space-between;
    margin-top: var(--spacing-sm);
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--border-color);
}

.stat-item {
    text-align: center;
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    display: block;
}

.stat-value {
    font-weight: 700;
    font-size: 0.9rem;
}

.stat-value.success {
    color: #00f2fe;
}

.remove-btn {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    background: rgba(245, 87, 108, 0.9);
    border: none;
    color: white;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    z-index: 2;
}

.remove-btn:hover {
    background: var(--accent-pink);
    transform: scale(1.1);
    box-shadow: 0 4px 12px rgba(245, 87, 108, 0.5);
}

/* ========================================
   BUTTONS
   ======================================== */
.btn {
    padding: 0.875rem 1.75rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-family: inherit;
    box-shadow: var(--shadow-sm);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.btn-primary {
    background: var(--primary-gradient);
    color: white;
}

.btn-primary:hover {
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.4);
}

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

.btn-secondary:hover {
    box-shadow: 0 8px 24px rgba(245, 87, 108, 0.4);
}

.btn-success {
    background: var(--success-gradient);
    color: white;
}

.btn-success:hover {
    box-shadow: 0 8px 24px rgba(79, 172, 254, 0.4);
}

.btn-download {
    width: 100%;
    margin-top: var(--spacing-sm);
    background: var(--success-gradient);
    color: white;
}

.btn-icon {
    font-size: 1.2rem;
}

.action-buttons {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
}

/* ========================================
   PROCESSING OVERLAY
   ======================================== */
.processing-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(26, 26, 46, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.processing-content {
    text-align: center;
}

.spinner {
    width: 60px;
    height: 60px;
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--accent-purple);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto var(--spacing-md);
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

.processing-text {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.processing-subtext {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* ========================================
   FOOTER
   ======================================== */
.footer {
    text-align: center;
    padding: var(--spacing-lg) 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer p {
    margin-bottom: var(--spacing-xs);
}

.footer-note {
    font-size: 0.85rem;
    opacity: 0.7;
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */
@media (max-width: 768px) {
    body {
        padding: var(--spacing-sm);
    }

    .title {
        font-size: 1.8rem;
        flex-direction: column;
        gap: var(--spacing-xs);
    }

    .subtitle {
        font-size: 1rem;
    }

    .drop-zone {
        padding: var(--spacing-lg);
    }

    .upload-icon {
        width: 60px;
        height: 60px;
    }

    .drop-zone h2 {
        font-size: 1.2rem;
    }

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

    .section-header {
        flex-direction: column;
        align-items: stretch;
    }

    .action-buttons {
        flex-direction: column;
    }

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

@media (max-width: 480px) {
    .title {
        font-size: 1.5rem;
    }

    .icon {
        font-size: 2rem;
    }

    .settings-section,
    .preview-section,
    .results-section {
        padding: var(--spacing-md);
    }
}