/* CSS Variables - Light Mode (Default) */
:root {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --accent-light: #e0e7ff;
    --border: #e2e8f0;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --radius: 12px;
    --radius-sm: 8px;
    /* Aliases */
    --background: var(--bg-primary);
    --text: var(--text-primary);
    --card-bg: var(--bg-secondary);
    --primary: var(--accent);
    --primary-hover: var(--accent-hover);
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent: #818cf8;
    --accent-hover: #6366f1;
    --accent-light: #312e81;
    --border: #334155;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
    /* Aliases */
    --background: var(--bg-primary);
    --text: var(--text-primary);
    --card-bg: var(--bg-secondary);
    --primary: var(--accent);
    --primary-hover: var(--accent-hover);
}

/* Theme Toggle */
.theme-toggle {
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: none;
    background: var(--bg-secondary);
    box-shadow: var(--shadow-lg);
    cursor: pointer;
    font-size: 1.25rem;
    transition: transform 0.2s;
    z-index: 100;
}
.theme-toggle:hover { transform: scale(1.1); }

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--background);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

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

/* Header */
header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, #6366f1, #ec4899);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

/* Trust Badges */
.badges {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-top: 1rem;
}

.badge {
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}

.badge-green {
    background: rgba(34, 197, 94, 0.15);
    color: #16a34a;
    border: 1px solid rgba(34, 197, 94, 0.3);
}

.badge-blue {
    background: rgba(59, 130, 246, 0.15);
    color: #2563eb;
    border: 1px solid rgba(59, 130, 246, 0.3);
}

.badge-purple {
    background: rgba(139, 92, 246, 0.15);
    color: #7c3aed;
    border: 1px solid rgba(139, 92, 246, 0.3);
}

/* Cards */
.info-card,
.controls-card,
.palette-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.info-card h2 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text);
}

/* Controls */
.control-row {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.control-group {
    flex: 1;
    min-width: 150px;
}

.control-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.control-group select,
.control-group input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    background: var(--background);
    color: var(--text);
    transition: border-color 0.2s;
}

.control-group select:focus,
.control-group input:focus {
    outline: none;
    border-color: var(--primary);
}

.color-input-wrapper {
    display: flex;
    gap: 0.5rem;
}

.color-input-wrapper input[type="color"] {
    width: 50px;
    height: 42px;
    padding: 2px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
}

.color-input-wrapper input[type="text"] {
    flex: 1;
}

/* Buttons */
.button-row {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    background: var(--primary-hover);
}

.btn-secondary {
    background: var(--background);
    color: var(--primary);
    border: 2px solid var(--primary);
}

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

/* Palette Display */
.palette-container {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.color-card {
    flex: 1;
    min-width: 100px;
    min-height: 120px;
    border-radius: var(--radius-sm);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 0.75rem;
    cursor: pointer;
    transition: transform 0.2s;
    border: 1px solid var(--border);
}

.color-card:hover {
    transform: scale(1.02);
}

.color-value {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 0.5rem;
    background: rgba(255,255,255,0.9);
    border-radius: 4px;
    text-align: center;
}

.hint {
    font-size: 0.875rem;
    color: var(--text-muted);
    text-align: center;
}

/* Export */
.export-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.export-btn {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    background: var(--background);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
}

.export-btn:hover,
.export-btn.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.export-output {
    display: none;
    position: relative;
    background: var(--background);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 1rem;
}

.export-output.show {
    display: block;
}

.export-output pre {
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.875rem;
    overflow-x: auto;
    white-space: pre-wrap;
    color: var(--text);
}

.copy-btn {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    padding: 0.5rem 0.75rem;
    font-size: 0.75rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

/* Image Upload */
.image-upload-zone {
    border: 2px dashed var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    background: var(--background);
}

.image-upload-zone:hover {
    border-color: var(--primary);
    background: var(--accent-light);
}

.upload-icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

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

/* Color Converter */
.converter-input {
    margin-bottom: 1rem;
}

.converter-input label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.converter-input input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    background: var(--background);
    color: var(--text);
}

.converter-results {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 0.75rem;
}

.converter-result {
    background: var(--background);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.75rem;
}

.converter-result label {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 0.25rem;
}

.converter-result span {
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.875rem;
    color: var(--text);
}

/* Saved Palettes */
.saved-palettes {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.saved-palette {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background: var(--background);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}

.saved-colors {
    display: flex;
    gap: 4px;
    flex: 1;
}

.saved-color {
    width: 24px;
    height: 24px;
    border-radius: 4px;
    border: 1px solid var(--border);
}

.saved-palette button {
    padding: 0.5rem 0.75rem;
    font-size: 0.75rem;
    background: var(--background);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    cursor: pointer;
}

.saved-palette button:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.empty-state {
    text-align: center;
    color: var(--text-muted);
    padding: 1rem;
}

/* FAQ */
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.faq-item {
    background: var(--card-bg);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.faq-item summary {
    padding: 1rem;
    cursor: pointer;
    font-weight: 600;
    list-style: none;
    color: var(--text);
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::before {
    content: '▶';
    margin-right: 0.5rem;
    font-size: 0.75rem;
    transition: transform 0.2s;
    display: inline-block;
}

.faq-item[open] summary::before {
    transform: rotate(90deg);
}

.faq-item p {
    padding: 0 1rem 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Footer */
footer {
    text-align: center;
    color: var(--text-muted);
    padding: 2rem 0;
}

footer p {
    margin: 0.25rem 0;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 5rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--text-primary);
    color: var(--bg-primary);
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-sm);
    font-weight: 500;
    opacity: 0;
    transition: all 0.3s;
    z-index: 1000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* Responsive */
@media (max-width: 600px) {
    header h1 {
        font-size: 1.75rem;
    }
    
    .control-row {
        flex-direction: column;
    }
    
    .control-group {
        width: 100%;
    }
    
    .button-row {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .color-card {
        min-width: 80px;
        min-height: 100px;
    }
}

/* Dark Mode Element Overrides */
[data-theme="dark"] body {
    background: #0f172a;
    color: #f1f5f9;
}

[data-theme="dark"] .info-card,
[data-theme="dark"] .controls-card,
[data-theme="dark"] .palette-card,
[data-theme="dark"] .faq-item {
    background: #1e293b;
}

[data-theme="dark"] input,
[data-theme="dark"] textarea,
[data-theme="dark"] select {
    background: #0f172a;
    color: #f1f5f9;
    border-color: #334155;
}

[data-theme="dark"] .btn-secondary,
[data-theme="dark"] .export-btn {
    background: #0f172a;
    color: #94a3b8;
    border-color: #334155;
}

[data-theme="dark"] .color-card {
    border-color: #334155;
}

[data-theme="dark"] .export-output {
    background: #0f172a;
    border-color: #334155;
}

[data-theme="dark"] .image-upload-zone {
    background: #0f172a;
    border-color: #334155;
}

[data-theme="dark"] .converter-result {
    background: #0f172a;
    border-color: #334155;
}

[data-theme="dark"] .saved-palette {
    background: #0f172a;
    border-color: #334155;
}

[data-theme="dark"] .toast {
    background: #f1f5f9;
    color: #0f172a;
}