:root {
    --primary: #1E90FF;
    --primary-hover: #187bcd;
    --secondary: #2C3E50;
    --secondary-hover: #1a252f;
    --accent: #FF0055;
    --accent-hover: #d40047;
    
    --bg: #F8F9FA;
    --bg-card: #FFFFFF;
    --text-main: #333333;
    --text-muted: #666666;
    --border: #E0E0E0;
    --focus-ring: rgba(30, 144, 255, 0.5);
    --error: #D32F2F;
    --success: #388E3C;
    
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

[data-theme="dark"] {
    --bg: #121212;
    --bg-card: #1E1E1E;
    --text-main: #F5F5F5;
    --text-muted: #AAAAAA;
    --border: #333333;
    --secondary: #3A3A3A;
    --secondary-hover: #4a4a4a;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg);
    color: var(--text-main);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

a {
    color: var(--primary);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.mt-4 { margin-top: 2rem; }
.mb-2 { margin-bottom: 1rem; }
.w-full { width: 100%; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    gap: 8px;
    text-align: center;
}

.btn:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

.btn-primary { background-color: var(--primary); color: #fff; }
.btn-primary:hover { background-color: var(--primary-hover); text-decoration: none; }

.btn-secondary { background-color: var(--secondary); color: #fff; }
.btn-secondary:hover { background-color: var(--secondary-hover); }

.btn-accent { background-color: var(--accent); color: #fff; }
.btn-accent:hover { background-color: var(--accent-hover); }

.btn-outline { background-color: transparent; border: 1px solid var(--border); color: var(--text-main); }
.btn-outline:hover { background-color: rgba(0,0,0,0.05); }
[data-theme="dark"] .btn-outline:hover { background-color: rgba(255,255,255,0.05); }

.btn-text { background-color: transparent; color: var(--text-muted); padding: 5px 10px; }
.btn-text:hover { color: var(--text-main); background-color: rgba(0,0,0,0.05); }
[data-theme="dark"] .btn-text:hover { background-color: rgba(255,255,255,0.05); }

.btn-small { padding: 6px 12px; font-size: 0.875rem; }
.btn-large { padding: 14px 28px; font-size: 1.125rem; }

.btn-icon {
    background: transparent;
    border: none;
    cursor: pointer;
    color: var(--text-main);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 8px;
    border-radius: 50%;
    transition: background 0.2s;
}
.btn-icon:hover { background: rgba(0,0,0,0.05); }
[data-theme="dark"] .btn-icon:hover { background: rgba(255,255,255,0.05); }

/* Header */
.header {
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}
.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}
.logo { display: flex; align-items: center; }
.logo img { max-height: 40px; width: auto; }

.nav-menu {
    display: flex;
    align-items: center;
    gap: 30px;
}
.nav-menu ul {
    display: flex;
    list-style: none;
    gap: 20px;
}
.nav-menu ul a {
    color: var(--text-main);
    font-weight: 500;
}
.nav-menu ul a:hover {
    color: var(--primary);
    text-decoration: none;
}
.header-buttons { display: flex; align-items: center; gap: 15px; }

/* Theme Icons */
.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 10px;
}
.menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--text-main);
    transition: 0.3s;
}

/* Hero */
.hero {
    text-align: center;
    padding: 60px 20px;
    background: linear-gradient(135deg, rgba(30,144,255,0.1) 0%, rgba(255,0,85,0.05) 100%);
    border-bottom: 1px solid var(--border);
}
.hero h1 { font-size: 3rem; margin-bottom: 16px; line-height: 1.2; color: var(--text-main); }
.hero p { font-size: 1.25rem; color: var(--text-muted); max-width: 700px; margin: 0 auto 24px; }
.badges { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-bottom: 30px; }
.badge {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-muted);
}

/* Cards */
.card {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow);
}

/* Converter */
.converter-section { padding: 60px 0; }
.workspace-header { text-align: center; margin-bottom: 40px; }
.workspace-header h2 { font-size: 2rem; margin-bottom: 8px; }

.converter-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 30px;
}

.input-panel label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
}
.input-group input {
    width: 100%;
    padding: 14px;
    font-size: 1.125rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background-color: var(--bg);
    color: var(--text-main);
    font-family: monospace;
}
.input-group input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--focus-ring);
}
.action-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 16px;
}
.error-msg {
    color: var(--error);
    background-color: rgba(211, 47, 47, 0.1);
    padding: 10px;
    border-radius: var(--radius-sm);
    margin-top: 10px;
    font-size: 0.875rem;
}

/* Picker & Preview */
.preview-panel { margin-top: 20px; text-align: center; }
.preview-panel h3 { margin-bottom: 16px; text-align: left; }
.color-picker-wrap {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    align-items: stretch;
}
input[type="color"] {
    -webkit-appearance: none;
    border: none;
    width: 80px;
    height: 120px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    padding: 0;
    background: none;
}
input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
input[type="color"]::-webkit-color-swatch { border: 1px solid var(--border); border-radius: var(--radius-sm); }
.large-preview {
    flex-grow: 1;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
    min-height: 120px;
}
.preview-text {
    display: flex;
    flex-direction: column;
    font-size: 1.5rem;
    font-weight: 700;
    font-family: monospace;
    text-shadow: 0px 1px 3px rgba(0,0,0,0.2);
}
.preview-actions { display: flex; gap: 10px; justify-content: center; }

/* Recent & Fav */
.recent-fav-section { margin-top: 20px; display: grid; gap: 20px; }
.card-header-row { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
.swatch-list { display: flex; flex-wrap: wrap; gap: 8px; }
.color-swatch {
    width: 32px;
    height: 32px;
    border-radius: 4px;
    border: 1px solid var(--border);
    cursor: pointer;
    position: relative;
    transition: transform 0.1s;
}
.color-swatch:hover { transform: scale(1.1); z-index: 2; }
.color-swatch.fav-swatch { width: 40px; height: 40px; display: flex; justify-content: center; align-items: center; }
.remove-fav {
    position: absolute;
    top: -5px; right: -5px;
    background: red; color: white;
    border-radius: 50%;
    width: 16px; height: 16px;
    font-size: 10px;
    display: flex; justify-content: center; align-items: center;
    border: none; cursor: pointer;
    opacity: 0; transition: opacity 0.2s;
}
.fav-swatch:hover .remove-fav { opacity: 1; }

/* Format Cards */
.format-cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 20px;
}
.format-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 16px;
    display: flex;
    flex-direction: column;
}
.fc-header { display: flex; justify-content: space-between; margin-bottom: 8px; align-items: center; }
.fc-name { font-weight: 600; font-size: 0.875rem; color: var(--text-muted); }
.fc-preview { width: 20px; height: 20px; border-radius: 4px; border: 1px solid var(--border); }
.fc-value { font-family: monospace; font-size: 1.125rem; word-break: break-all; margin-bottom: 12px; flex-grow: 1; }
.fc-action { margin-top: auto; }

/* Tools Section */
.tools-section { padding: 40px 0; background-color: var(--bg); }
.tools-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }

/* Info Grid */
.info-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 16px; }
.info-item {
    background: var(--bg);
    padding: 12px;
    border-radius: var(--radius-sm);
    text-align: center;
    border: 1px solid var(--border);
}
.info-label { font-size: 0.75rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px; }
.info-val { font-size: 1.25rem; font-weight: 700; margin-top: 4px; }

/* Contrast */
.contrast-demo { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin: 16px 0; }
.contrast-box {
    padding: 24px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    text-align: center;
}
.text-dark { color: #000 !important; }
.text-light { color: #FFF !important; }
.large-a { font-size: 3rem; font-weight: bold; line-height: 1; display: block; margin-bottom: 8px; }
.contrast-results { display: flex; justify-content: space-between; align-items: center; border-top: 1px solid var(--border); padding-top: 16px; }
.wcag-scores { display: flex; gap: 16px; }
.wcag-score { display: flex; flex-direction: column; font-size: 0.875rem; }
.badge.pass { background-color: rgba(56, 142, 60, 0.1); color: var(--success); border-color: var(--success); }
.badge.fail { background-color: rgba(211, 47, 47, 0.1); color: var(--error); border-color: var(--error); }

/* Palettes & Strips */
.generator-section { padding: 40px 0; }
.ts-row, .palette-row { margin-bottom: 24px; }
.ts-row h4, .palette-row h4 { margin-bottom: 10px; font-size: 1rem; color: var(--text-muted); }
.color-strip { display: flex; height: 60px; border-radius: var(--radius-sm); overflow: hidden; border: 1px solid var(--border); }
.strip-item { flex-grow: 1; cursor: pointer; transition: opacity 0.2s; position: relative; }
.strip-item:hover { opacity: 0.8; }
.strip-item::after {
    content: "Copy";
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0,0,0,0.6); color: white;
    font-size: 0.75rem; padding: 2px 6px; border-radius: 4px;
    opacity: 0; pointer-events: none; transition: opacity 0.2s;
}
.strip-item:hover::after { opacity: 1; }

/* CSS Export */
.css-snippets { margin-top: 16px; }
.snippet-row {
    display: flex; justify-content: space-between; align-items: center;
    background: var(--bg); padding: 12px 16px; border-radius: var(--radius-sm);
    margin-bottom: 8px; border: 1px solid var(--border);
}
code { font-family: monospace; font-size: 1rem; color: var(--text-main); }

/* Content & FAQ */
.content-section, .faq-section { padding: 60px 0; border-top: 1px solid var(--border); }
.content-container h2 { margin-bottom: 20px; margin-top: 40px; font-size: 1.75rem; }
.content-container h2:first-child { margin-top: 0; }
.content-container p { margin-bottom: 16px; font-size: 1.125rem; }
.content-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin: 40px 0; }
.content-box { background: var(--bg-card); padding: 24px; border-radius: var(--radius); border: 1px solid var(--border); }
.content-box h3 { margin-bottom: 12px; }

.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { margin-bottom: 24px; padding-bottom: 24px; border-bottom: 1px solid var(--border); }
.faq-item h3 { margin-bottom: 10px; font-size: 1.25rem; }

/* Footer */
.footer { background-color: var(--secondary); color: #fff; padding: 60px 0 20px; margin-top: 40px; }
.footer-container { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.footer-brand p { color: #aaa; margin-top: 10px; max-width: 300px; }
.footer-links { display: flex; gap: 20px; align-items: flex-start; justify-content: flex-end; }
.footer-links a { color: #fff; opacity: 0.8; }
.footer-links a:hover { opacity: 1; }
.footer-bottom { grid-column: 1 / -1; border-top: 1px solid rgba(255,255,255,0.1); padding-top: 20px; display: flex; justify-content: space-between; font-size: 0.875rem; color: #aaa; margin-top: 20px; }

/* Toast */
.toast {
    position: fixed;
    bottom: 30px; left: 50%;
    transform: translateX(-50%) translateY(100px);
    background-color: var(--text-main); color: var(--bg);
    padding: 12px 24px; border-radius: 30px; font-weight: 600;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    z-index: 1000;
}
.toast.show { transform: translateX(-50%) translateY(0); }

/* Responsive */
@media (max-width: 992px) {
    .converter-grid { grid-template-columns: 1fr; }
    .format-cards { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
    .header-container { position: relative; }
    .nav-menu {
        display: none;
        position: absolute;
        top: 70px; left: 0; width: 100%;
        background: var(--bg-card);
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid var(--border);
        box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
    }
    .nav-menu.active { display: flex; }
    .nav-menu ul { flex-direction: column; width: 100%; align-items: center; }
    .menu-toggle { display: flex; }
    
    .hero h1 { font-size: 2.25rem; }
    .tools-grid, .content-grid, .footer-container { grid-template-columns: 1fr; }
    .footer-links { justify-content: flex-start; }
    .footer-bottom { flex-direction: column; gap: 10px; text-align: center; }
    .info-grid { grid-template-columns: 1fr 1fr; }
    .color-picker-wrap { flex-direction: column; align-items: center; }
    input[type="color"] { width: 100%; height: 60px; }
    .large-preview { width: 100%; }
}

@media (max-width: 480px) {
    .format-cards { grid-template-columns: 1fr; }
    .info-grid { grid-template-columns: 1fr; }
    .contrast-demo { grid-template-columns: 1fr; }
    .snippet-row { flex-direction: column; align-items: flex-start; gap: 10px; }
    .snippet-row .btn { width: 100%; }
}