/* ==========================================================================
   RenkKoru - Renk Erisilebilik Araci
   Accessible-first CSS
   ========================================================================== */

/* ---------- Custom Properties (Light Theme) ---------- */
:root {
    /* Primary palette - all pass WCAG AA on their respective backgrounds */
    --color-primary: #1D4ED8;
    --color-primary-hover: #1E40AF;
    --color-primary-light: #DBEAFE;
    --color-on-primary: #FFFFFF;

    --color-secondary: #7C3AED;
    --color-secondary-hover: #6D28D9;

    /* Semantic */
    --color-success: #15803D;
    --color-success-bg: #DCFCE7;
    --color-warning: #92400E;
    --color-warning-bg: #FEF3C7;
    --color-error: #B91C1C;
    --color-error-bg: #FEE2E2;

    /* Surfaces */
    --color-bg: #FFFFFF;
    --color-bg-secondary: #F8FAFC;
    --color-bg-tertiary: #F1F5F9;
    --color-surface: #FFFFFF;
    --color-surface-hover: #F8FAFC;

    /* Text - all meet WCAG AAA (7:1) on white */
    --color-text: #0F172A;
    --color-text-secondary: #475569;
    --color-text-muted: #64748B;

    /* Borders */
    --color-border: #CBD5E1;
    --color-border-light: #E2E8F0;

    /* Focus */
    --color-focus: #2563EB;
    --focus-ring: 0 0 0 3px rgba(37, 99, 235, 0.4);

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', 'Roboto Mono', monospace;

    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;

    --leading-tight: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.75;

    /* Layout */
    --container-max: 1200px;
    --header-height: 4rem;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
}

/* ---------- Dark Theme ---------- */
[data-theme="dark"] {
    --color-primary: #60A5FA;
    --color-primary-hover: #93BBFD;
    --color-primary-light: #1E3A5F;
    --color-on-primary: #0F172A;

    --color-secondary: #A78BFA;
    --color-secondary-hover: #C4B5FD;

    --color-success: #4ADE80;
    --color-success-bg: #14532D;
    --color-warning: #FBBF24;
    --color-warning-bg: #78350F;
    --color-error: #F87171;
    --color-error-bg: #7F1D1D;

    --color-bg: #0F172A;
    --color-bg-secondary: #1E293B;
    --color-bg-tertiary: #334155;
    --color-surface: #1E293B;
    --color-surface-hover: #334155;

    --color-text: #F1F5F9;
    --color-text-secondary: #CBD5E1;
    --color-text-muted: #94A3B8;

    --color-border: #475569;
    --color-border-light: #334155;

    --color-focus: #60A5FA;
    --focus-ring: 0 0 0 3px rgba(96, 165, 250, 0.4);

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.4);
}

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

html {
    font-size: 100%;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

body {
    font-family: var(--font-family);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

main {
    flex: 1;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--color-primary);
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 2px;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-primary-hover);
}

a:focus-visible {
    outline: 2px solid var(--color-focus);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}

button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--color-focus);
    outline-offset: 2px;
}

/* ---------- Skip Link ---------- */
.skip-link {
    position: absolute;
    top: -100%;
    left: var(--space-md);
    z-index: 1000;
    padding: var(--space-sm) var(--space-md);
    background: var(--color-primary);
    color: var(--color-on-primary);
    border-radius: var(--radius-md);
    font-weight: 600;
    text-decoration: none;
}

.skip-link:focus {
    top: var(--space-md);
}

/* ---------- Container ---------- */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin-inline: auto;
    padding-inline: var(--space-lg);
}

/* ---------- Header ---------- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border-light);
    height: var(--header-height);
    display: flex;
    align-items: center;
    backdrop-filter: blur(8px);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-lg);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    text-decoration: none;
    color: var(--color-text);
    font-size: var(--text-xl);
    font-weight: 400;
    flex-shrink: 0;
}

.logo strong {
    font-weight: 800;
}

.logo-icon {
    display: flex;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: var(--space-xs);
}

.nav-list a {
    display: block;
    padding: var(--space-sm) var(--space-md);
    text-decoration: none;
    color: var(--color-text-secondary);
    font-weight: 500;
    font-size: var(--text-sm);
    border-radius: var(--radius-md);
    transition: background var(--transition-fast), color var(--transition-fast);
}

.nav-list a:hover {
    background: var(--color-bg-tertiary);
    color: var(--color-text);
}

.nav-list a.active {
    background: var(--color-primary-light);
    color: var(--color-primary);
    font-weight: 600;
}

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

/* ---------- Theme Toggle ---------- */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: background var(--transition-fast), color var(--transition-fast);
}

.theme-toggle:hover {
    background: var(--color-bg-tertiary);
    color: var(--color-text);
}

[data-theme="light"] .icon-moon {
    display: none;
}

[data-theme="dark"] .icon-sun {
    display: none;
}

/* ---------- Mobile Menu ---------- */
.mobile-menu-toggle {
    display: none;
    width: 2.5rem;
    height: 2.5rem;
    border: none;
    background: none;
    cursor: pointer;
    position: relative;
}

.hamburger,
.hamburger::before,
.hamburger::after {
    display: block;
    width: 1.25rem;
    height: 2px;
    background: var(--color-text);
    border-radius: 1px;
    transition: transform var(--transition-normal);
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.hamburger {
    top: 50%;
    transform: translate(-50%, -50%);
}

.hamburger::before {
    content: '';
    top: -6px;
    left: 0;
    transform: none;
}

.hamburger::after {
    content: '';
    top: 6px;
    left: 0;
    transform: none;
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 0.625rem var(--space-lg);
    font-family: var(--font-family);
    font-size: var(--text-sm);
    font-weight: 600;
    line-height: 1;
    text-decoration: none;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background var(--transition-fast), color var(--transition-fast), box-shadow var(--transition-fast);
    white-space: nowrap;
}

.btn:focus-visible {
    box-shadow: var(--focus-ring);
}

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

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

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text);
    border-color: var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-bg-tertiary);
}

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

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

.btn-sm {
    padding: 0.375rem var(--space-md);
    font-size: var(--text-xs);
}

.btn-lg {
    padding: 0.875rem var(--space-xl);
    font-size: var(--text-base);
}

/* ---------- Form Controls ---------- */
.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.form-label {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-text);
}

.form-input,
.form-select {
    width: 100%;
    padding: 0.625rem var(--space-md);
    font-family: var(--font-family);
    font-size: var(--text-base);
    color: var(--color-text);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-select:focus {
    border-color: var(--color-focus);
    box-shadow: var(--focus-ring);
    outline: none;
}

.form-input::placeholder {
    color: var(--color-text-muted);
}

.color-input-group {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.color-input-group input[type="color"] {
    width: 3rem;
    height: 2.5rem;
    padding: 2px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    background: var(--color-surface);
}

.color-input-group input[type="text"] {
    flex: 1;
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    text-transform: uppercase;
}

/* ---------- Cards ---------- */
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-fast);
}

.card:hover {
    box-shadow: var(--shadow-md);
}

.card-header {
    margin-bottom: var(--space-lg);
}

.card-title {
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--color-text);
}

.card-subtitle {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-top: var(--space-xs);
}

/* ---------- Hero Section ---------- */
.hero {
    padding: var(--space-3xl) 0;
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border-light);
}

.hero-content {
    text-align: center;
    max-width: 700px;
    margin-inline: auto;
    margin-bottom: var(--space-2xl);
}

.hero-title {
    font-size: var(--text-4xl);
    font-weight: 800;
    line-height: var(--leading-tight);
    color: var(--color-text);
    margin-bottom: var(--space-md);
}

.hero-subtitle {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

/* ---------- Contrast Checker (Hero) ---------- */
.contrast-checker {
    max-width: 800px;
    margin-inline: auto;
}

.checker-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.checker-result {
    text-align: center;
    padding: var(--space-xl);
    background: var(--color-surface);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
}

.ratio-display {
    font-size: var(--text-4xl);
    font-weight: 800;
    font-family: var(--font-mono);
    margin-bottom: var(--space-md);
}

.wcag-badges {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.wcag-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-md);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    font-weight: 600;
}

.wcag-badge.pass {
    background: var(--color-success-bg);
    color: var(--color-success);
}

.wcag-badge.fail {
    background: var(--color-error-bg);
    color: var(--color-error);
}

.badge-icon {
    font-size: var(--text-base);
}

/* ---------- Live Preview ---------- */
.live-preview {
    margin-top: var(--space-lg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--color-border-light);
}

.preview-bar {
    padding: var(--space-sm) var(--space-md);
    background: var(--color-bg-tertiary);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.preview-content {
    padding: var(--space-xl);
    min-height: 120px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--space-sm);
}

.preview-large-text {
    font-size: var(--text-2xl);
    font-weight: 700;
}

.preview-normal-text {
    font-size: var(--text-base);
}

.preview-small-text {
    font-size: var(--text-sm);
}

/* ---------- Section ---------- */
.section {
    padding: var(--space-3xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.section-title {
    font-size: var(--text-3xl);
    font-weight: 800;
    color: var(--color-text);
    margin-bottom: var(--space-sm);
}

.section-subtitle {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
}

/* ---------- Color Swatches Grid ---------- */
.palette-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--space-lg);
}

.palette-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: box-shadow var(--transition-fast), transform var(--transition-fast);
}

.palette-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.palette-colors {
    display: flex;
    height: 80px;
}

.palette-color {
    flex: 1;
    position: relative;
    cursor: pointer;
    transition: flex var(--transition-normal);
}

.palette-color:hover {
    flex: 1.5;
}

.palette-color-label {
    position: absolute;
    bottom: var(--space-xs);
    left: 50%;
    transform: translateX(-50%);
    font-size: var(--text-xs);
    font-family: var(--font-mono);
    padding: 1px 4px;
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.5);
    color: #fff;
    opacity: 0;
    transition: opacity var(--transition-fast);
    white-space: nowrap;
}

.palette-color:hover .palette-color-label {
    opacity: 1;
}

.palette-info {
    padding: var(--space-md);
}

.palette-name {
    font-weight: 600;
    font-size: var(--text-sm);
    color: var(--color-text);
    margin-bottom: var(--space-xs);
}

.palette-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: var(--text-xs);
    color: var(--color-text-muted);
}

/* ---------- Feature Cards ---------- */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
}

.feature-card {
    padding: var(--space-xl);
    background: var(--color-surface);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    text-align: center;
}

.feature-icon {
    width: 3rem;
    height: 3rem;
    margin-inline: auto;
    margin-bottom: var(--space-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary-light);
    color: var(--color-primary);
    border-radius: var(--radius-lg);
    font-size: var(--text-xl);
}

.feature-title {
    font-size: var(--text-lg);
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.feature-desc {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

/* ---------- Contrast Checker Page ---------- */
.checker-page {
    padding: var(--space-2xl) 0;
}

.checker-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
    align-items: start;
}

.checker-controls {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.swap-btn {
    align-self: center;
    width: 2.5rem;
    height: 2.5rem;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--color-border);
    background: var(--color-surface);
    cursor: pointer;
    font-size: var(--text-lg);
    transition: background var(--transition-fast);
}

.swap-btn:hover {
    background: var(--color-bg-tertiary);
}

.results-panel {
    position: sticky;
    top: calc(var(--header-height) + var(--space-lg));
}

.result-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md);
    border-bottom: 1px solid var(--color-border-light);
}

.result-item:last-child {
    border-bottom: none;
}

.result-label {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

.result-value {
    font-weight: 700;
    font-family: var(--font-mono);
}

/* ---------- Palette Generator Page ---------- */
.palette-page {
    padding: var(--space-2xl) 0;
}

.generator-controls {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
    align-items: flex-end;
}

.palette-display {
    display: flex;
    height: 200px;
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--color-border-light);
    margin-bottom: var(--space-xl);
}

.palette-display-color {
    flex: 1;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding: var(--space-md);
    cursor: pointer;
    transition: flex var(--transition-normal);
    position: relative;
}

.palette-display-color:hover {
    flex: 1.5;
}

.palette-display-label {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 600;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.4);
    color: #fff;
}

.export-section {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.export-output {
    width: 100%;
    margin-top: var(--space-md);
    padding: var(--space-md);
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    border: 1px solid var(--color-border-light);
    white-space: pre-wrap;
    word-break: break-all;
    max-height: 300px;
    overflow-y: auto;
    color: var(--color-text);
}

/* ---------- Simulation Page ---------- */
.simulation-page {
    padding: var(--space-2xl) 0;
}

.simulation-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-lg);
}

.simulation-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.simulation-header {
    padding: var(--space-md) var(--space-lg);
    background: var(--color-bg-tertiary);
    border-bottom: 1px solid var(--color-border-light);
}

.simulation-title {
    font-weight: 700;
    font-size: var(--text-base);
}

.simulation-desc {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    margin-top: var(--space-xs);
}

.simulation-preview {
    padding: var(--space-lg);
    min-height: 150px;
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.sim-color-pair {
    display: flex;
    gap: var(--space-sm);
    align-items: center;
}

.sim-swatch {
    width: 3rem;
    height: 3rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border-light);
    flex-shrink: 0;
}

.sim-info {
    font-size: var(--text-sm);
}

.sim-hex {
    font-family: var(--font-mono);
    font-weight: 600;
}

.sim-label {
    color: var(--color-text-muted);
    font-size: var(--text-xs);
}

/* ---------- Image Upload Area ---------- */
.upload-area {
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-2xl);
    text-align: center;
    cursor: pointer;
    transition: border-color var(--transition-fast), background var(--transition-fast);
    margin-bottom: var(--space-xl);
}

.upload-area:hover,
.upload-area.dragover {
    border-color: var(--color-primary);
    background: var(--color-primary-light);
}

.upload-icon {
    font-size: var(--text-3xl);
    margin-bottom: var(--space-md);
    color: var(--color-text-muted);
}

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

/* ---------- Tabs ---------- */
.tabs {
    display: flex;
    border-bottom: 1px solid var(--color-border-light);
    margin-bottom: var(--space-xl);
    gap: var(--space-xs);
}

.tab-btn {
    padding: var(--space-sm) var(--space-lg);
    font-family: var(--font-family);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-text-muted);
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    cursor: pointer;
    transition: color var(--transition-fast), border-color var(--transition-fast);
    margin-bottom: -1px;
}

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

.tab-btn.active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
    font-weight: 600;
}

.tab-panel {
    display: none;
}

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

/* ---------- Accessibility Info ---------- */
.info-box {
    padding: var(--space-lg);
    border-radius: var(--radius-lg);
    margin: var(--space-lg) 0;
    font-size: var(--text-sm);
    line-height: var(--leading-relaxed);
}

.info-box-info {
    background: var(--color-primary-light);
    border-left: 4px solid var(--color-primary);
    color: var(--color-text);
}

.info-box-success {
    background: var(--color-success-bg);
    border-left: 4px solid var(--color-success);
}

.info-box-warning {
    background: var(--color-warning-bg);
    border-left: 4px solid var(--color-warning);
}

.info-box h4 {
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

/* ---------- Footer ---------- */
.site-footer {
    background: var(--color-bg-secondary);
    border-top: 1px solid var(--color-border-light);
    padding: var(--space-3xl) 0 var(--space-xl);
    margin-top: auto;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-2xl);
    margin-bottom: var(--space-2xl);
}

.footer-brand p {
    margin-top: var(--space-md);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
    max-width: 300px;
}

.footer-links h3 {
    font-size: var(--text-sm);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text);
    margin-bottom: var(--space-md);
}

.footer-links ul {
    list-style: none;
}

.footer-links li + li {
    margin-top: var(--space-sm);
}

.footer-links a {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    text-decoration: none;
}

.footer-links a:hover {
    color: var(--color-primary);
    text-decoration: underline;
}

.footer-bottom {
    padding-top: var(--space-xl);
    border-top: 1px solid var(--color-border-light);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

.footer-note {
    margin-top: var(--space-sm);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
}

/* ---------- Utilities ---------- */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

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

.text-mono {
    font-family: var(--font-mono);
}

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }

/* Copied notification */
.copied-toast {
    position: fixed;
    bottom: var(--space-xl);
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--color-text);
    color: var(--color-bg);
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    font-weight: 600;
    opacity: 0;
    transition: transform var(--transition-normal), opacity var(--transition-normal);
    z-index: 1000;
    pointer-events: none;
}

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

/* ---------- Page-level Heading ---------- */
.page-header {
    padding: var(--space-2xl) 0 var(--space-lg);
    border-bottom: 1px solid var(--color-border-light);
    background: var(--color-bg-secondary);
    margin-bottom: var(--space-xl);
}

.page-title {
    font-size: var(--text-3xl);
    font-weight: 800;
}

.page-desc {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    margin-top: var(--space-sm);
    max-width: 600px;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }

    .main-nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--color-bg);
        padding: var(--space-lg);
        transform: translateX(-100%);
        transition: transform var(--transition-normal);
        z-index: 99;
    }

    .main-nav.open {
        transform: translateX(0);
    }

    .nav-list {
        flex-direction: column;
        gap: var(--space-xs);
    }

    .nav-list a {
        font-size: var(--text-lg);
        padding: var(--space-md);
    }

    .hero-title {
        font-size: var(--text-3xl);
    }

    .checker-inputs {
        grid-template-columns: 1fr;
    }

    .checker-layout {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }

    .palette-display {
        height: 120px;
    }

    .generator-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .simulation-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: var(--text-2xl);
    }

    .hero {
        padding: var(--space-2xl) 0;
    }

    .section {
        padding: var(--space-2xl) 0;
    }

    .container {
        padding-inline: var(--space-md);
    }
}

/* ---------- Print Styles ---------- */
@media print {
    .site-header,
    .site-footer,
    .theme-toggle,
    .mobile-menu-toggle,
    .btn,
    .skip-link {
        display: none !important;
    }

    body {
        background: #fff;
        color: #000;
        font-size: 12pt;
    }

    .card {
        box-shadow: none;
        border: 1px solid #ccc;
    }
}