/* ===== CSS Custom Properties ===== */
:root {
    --color-bg: #FAF8F5;
    --color-surface: #FFFFFF;
    --color-text: #2C3E50;
    --color-text-light: #5A6C7D;
    --color-accent: #D4A373;
    --color-accent-dark: #B5835A;
    --color-border: #E0DCD3;
    --color-shadow: rgba(44, 62, 80, 0.08);
    --color-section-alt: #F4F1EA;
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --font-sans: system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --max-width: 1100px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2.5rem;
    --spacing-xl: 4rem;
}

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

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

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img, svg {
    display: block;
    max-width: 100%;
}

/* ===== Skip Link ===== */
.skip-link {
    position: absolute;
    top: -100%;
    left: var(--spacing-sm);
    background: var(--color-accent);
    color: #fff;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    z-index: 1000;
    font-weight: 600;
    text-decoration: none;
}

.skip-link:focus {
    top: var(--spacing-sm);
}

/* ===== Container ===== */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===== Header ===== */
.site-header {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 1px 4px var(--color-shadow);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-text {
    font-weight: 700;
    font-size: 1.25rem;
    letter-spacing: -0.02em;
    color: var(--color-text);
}

.logo-text .accent {
    color: var(--color-accent);
}

.nav-list {
    list-style: none;
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.nav-list a {
    text-decoration: none;
    color: var(--color-text-light);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.25rem 0;
    border-bottom: 2px solid transparent;
    transition: color 0.2s, border-color 0.2s;
}

.nav-list a:hover,
.nav-list a:focus {
    color: var(--color-accent-dark);
    border-bottom-color: var(--color-accent);
    outline: none;
}

/* ===== Hero ===== */
.hero {
    text-align: center;
    padding: var(--spacing-xl) 0 var(--spacing-lg);
}

.hero h1 {
    font-size: clamp(2rem, 5vw, 2.8rem);
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--color-text-light);
    max-width: 650px;
    margin: 0 auto;
    line-height: 1.6;
}

/* ===== Section Common ===== */
.visualizer-section,
.info-section {
    padding: var(--spacing-xl) 0;
}

.info-section.bg-alt {
    background: var(--color-section-alt);
}

h2 {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: var(--spacing-sm);
}

.section-intro {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-lg);
    max-width: 600px;
}

/* ===== Visualizer Layout ===== */
.visualizer-layout {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: var(--spacing-lg);
    align-items: start;
}

.controls-panel {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    box-shadow: 0 4px 12px var(--color-shadow);
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.control-group label {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--color-text);
}

.color-input-wrapper {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

input[type="color"] {
    -webkit-appearance: none;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-sm);
    width: 48px;
    height: 40px;
    cursor: pointer;
    background: none;
    padding: 2px;
}

input[type="color"]::-webkit-color-swatch-wrapper {
    padding: 0;
}

input[type="color"]::-webkit-color-swatch {
    border: none;
    border-radius: 3px;
}

.color-hex {
    font-family: monospace;
    font-size: 0.9rem;
    color: var(--color-text-light);
    background: var(--color-section-alt);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
}

.preset-colors {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.preset-swatch {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    border: 2px solid var(--color-border);
    cursor: pointer;
    transition: transform 0.15s, border-color 0.15s;
    flex-shrink: 0;
}

.preset-swatch:hover,
.preset-swatch:focus {
    transform: scale(1.2);
    border-color: var(--color-accent);
    outline: none;
}

select {
    padding: 0.6rem 0.75rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: 0.95rem;
    background: var(--color-surface);
    cursor: pointer;
    color: var(--color-text);
}

input[type="range"] {
    width: 100%;
    accent-color: var(--color-accent);
}

.btn-secondary {
    background: var(--color-section-alt);
    border: 1px solid var(--color-border);
    padding: 0.6rem 1rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9rem;
    transition: background 0.2s;
    color: var(--color-text);
}

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

/* ===== Preview Panel ===== */
.preview-panel {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    box-shadow: 0 4px 12px var(--color-shadow);
}

.preview-label {
    font-weight: 600;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-sm);
}

.tile-canvas {
    width: 100%;
    aspect-ratio: 1 / 1;
    max-height: 500px;
    border-radius: var(--radius-sm);
    overflow: hidden;
    background: #ccc;
    display: grid;
    transition: gap 0.2s;
}

.preview-caption {
    font-size: 0.8rem;
    color: var(--color-text-light);
    margin-top: var(--spacing-sm);
    font-style: italic;
}

/* ===== Info Grid ===== */
.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.info-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    box-shadow: 0 2px 8px var(--color-shadow);
}

.info-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.info-card p {
    color: var(--color-text-light);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ===== Tips Grid ===== */
.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.tip-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.tip-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--color-accent);
    line-height: 1;
}

.tip-item h4 {
    font-size: 1.05rem;
    font-weight: 700;
}

.tip-item p {
    color: var(--color-text-light);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* ===== Footer ===== */
.site-footer {
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-lg) 0;
    text-align: center;
    color: var(--color-text-light);
    font-size: 0.9rem;
}

.footer-nav {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin: var(--spacing-sm) 0;
    flex-wrap: wrap;
}

.footer-nav a {
    color: var(--color-text-light);
    text-decoration: underline;
    text-underline-offset: 2px;
}

.footer-nav a:hover {
    color: var(--color-accent-dark);
}

.copyright {
    margin-top: var(--spacing-xs);
    font-size: 0.8rem;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .visualizer-layout {
        grid-template-columns: 1fr;
    }

    .controls-panel {
        order: 1;
    }

    .preview-panel {
        order: 0;
    }

    .site-header .container {
        height: auto;
        padding-top: var(--spacing-sm);
        padding-bottom: var(--spacing-sm);
    }

    .hero {
        padding: var(--spacing-lg) 0;
    }

    .info-grid,
    .tips-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .nav-list {
        gap: 0.75rem;
    }

    .preset-colors {
        gap: 0.35rem;
    }

    .preset-swatch {
        width: 24px;
        height: 24px;
    }
}

/* ===== Legal Pages ===== */
.legal-page {
    max-width: 720px;
    margin: var(--spacing-xl) auto;
    padding: 0 var(--spacing-md);
}

.legal-page h1 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.legal-marker {
    min-height: 400px;
    background: var(--color-section-alt);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    color: var(--color-text-light);
}



/* Factory-injected deployment helpers. The AI owns the site design above this block. */
.ad-unit {
  width: min(100%, 720px);
  min-height: 120px;
  margin: 24px auto;
  display: block;
}

.legal-page {
  width: min(900px, calc(100% - 32px));
  margin: 40px auto;
}

.site-utility-links {
  width: min(900px, calc(100% - 32px));
  margin: 32px auto;
  padding-top: 16px;
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  border-top: 1px solid rgba(127, 127, 127, 0.25);
  font-size: 0.9rem;
}

.site-utility-links a {
  color: inherit;
  opacity: 0.75;
}