/* ============================================================
   YouSeeTech — SEO-Optimized Static Site
   Lightweight, responsive, modern design
   ============================================================ */

/* ── CSS Reset & Variables ──────────────────────────────────── */
:root {
    --c-primary: #1a56db;
    --c-primary-dark: #1e40af;
    --c-primary-light: #dbeafe;
    --c-accent: #0ea5e9;
    --c-text: #1e293b;
    --c-text-light: #64748b;
    --c-bg: #ffffff;
    --c-bg-alt: #f8fafc;
    --c-bg-dark: #0f172a;
    --c-border: #e2e8f0;
    --c-success: #16a34a;
    --c-warning: #d97706;
    --radius: 8px;
    --shadow: 0 1px 3px rgba(0,0,0,.1);
    --shadow-lg: 0 10px 40px rgba(0,0,0,.08);
    --max-w: 1200px;
    --font: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: var(--font);
    color: var(--c-text);
    background: var(--c-bg);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

/* ── Skip Link ─────────────────────────────────────────────── */
.skip-link {
    position: absolute; top: -100px; left: 0;
    background: var(--c-primary); color: #fff; padding: .5rem 1rem;
    z-index: 999;
}
.skip-link:focus { top: 0; }

/* ── Container ──────────────────────────────────────────────── */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 1.5rem; }

/* ── Header ─────────────────────────────────────────────────── */
.site-header {
    background: #fff; border-bottom: 1px solid var(--c-border);
    position: sticky; top: 0; z-index: 100;
}
.site-header .container {
    display: flex; align-items: center; justify-content: space-between;
    height: 64px;
}
.logo {
    display: flex; align-items: center;
    text-decoration: none;
}
.logo img {
    width: auto;
    height: 50px;
    display: block;
}
.logo-icon { font-size: 1.5rem; }
.logo-text { color: var(--c-text); }
.logo-accent { color: var(--c-primary); }

/* ── Navigation ���────────────────────────────────────────────── */
.main-nav ul { display: flex; list-style: none; gap: .25rem; }
.main-nav a {
    text-decoration: none; color: var(--c-text-light);
    padding: .5rem 1rem; border-radius: var(--radius);
    font-weight: 500; font-size: .95rem; transition: all .2s;
}
.main-nav a:hover { color: var(--c-primary); background: var(--c-primary-light); }
.main-nav a.active { color: var(--c-primary); background: var(--c-primary-light); }

.nav-toggle { display: none; }

/* ── Breadcrumb ─────────────────────────────────────────────── */
.breadcrumb {
    max-width: var(--max-w); margin: 1rem auto 0; padding: 0 1.5rem;
    font-size: .85rem; color: var(--c-text-light);
}
.breadcrumb ol {
    list-style: none; display: flex; flex-wrap: wrap; gap: .25rem;
}
.breadcrumb li::after { content: '/'; margin: 0 .35rem; color: var(--c-border); }
.breadcrumb li:last-child::after { content: ''; }
.breadcrumb a { color: var(--c-primary); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb [aria-current="page"] { color: var(--c-text); }

/* ── Hero ──────────────────────────────────────────────────── */
.hero {
    background: linear-gradient(135deg, var(--c-bg-dark) 0%, #1e3a5f 100%);
    color: #fff; padding: 5rem 0; text-align: center;
}
.hero h1 { font-size: clamp(1.8rem, 4vw, 2.8rem); line-height: 1.3; margin-bottom: 1rem; }
.hero-subtitle { font-size: 1.2rem; color: var(--c-accent); margin-bottom: .75rem; font-weight: 500; }
.hero-desc { max-width: 700px; margin: 0 auto 2rem; color: #cbd5e1; font-size: 1.05rem; }
.hero-cta { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

/* ── Content Sections ───────────────────────────────────────── */
.content-section { padding: 4rem 0; }
.content-section h1 { font-size: 2.2rem; margin-bottom: .5rem; }
.content-section h2 { font-size: 1.7rem; margin: 2rem 0 1rem; }
.content-section h3 { font-size: 1.25rem; margin: 1.5rem 0 .75rem; }
.content-section p { margin-bottom: 1rem; color: var(--c-text-light); max-width: 800px; }
.content-section ul, .content-section ol {
    margin: 0 0 1.5rem 1.5rem; color: var(--c-text-light);
}
.content-section li { margin-bottom: .4rem; }
.section-intro { font-size: 1.1rem; text-align: center; max-width: 600px; margin: 0 auto 3rem; }

/* ── Product Grid ───────────────────────────────────────────── */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 1.5rem;
}
.product-card {
    background: #fff; border: 1px solid var(--c-border);
    border-radius: var(--radius); overflow: hidden;
    transition: box-shadow .2s, transform .2s;
}
.product-card:hover {
    box-shadow: var(--shadow-lg); transform: translateY(-2px);
}
.product-card .card-body { padding: 1.5rem; }
.product-card h3 { margin: 0 0 .25rem; font-size: 1.1rem; }
.product-card h3 a {
    color: var(--c-text); text-decoration: none;
    transition: color .2s;
}
.product-card h3 a:hover { color: var(--c-primary); }
.card-subtitle { color: var(--c-accent); font-size: .85rem; margin-bottom: .5rem; font-weight: 500; }
.card-desc { color: var(--c-text-light); font-size: .92rem; margin-bottom: .75rem; }
.card-link {
    color: var(--c-primary); font-weight: 600; text-decoration: none;
    font-size: .9rem;
}
.card-link:hover { text-decoration: underline; }

/* ── Product Detail ─────────────────────────────────────────── */
.product-hero {
    background: var(--c-bg-alt); padding: 2rem;
    border-radius: var(--radius); border-left: 4px solid var(--c-primary);
    margin-bottom: 2rem;
}
.product-hero h2 { margin-top: 0; }
.product-tagline { font-size: 1.1rem; color: var(--c-text-light); }

.feature-list { list-style: none !important; margin-left: 0 !important; }
.feature-list li {
    padding: .5rem 0 .5rem 1.5rem; position: relative;
}
.feature-list li::before {
    content: '✓'; position: absolute; left: 0; color: var(--c-success);
    font-weight: 700;
}

/* ── Spec Table ─────────────────────────────────────────────── */
.spec-table {
    width: 100%; border-collapse: collapse; margin: 1rem 0 2rem;
    font-size: .95rem;
}
.spec-table td, .spec-table th {
    padding: .75rem 1rem; border-bottom: 1px solid var(--c-border);
    text-align: left;
}
.spec-table td:first-child { font-weight: 600; width: 200px; color: var(--c-text); }
.spec-table th { background: var(--c-bg-alt); font-weight: 600; }
.spec-table tr:nth-child(even) { background: var(--c-bg-alt); }

/* ── CTA Section ────────────────────────────────────────────── */
.cta-section {
    background: var(--c-primary-light); padding: 2rem;
    border-radius: var(--radius); text-align: center; margin-top: 3rem;
}
.cta-section h3 { margin-top: 0; color: var(--c-primary-dark); }
.cta-section p { color: var(--c-text); margin-bottom: 1.25rem; }

/* ── Highlight Section ──────────────────────────────────────── */
.highlight-section { background: var(--c-bg-alt); }
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}
.feature-item { text-align: center; }
.feature-icon { font-size: 2.5rem; display: block; margin-bottom: .75rem; }
.feature-item h3 { margin: 0 0 .5rem; font-size: 1.15rem; }
.feature-item p { color: var(--c-text-light); font-size: .95rem; }

/* ── Buttons ────────────────────────────────────────────────── */
.btn {
    display: inline-block; padding: .75rem 1.75rem;
    border-radius: var(--radius); text-decoration: none;
    font-weight: 600; font-size: 1rem; transition: all .2s;
    cursor: pointer; border: 2px solid transparent;
}
.btn-primary {
    background: var(--c-primary); color: #fff;
}
.btn-primary:hover { background: var(--c-primary-dark); }
.btn-outline {
    border-color: var(--c-primary); color: var(--c-primary); background: transparent;
}
.btn-outline:hover { background: var(--c-primary); color: #fff; }
.hero .btn-outline { border-color: #fff; color: #fff; }
.hero .btn-outline:hover { background: #fff; color: var(--c-primary-dark); }

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

/* ── Contact Grid ───────────────────────────────────────────── */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 3rem;
    align-items: start;
}
.contact-info-card, .contact-form-card {
    background: #fff; padding: 2rem;
    border: 1px solid var(--c-border); border-radius: var(--radius);
}
.contact-info-card h2, .contact-form-card h2 { margin-top: 0; }
.info-item {
    display: flex; gap: .75rem; margin-bottom: 1.25rem; align-items: flex-start;
}
.info-icon { font-size: 1.25rem; flex-shrink: 0; margin-top: 2px; }
.info-item strong { display: block; margin-bottom: .15rem; }

/* ── Form ───────────────────────────────────────────────────── */
.form-group { margin-bottom: 1.25rem; }
.form-group label { display: block; font-weight: 600; margin-bottom: .35rem; }
.form-group input, .form-group textarea, .form-group select {
    width: 100%; padding: .65rem .85rem;
    border: 1px solid var(--c-border); border-radius: var(--radius);
    font-size: 1rem; font-family: inherit; transition: border-color .2s;
}
.form-group input:focus, .form-group textarea:focus {
    outline: none; border-color: var(--c-primary);
    box-shadow: 0 0 0 3px var(--c-primary-light);
}
.form-note { font-size: .85rem; color: var(--c-text-light); margin-top: .75rem; }

/* ── Footer ─────────────────────────────────────────────────── */
.site-footer {
    background: var(--c-bg-dark); color: #cbd5e1;
    padding: 3rem 0 1.5rem; margin-top: 3rem;
}
.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 2rem; margin-bottom: 2rem;
}
.footer-col h3 {
    color: #fff; font-size: 1.1rem; margin: 0 0 1rem;
}
.footer-col p, .footer-col li { font-size: .92rem; line-height: 1.6; }
.footer-col ul { list-style: none; }
.footer-col a { color: #94a3b8; text-decoration: none; transition: color .2s; }
.footer-col a:hover { color: #fff; }
.footer-bottom {
    border-top: 1px solid #334155; padding-top: 1.5rem;
    text-align: center; font-size: .85rem;
}

/* ── Responsive ──────────────────────────────────────────────── */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex; flex-direction: column; gap: 5px;
        background: none; border: none; cursor: pointer; padding: .5rem;
    }
    .nav-toggle span {
        display: block; width: 24px; height: 2px;
        background: var(--c-text); transition: all .3s;
    }
    .main-nav {
        display: none;
        position: absolute; top: 64px; left: 0; right: 0;
        background: #fff; border-bottom: 1px solid var(--c-border);
    }
    .main-nav.open { display: block; }
    .main-nav ul {
        flex-direction: column; padding: 1rem;
    }
    .main-nav a { display: block; padding: .75rem 1rem; }

    .hero { padding: 3rem 0; }
    .contact-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .product-grid { grid-template-columns: 1fr; }
    .feature-grid { grid-template-columns: 1fr; }
    .spec-table td:first-child { width: 130px; }
    .spec-table { font-size: .85rem; }
}

@media (max-width: 480px) {
    .hero h1 { font-size: 1.5rem; }
    .content-section h1 { font-size: 1.6rem; }
    .hero-cta { flex-direction: column; align-items: center; }
}

/* ── Product Gallery ────────────────────────────────────────── */
.product-gallery {
    background: #f8fafc;
    padding: 2rem 0;
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 1rem;
}

.gallery-item {
    margin: 0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,.1);
    transition: box-shadow .2s, transform .2s;
    background: #fff;
    aspect-ratio: 4 / 3;
}

.gallery-item:hover {
    box-shadow: 0 4px 16px rgba(0,0,0,.18);
    transform: translateY(-2px);
}

.gallery-item a {
    display: block;
    width: 100%;
    height: 100%;
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

@media (max-width: 600px) {
    .gallery-grid { grid-template-columns: 1fr; }
}

/* ── Top Product Gallery (above the fold) ─────────────────────── */
.top-gallery {
    padding: 1.5rem 0 0;
    background: transparent;
}
.top-gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
}
.top-gallery-item {
    margin: 0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,.1);
    background: #fff;
    aspect-ratio: 4 / 3;
    transition: box-shadow .2s, transform .2s;
}
.top-gallery-item:hover {
    box-shadow: 0 4px 16px rgba(0,0,0,.18);
    transform: translateY(-2px);
}
.top-gallery-item a {
    display: block;
    width: 100%;
    height: 100%;
}
.top-gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
    background: #f8f9fa;
}
.top-gallery-single {
    max-width: 720px;
    margin: 0 auto;
}
.top-gallery-single .top-gallery-item {
    width: 100%;
    aspect-ratio: 4 / 3;
}
@media (max-width: 600px) {
    .top-gallery-grid { grid-template-columns: repeat(2, 1fr); }
}