/* ==========================================================
   Layout — Container, Header, Footer, Grid
   ========================================================== */

/* ── Container ──────────────────────────────────────── */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-6);
}

/* ── Main Content ───────────────────────────────────── */
main {
    padding-top: 5rem;
    /* offset for fixed header */
}

/* ── Header ─────────────────────────────────────────── */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--color-header-bg);
    border-bottom: none;
    transition: background-color var(--transition-slow), border-color var(--transition-slow);
}

@supports (backdrop-filter: blur(12px)) {
    .site-header {
        background: var(--color-header-blur);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
    }
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.header-left {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    font-weight: var(--font-weight-bold);
    font-size: 1.125rem;
    color: var(--color-text-primary);
    text-decoration: none;
}

.logo-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2rem;
    height: 2rem;
    background: var(--color-text-primary);
    color: var(--color-background);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-small);
    font-weight: var(--font-weight-bold);
    letter-spacing: 0.02em;
}

.header-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
}

/* ── Navigation ─────────────────────────────────────── */
.main-nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-1);
}

.main-nav a {
    padding: var(--spacing-2) var(--spacing-3);
    font-size: var(--font-size-caption);
    font-weight: var(--font-weight-medium);
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    transition: color var(--transition-base), background-color var(--transition-base);
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--color-text-primary);
    background-color: var(--color-surface);
}

/* Mobile Nav Toggle */
.nav-toggle {
    display: none;
    background: none;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-2);
    cursor: pointer;
    color: var(--color-text-primary);
}

/* ── Section ────────────────────────────────────────── */
.section {
    padding: var(--spacing-24) 0;
}

.section:first-child {
    padding-top: var(--spacing-16);
}

/* ── Card Grid ──────────────────────────────────────── */
.card-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-6);
}

/* ── Footer ─────────────────────────────────────────── */
.site-footer {
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-16) 0;
    margin-top: var(--spacing-24);
    transition: border-color var(--transition-slow);
}

.footer-inner {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-8);
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
}

.footer-brand p {
    font-size: var(--font-size-caption);
    color: var(--color-text-muted);
    max-width: 30ch;
}

.footer-links h4 {
    font-size: var(--font-size-caption);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-4);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2);
}

.footer-links a {
    font-size: var(--font-size-caption);
    color: var(--color-text-muted);
    transition: color var(--transition-base);
}

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

.footer-social {
    display: flex;
    gap: var(--spacing-4);
}

.footer-social a {
    color: var(--color-text-muted);
    transition: color var(--transition-base);
}

.footer-social a:hover {
    color: var(--color-text-primary);
}

.footer-bottom {
    margin-top: var(--spacing-8);
    padding-top: var(--spacing-8);
    border-top: 1px solid var(--color-border);
}

.footer-bottom p {
    font-size: var(--font-size-small);
    color: var(--color-text-muted);
}

/* ==========================================================
   Responsive — Tablet
   ========================================================== */
@media (min-width: 768px) {
    .card-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-inner {
        grid-template-columns: 2fr 1fr 1fr;
    }
}

/* ==========================================================
   Responsive — Desktop
   ========================================================== */
@media (min-width: 1024px) {
    .card-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* ==========================================================
   Responsive — Mobile
   ========================================================== */
@media (max-width: 767px) {
    .main-nav {
        display: none;
        position: absolute;
        top: 4rem;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--color-background);
        border-bottom: 1px solid var(--color-border);
        padding: var(--spacing-4);
        gap: var(--spacing-1);
    }

    .main-nav.open {
        display: flex;
    }

    .main-nav a {
        width: 100%;
        padding: var(--spacing-3) var(--spacing-4);
    }

    .nav-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .container {
        padding: 0 var(--spacing-4);
    }
}