/* ============================================================
   layout.css — Nav, footer, containers, section structure
   ============================================================ */

/* ---------- Skip link ---------- */
.skip-link {
    position: absolute;
    top: -40px;
    left: 8px;
    background: var(--color-accent);
    color: var(--color-bg);
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    z-index: 1000;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 8px;
}

/* ---------- Navigation ---------- */
.site-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(25, 25, 25, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    height: var(--nav-height);
    display: flex;
    align-items: center;
}

.nav-container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-brand {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: -0.02em;
}

.nav-brand .accent {
    color: var(--color-accent);
}

.nav-links {
    display: flex;
    gap: var(--space-md);
    align-items: center;
}

.nav-links a {
    color: var(--color-text-muted);
    font-size: 1.5rem;
    font-weight: 500;
    padding: 6px 4px;
    position: relative;
    transition: color var(--transition-fast);
}

.nav-links a::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width var(--transition-base);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-text);
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

/* Mobile nav toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
    border-radius: var(--radius-sm);
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: transform var(--transition-base), opacity var(--transition-fast);
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ---------- Main / Sections ---------- */
main {
    display: block;
    flex: 1 0 auto;
}

.section {
    width: 100%;
    padding: var(--space-2xl) var(--space-md);
}

.section--tight {
    padding: var(--space-xl) var(--space-md);
}

.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
}

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

.section-header h2 {
    margin-bottom: var(--space-sm);
}

.section-header p {
    color: var(--color-text-dim);
    max-width: 60ch;
    margin: 0 auto;
}

.eyebrow {
    display: inline-block;
    color: var(--color-accent);
    font-size: 1.3rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    margin-bottom: var(--space-xs);
}

/* ---------- Footer ---------- */
.site-footer {
    background: var(--color-bg-elevated);
    border-top: 1px solid var(--color-border);
    padding: var(--space-lg) var(--space-md);
}

.footer-container {
    max-width: var(--container-max);
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
    align-items: center;
    justify-content: space-between;
}

.footer-container p {
    color: var(--color-text-dim);
    font-size: 1.4rem;
}

.footer-container a {
    color: var(--color-text-muted);
    font-size: 1.4rem;
}

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

/* ---------- Particles background wrapper ---------- */
.particles-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.particles-bg canvas {
    display: block;
}