/*
 * layout.css
 * Structural layout: sidebar nav, main wrapper, section shell, reveal
 * utilities, and footer. These are the "skeleton" concerns — not
 * section-specific content.
 * Depends on: tokens.css
 */

/* ─── SIDEBAR NAV ─────────────────────────────────────────────────────────── */

.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 72px;
    height: 100vh;
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 32px;
    z-index: 100;
    background: var(--bg);
}

.sidebar-logo {
    position: absolute;
    top: 32px;
    font-family: var(--display);
    font-weight: 300;
    font-size: 1.1rem;
    color: var(--ink2);
    letter-spacing: 0.05em;
    writing-mode: vertical-rl;
    text-orientation: mixed;
    text-decoration: none;
    transition: color 0.2s;
}
.sidebar-logo:hover {
    color: var(--ink);
}

.sidebar-links {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 28px;
}

.sidebar-link {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-family: var(--mono);
    font-size: 0.6rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--ink2);
    text-decoration: none;
    transition: color 0.2s;
    padding: 4px;
}
.sidebar-link:hover {
    color: var(--ink);
}
.sidebar-link.active {
    color: var(--warm1);
}

.sidebar-bottom {
    position: absolute;
    bottom: 32px;
    width: 1px;
    height: 48px;
    background: var(--border);
}

/* ─── MAIN WRAPPER ─────────────────────────────────────────────────────────── */

.main {
    margin-left: 72px;
}

/* ─── SECTION SHELL ────────────────────────────────────────────────────────── */

section {
    border-bottom: 1px solid var(--border);
}

.section-inner {
    padding: 96px 64px;
}

.section-header {
    display: flex;
    align-items: baseline;
    gap: 20px;
    margin-bottom: 64px;
}

.section-num {
    font-family: var(--mono);
    font-size: 0.6rem;
    letter-spacing: 0.18em;
    color: var(--warm1);
    flex-shrink: 0;
}

.section-title {
    font-family: var(--display);
    font-weight: 300;
    font-size: clamp(32px, 4vw, 52px);
    line-height: 1.05;
    letter-spacing: -0.01em;
}
.section-title em {
    font-style: italic;
    color: var(--ink2);
}

.section-rule {
    flex: 1;
    height: 1px;
    background: var(--border);
}

/* ─── SCROLL REVEAL UTILITY ────────────────────────────────────────────────── */

.reveal {
    opacity: 0;
    transform: translateY(20px);
    transition:
        opacity 0.65s ease,
        transform 0.65s ease;
}
.reveal.in {
    opacity: 1;
    transform: translateY(0);
}
.reveal-d1 {
    transition-delay: 0.1s;
}
.reveal-d2 {
    transition-delay: 0.2s;
}
.reveal-d3 {
    transition-delay: 0.3s;
}

/* ─── FOOTER ────────────────────────────────────────────────────────────────── */

footer {
    padding: 32px 64px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

footer p {
    font-family: var(--mono);
    font-size: 0.58rem;
    letter-spacing: 0.12em;
    color: var(--ink3);
}

footer p span {
    color: var(--warm1);
}