/* ============================================================
   layout.css — page-level structural primitives.
   Floating navbar, scroll-snap sections, grids, footer.
   ============================================================ */

/* ---------- Floating top navbar ---------- */
.navbar {
    position: fixed;
    top: var(--space-4);
    left: 50%;
    transform: translateX(-50%);
    z-index: var(--z-nav);
    width: calc(100% - var(--space-6) * 2);
    max-width: var(--container-max);
    height: var(--nav-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--space-5);
    background: var(--surface);
    backdrop-filter: blur(18px) saturate(160%);
    -webkit-backdrop-filter: blur(18px) saturate(160%);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: transform var(--dur) var(--ease-out),
                background var(--dur) var(--ease-out),
                box-shadow var(--dur) var(--ease-out);
}
.navbar.is-hidden { transform: translateX(-50%) translateY(-130%); }
.navbar__left { display: flex; align-items: center; gap: var(--space-3); }
.navbar__right { display: flex; align-items: center; gap: var(--space-2); }

.brand {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    color: var(--text);
    line-height: 0;
}
.brand:hover { color: var(--text); }
.brand__logo {
    height: 30px;
    width: auto;
    display: block;
    object-fit: contain;
    opacity: 0.95;
    transition: opacity var(--dur-fast) var(--ease-out), transform var(--dur-fast) var(--ease-out);
}
.brand:hover .brand__logo { opacity: 1; transform: translateY(-1px); }
.brand__logo--sm { height: 24px; }

.theme-toggle {
    position: relative;
    width: 2.6em;
    height: 2.6em;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: color var(--dur-fast), background var(--dur-fast), transform var(--dur-fast);
}
.theme-toggle:hover { color: var(--accent); background: var(--surface-hover); transform: rotate(15deg); }
.theme-toggle svg { width: 1.2em; height: 1.2em; }
.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: block; }
[data-theme="light"] .theme-toggle .icon-sun { display: block; }
[data-theme="light"] .theme-toggle .icon-moon { display: none; }

/* Avatar button that opens the dropdown */
.avatar-btn {
    background: transparent;
    border: none;
    padding: 0;
    cursor: pointer;
    border-radius: var(--radius-full);
    line-height: 0;
    transition: transform var(--dur-fast) var(--ease-out), box-shadow var(--dur-fast);
}
.avatar-btn:hover { transform: scale(1.05); box-shadow: 0 0 0 3px var(--accent-soft); }

/* Auth-gated navbar groups. auth.js toggles `body.is-authed`.
   Default (logged out): show Start CTA, hide avatar/dashboard. */
.nav-logged-out { display: inline-flex; align-items: center; }
.nav-logged-in { display: none; }
body.is-authed .nav-logged-out { display: none; }
body.is-authed .nav-logged-in { display: inline-flex; align-items: center; }

/* ---------- Scroll-snap page (landing) ---------- */
.snap-page {
    height: 100vh;
    overflow-y: scroll;
    scroll-snap-type: y mandatory;
    scroll-behavior: smooth;
    scrollbar-width: none;
}
.snap-page::-webkit-scrollbar { display: none; }

.snap-section {
    min-height: 100vh;
    scroll-snap-align: start;
    scroll-snap-stop: always;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: calc(var(--nav-height) + var(--space-6)) var(--space-5) var(--space-6);
    position: relative;
}
.snap-section__inner {
    width: 100%;
    max-width: var(--container-max);
    margin-inline: auto;
}

/* Section eyebrow label */
.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: var(--space-3);
}
.eyebrow::before {
    content: '';
    width: 1.5rem;
    height: 1px;
    background: var(--accent);
}

.section-title {
    font-size: var(--text-3xl);
    margin-bottom: var(--space-3);
}
.section-lead {
    max-width: 56ch;
    color: var(--text-muted);
    font-size: var(--text-lg);
    margin-bottom: var(--space-6);
}

/* ---------- Grids ---------- */
.grid { display: grid; gap: var(--space-5); }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 900px) {
    .grid--3, .grid--4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
    .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
}

/* ---------- Footer ---------- */
.site-footer {
    border-top: 1px solid var(--border);
    padding: var(--space-7) var(--space-5);
    background: var(--bg-sunken);
}
.site-footer__inner {
    max-width: var(--container-max);
    margin-inline: auto;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-5);
    color: var(--text-muted);
    font-size: var(--text-sm);
}
.site-footer__links { display: flex; gap: var(--space-5); flex-wrap: wrap; }
.site-footer__links a { color: var(--text-muted); }
.site-footer__links a:hover { color: var(--accent); }

/* ---------- Account shell (profile/subscription/security) ---------- */
.account-shell {
    max-width: 880px;
    margin-inline: auto;
    padding: calc(var(--nav-height) + var(--space-7)) var(--space-5) var(--space-8);
}
.account-shell h1 { font-size: var(--text-3xl); margin-bottom: var(--space-2); }
.account-head {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    margin-bottom: var(--space-6);
}
.account-tabs {
    display: flex;
    gap: var(--space-2);
    margin-bottom: var(--space-6);
    border-bottom: 1px solid var(--border);
}
.account-tabs a {
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--text-muted);
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
    transition: color var(--dur-fast), border-color var(--dur-fast);
}
.account-tabs a:hover { color: var(--text); }
.account-tabs a.is-active { color: var(--accent); border-bottom-color: var(--accent); }