.site-shell {
    width: min(var(--container-hero), calc(100% - 2rem));
    margin: 0 auto;
    padding: 1rem 0 var(--edu-space-3xl);
}

.site-shell--content {
    min-height: 100vh;
}

.site-header {
    position: sticky;
    top: 0.75rem;
    z-index: 30;
    margin-bottom: clamp(1.5rem, 4vw, 3rem);
}

.site-header-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--edu-space-lg);
    padding: 0.95rem 1.2rem;
    border: 1px solid var(--edu-border);
    border-radius: 1.3rem;
    background: var(--edu-header-surface);
    box-shadow: var(--edu-shadow-soft);
    backdrop-filter: blur(18px);
    transition:
        background-color var(--motion-base),
        border-color var(--motion-base),
        box-shadow var(--motion-base),
        transform var(--motion-base),
        padding var(--motion-base);
}

body.site-scrolled .site-header-bar {
    padding: 0.82rem 1.15rem;
    border-color: var(--edu-border);
    background: var(--surface-header-scrolled);
    box-shadow: var(--edu-shadow-soft);
    transform: translateY(-1px);
}

.site-brand {
    display: inline-flex;
    align-items: center;
    gap: 0.85rem;
    color: var(--edu-ink);
    text-decoration: none;
    min-width: 0;
}

.site-brand:hover,
.site-brand:focus-visible {
    color: var(--edu-ink);
    text-decoration: none;
}

.site-brand-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.55rem;
    height: 2.55rem;
    border-radius: 0.9rem;
    background: var(--edu-icon-surface);
    color: var(--edu-ink);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.35);
}

.site-brand-emoji {
    font-size: 1.38rem;
    line-height: 1;
    transform: translateY(0.02rem);
}

.site-brand-copy {
    display: grid;
    gap: 0.12rem;
    min-width: 0;
}

.site-brand-copy strong {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    font-weight: 600;
    line-height: 1.1;
    letter-spacing: -0.045em;
    color: var(--edu-ink);
    text-wrap: balance;
}

.site-brand:hover .site-brand-copy strong,
.site-brand:focus-visible .site-brand-copy strong {
    color: var(--edu-accent-strong);
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 1.35rem;
}

.site-nav a {
    color: var(--edu-ink-soft);
    font-size: 0.88rem;
    font-weight: 600;
    letter-spacing: 0.01em;
    text-decoration: none;
}

.site-nav a:hover,
.site-nav a:focus-visible {
    color: var(--edu-secondary);
    text-decoration: none;
}

.site-header-actions {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    flex-shrink: 0;
}

.nav-login {
    color: var(--edu-ink-soft);
    font-size: 0.88rem;
    font-weight: 600;
    letter-spacing: 0.01em;
    text-decoration: none;
    white-space: nowrap;
    transition: color var(--motion-fast);
}

.nav-login:hover,
.nav-login:focus-visible {
    color: var(--edu-ink);
    text-decoration: none;
}

.menu-toggle {
    display: none;
    align-items: center;
    gap: 0.75rem;
    min-height: 44px;
    margin: 0;
    padding: 0.7rem 0.95rem;
    border: 1px solid var(--edu-border);
    border-radius: var(--radius-pill);
    background: var(--edu-surface-strong);
    color: var(--edu-ink);
    font-size: 0.92rem;
    font-weight: 600;
    box-shadow: none;
}

.menu-toggle-lines {
    display: grid;
    gap: 0.22rem;
}

.menu-toggle-lines span {
    display: block;
    width: 1rem;
    height: 2px;
    border-radius: var(--radius-pill);
    background: currentColor;
}

.mobile-nav {
    position: fixed;
    inset: 0;
    z-index: 40;
}

.mobile-nav-backdrop {
    position: absolute;
    inset: 0;
    border: 0;
    background: rgba(11, 19, 32, 0.36);
}

.mobile-nav-panel {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    width: min(24rem, calc(100% - 1.5rem));
    padding: 1rem;
    border: 1px solid var(--edu-border);
    border-radius: 1.25rem;
    background: var(--edu-surface-strong);
    box-shadow: var(--edu-shadow);
    backdrop-filter: blur(18px);
}

.mobile-nav-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--edu-border);
}

.mobile-nav-close {
    min-height: 44px;
    margin: 0;
    padding: 0.55rem 0.9rem;
    border: 1px solid var(--edu-border);
    border-radius: var(--radius-pill);
    background: var(--edu-surface);
    color: var(--edu-ink);
    font-size: 0.88rem;
    font-weight: 600;
    box-shadow: none;
}

.mobile-nav-links {
    display: grid;
    gap: 0.45rem;
    padding-top: 1rem;
}

.mobile-nav-links a {
    display: block;
    padding: 0.7rem 0;
    color: var(--edu-ink);
    font-weight: 600;
    text-decoration: none;
}

.site-footer {
    width: min(var(--container-page), calc(100% - 2.4rem));
    margin: 0 auto;
    margin-top: var(--edu-space-2xl);
    padding-top: 1.4rem;
    border-top: 1px solid var(--edu-divider);
    display: grid;
    grid-template-columns: minmax(0, 1.3fr) auto;
    align-items: start;
    gap: 1rem 2rem;
}

.footer-copy {
    display: grid;
    gap: 0.35rem;
    max-width: 32rem;
}

.footer-brand {
    margin: 0;
    color: var(--edu-ink);
    font-size: 0.95rem;
    font-weight: 700;
}

.footer-blurb {
    margin: 0;
    color: var(--edu-ink-soft);
    font-size: 0.89rem;
    line-height: 1.5;
}

.footer-note {
    margin: 0.1rem 0 0;
    color: var(--edu-ink-soft);
    font-size: 0.8rem;
    line-height: 1.4;
}

.footer-nav {
    display: grid;
    grid-template-columns: repeat(2, max-content);
    gap: 0.5rem 1.4rem;
}

.footer-nav a {
    color: var(--edu-ink);
    font-size: 0.88rem;
    font-weight: 500;
    opacity: 0.78;
    text-decoration: none;
}

.footer-nav a:hover,
.footer-nav a:focus-visible {
    color: var(--edu-ink);
    opacity: 1;
    text-decoration: underline;
}

@media (max-width: 900px) {
    .site-shell {
        width: min(100%, calc(100% - 1rem));
        padding-top: 0.7rem;
    }

    .site-header {
        top: 0.45rem;
        margin-bottom: 1.25rem;
    }

    .site-nav {
        display: none;
    }

    .menu-toggle {
        display: inline-flex;
    }

    .site-footer {
        grid-template-columns: 1fr;
        gap: 0.9rem;
    }
}

@media (max-width: 720px) {
    .site-shell {
        padding-top: 0.9rem;
        padding-bottom: var(--edu-space-2xl);
    }

    .site-header {
        top: 0.35rem;
        margin-bottom: 1rem;
    }

    .site-header-bar {
        gap: 0.75rem;
        padding: 0.8rem 0.9rem;
    }

    .site-footer {
        width: min(calc(100% - 1.4rem), 36rem);
    }

    .footer-nav {
        width: 100%;
        grid-template-columns: 1fr;
        gap: 0.45rem;
    }

    .mobile-nav-panel {
        right: 0.5rem;
        left: 0.5rem;
        width: auto;
    }
}