/* Shared public navigation. Keep these selectors independent of page styles. */
:root {
    --public-header-height: 80px;
    --public-page-gutter: 30px;
}
html { scroll-padding-top: calc(var(--public-header-height) + 20px); scrollbar-gutter: stable; }
.public-overview-link { display: inline-flex; align-items: center; min-height: 44px; margin-top: 14px; color: #2456a5; font-size: 17px; font-weight: 500; text-underline-offset: 4px; }
body.public-course-detail { padding-top: var(--public-header-height); }
.public-site-header {
    position: fixed;
    inset: 0 0 auto;
    z-index: 1000;
    height: var(--public-header-height);
    padding: 0;
    background: rgba(255, 255, 255, .98);
    box-shadow: 0 4px 30px rgba(0, 0, 0, .1);
    backdrop-filter: blur(20px);
    font-family: 'Fredoka', sans-serif;
    box-sizing: border-box;
}
.public-site-header *, .public-site-header *::before, .public-site-header *::after { box-sizing: border-box; }
.public-site-header .public-nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    width: 100%;
    max-width: 1400px;
    height: var(--public-header-height);
    margin: 0 auto;
    padding: 0 var(--public-page-gutter);
}
.public-site-header .public-brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
    color: #3b82f6;
    background: linear-gradient(135deg, #3b82f6, #60a5fa);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    font-size: 28px;
    font-weight: 700;
    line-height: 1;
    white-space: nowrap;
    text-decoration: none;
}
.public-site-header .public-brand img {
    width: 50px;
    height: 50px;
    padding: 2px;
    object-fit: contain;
    background: white;
    border-radius: 50%;
    box-shadow: 0 4px 15px rgba(0, 0, 0, .1);
}
.public-site-header .public-nav-links {
    display: flex;
    align-items: center;
    gap: 35px;
    position: static;
    width: auto;
    height: auto;
    margin: 0;
    padding: 0;
    list-style: none;
}
.public-site-header .public-nav-links li { margin: 0; padding: 0; }
.public-site-header .public-nav-links a {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
    padding: 8px 0;
    color: #2d3748;
    font-size: 16px;
    font-weight: 600;
    line-height: 1.4;
    white-space: nowrap;
    text-decoration: none;
    border-bottom: 3px solid transparent;
    transition: color .3s ease, border-color .3s ease;
}
.public-site-header .public-nav-links a:hover,
.public-site-header .public-nav-links a[aria-current] { border-bottom-color: #ff6b6b; }
.public-site-header .public-nav-links a.public-portal-link {
    justify-content: center;
    padding: 12px 30px;
    color: #2d3748;
    background: linear-gradient(135deg, #ff6b6b, #ff8e53);
    border: 0;
    border-radius: 25px;
    box-shadow: 0 5px 20px rgba(255, 107, 107, .4);
    transition: transform .3s ease, box-shadow .3s ease;
}
.public-site-header .public-nav-links a.public-portal-link:hover { transform: translateY(-3px); box-shadow: 0 8px 30px rgba(255, 107, 107, .6); }
.public-site-header .public-nav-toggle {
    display: none;
    flex: 0 0 44px;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 5px;
    width: 44px;
    height: 44px;
    margin: 0;
    padding: 8px;
    background: none;
    border: 0;
    border-radius: 10px;
    cursor: pointer;
}
.public-site-header .public-nav-toggle span {
    display: block;
    width: 26px;
    height: 3px;
    border-radius: 2px;
    background: #2d3748;
    transition: transform .18s ease, opacity .18s ease;
}
.public-site-header .public-nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.public-site-header .public-nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.public-site-header .public-nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }
.public-site-header a:focus-visible, .public-site-header button:focus-visible {
    outline: 3px solid #2563eb;
    outline-offset: 4px;
    border-radius: 6px;
}
.public-nav-skip {
    position: fixed;
    top: 8px;
    left: var(--public-page-gutter);
    z-index: 1002;
    padding: 12px 18px;
    background: white;
    color: #1d4ed8;
    border: 2px solid #1d4ed8;
    border-radius: 8px;
    transform: translateY(-160%);
}
.public-nav-skip:focus { transform: translateY(0); }
@media (max-width: 1100px) {
    .public-site-header .public-nav { gap: 20px; }
    .public-site-header .public-nav-links { gap: 18px; }
    .public-site-header .public-nav-links a { font-size: 15px; }
    .public-site-header .public-nav-links a.public-portal-link { padding-inline: 18px; }
}
@media (max-width: 968px) {
    :root { --public-page-gutter: 20px; }
    .public-nav-ready .public-nav-toggle:not([hidden]) { display: flex; }
    .public-nav-ready .public-nav-links {
        position: fixed;
        inset: var(--public-header-height) 0 auto;
        width: 100%;
        height: calc(100vh - var(--public-header-height));
        height: calc(100dvh - var(--public-header-height));
        padding: 40px max(40px, var(--public-page-gutter)) max(40px, env(safe-area-inset-bottom));
        align-items: center;
        justify-content: flex-start;
        flex-direction: column;
        gap: 35px;
        overflow-y: auto;
        overscroll-behavior: contain;
        background: white;
        visibility: hidden;
        opacity: 0;
        pointer-events: none;
        transition: opacity .18s ease;
    }
    .public-nav-ready .public-nav-links.is-open { visibility: visible; opacity: 1; pointer-events: auto; }
    .public-site-header .public-nav-links a { display: flex; min-height: 44px; padding: 12px 0; font-size: 18px; }
    .public-site-header .public-nav-links a.public-portal-link { width: 217px; max-width: 100%; margin-top: 20px; min-height: 52px; padding: 18px 30px; border-radius: 30px; font-size: 20px; }
    /* Links remain usable if JavaScript is disabled. */
    .public-site-header:not(.public-nav-ready) { position: relative; height: auto; }
    .public-site-header:not(.public-nav-ready) .public-nav { height: auto; flex-wrap: wrap; padding-block: 15px; }
    .public-site-header:not(.public-nav-ready) .public-nav-links { flex-wrap: wrap; gap: 4px; }
}
@media (max-width: 480px) {
    .public-site-header .public-brand { gap: 9px; font-size: 23px; }
    .public-site-header .public-brand img { width: 46px; height: 46px; }
}
@media (prefers-reduced-motion: reduce) {
    .public-site-header *, .public-nav-skip { transition: none; }
}