/* =====================================================================
   OOPbuy Spreadsheet — Site Chrome (header / nav / footer) — v3.0
   header 收紧到 64px、nav-link 改方角胶囊、footer 信息密度提高
   ===================================================================== */

/* ---------------- Header ---------------- */
.site-header {
    position: fixed;
    inset: 0 0 auto 0;
    z-index: var(--z-header);
    background: var(--glass-bg);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    border-bottom: 1px solid var(--border);
    transition: background var(--dur-base) var(--ease-out),
                border-color var(--dur-base) var(--ease-out);
}

.nav-inner {
    height: var(--header-height);
    display: flex;
    align-items: center;
    gap: var(--space-5);
}

/* Logo */
.logo-link {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    color: var(--text-strong);
    font-weight: var(--fw-black);
    font-size: var(--fs-lg);
    letter-spacing: -0.02em;
    flex-shrink: 0;
}
.logo-link:hover { color: var(--text-strong); }
.logo-link .logo-accent { color: var(--accent); }
.logo-mark { width: 32px; height: 32px; border-radius: 8px; display: block; flex-shrink: 0; }
.nav-link { white-space: nowrap; }

/* Primary nav */
.nav-links {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 2px;
    margin: 0;
    padding: 0;
    flex: 1;
}
.nav-link {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
    padding: 8px 14px;
    color: var(--text-weak);
    font-size: var(--fs-sm);
    font-weight: var(--fw-medium);
    border-radius: var(--radius-sm);
    transition: background var(--dur-fast) var(--ease-out),
                color var(--dur-fast) var(--ease-out);
}
.nav-link:hover,
.nav-link.is-active {
    background: var(--surface-hover);
    color: var(--text-strong);
}

/* Dropdown */
.has-dropdown { position: relative; }
.dropdown-menu {
    position: absolute;
    top: calc(100% + 6px);
    left: 0;
    min-width: 220px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    padding: var(--space-2);
    list-style: none;
    margin: 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-4px);
    transition: opacity var(--dur-fast) var(--ease-out),
                transform var(--dur-fast) var(--ease-out),
                visibility var(--dur-fast) var(--ease-out);
    z-index: var(--z-dropdown);
}
.has-dropdown:hover > .dropdown-menu,
.has-dropdown:focus-within > .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.dropdown-menu li a {
    display: block;
    padding: 8px 12px;
    color: var(--text);
    font-size: var(--fs-sm);
    border-radius: var(--radius-xs);
}
.dropdown-menu li a:hover { background: var(--surface-hover); color: var(--accent); }
.dropdown-icon { width: 10px; height: 10px; opacity: 0.55; }

/* Actions (theme toggle + CTA) */
.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    margin-left: auto;
}
.nav-cta {
    padding: 8px 16px;
    border-radius: var(--radius-md);
    background: var(--accent);
    color: var(--accent-on);
    font-size: var(--fs-sm);
    font-weight: var(--fw-semibold);
    white-space: nowrap;
    transition: background var(--dur-fast) var(--ease-out);
}
.nav-cta:hover { background: var(--accent-hover); color: var(--accent-on); }

/* Theme toggle button */
.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    color: var(--text-weak);
    background: transparent;
    border: 1px solid var(--border);
    transition: all var(--dur-fast) var(--ease-out);
}
.theme-toggle:hover {
    background: var(--surface-hover);
    border-color: var(--border-strong);
    color: var(--text-strong);
}
.theme-toggle svg { width: 16px; height: 16px; }
.theme-toggle .icon-sun,
.theme-toggle .icon-moon,
.theme-toggle .icon-auto { display: none; }
.theme-toggle[data-mode="auto"] .icon-auto { display: block; }
.theme-toggle[data-mode="light"] .icon-sun { display: block; }
.theme-toggle[data-mode="dark"] .icon-moon { display: block; }

/* Mobile menu toggle */
.menu-toggle {
    display: none;
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    color: var(--text);
    background: transparent;
    border: 1px solid var(--border);
}
.menu-toggle:hover { background: var(--surface-hover); }
.menu-toggle svg { width: 18px; height: 18px; }

/* Top announcement bar */
.top-ad {
    position: relative;
    background: var(--text-strong);
    color: #fff;
    text-align: center;
    padding: 8px 48px;
    font-size: var(--fs-xs);
    font-weight: var(--fw-medium);
    letter-spacing: 0.02em;
}
.top-ad a { color: var(--accent-alt); text-decoration: underline; text-underline-offset: 2px; }
.top-ad a:hover { color: #fff; }
.top-ad .close-ad {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    width: 24px;
    height: 24px;
    border-radius: var(--radius-xs);
    background: rgba(255, 255, 255, 0.12);
    color: #fff;
    font-size: 16px;
    line-height: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}
.top-ad .close-ad:hover { background: rgba(255, 255, 255, 0.22); }

body.has-ad { padding-top: calc(var(--header-height) + 32px); }
body.has-ad .site-header { top: 32px; }

/* ---------------- Mobile nav ---------------- */
@media (max-width: 960px) {
    .menu-toggle { display: inline-flex; }
    .nav-links {
        position: fixed;
        inset: calc(var(--header-height) + 1px) 0 0 0;
        background: var(--bg);
        flex-direction: column;
        align-items: stretch;
        padding: var(--space-4);
        gap: var(--space-1);
        overflow-y: auto;
        transform: translateX(100%);
        transition: transform var(--dur-base) var(--ease-out);
        z-index: var(--z-dropdown);
        border-top: 1px solid var(--border);
    }
    body.nav-open .nav-links { transform: translateX(0); }
    body.nav-open { overflow: hidden; }

    .nav-link {
        justify-content: space-between;
        padding: 12px 14px;
        border-radius: var(--radius-md);
        font-size: var(--fs-base);
    }
    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        border: 0;
        background: transparent;
        padding: 0 0 0 var(--space-4);
        display: none;
    }
    .has-dropdown.is-open > .dropdown-menu { display: block; }
    .nav-actions { margin-left: auto; }
    .nav-cta { display: none; }
}

@media (max-width: 480px) {
    .nav-inner { gap: var(--space-3); padding-inline: var(--space-4); }
    .logo-link { font-size: var(--fs-base); }
}

/* ---------------- Footer ---------------- */
.site-footer {
    margin-top: var(--space-16);
    padding: var(--space-12) 0 var(--space-6);
    background: var(--bg-soft);
    border-top: 1px solid var(--border);
    color: var(--text-weak);
    font-size: var(--fs-sm);
}
.footer-grid {
    display: grid;
    grid-template-columns: 1.4fr repeat(3, 1fr);
    gap: var(--space-8);
    margin-bottom: var(--space-8);
}
.footer-brand h3 {
    color: var(--text-strong);
    font-size: var(--fs-lg);
    margin-bottom: var(--space-2);
}
.footer-brand p { max-width: 320px; line-height: 1.6; }
.footer-col h4 {
    color: var(--text-strong);
    font-size: var(--fs-xs);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-3);
    font-weight: var(--fw-semibold);
}
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin-bottom: 6px; }
.footer-col a { color: var(--text-weak); font-size: var(--fs-sm); }
.footer-col a:hover { color: var(--accent); }

.footer-social {
    display: flex;
    gap: var(--space-2);
    margin-top: var(--space-3);
}
.footer-social a {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    background: var(--surface);
    border: 1px solid var(--border);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--text-weak);
    transition: all var(--dur-fast) var(--ease-out);
}
.footer-social a:hover {
    background: var(--text-strong);
    color: var(--bg);
    border-color: var(--text-strong);
}
.footer-social svg { width: 14px; height: 14px; }

.footer-bottom {
    padding-top: var(--space-5);
    border-top: 1px solid var(--divider);
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: var(--space-4);
    color: var(--text-muted);
    font-size: var(--fs-xs);
}
.footer-bottom nav { display: flex; flex-wrap: wrap; gap: var(--space-4); }
.footer-bottom a { color: var(--text-muted); }
.footer-bottom a:hover { color: var(--accent); }

@media (max-width: 768px) {
    .footer-grid { grid-template-columns: 1fr 1fr; gap: var(--space-6); }
    .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 480px) {
    .footer-grid { grid-template-columns: 1fr; }
    .footer-bottom { flex-direction: column; align-items: flex-start; }
}

/* ---------------- Footer 5-column variant ---------------- */
.footer-grid-5 {
    display: grid;
    grid-template-columns: 0.8fr 0.8fr 0.8fr 0.8fr 1.4fr;
    gap: var(--space-8);
    margin-bottom: var(--space-8);
}
@media (max-width: 960px) {
    .footer-grid-5 { grid-template-columns: 1fr 1fr 1fr; gap: var(--space-6); }
    .footer-disclaimer { grid-column: 1 / -1; }
}
@media (max-width: 560px) {
    .footer-grid-5 { grid-template-columns: 1fr 1fr; }
    .footer-disclaimer { grid-column: 1 / -1; }
}
.footer-grid-6 {
    display: grid;
    grid-template-columns: 0.8fr 0.8fr 0.8fr 0.8fr 0.8fr 1.4fr;
    gap: var(--space-8);
    margin-bottom: var(--space-8);
}
@media (max-width: 960px) {
    .footer-grid-6 { grid-template-columns: 1fr 1fr 1fr; gap: var(--space-6); }
    .footer-grid-6 .footer-disclaimer { grid-column: 1 / -1; }
}
@media (max-width: 560px) {
    .footer-grid-6 { grid-template-columns: 1fr 1fr; }
    .footer-grid-6 .footer-disclaimer { grid-column: 1 / -1; }
}
.footer-community { margin-top: var(--space-4); }
.footer-community a { display: inline-block; }

.footer-disclaimer p {
    color: var(--text-weak);
    font-size: var(--fs-sm);
    line-height: 1.55;
    margin: 0 0 var(--space-3);
    max-width: 280px;
}