/* ==========================================================================
   Stack.infiaite.com - Global Styles
   Self-contained. No external CSS framework.
   ========================================================================== */

/* ---------- CSS Variables ---------- */
:root {
    --sidebar-w: 280px;
    --sidebar-w-collapsed: 80px;
    --sidebar-bg: #2c2e2f;
    --sidebar-border: #313437;
    --sidebar-text: #979898;
    --sidebar-text-active: #ffffff;
    --page-bg: #f9f9f9;
    --card-bg: #ffffff;
    --card-border: #e4ecf3;
    --card-title: #2c2e2f;
    --card-desc: #979898;
    --text-primary: #2c2e2f;
    --text-secondary: #555555;
    --text-muted: #979898;
    --text-footer: #6b7280;
    --accent: #2563eb;
    --topbar-h: 75px;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
    margin: 0;
    font-family: "Arimo", "Helvetica Neue", Helvetica, Arial,
                 "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    font-size: 13px;
    line-height: 1.42857;
    color: var(--text-primary);
    background: var(--page-bg);
}
a { color: inherit; text-decoration: none; }
a:hover, a:focus { text-decoration: none; }
img { border: 0; vertical-align: middle; }
ul { list-style: none; padding: 0; margin: 0; }
h4 { margin: 9px 0; font-size: 17px; font-weight: 500; }

/* ---------- Layout ---------- */
.page {
    display: flex;
    min-height: 100vh;
}

/* ---------- Sidebar ---------- */
.sidebar {
    width: var(--sidebar-w);
    flex: 0 0 var(--sidebar-w);
    background: var(--sidebar-bg);
    position: relative;
    z-index: 2;
    transition: width 0.2s ease, flex-basis 0.2s ease;
}
.sidebar.collapsed {
    width: var(--sidebar-w-collapsed);
    flex-basis: var(--sidebar-w-collapsed);
}

.sidebar-inner {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: var(--sidebar-w);
    overflow-x: hidden;
    overflow-y: auto;
    transition: width 0.2s ease;
}
.sidebar.collapsed .sidebar-inner {
    width: var(--sidebar-w-collapsed);
}

/* Brand / Logo */
.brand {
    padding: 19px 45px;
    border-bottom: 1px solid var(--sidebar-border);
    position: relative;
}
.brand-logo { display: block; }
.brand-logo img { display: block; width: 100%; }
.brand-logo-collapsed { display: none; }
.brand-logo-collapsed img { display: block; width: 40px; }
.sidebar.collapsed .brand { padding: 18px 0; text-align: center; }
.sidebar.collapsed .brand-logo { display: none; }
.sidebar.collapsed .brand-logo-collapsed { display: inline-block; }

/* Nav */
.nav {
    padding: 20px 40px;
}
.nav-item { position: relative; }
.nav-link {
    display: block;
    padding: 13px 5px;
    color: var(--sidebar-text);
    border-bottom: 1px solid var(--sidebar-border);
    position: relative;
    transition: color 0.2s ease;
}
.nav-link i {
    display: inline-block;
    margin-right: 10px;
    font-size: 14px;
}
.nav-link .title {
    display: inline-block;
    padding-right: 10px;
}
.nav-link:hover { color: var(--sidebar-text-active); }
.nav-item.active > .nav-link { color: var(--sidebar-text-active); }

/* Collapsed nav */
.sidebar.collapsed .nav { padding: 20px 0; }
.sidebar.collapsed .nav-link {
    text-align: center;
    padding: 13px 0;
}
.sidebar.collapsed .nav-link i {
    margin-right: 0;
    font-size: 16px;
}
.sidebar.collapsed .nav-link .title { display: none; }

/* ---------- Main Content ---------- */
.main {
    flex: 1;
    min-width: 0;
    padding: 30px;
    padding-bottom: 0;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* ---------- Topbar ---------- */
.topbar {
    background: #fff;
    margin: -30px -30px 30px -30px;
    height: var(--topbar-h);
    flex: 0 0 var(--topbar-h);
    display: flex;
    align-items: stretch;
    position: relative;
    z-index: 3;
}
.topbar-list {
    display: flex;
    align-items: stretch;
    margin: 0;
    padding: 0;
}
.topbar-item {
    display: flex;
    align-items: stretch;
    position: relative;
}
.topbar-link {
    display: flex;
    align-items: center;
    padding: 0 20px;
    height: 100%;
    color: var(--text-muted);
    transition: color 0.2s ease;
    cursor: pointer;
}
.topbar-link:hover { color: #606161; }
.topbar-link svg { display: block; }

/* Language switcher */
.lang-switcher > .topbar-link img {
    display: inline-block;
    margin-right: 6px;
    position: relative;
    top: -1px;
}
.lang-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 200px;
    background: #fff;
    border: 1px solid #ddd;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.175);
    z-index: 1000;
}
.lang-switcher.open .lang-menu { display: block; }
.lang-menu a {
    display: flex;
    align-items: center;
    padding: 10px 20px;
    color: #777879;
    font-size: 13px;
}
.lang-menu a img { display: inline-block; margin-right: 6px; }
.lang-menu a:hover { background: #fbfbfb; }
.lang-menu li.active a {
    background: #f6f6f6;
    color: var(--text-primary);
}
.lang-menu li + li { border-top: 1px solid #eee; }

/* ---------- Section (category) ---------- */
.section {
    color: var(--text-secondary);
    margin: 9px 0;
    font-size: 17px;
    font-weight: 500;
    display: flex;
    align-items: center;
    scroll-margin-top: 20px;
}
.section i {
    margin-right: 7px;
    font-size: 14px;
    color: var(--text-secondary);
}

/* ---------- Cards grid ---------- */
.cards {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -15px;
}
.card-col {
    padding: 0 15px;
    width: 25%;
    min-width: 0;
}
@media (max-width: 991px) {
    .card-col { width: 33.3333%; }
}
@media (max-width: 767px) {
    .card-col { width: 50%; }
}
@media (max-width: 479px) {
    .card-col { width: 100%; }
}

/* ---------- Card (now an <a>) ---------- */
.card {
    display: block;
    height: 86px;
    padding: 0 30px;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 4px;
    margin: 20px 0 0 0;
    color: inherit;
    cursor: pointer;
    position: relative;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    overflow: hidden;
}
.card:hover,
.card:focus-visible {
    transform: translateY(-6px);
    box-shadow: 0 26px 40px -24px rgba(0, 36, 100, 0.3);
}
.card:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}
.card-icon {
    position: absolute;
    left: 30px;
    top: 50%;
    transform: translateY(-50%);
    width: 40px;
    height: 40px;
}
.card-icon img {
    display: block;
    width: 40px;
    height: 40px;
    border-radius: 50%;
}
.card-body {
    position: absolute;
    left: 80px;
    right: 30px;
    top: 50%;
    transform: translateY(-50%);
    min-width: 0;
}
.card-title {
    display: block;
    color: var(--card-title);
    font-weight: 700;
    margin-bottom: 5px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.card-title strong { font-weight: 700; }
.card-desc {
    margin: 0;
    color: var(--card-desc);
    font-size: 12px;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ---------- Footer ---------- */
.footer {
    margin: 20px -30px 0 -30px;
    padding: 12px 30px;
    background: #fff;
    border-top: 1px solid #e5e7eb;
    text-align: center;
    font-size: 12px;
    color: var(--text-footer);
    line-height: 1.5;
    flex-shrink: 0;
}
.footer strong { color: var(--accent); font-weight: 700; }
.footer a { color: var(--accent); }
.footer a:hover { text-decoration: underline; }

/* ---------- Tooltip ---------- */
.stack-tooltip {
    position: fixed;
    z-index: 2000;
    pointer-events: none;
    background: #000;
    color: #fff;
    font-size: 12px;
    padding: 3px 8px;
    border-radius: 0;
    max-width: 320px;
    word-break: break-all;
    white-space: normal;
    opacity: 0;
    transition: opacity 0.15s;
}
.stack-tooltip.visible { opacity: 0.9; }
.stack-tooltip::after {
    content: "";
    position: absolute;
    top: -5px;
    left: 50%;
    margin-left: -5px;
    border: 5px solid transparent;
    border-bottom-color: #000;
}
.stack-tooltip.above::after {
    top: 100%;
    border-bottom-color: transparent;
    border-top-color: #000;
}

/* ---------- Utility ---------- */
.text-gray { color: var(--text-secondary); }

/* ---------- Responsive: 移动端侧边栏默认折叠 ---------- */
@media (max-width: 767px) {
    /* 侧边栏强制折叠形态 */
    .sidebar {
        width: var(--sidebar-w-collapsed);
        flex-basis: var(--sidebar-w-collapsed);
    }
    .sidebar-inner {
        width: var(--sidebar-w-collapsed);
    }
    .brand {
        padding: 18px 0;
        text-align: center;
    }
    .brand-logo { display: none; }
    .brand-logo-collapsed { display: inline-block; }
    .nav { padding: 20px 0; }
    .nav-link {
        text-align: center;
        padding: 13px 0;
    }
    .nav-link i { margin-right: 0; font-size: 16px; }
    .nav-link .title { display: none; }

    /* 主内容与顶栏内边距 */
    .main { padding: 20px 15px 0; }
    .topbar { margin: -20px -15px 20px -15px; }
    .footer { margin: 20px -15px 0 -15px; padding: 12px 15px; }

    .card { padding: 0 20px; }
    .card-icon { left: 20px; }
    .card-body { left: 70px; right: 20px; }
}