/* ============================================================
   习思全日制学习中心 · qrz.xisi.chat
   共享样式（移动端优先，全站自适应）
   ============================================================ */
:root {
    --brand: #2E7FA8;
    --brand-dark: #1F5C7D;
    --brand-darker: #17455E;
    --brand-light: #EAF4F9;
    --accent: #E8912D;
    --accent-soft: #FDF3E5;
    --ink: #1C2B36;
    --ink-2: #3D5261;
    --muted: #6B7F8D;
    --line: #DCE7EE;
    --bg: #F6FAFC;
    --card: #FFFFFF;
    --red: #C0453E;
    --radius: 14px;
    --shadow: 0 6px 24px rgba(31, 92, 125, .08);
    --shadow-lg: 0 12px 40px rgba(31, 92, 125, .14);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
    font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
    color: var(--ink);
    background: var(--bg);
    line-height: 1.75;
    font-size: 16px;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }

.container {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ---------- 顶部导航 ---------- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, .96);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--line);
}

.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    height: 64px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 18px;
    color: var(--brand-dark);
    white-space: nowrap;
}

.brand img {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: var(--brand);
}

.brand small {
    display: block;
    font-size: 11px;
    font-weight: 400;
    color: var(--muted);
    letter-spacing: 1px;
    line-height: 1.2;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 6px;
}

.nav-menu > li > a {
    display: block;
    padding: 8px 16px;
    border-radius: 999px;
    font-size: 15px;
    color: var(--ink-2);
    transition: all .2s;
}

.nav-menu > li > a:hover { background: var(--brand-light); color: var(--brand-dark); }
.nav-menu > li > a.active { background: var(--brand); color: #fff; }

.nav-menu .nav-home {
    border: 1px solid var(--line);
    color: var(--muted);
    font-size: 14px;
}

.nav-toggle {
    display: none;
    border: 1px solid var(--line);
    background: #fff;
    border-radius: 10px;
    width: 42px;
    height: 42px;
    font-size: 20px;
    color: var(--brand-dark);
    cursor: pointer;
}

/* ---------- Highlight 横幅 ---------- */
.highlight-banner {
    background: linear-gradient(120deg, var(--brand-dark), var(--brand));
    color: #fff;
    padding: 14px 0;
    font-size: 14.5px;
    text-align: center;
    letter-spacing: .5px;
}

.highlight-banner strong { color: #FFE1B3; font-weight: 600; }

/* ---------- Hero ---------- */
.hero {
    background:
        radial-gradient(600px 300px at 85% -10%, rgba(46, 127, 168, .14), transparent),
        radial-gradient(500px 260px at 5% 110%, rgba(232, 145, 45, .10), transparent),
        #fff;
    padding: 72px 0 64px;
    border-bottom: 1px solid var(--line);
}

.hero .badge {
    display: inline-block;
    background: var(--brand-light);
    color: var(--brand-dark);
    font-size: 13.5px;
    font-weight: 600;
    padding: 6px 14px;
    border-radius: 999px;
    margin-bottom: 18px;
    letter-spacing: 1px;
}

.hero h1 {
    font-size: 40px;
    line-height: 1.3;
    color: var(--brand-darker);
    margin-bottom: 16px;
    letter-spacing: 1px;
}

.hero h1 .em { color: var(--accent); }

.hero .subtitle {
    font-size: 17px;
    color: var(--ink-2);
    max-width: 760px;
}

/* ---------- 核心数据栏 ---------- */
.stats-strip {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-top: 40px;
}

.stat {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 22px 18px;
    text-align: center;
    box-shadow: var(--shadow);
}

.stat b {
    display: block;
    font-size: 24px;
    color: var(--brand);
    margin-bottom: 6px;
    line-height: 1.3;
}

.stat span { font-size: 13.5px; color: var(--muted); }

/* ---------- 通用 Section ---------- */
.section { padding: 72px 0; }
.section.alt { background: #fff; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }

.section-head { text-align: center; max-width: 720px; margin: 0 auto 44px; }

.section-head .label {
    font-size: 13px;
    letter-spacing: 3px;
    color: var(--accent);
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 10px;
}

.section-head h2 {
    font-size: 30px;
    color: var(--brand-darker);
    margin-bottom: 12px;
}

.section-head p { color: var(--muted); font-size: 15.5px; }

/* ---------- 卡片网格 ---------- */
.grid { display: grid; gap: 20px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 26px 24px;
    box-shadow: var(--shadow);
    transition: transform .25s, box-shadow .25s;
}

.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }

.card .icon { font-size: 34px; margin-bottom: 12px; }
.card h3 { font-size: 18px; color: var(--brand-dark); margin-bottom: 8px; }
.card p { font-size: 14.5px; color: var(--ink-2); }

/* ---------- 产品线大卡 ---------- */
.product-card {
    position: relative;
    overflow: hidden;
    border-radius: 18px;
    padding: 36px 32px;
    color: #fff;
    box-shadow: var(--shadow-lg);
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.product-card.blue { background: linear-gradient(135deg, #2E7FA8, #1F5C7D); }
.product-card.red { background: linear-gradient(135deg, #C0453E, #8E2F2A); }

.product-card .pc-tag {
    display: inline-block;
    align-self: flex-start;
    background: rgba(255, 255, 255, .18);
    border: 1px solid rgba(255, 255, 255, .35);
    padding: 4px 12px;
    border-radius: 999px;
    font-size: 13px;
    letter-spacing: 1px;
}

.product-card h3 { font-size: 26px; }
.product-card p { font-size: 15px; opacity: .92; }

.product-card ul { display: grid; gap: 8px; margin-top: 6px; font-size: 14.5px; }
.product-card ul li::before { content: "✓ "; color: #FFD9A0; font-weight: 700; }

.product-card .pc-link {
    margin-top: auto;
    align-self: flex-start;
    background: #fff;
    color: var(--brand-dark);
    font-weight: 600;
    font-size: 14.5px;
    padding: 10px 22px;
    border-radius: 999px;
    transition: transform .2s;
}

.product-card.red .pc-link { color: var(--red); }
.product-card .pc-link:hover { transform: translateX(4px); }

/* ---------- 痛点 vs 方案 双栏 ---------- */
.vs-wrap {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.vs-col {
    border-radius: var(--radius);
    padding: 28px 24px;
    border: 1px solid var(--line);
}

.vs-col.pain { background: #FBF1F0; border-color: #EDD4D2; }
.vs-col.fix { background: var(--brand-light); border-color: #C9E0EC; }

.vs-col h3 {
    font-size: 18px;
    margin-bottom: 18px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.vs-col.pain h3 { color: var(--red); }
.vs-col.fix h3 { color: var(--brand-dark); }

.vs-item {
    background: #fff;
    border-radius: 10px;
    padding: 14px 16px;
    font-size: 14.5px;
    color: var(--ink-2);
    box-shadow: 0 2px 8px rgba(0, 0, 0, .04);
}

.vs-item + .vs-item { margin-top: 12px; }
.vs-item b { color: var(--ink); }

/* ---------- 课表 ---------- */
.schedule { display: grid; gap: 14px; }

.schedule-row {
    display: grid;
    grid-template-columns: 150px 1fr;
    gap: 18px;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 20px 24px;
    align-items: start;
}

.schedule-row .time {
    font-weight: 700;
    color: var(--brand-dark);
    font-size: 15.5px;
}

.schedule-row .time small {
    display: block;
    font-weight: 400;
    color: var(--accent);
    font-size: 13px;
    margin-top: 2px;
}

.schedule-row .desc { font-size: 14.5px; color: var(--ink-2); }
.schedule-row .desc b { color: var(--ink); }

/* ---------- 时间轴 ---------- */
.timeline { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }

.tl-item {
    position: relative;
    background: var(--card);
    border: 1px solid var(--line);
    border-top: 4px solid var(--brand);
    border-radius: var(--radius);
    padding: 24px 20px;
    box-shadow: var(--shadow);
}

.tl-item .phase {
    font-size: 13px;
    color: var(--accent);
    font-weight: 700;
    letter-spacing: 1px;
    margin-bottom: 6px;
}

.tl-item h3 { font-size: 17px; color: var(--brand-darker); margin-bottom: 8px; }
.tl-item p { font-size: 14px; color: var(--ink-2); }

/* ---------- 表格 ---------- */
.table-wrap {
    overflow-x: auto;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    background: #fff;
    -webkit-overflow-scrolling: touch;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14.5px;
    min-width: 640px;
}

thead th {
    background: var(--brand-dark);
    color: #fff;
    font-weight: 600;
    padding: 14px 16px;
    text-align: left;
    white-space: nowrap;
}

tbody td {
    padding: 13px 16px;
    border-top: 1px solid var(--line);
    color: var(--ink-2);
}

tbody tr:nth-child(even) { background: var(--bg); }
tbody td:first-child { font-weight: 600; color: var(--ink); white-space: nowrap; }

.table-note {
    font-size: 13px;
    color: var(--muted);
    margin-top: 10px;
    text-align: right;
}

/* ---------- 列表块 ---------- */
.tick-list { display: grid; gap: 12px; }

.tick-list li {
    background: var(--card);
    border: 1px solid var(--line);
    border-left: 4px solid var(--accent);
    border-radius: 10px;
    padding: 15px 18px;
    font-size: 14.5px;
    color: var(--ink-2);
}

.tick-list li b { color: var(--brand-dark); }

/* ---------- 本地适配 ---------- */
.local-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }

.local-item {
    display: flex;
    gap: 14px;
    background: linear-gradient(135deg, #fff, var(--brand-light));
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 20px;
}

.local-item .n {
    flex: none;
    width: 38px;
    height: 38px;
    border-radius: 10px;
    background: var(--brand);
    color: #fff;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
}

.local-item h3 { font-size: 15.5px; color: var(--brand-darker); margin-bottom: 4px; }
.local-item p { font-size: 14px; color: var(--ink-2); }

/* ---------- 纯内容声明 ---------- */
.declaration {
    background: var(--brand-darker);
    color: rgba(255, 255, 255, .85);
    text-align: center;
    padding: 34px 0;
    font-size: 14px;
}

.declaration b { color: #FFD9A0; }

/* ---------- 页脚 ---------- */
.site-footer {
    background: #122D3D;
    color: rgba(255, 255, 255, .72);
    padding: 44px 0 28px;
    font-size: 14px;
}

.footer-grid {
    display: flex;
    justify-content: space-between;
    gap: 32px;
    flex-wrap: wrap;
    margin-bottom: 28px;
}

.footer-brand { display: flex; align-items: center; gap: 10px; color: #fff; font-weight: 700; font-size: 17px; margin-bottom: 8px; }
.footer-brand img { width: 36px; height: 36px; border-radius: 8px; }

.footer-col h4 { color: #fff; font-size: 15px; margin-bottom: 12px; }
.footer-col a { display: block; padding: 3px 0; transition: color .2s; }
.footer-col a:hover { color: #FFD9A0; }

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, .12);
    padding-top: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    font-size: 13px;
}

.footer-beian { display: flex; gap: 16px; align-items: center; flex-wrap: wrap; }
.footer-beian a { color: rgba(255, 255, 255, .55); }
.footer-beian img { display: inline-block; width: 14px; height: 14px; vertical-align: -2px; margin-right: 4px; }

/* ---------- 返回顶部/页面内小字 ---------- */
.crumb {
    font-size: 13.5px;
    color: var(--muted);
    padding: 14px 0 0;
}

.crumb a { color: var(--brand); }

/* ============================================================
   移动端适配
   ============================================================ */
@media (max-width: 960px) {
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
    .timeline { grid-template-columns: repeat(2, 1fr); }
    .stats-strip { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 720px) {
    body { font-size: 15px; }

    /* 导航：汉堡菜单 */
    .nav-toggle { display: block; }

    .nav-menu {
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        display: none;
        flex-direction: column;
        align-items: stretch;
        background: #fff;
        border-bottom: 1px solid var(--line);
        box-shadow: 0 16px 30px rgba(31, 92, 125, .12);
        padding: 10px 16px 16px;
        gap: 4px;
    }

    .nav-menu.mobile-open { display: flex; }

    .nav-menu > li > a {
        padding: 12px 14px;
        border-radius: 10px;
        font-size: 16px;
    }

    .hero { padding: 48px 0 44px; }
    .hero h1 { font-size: 27px; }
    .hero .subtitle { font-size: 15.5px; }

    .section { padding: 52px 0; }
    .section-head h2 { font-size: 24px; }

    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .vs-wrap { grid-template-columns: 1fr; }
    .local-grid { grid-template-columns: 1fr; }
    .timeline { grid-template-columns: 1fr; }

    .schedule-row { grid-template-columns: 1fr; gap: 6px; padding: 18px; }

    .product-card { padding: 28px 22px; }
    .product-card h3 { font-size: 22px; }

    .highlight-banner { font-size: 13px; padding: 12px 8px; }

    .footer-grid { flex-direction: column; gap: 24px; }
    .footer-bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 400px) {
    .stats-strip { grid-template-columns: 1fr 1fr; gap: 10px; }
    .stat { padding: 16px 10px; }
    .stat b { font-size: 19px; }
    .container { padding: 0 14px; }
}