:root {
    --brand: #4f46e5;
    --brand-dark: #4338ca;
    --bg: #ffffff;
    --bg-soft: #f6f7fb;
    --text: #1e2230;
    --muted: #6b7280;
    --border: #e5e7eb;
    --radius: 12px;
    --shadow: 0 10px 30px rgba(15, 23, 42, .08);
    --max: 1180px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Roboto, sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
}

a { color: var(--brand); text-decoration: none; }
a:hover { color: var(--brand-dark); }

.container { max-width: var(--max); margin: 0 auto; padding: 0 20px; }

/* ---------- 头部 ---------- */
.site-header {
    position: sticky; top: 0; z-index: 50;
    background: rgba(255, 255, 255, .92);
    backdrop-filter: saturate(180%) blur(8px);
    border-bottom: 1px solid var(--border);
}
.site-header .container {
    display: flex; align-items: center; gap: 18px; height: 64px;
}
.site-logo { display: flex; align-items: center; gap: 8px; color: var(--text); font-weight: 700; font-size: 18px; }
.logo-mark { width: 26px; height: 26px; fill: var(--brand); }
.site-nav { display: flex; gap: 6px; margin-left: 10px; }
.nav-link { padding: 8px 12px; border-radius: 8px; color: var(--muted); font-size: 15px; }
.nav-link:hover, .nav-link.active { color: var(--brand); background: var(--bg-soft); }
.site-user { margin-left: auto; display: flex; align-items: center; gap: 10px; }
.user-name { font-size: 14px; color: var(--text); font-weight: 600; }

/* ---------- 按钮 ---------- */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 6px;
    padding: 10px 18px; border-radius: 10px; border: 1px solid transparent;
    font-size: 14px; font-weight: 600; cursor: pointer; transition: all .2s;
}
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); color: #fff; transform: translateY(-1px); }
.btn-ghost { background: #fff; color: var(--text); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }
.btn-lg { padding: 13px 28px; font-size: 16px; }
.btn-block { width: 100%; }
.btn-mini { padding: 4px 10px; font-size: 12px; border-radius: 7px; }

/* ---------- 首页 Hero ---------- */
.hero { background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 60%, #2563eb 100%); color: #fff; padding: 64px 0 72px; overflow: hidden; }
.hero .container { display: grid; grid-template-columns: 1.1fr .9fr; gap: 40px; align-items: center; }
.hero-title { font-size: 40px; line-height: 1.25; margin: 0 0 18px; font-weight: 800; }
.hero-sub { font-size: 17px; opacity: .92; margin: 0 0 26px; max-width: 520px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-actions .btn-ghost { background: rgba(255,255,255,.14); color: #fff; border-color: rgba(255,255,255,.3); }
.hero-actions .btn-ghost:hover { background: rgba(255,255,255,.24); color: #fff; }
.hero-meta { display: flex; gap: 22px; margin-top: 26px; font-size: 14px; opacity: .9; flex-wrap: wrap; }
.hero-meta span { display: inline-flex; align-items: center; gap: 6px; }
.hero-meta .icon { width: 18px; height: 18px; }

.code-card { background: #0f172a; border-radius: 14px; box-shadow: var(--shadow); overflow: hidden; }
.code-card-bar { display: flex; gap: 6px; padding: 12px 14px; background: #1e293b; }
.code-card-bar i { width: 11px; height: 11px; border-radius: 50%; background: #475569; }
.code-card-bar i:nth-child(1) { background: #ef4444; }
.code-card-bar i:nth-child(2) { background: #eab308; }
.code-card-bar i:nth-child(3) { background: #22c55e; }
.code-card-body { margin: 0; padding: 18px; color: #cbd5e1; font: 13px/1.7 ui-monospace, SFMono-Regular, Consolas, monospace; white-space: pre; overflow: auto; max-height: 300px; }

/* ---------- 区块标题 ---------- */
.section-title { text-align: center; font-size: 28px; font-weight: 800; margin: 56px 0 32px; }
.features { padding: 10px 0 30px; }
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.feature-card { background: var(--bg-soft); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px 22px; transition: transform .2s, box-shadow .2s; }
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.feature-icon { width: 46px; height: 46px; border-radius: 12px; background: #eef2ff; color: var(--brand); display: flex; align-items: center; justify-content: center; margin-bottom: 14px; }
.feature-icon .icon { width: 24px; height: 24px; }
.feature-card h3 { margin: 0 0 8px; font-size: 17px; }
.feature-card p { margin: 0; color: var(--muted); font-size: 14px; }

/* ---------- 语言 ---------- */
.languages { padding: 10px 0 40px; }
.lang-grid { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.lang-chip { padding: 10px 20px; border-radius: 999px; background: #fff; border: 1px solid var(--border); color: var(--text); font-weight: 600; font-size: 14px; }
.lang-chip:hover { border-color: var(--brand); color: var(--brand); }

/* ---------- CTA ---------- */
.cta { padding: 56px 0; text-align: center; background: var(--bg-soft); border-top: 1px solid var(--border); }
.cta h2 { font-size: 26px; margin: 0 0 22px; }

/* ---------- 通用页面 ---------- */
.page { padding: 48px 0; min-height: 60vh; }
.simple-page .container { max-width: 880px; }
.page-title, .page-head h1 { font-size: 26px; margin: 0 0 22px; }
.page-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 22px; }

/* ---------- 表单 ---------- */
.form-group { margin-bottom: 16px; }
.form-group label { display: block; margin-bottom: 6px; font-size: 14px; font-weight: 600; color: #374151; }
.form-group input, .form-group select, .form-group textarea {
    width: 100%; padding: 10px 14px; border: 1px solid var(--border); border-radius: 9px;
    font-size: 14px; background: #fff; color: var(--text); outline: none; transition: border-color .2s, box-shadow .2s;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus { border-color: var(--brand); box-shadow: 0 0 0 3px rgba(79,70,229,.12); }

/* ---------- 认证页 ---------- */
.auth-page { display: flex; align-items: center; justify-content: center; min-height: calc(100vh - 64px); }
.auth-card { width: 100%; max-width: 400px; background: #fff; border: 1px solid var(--border); border-radius: 16px; padding: 34px 30px; box-shadow: var(--shadow); }
.auth-title { text-align: center; margin: 0 0 24px; font-size: 24px; }
.auth-form .btn { margin-top: 6px; }
.auth-tip { text-align: center; margin: 18px 0 0; font-size: 14px; color: var(--muted); }

/* ---------- 提示 ---------- */
.flash { padding: 12px 16px; border-radius: 9px; margin-bottom: 18px; font-size: 14px; }
.flash-success { background: #ecfdf5; color: #047857; border: 1px solid #a7f3d0; }
.flash-error { background: #fef2f2; color: #b91c1c; border: 1px solid #fecaca; }
.flash-info { background: #eff6ff; color: #1d4ed8; border: 1px solid #bfdbfe; }

/* ---------- 数据表 ---------- */
.data-table { width: 100%; border-collapse: collapse; background: #fff; border: 1px solid var(--border); border-radius: 10px; overflow: hidden; }
.data-table th, .data-table td { padding: 12px 14px; text-align: left; border-bottom: 1px solid var(--border); font-size: 14px; }
.data-table th { background: var(--bg-soft); font-weight: 600; }
.data-table tr:last-child td { border-bottom: none; }
.row-actions { display: flex; gap: 12px; align-items: center; }
.link { color: var(--brand); font-size: 14px; }
.link-danger { color: #dc2626; background: none; border: none; padding: 0; cursor: pointer; font: inherit; }
.inline-form { display: inline; }
.empty-tip, .side-empty { color: var(--muted); font-size: 14px; }

/* ---------- 个人中心 ---------- */
.profile-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.profile-card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.profile-card h2 { margin: 0 0 16px; font-size: 18px; }
.info-list { list-style: none; margin: 0 0 18px; padding: 0; }
.info-list li { display: flex; justify-content: space-between; padding: 10px 0; border-bottom: 1px dashed var(--border); font-size: 14px; }
.info-list li span { color: var(--muted); }
.profile-actions { display: flex; gap: 10px; }

/* ---------- 底部 ---------- */
.site-footer { background: #0f172a; color: #cbd5e1; padding: 48px 0 24px; margin-top: 40px; }
.site-footer .container { max-width: var(--max); margin: 0 auto; padding: 0 20px; }
.footer-main { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 30px; }
.footer-brand .site-logo { color: #fff; }
.footer-brand p { color: #94a3b8; font-size: 14px; margin: 12px 0 0; max-width: 320px; }
.footer-col h4 { color: #fff; font-size: 15px; margin: 0 0 14px; }
.footer-col ul { list-style: none; margin: 0; padding: 0; }
.footer-col li { margin-bottom: 9px; font-size: 14px; }
.footer-col a { color: #cbd5e1; }
.footer-col a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid #1e293b; margin-top: 30px; padding-top: 18px; text-align: center; font-size: 13px; color: #64748b; }
.footer-bottom a { color: #94a3b8; }

/* ---------- 图标 ---------- */
.icon { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; vertical-align: middle; }

/* ---------- 移动端 ---------- */
.nav-toggle { display: none; margin-left: auto; flex-direction: column; gap: 4px; background: none; border: none; cursor: pointer; padding: 6px; }
.nav-toggle span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; }

@media (max-width: 900px) {
    .hero .container { grid-template-columns: 1fr; }
    .hero-preview { display: none; }
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .profile-grid { grid-template-columns: 1fr; }
    .footer-main { grid-template-columns: 1fr 1fr; }
    .site-nav, .site-user { display: none; }
    .nav-toggle { display: flex; }
    .site-nav.open { display: flex; position: absolute; top: 64px; left: 0; right: 0; flex-direction: column; background: #fff; border-bottom: 1px solid var(--border); padding: 10px; }
    .site-user.open { display: flex; }
}