:root {
    --bg: #0b0d14;
    --bg2: #121522;
    --card: #171b2b;
    --card2: #1d2233;
    --line: #262c42;
    --text: #e8ecf7;
    --muted: #8b93ad;
    --accent: #7c5cff;
    --accent2: #22d3ee;
    --ok: #34d399;
    --warn: #fbbf24;
    --err: #f87171;
    --radius: 14px;
}

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

body {
    font-family: -apple-system, "Segoe UI", "Microsoft YaHei", system-ui, sans-serif;
    background: radial-gradient(1200px 600px at 15% -10%, #1b2140 0%, transparent 60%),
                radial-gradient(900px 500px at 100% 0%, #22183d 0%, transparent 55%),
                var(--bg);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.6;
}

a { color: var(--accent2); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

/* 顶部导航 */
header.nav {
    position: sticky; top: 0; z-index: 50;
    backdrop-filter: blur(12px);
    background: rgba(11, 13, 20, .78);
    border-bottom: 1px solid var(--line);
}
header.nav .inner { display: flex; align-items: center; gap: 18px; height: 62px; }
header.nav .brand { font-weight: 700; font-size: 19px; letter-spacing: .5px; }
header.nav .brand span { color: var(--accent); }
header.nav nav { margin-left: auto; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
header.nav nav a.link { color: var(--muted); padding: 7px 10px; border-radius: 8px; font-size: 14px; }
header.nav nav a.link:hover { color: var(--text); background: var(--card2); text-decoration: none; }

/* 按钮 */
.btn {
    display: inline-flex; align-items: center; gap: 7px;
    border: 1px solid var(--line); background: var(--card2); color: var(--text);
    padding: 9px 16px; border-radius: 10px; font-size: 14px; cursor: pointer;
    transition: .15s; font-family: inherit;
}
.btn:hover { border-color: var(--accent); transform: translateY(-1px); }
.btn.primary { background: linear-gradient(135deg, var(--accent), #5b46d6); border: none; font-weight: 600; }
.btn.primary:hover { box-shadow: 0 8px 24px rgba(124, 92, 255, .35); }
.btn.ghost { background: transparent; }
.btn.sm { padding: 6px 11px; font-size: 13px; border-radius: 8px; }
.btn.danger { border-color: #5b2330; color: #ffb4b4; }
.btn:disabled { opacity: .5; cursor: not-allowed; transform: none; }

/* 卡片 */
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.card + .card { margin-top: 18px; }
.grid { display: grid; gap: 16px; }
.grid.cols2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid.cols3 { grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); }

h1 { font-size: clamp(30px, 5vw, 46px); line-height: 1.18; letter-spacing: -.5px; }
h2 { font-size: 22px; margin-bottom: 14px; }
h3 { font-size: 17px; margin-bottom: 8px; }
p.muted, .muted { color: var(--muted); }
.small { font-size: 13px; }

/* 表单 */
label { display: block; font-size: 13px; color: var(--muted); margin: 14px 0 6px; }
input[type=text], input[type=password], input[type=email], input[type=number], select, textarea {
    width: 100%; padding: 11px 13px; background: #0e1120; color: var(--text);
    border: 1px solid var(--line); border-radius: 10px; font-size: 15px; font-family: inherit;
}
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--accent); }
textarea { min-height: 78px; resize: vertical; }
.form-narrow { max-width: 430px; margin: 60px auto; }

/* 提示条 */
.flash { padding: 11px 14px; border-radius: 10px; font-size: 14px; margin-top: 16px; display: none; }
.flash.show { display: block; }
.flash.ok { background: rgba(52, 211, 153, .12); border: 1px solid rgba(52, 211, 153, .4); color: #a7f3d0; }
.flash.err { background: rgba(248, 113, 113, .12); border: 1px solid rgba(248, 113, 113, .4); color: #fecaca; }

/* 表格 */
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); }
th { color: var(--muted); font-weight: 500; font-size: 13px; }
tr:last-child td { border-bottom: none; }

/* 徽章 */
.badge { display: inline-block; padding: 2px 9px; border-radius: 999px; font-size: 12px; border: 1px solid var(--line); color: var(--muted); }
.badge.ok { color: #a7f3d0; border-color: rgba(52, 211, 153, .45); background: rgba(52, 211, 153, .1); }
.badge.err { color: #fecaca; border-color: rgba(248, 113, 113, .45); background: rgba(248, 113, 113, .1); }
.badge.warn { color: #fde68a; border-color: rgba(251, 191, 36, .45); background: rgba(251, 191, 36, .1); }
code, .mono { font-family: ui-monospace, Consolas, monospace; }
code { background: #0e1120; padding: 2px 7px; border-radius: 6px; border: 1px solid var(--line); font-size: 13px; }

/* 价格卡 */
.plan { background: var(--card2); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; text-align: center; transition: .18s; }
.plan:hover { border-color: var(--accent); transform: translateY(-3px); }
.plan .price { font-size: 30px; font-weight: 700; color: var(--accent2); margin: 6px 0; }
.plan .price small { font-size: 14px; color: var(--muted); font-weight: 400; }
.plan.popular { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent) inset, 0 10px 30px rgba(124, 92, 255, .18); }

/* 视频 */
.video-box { position: relative; width: 100%; aspect-ratio: 16 / 9; background: #05070d; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.video-box video, .video-box iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.video-empty { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; color: var(--muted); gap: 8px; text-align: center; padding: 20px; }

/* 视频跳转卡片（外链到 B 站） */
.videolink {
    display: flex; align-items: stretch; gap: 0; overflow: hidden;
    background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
    color: inherit; text-decoration: none; transition: .18s; max-width: 780px;
}
.videolink:hover { border-color: var(--accent); transform: translateY(-2px); text-decoration: none; }
.vl-thumb {
    position: relative; flex: 0 0 220px; min-height: 124px;
    background: linear-gradient(135deg, #7c5cff33, #22d3ee26), #0d1020;
    display: flex; align-items: center; justify-content: center; overflow: hidden;
}
.vl-thumb img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.vl-play {
    position: relative; z-index: 1; width: 46px; height: 46px; border-radius: 50%;
    background: rgba(0, 0, 0, .55); border: 2px solid rgba(255, 255, 255, .85);
    color: #fff; display: flex; align-items: center; justify-content: center; font-size: 17px; padding-left: 3px;
}
.vl-body { display: flex; flex-direction: column; justify-content: center; gap: 5px; padding: 18px 20px; }
.vl-title { font-size: 16px; font-weight: 600; color: var(--text); line-height: 1.4; }

@media (max-width: 620px) {
    .videolink { flex-direction: column; }
    .vl-thumb { flex: 0 0 160px; }
}

/* 布局片段 */
.hero { padding: 64px 0 40px; }
.hero .tag { display: inline-block; padding: 5px 12px; border: 1px solid var(--line); border-radius: 999px; font-size: 13px; color: var(--muted); margin-bottom: 18px; }
.hero .actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 26px; }
.section { padding: 40px 0; }
.section > h2 { font-size: 26px; margin-bottom: 6px; }
.section > .muted { margin-bottom: 22px; }

.notice { background: rgba(251, 191, 36, .1); border: 1px solid rgba(251, 191, 36, .35); color: #fde68a; padding: 11px 14px; border-radius: 10px; font-size: 14px; }

footer.site { border-top: 1px solid var(--line); margin-top: 40px; padding: 26px 0; color: var(--muted); font-size: 13px; text-align: center; }

.stat { text-align: center; padding: 16px; }
.stat .n { font-size: 26px; font-weight: 700; color: var(--accent2); }
.stat .l { font-size: 13px; color: var(--muted); }

.tabs { display: flex; gap: 6px; border-bottom: 1px solid var(--line); margin-bottom: 18px; flex-wrap: wrap; }
.tabs button { background: none; border: none; border-bottom: 2px solid transparent; color: var(--muted); padding: 10px 14px; cursor: pointer; font-size: 15px; font-family: inherit; }
.tabs button.active { color: var(--text); border-bottom-color: var(--accent); }
.tabpane { display: none; }
.tabpane.active { display: block; }

.row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.kv { display: grid; grid-template-columns: 130px 1fr; gap: 8px 14px; font-size: 14px; }
.kv dt { color: var(--muted); }

@media (max-width: 620px) {
    .hero { padding: 36px 0 24px; }
    header.nav .inner { height: auto; padding: 10px 0; flex-wrap: wrap; }
    .kv { grid-template-columns: 1fr; gap: 2px 0; }
    .kv dt { margin-top: 8px; }
}