:root {
  --bg: #f6f8fc;
  --ink: #1c2430;
  --muted: #64748b;
  --brand: #2563eb;
  --brand2: #7c3aed;
  --accent: #f59e0b;
  --card: #ffffff;
  --radius: 22px;
  --shadow: 0 14px 40px rgba(30, 41, 59, .10);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
}
a { color: var(--brand); text-decoration: none; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 22px; }

/* header */
header.site {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.82);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(30,41,59,.08);
}
nav { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-weight: 800; font-size: 22px; letter-spacing: .5px; color: var(--ink); }
.logo b { color: var(--brand); }
.menu { display: flex; gap: 20px; align-items: center; }
.menu a { color: var(--muted); font-size: 14.5px; font-weight: 600; }
.menu a:hover { color: var(--brand); }

/* hero */
.hero {
  position: relative;
  color: #fff;
  padding: 96px 0 110px;
  background:
    radial-gradient(1000px 500px at 85% -10%, rgba(124,58,237,.55), transparent 60%),
    radial-gradient(900px 480px at -10% 20%, rgba(37,99,235,.55), transparent 60%),
    linear-gradient(135deg, #0f172a 0%, #1e3a8a 55%, #312e81 100%);
  overflow: hidden;
}
.hero::after {
  content: "";
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: linear-gradient(to bottom, rgba(0,0,0,.5), transparent 85%);
  pointer-events: none;
}
.hero .wrap { position: relative; text-align: center; }
.hero .badge {
  display: inline-block; padding: 7px 16px; border-radius: 999px;
  background: rgba(255,255,255,.14); border: 1px solid rgba(255,255,255,.25);
  font-size: 13px; letter-spacing: 1px; margin-bottom: 22px;
}
.hero h1 { font-size: clamp(48px, 9vw, 92px); font-weight: 900; letter-spacing: 2px; line-height: 1.05; }
.hero h1 span { background: linear-gradient(90deg, #60a5fa, #c084fc, #fbbf24); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p.lead { max-width: 640px; margin: 22px auto 8px; font-size: 18px; color: rgba(255,255,255,.85); }
.hero p.sub { font-size: 14px; color: rgba(255,255,255,.6); }
.hero .cta { margin-top: 34px; display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 12px 26px; border-radius: 999px;
  font-weight: 700; font-size: 15px; transition: transform .15s ease, box-shadow .15s ease;
}
.btn.primary { background: #fff; color: #1e3a8a; box-shadow: 0 8px 24px rgba(0,0,0,.25); }
.btn.ghost { border: 1px solid rgba(255,255,255,.5); color: #fff; }
.btn:hover { transform: translateY(-3px) scale(1.06); }

/* sections */
section { padding: 72px 0; }
.sec-head { text-align: center; margin-bottom: 44px; }
.sec-head .tag { color: var(--brand); font-weight: 800; letter-spacing: 2px; font-size: 13px; }
.sec-head .tag::before { content: "✨ "; }
.sec-head .tag::after { content: " ✨"; }
.sec-head h2 { font-size: 34px; margin-top: 8px; background: linear-gradient(90deg,#2563eb,#7c3aed,#f59e0b); -webkit-background-clip: text; background-clip: text; color: transparent; }
.sec-head p { color: var(--muted); margin-top: 10px; }

.about-card {
  background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 36px 40px; display: flex; gap: 32px; align-items: center; flex-wrap: wrap;
}
.about-card .avatar {
  width: 110px; height: 110px; border-radius: 28px; flex: none;
  display: grid; place-items: center; font-size: 54px;
  background: linear-gradient(135deg, #dbeafe, #ede9fe);
}
.about-card h3 { font-size: 22px; }
.about-card p { color: var(--muted); margin-top: 10px; }

/* cards */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 22px; }
.card {
  background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow);
  border-top: 6px solid #dbeafe;
  padding: 28px 26px; transition: transform .18s ease, box-shadow .18s ease;
  display: block; color: var(--ink);
}
.card:hover { transform: translateY(-6px) rotate(-1.2deg); box-shadow: 0 22px 52px rgba(30,41,59,.18); }
.card .ico {
  width: 58px; height: 58px; border-radius: 16px; display: grid; place-items: center;
  font-size: 30px; margin-bottom: 18px;
}
.card h3 { font-size: 19px; }
.card p { color: var(--muted); font-size: 14.5px; margin-top: 8px; }
.card .more { margin-top: 16px; font-weight: 700; font-size: 14px; }
.c1 { border-top-color: #60a5fa; } .c1 .ico { background: #dbeafe; } .c1 .more { color: #2563eb; }
.c2 { border-top-color: #818cf8; } .c2 .ico { background: #e0e7ff; } .c2 .more { color: #4f46e5; }
.c3 { border-top-color: #fbbf24; } .c3 .ico { background: #fef3c7; } .c3 .more { color: #d97706; }
.c4 { border-top-color: #34d399; } .c4 .ico { background: #d1fae5; } .c4 .more { color: #059669; }

/* page hero */
.page-hero {
  color: #fff; padding: 70px 0 84px; text-align: center;
  background: radial-gradient(800px 400px at 80% -10%, rgba(255,255,255,.18), transparent 60%),
    linear-gradient(135deg, #1e3a8a, #4338ca 60%, #6d28d9);
}
.page-hero .tag { font-size: 13px; letter-spacing: 2px; opacity: .75; }
.page-hero h1 { font-size: clamp(34px, 6vw, 52px); margin-top: 10px; }
.page-hero p { max-width: 640px; margin: 14px auto 0; color: rgba(255,255,255,.82); }

.prose { max-width: 780px; margin: 0 auto; }
.prose h3 { font-size: 21px; margin: 34px 0 12px; }
.prose p { color: var(--muted); }
.prose ul { list-style: none; margin: 16px 0; }
.prose li { padding: 10px 14px; background: var(--card); border-radius: 12px; margin-bottom: 10px; box-shadow: 0 4px 14px rgba(30,41,59,.06); }
.prose li b { color: var(--ink); }
.feature-list { display: grid; gap: 14px; }

/* quiz */
.quiz { max-width: 720px; margin: 34px auto 0; }
.quiz .q { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 24px 26px; margin-bottom: 18px; }
.quiz .q h4 { font-size: 16.5px; margin-bottom: 14px; }
.quiz .opt { display: block; padding: 10px 14px; border: 1.5px solid #e2e8f0; border-radius: 12px; margin-bottom: 8px; cursor: pointer; font-size: 14.5px; transition: all .12s; }
.quiz .opt:hover { border-color: var(--brand); background: #eff6ff; }
.quiz .opt.ok { border-color: #10b981; background: #ecfdf5; }
.quiz .opt.bad { border-color: #ef4444; background: #fef2f2; }
.quiz button {
  border: 0; background: var(--brand); color: #fff; font-weight: 700; font-size: 15px;
  padding: 12px 28px; border-radius: 999px; cursor: pointer;
}
.quiz .result { margin-top: 14px; font-weight: 700; }

footer.site {
  border-top: 1px solid rgba(30,41,59,.08); padding: 40px 0 46px; text-align: center;
  color: var(--muted); font-size: 14px;
}
footer.site .big { color: var(--ink); font-weight: 800; font-size: 17px; }

@media (max-width: 640px) {
  .menu a { font-size: 13px; gap: 12px; }
  .about-card { padding: 26px 22px; }
}