:root {
  --ink: #25232a;
  --muted: #716c78;
  --line: #e9e5ed;
  --paper: #f8f7fb;
  --white: #ffffff;
  --navy: #312f38;
  --blue: #8b78e6;
  --blue-deep: #6d5bd3;
  --cyan: #a8d5ba;
  --orange: #ffb86b;
  --shadow: 0 18px 45px rgba(66, 55, 100, .12);
  --shadow-soft: 0 10px 30px rgba(66, 55, 100, .08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  line-height: 1.75;
}
a { color: inherit; text-decoration: none; }
button, input, select { font: inherit; }
::selection { background: rgba(168, 213, 186, .48); color: var(--navy); }
:focus-visible { outline: 3px solid rgba(255, 157, 92, .8); outline-offset: 3px; }
.container { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }

.hero {
  color: var(--ink);
  background: linear-gradient(135deg, #f8f1ff 0%, #fff8ef 55%, #f1f9f2 100%);
  min-height: 640px;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  opacity: .55;
  background-image: linear-gradient(rgba(139,120,230,.09) 1px, transparent 1px), linear-gradient(90deg, rgba(139,120,230,.09) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(125deg, black, transparent 76%);
}
.hero::after {
  content: "";
  position: absolute;
  right: -80px;
  bottom: -150px;
  width: 520px;
  height: 520px;
  border: 1px solid rgba(139,120,230,.17);
  border-radius: 50%;
  box-shadow: 0 0 0 35px rgba(139,120,230,.05), 0 0 0 70px rgba(255,184,107,.045), 0 0 0 105px rgba(168,213,186,.04);
}
.nav { display: flex; align-items: center; justify-content: space-between; padding: 13px 18px; margin-top: 17px; position: relative; z-index: 1; border: 1px solid rgba(255,255,255,.76); border-radius: 18px; background: rgba(255,255,255,.62); box-shadow: 0 10px 24px rgba(66,55,100,.08); backdrop-filter: blur(16px); }
.brand { font-size: 1.05rem; font-weight: 900; letter-spacing: .08em; display: inline-flex; align-items: center; gap: 10px; }
.brand::before { content: ""; width: 10px; height: 10px; border-radius: 50%; background: var(--orange); box-shadow: 0 0 0 5px rgba(255, 209, 122, .16); }
.nav-links { display: flex; gap: 5px; color: #5f5969; font-size: .86rem; }
.nav-links a { padding: 7px 11px; border-radius: 10px; transition: background .2s, color .2s; }
.nav-links a:hover { color: var(--ink); background: rgba(139,120,230,.12); }
.hero-content { padding: 104px 0 112px; position: relative; z-index: 1; max-width: 900px; margin-left: max(20px, calc((100vw - 1120px) / 2)); }
.eyebrow, .section-kicker { color: var(--blue-deep); letter-spacing: .15em; text-transform: uppercase; font-size: .78rem; font-weight: 800; }
.hero h1 { font-size: clamp(2.4rem, 6vw, 5rem); line-height: 1.12; max-width: 850px; margin: 20px 0 25px; letter-spacing: -.04em; text-wrap: balance; }
.hero-copy { color: rgba(37,35,42,.72); font-size: 1.08rem; max-width: 700px; margin: 0; }
.hero-actions { display: flex; gap: 14px; margin: 35px 0 20px; }
.button { border: 0; border-radius: 999px; padding: 11px 24px; cursor: pointer; font-weight: 800; transition: transform .2s, box-shadow .2s, background .2s; display: inline-flex; justify-content: center; align-items: center; }
.button:hover { transform: translateY(-2px); box-shadow: 0 8px 18px rgba(66,55,100,.16); }
.button.primary { background: var(--orange); color: #332a25; box-shadow: 0 9px 22px rgba(255, 209, 122, .18); }
.button.ghost { background: rgba(255,255,255,.66); color: var(--ink); border: 1px solid rgba(255,255,255,.8); }
.hero-note { color: rgba(37,35,42,.56); font-size: .84rem; }

.section { padding: 100px 0; }
.intro-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 70px; align-items: center; }
h2 { font-size: clamp(1.8rem, 3vw, 2.6rem); line-height: 1.25; letter-spacing: -.03em; margin: 11px 0 20px; }
.intro-grid p, .source-intro { color: var(--muted); max-width: 600px; }
.principles { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; }
.principle { background: rgba(255,255,255,.82); border: 1px solid rgba(231,224,219,.92); border-radius: 20px; padding: 24px; box-shadow: var(--shadow-soft); position: relative; overflow: hidden; }
.principle::after { content: ""; position: absolute; width: 90px; height: 90px; right: -40px; bottom: -42px; border-radius: 50%; background: rgba(207,109,86,.12); }
.principle span, .card-number { color: var(--blue); font-weight: 900; font-size: .75rem; letter-spacing: .1em; }
.principle strong { display: block; font-size: 1.22rem; margin-top: 12px; }
.principle small { display: block; color: var(--muted); margin-top: 5px; }

.cards-section { background: #f3f0f8; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 30px; margin-bottom: 35px; }
.toolbar { display: flex; gap: 10px; align-items: center; }
.search-box { background: rgba(255,255,255,.88); border: 1px solid var(--line); border-radius: 14px; display: flex; gap: 7px; align-items: center; padding: 0 13px; color: var(--muted); box-shadow: 0 6px 15px rgba(62,47,44,.05); }
.search-box input { width: 190px; border: 0; outline: 0; padding: 10px 0; background: transparent; color: var(--ink); }
select { border: 1px solid var(--line); border-radius: 14px; padding: 10px 12px; color: var(--ink); background: rgba(255,255,255,.88); outline: 0; box-shadow: 0 6px 15px rgba(62,47,44,.05); }
.card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.knowledge-card { background: rgba(255,255,255,.95); border: 1px solid rgba(231,224,219,.92); border-radius: 20px; padding: 25px; min-height: 300px; display: flex; flex-direction: column; box-shadow: 0 10px 28px rgba(62, 47, 44, .06); transition: transform .2s, box-shadow .2s, border-color .2s; position: relative; overflow: hidden; }
.knowledge-card[hidden] { display: none; }
.knowledge-card::before { content: ""; height: 4px; position: absolute; inset: 0 0 auto; background: var(--blue); opacity: .88; }
.knowledge-card:hover { transform: translateY(-5px); box-shadow: var(--shadow); }
.knowledge-card:hover { border-color: rgba(139,120,230,.36); }
.card-top { display: flex; justify-content: space-between; align-items: center; }
.tag { color: #756021; background: #f4edc7; border-radius: 999px; padding: 3px 10px; font-size: .73rem; font-weight: 800; }
.knowledge-card h3 { font-size: 1.28rem; line-height: 1.4; margin: 20px 0 10px; }
.knowledge-card p { color: var(--muted); font-size: .92rem; margin: 0; }
.takeaway { color: #584c4a; background: #fbf4e9; border: 1px solid #eee0ce; border-radius: 12px; padding: 11px 13px; margin-top: auto; font-size: .82rem; }
.takeaway b { color: var(--blue); }
.empty-state { text-align: center; color: var(--muted); padding: 40px; }

.checklist-section { background: linear-gradient(135deg, #f0ebff 0%, #fff1e6 100%); color: var(--ink); }
.checklist-grid { display: grid; grid-template-columns: .9fr 1.1fr; align-items: center; gap: 80px; }
.checklist-section .section-kicker { color: var(--blue-deep); }
.checklist { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.checklist li { border: 1px solid rgba(139,120,230,.18); background: rgba(255,255,255,.68); border-radius: 14px; padding: 15px 16px; font-size: .96rem; box-shadow: 0 8px 22px rgba(66,55,100,.06); transition: background .2s, transform .2s; }
.checklist li:hover { background: rgba(255,255,255,.92); transform: translateY(-2px); }
.checklist span { display: block; color: var(--blue-deep); font-weight: 900; letter-spacing: .08em; margin-bottom: 4px; font-size: .8rem; }

.quiz-section { background: var(--white); }
.quiz-progress { color: var(--blue); font-weight: 900; }
.quiz-list { display: grid; gap: 14px; }
.quiz-item { border: 1px solid var(--line); border-radius: 17px; padding: 19px 22px; background: #fffdfb; box-shadow: 0 5px 16px rgba(62,47,44,.04); transition: border-color .2s, box-shadow .2s; }
.quiz-item:has(input:checked) { border-color: rgba(139,120,230,.42); box-shadow: 0 7px 18px rgba(139,120,230,.10); }
.quiz-item.correct { border-color: #59b996; background: #f0fbf7; }
.quiz-item.incorrect { border-color: #e99b82; background: #fff6f2; }
.quiz-question { font-weight: 800; margin-bottom: 10px; }
.quiz-options { display: grid; gap: 7px; color: var(--muted); font-size: .92rem; }
.quiz-options label { cursor: pointer; display: flex; gap: 8px; align-items: flex-start; }
.quiz-options input { accent-color: var(--blue); margin-top: 6px; }
.quiz-explain { color: #6d6177; font-size: .82rem; margin: 11px 0 0; }
.quiz-actions { display: flex; align-items: center; gap: 12px; margin-top: 26px; flex-wrap: wrap; }
.quiz-section .button.primary { background: var(--blue); color: white; box-shadow: 0 9px 22px rgba(139,120,230,.20); }
.quiz-section .button.ghost { color: var(--blue-deep); background: white; border: 1px solid var(--line); }
.quiz-result { color: var(--blue); font-weight: 800; }

.sources-section { padding-bottom: 55px; }
.source-list { display: grid; gap: 10px; margin-top: 25px; }
.source-list a { display: grid; grid-template-columns: 42px 1fr 30px; align-items: center; gap: 13px; padding: 16px 18px; border: 1px solid var(--line); border-radius: 15px; background: rgba(255,255,255,.85); transition: border-color .2s, transform .2s, box-shadow .2s; }
.source-list a:hover { border-color: var(--blue); transform: translateX(3px); }
.source-list a:hover { box-shadow: var(--shadow-soft); }
.source-list span { color: var(--blue); font-weight: 900; }
.source-list b { display: block; font-size: .95rem; }
.source-list small { display: block; color: var(--muted); font-size: .78rem; }
.source-list em { color: var(--blue); font-style: normal; text-align: right; }
.footer-note { border-top: 1px solid var(--line); color: var(--muted); font-size: .78rem; margin-top: 45px; padding-top: 20px; }

@media (max-width: 800px) {
  .container { width: min(100% - 28px, 620px); }
  .nav-links { gap: 12px; font-size: .78rem; }
  .hero { min-height: 680px; }
  .hero-content { margin-left: auto; padding: 75px 0 90px; }
  .hero h1 { font-size: 2.8rem; }
  .intro-grid, .checklist-grid { grid-template-columns: 1fr; gap: 35px; }
  .section { padding: 70px 0; }
  .section-heading { display: block; }
  .toolbar { margin-top: 20px; flex-wrap: wrap; }
  .search-box { flex: 1; }
  .search-box input { width: 100%; }
  .card-grid { grid-template-columns: 1fr; }
  .checklist { grid-template-columns: 1fr; }
}

@media (max-width: 430px) {
  .nav { align-items: flex-start; }
  .nav-links { flex-direction: column; align-items: flex-end; gap: 2px; }
  .hero h1 { font-size: 2.25rem; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .principles { gap: 9px; }
  .principle { padding: 17px; }
}