@charset "UTF-8";
:root {
  --paper: #f4f6f1; --surface: #fff; --ink: #17372c; --muted: #4e6459;
  --line: #ccd9d0; --green: #126845; --mint: #deefe3; --blue: #254fa5;
  --orange: #a84717; --rose: #a4385b; --body-size: 20px;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink); background: var(--paper);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 110px; }
body { margin: 0; font-size: var(--body-size); line-height: 1.6; }
body[data-theme="dark"] {
  --paper: #0f1d18; --surface: #1b2e25; --ink: #eef8ef; --muted: #bacec0;
  --line: #496454; --green: #a4e2bb; --mint: #284735; --blue: #aec8ff;
  --orange: #ffc095; --rose: #ffbad0; color-scheme: dark;
}
body.large-text { --body-size: 24px; }
button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
button { cursor: pointer; }
a { color: inherit; }
button:focus-visible, a:focus-visible, input:focus-visible { outline: 3px solid #a65112; outline-offset: 4px; }
[hidden] { display: none !important; }
.skip-link { position: fixed; top: -100px; left: 12px; z-index: 200; padding: 12px; background: var(--surface); }
.skip-link:focus { top: 12px; }
.site-header { background: var(--surface); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 20; }
.header-inner { max-width: 1480px; margin: auto; padding: 16px 36px; display: flex; align-items: center; gap: 36px; min-height: 86px; }
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; flex-shrink: 0; }
.brand-mark { width: 46px; height: 46px; border-radius: 12px; background: #173d32; color: #d9f4e2; display: grid; place-items: center; font: 800 34px Georgia, serif; }
.brand strong { font-size: 25px; letter-spacing: -.02em; display: block; line-height: 1.3; }
.brand span:not(.brand-mark) { display: block; font-size: 15px; color: var(--muted); letter-spacing: .04em; }
.header-nav { display: flex; gap: 26px; margin-left: auto; }
.header-nav a { font-size: 19px; text-decoration: none; padding: 7px 0; border-bottom: 2px solid transparent; }
.header-nav a:hover { border-color: var(--green); }
.header-tools { display: flex; gap: 8px; }
.header-tools button { min-height: 44px; padding: 7px 12px; background: var(--surface); border: 1px solid var(--line); border-radius: 8px; color: var(--ink); font-size: 18px; }
.header-tools button[aria-pressed="true"] { background: var(--mint); border-color: var(--green); }
.page-wrap { max-width: 1480px; margin: auto; padding: 0 36px; }
.hero { padding: 46px 0 38px; display: grid; grid-template-columns: 1.15fr 1fr; gap: 48px; align-items: center; }
.eyebrow { display: flex; align-items: center; gap: 9px; font-size: 18px; color: var(--green); font-weight: 700; }
.eyebrow::before { content: ''; width: 9px; height: 9px; background: var(--green); border-radius: 50%; }
.hero h1 { font-size: clamp(44px, 4.7vw, 64px); line-height: 1.2; letter-spacing: -.035em; margin: 18px 0 20px; font-weight: 800; }
.hero h1 em { font-style: normal; color: var(--green); position: relative; display: inline-block; }
.hero h1 em::after { content: ''; position: absolute; height: 8px; bottom: 2px; left: 0; right: 0; background: #9fd0b28c; z-index: -1; transform: rotate(-1.2deg); }
.hero p { max-width: 610px; margin: 0; color: var(--muted); font-size: calc(var(--body-size) + 2px); line-height: 1.75; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 26px; }
.button-link { padding: 12px 20px; display: inline-flex; gap: 22px; align-items: center; min-height: 54px; border: 1px solid var(--line); border-radius: 9px; text-decoration: none; font-size: var(--body-size); font-weight: 650; background: var(--surface); }
.button-link.primary { color: #fff; background: #176c48; border-color: #176c48; }
.button-link:hover { box-shadow: 0 4px 0 #17372c15; transform: translateY(-1px); }
.hero-visual { background: #173d32; border-radius: 20px; position: relative; overflow: hidden; min-height: 300px; }
.hero-visual svg { width: 100%; height: auto; display: block; }
.hero-visual .visual-caption { position: absolute; bottom: 16px; left: 24px; right: 24px; display: flex; justify-content: space-between; font-size: 16px; color: #d1e9d9; }
.hero-visual text { font-family: Georgia, "PingFang SC", serif; }
.method-strip { padding: 17px 22px; display: flex; gap: 25px; align-items: center; border: 1px solid var(--line); border-radius: 12px; background: var(--surface); margin-bottom: 38px; }
.method-intro { padding-right: 25px; border-right: 1px solid var(--line); }
.method-intro strong { display: block; font-size: 22px; line-height: 1.3; }
.method-intro span { font-size: 17px; color: var(--muted); }
.method-steps { display: flex; flex: 1; justify-content: space-between; gap: 15px; }
.method-step { display: flex; align-items: center; gap: 10px; }
.step-number { color: var(--green); background: var(--mint); width: 37px; height: 37px; border-radius: 50%; display: grid; place-items: center; font: 600 18px Georgia, serif; }
.method-step b { font-size: 21px; font-weight: 650; }
.method-arrow { color: var(--muted); }
.catalog-layout { display: grid; grid-template-columns: 230px minmax(0,1fr); gap: 32px; align-items: start; padding-bottom: 52px; }
#experiments, #teachingGuide { scroll-margin-top: 110px; }
.catalog-sidebar { position: sticky; top: 111px; }
.sidebar-label { font-size: 16px; color: var(--muted); font-weight: 650; letter-spacing: .12em; margin-bottom: 12px; }
.category-nav { display: flex; flex-direction: column; gap: 7px; }
.category-button { display: flex; align-items: center; gap: 12px; width: 100%; border: 1px solid transparent; border-radius: 9px; background: transparent; color: var(--ink); text-align: left; padding: 13px 12px; font-size: 20px; }
.category-button .symbol { font: 700 22px Georgia, serif; width: 29px; text-align: center; }
.category-button .count { margin-left: auto; font-size: 17px; color: var(--muted); }
.category-button[aria-pressed="true"] { background: #173d32; color: #fff; border-color: #173d32; font-weight: 700; }
.category-button[aria-pressed="true"] .count { color: #d3e8db; }
.category-button:hover:not([aria-pressed="true"]) { background: var(--mint); }
.sidebar-tip { margin-top: 30px; padding: 18px 16px; border: 1px solid var(--line); border-radius: 11px; background: var(--surface); }
.sidebar-tip b { display: block; font-size: 20px; margin-bottom: 8px; }
.sidebar-tip p { font-size: 18px; line-height: 1.7; color: var(--muted); margin: 0; }
.catalog-header { display: flex; justify-content: space-between; gap: 24px; align-items: center; margin-bottom: 24px; }
.catalog-header h2 { font-size: 32px; line-height: 1.35; margin: 0 0 2px; }
.catalog-header p { font-size: 18px; margin: 0; color: var(--muted); }
.search-box { display: flex; gap: 10px; align-items: center; max-width: 410px; width: 45%; min-height: 52px; background: var(--surface); border: 1px solid #a7bdad; border-radius: 9px; padding: 8px 12px; }
.search-box svg { flex: 0 0 22px; color: var(--muted); }
.search-box input { min-width: 0; width: 100%; border: 0; outline: 0; background: transparent; font-size: 18px; color: var(--ink); padding: 4px 0; }
.search-box input::placeholder { color: var(--muted); }
.search-box:focus-within { outline: 3px solid #a65112; outline-offset: 3px; }
.search-box input:focus-visible { outline: 0; }
.search-box button { border: 0; background: transparent; font-size: 24px; color: var(--muted); min-width: 30px; }
.catalog-group { margin-bottom: 34px; }
.group-header { display: flex; gap: 14px; align-items: baseline; margin-bottom: 16px; }
.group-header h3 { margin: 0; font-size: 24px; font-weight: 700; }
.group-header span { font-size: 18px; color: var(--muted); }
.lab-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 18px; }
.lab-card { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; position: relative; transition: transform .15s ease, box-shadow .15s ease; }
.lab-card:hover { transform: translateY(-4px); box-shadow: 0 10px 22px #17372c12; border-color: var(--green); }
.card-link { display: flex; flex-direction: column; height: 100%; color: var(--ink); text-decoration: none; }
.card-link:focus-visible { outline-offset: -4px; border-radius: 12px; }
.card-graphic { height: 122px; border-bottom: 1px solid var(--line); display: flex; align-items: center; justify-content: center; background: #e9f2e9; color: #176443; overflow: hidden; }
.card-graphic svg { width: 100%; height: 100%; }
.lab-card.blue .card-graphic { background: #edf0fb; color: #254fa5; }
.lab-card.orange .card-graphic { background: #faf0e3; color: #a84717; }
.lab-card.rose .card-graphic { background: #f9ebee; color: #a4385b; }
.card-content { padding: 18px 18px 17px; display: flex; flex-direction: column; flex: 1; }
.card-title { margin: 0 0 10px; font-size: 24px; line-height: 1.4; font-weight: 750; overflow-wrap: anywhere; }
.card-desc { margin: 0 0 17px; font-size: calc(var(--body-size) - 2px); line-height: 1.75; color: var(--muted); }
.card-meta { display: flex; justify-content: space-between; align-items: center; gap: 8px; margin-top: auto; font-size: 17px; }
.card-type { color: var(--green); background: var(--mint); padding: 3px 8px; border-radius: 5px; }
.blue .card-type { color: var(--blue); background: #edf0fb; }
.orange .card-type { color: var(--orange); background: #faf0e3; }
.rose .card-type { color: var(--rose); background: #f9ebee; }
body[data-theme="dark"] .card-type { background: #2c4235; }
.card-open { color: var(--muted); font-weight: 650; }
.empty-results { text-align: center; padding: 60px 24px; border: 1px dashed var(--line); border-radius: 12px; background: var(--surface); }
.empty-results h3 { font-size: 28px; }
.empty-results p { color: var(--muted); }
.empty-results button { padding: 12px 22px; color: #fff; background: #176c48; border: 0; border-radius: 9px; }
.teaching-guide { padding: 32px; border: 1px solid var(--line); border-radius: 15px; background: var(--surface); margin-bottom: 38px; }
.guide-heading { display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.guide-heading h2 { font-size: 28px; margin: 0; }
.guide-heading a { color: var(--green); font-size: 18px; }
.guide-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 28px; margin-top: 22px; }
.guide-grid h3 { font-size: 22px; margin: 0 0 8px; }
.guide-grid p { margin: 0; font-size: var(--body-size); color: var(--muted); }
.site-footer { display: flex; justify-content: space-between; gap: 20px; font-size: 17px; color: var(--muted); padding: 25px 0 30px; border-top: 1px solid var(--line); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
@media (max-width: 1250px) { .lab-grid { grid-template-columns: repeat(2,minmax(0,1fr)); } .hero { gap: 30px; } .header-inner { gap: 20px; } .header-nav { gap: 16px; } }
@media (max-width: 1000px) { .page-wrap { padding: 0 24px; } .header-inner { padding: 14px 24px; } .header-nav { display: none; } .header-tools { margin-left: auto; } .catalog-layout { grid-template-columns: 200px minmax(0,1fr); gap: 24px; } .category-button { font-size: 18px; padding: 12px 8px; } .category-button .symbol { width: 23px; } .catalog-header { flex-wrap: wrap; gap: 14px; } .search-box { width: 100%; max-width: none; } .hero h1 { font-size: 48px; } .hero p { font-size: 20px; } .method-strip { gap: 18px; padding: 18px; } .method-intro { padding-right: 18px; } .method-steps { gap: 10px; } .method-arrow { display: none; } }
@media (max-width: 760px) {
  html { scroll-padding-top: 145px; }
  .hero { grid-template-columns: 1fr; gap: 25px; padding-top: 32px; }
  .hero h1 { font-size: 48px; }
  .hero-visual { min-height: 0; max-width: 560px; }
  .catalog-layout { grid-template-columns: 1fr; }
  .catalog-sidebar { position: static; }
  .category-nav { flex-direction: row; flex-wrap: wrap; gap: 8px; }
  .category-button { width: auto; border: 1px solid var(--line); background: var(--surface); flex: 1 1 auto; gap: 8px; padding: 10px 12px; }
  .category-button .count { margin-left: 5px; }
  .sidebar-tip { display: none; }
  .method-strip { align-items: flex-start; flex-direction: column; margin-bottom: 28px; }
  .method-intro { border: 0; }
  .method-steps { width: 100%; }
  .method-step { gap: 8px; }
  .guide-grid { grid-template-columns: 1fr; gap: 22px; }
  .site-footer { flex-direction: column; gap: 8px; }
}
@media (max-width: 500px) {
  .page-wrap { padding: 0 16px; }
  .header-inner { padding: 12px 16px; gap: 12px; flex-wrap: wrap; }
  .brand strong { font-size: 22px; }
  .brand span:not(.brand-mark) { font-size: 13px; }
  .brand-mark { width: 40px; height: 40px; }
  .header-tools { gap: 6px; }
  .header-tools button { font-size: 16px; padding: 6px 9px; }
  .hero h1 { font-size: 44px; }
  .hero-actions { gap: 10px; }
  .button-link { padding: 12px 15px; gap: 15px; font-size: 18px; }
  .method-step { flex-direction: column; }
  .method-step b { font-size: 19px; }
  .lab-grid { grid-template-columns: 1fr; }
  .card-graphic { height: 135px; }
  .card-title { font-size: 25px; }
  .card-desc { font-size: 20px; }
  .group-header { flex-wrap: wrap; gap: 4px 12px; }
  .teaching-guide { padding: 24px 20px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } *, *::before, *::after { transition: none !important; } }