:root {
  font-family: "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  color: #283c34;
  background: #f7f6f0;
  --ink: #283c34;
  --green: #355f4b;
  --muted: #687b6e;
  --line: #dcdfd3;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; }
button, input { font: inherit; }
button { cursor: pointer; }
a { color: inherit; text-decoration: none; }
[hidden] { display: none !important; }
.site-shell { max-width: 1510px; margin: auto; padding: 0 clamp(20px, 2.8vw, 44px); }
.site-header { height: 130px; border-bottom: 1px solid var(--line); display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: flex; align-items: center; gap: 17px; flex: none; }
.brand-mark { color: #b2783b; font-size: 55px; line-height: 1; font-weight: 200; }
.brand-copy { display: grid; gap: 2px; }
.brand-copy strong { font-size: 31px; line-height: 1.2; letter-spacing: .02em; }
.brand-copy small { font-size: 11px; letter-spacing: .29em; white-space: nowrap; }
.site-nav { display: flex; align-items: center; gap: 27px; font-size: 18px; font-weight: 700; }
.site-nav > a { position: relative; white-space: nowrap; padding: 8px 0; }
.site-nav > a.current::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 3px; border-radius: 3px; background: var(--green); }
.site-nav .account-link { font-size: 16px; font-weight: 400; border: 1px solid #c3d0c4; border-radius: 40px; padding: 18px 20px; }
.mobile-menu { display: none; }
.intro { min-height: 540px; display: grid; grid-template-columns: 1.1fr .9fr; align-items: center; gap: 50px; padding: 54px 0 65px; }
.eyebrow { color: #75846a; font-size: 14px; font-weight: 800; letter-spacing: .2em; }
.intro h1 { color: #2c4035; font-size: clamp(43px, 5vw, 75px); line-height: 1.44; letter-spacing: -.06em; margin: 20px 0 24px; }
.intro h1 span { color: #718866; }
.intro p { color: #687971; font-size: 20px; line-height: 2.1; margin: 0 0 30px; }
.intro-link { min-width: 245px; display: inline-flex; align-items: center; justify-content: space-between; gap: 36px; padding: 18px 28px; border-radius: 50px; background: var(--green); color: white; font-size: 17px; font-weight: 800; }
.intro-link span { font-size: 24px; line-height: 1; }
.intro-side { height: 390px; position: relative; display: flex; flex-direction: column; align-items: center; justify-content: center; overflow: hidden; border-radius: 260px 260px 35px 35px; background: #e8eddf; color: #365242; }
.intro-side::before, .intro-side::after { content: ""; position: absolute; width: 580px; height: 245px; border-radius: 50%; bottom: -160px; left: -70px; background: #c4d1ad; transform: rotate(-9deg); }
.intro-side::after { bottom: -192px; left: 90px; background: #a4ba8e; transform: rotate(10deg); }
.intro-sun { position: absolute; right: 14%; top: 12%; z-index: 2; color: #dcb76b; font-size: 78px; line-height: 1; }
.intro-side strong { z-index: 1; font-size: clamp(65px, 8vw, 110px); letter-spacing: -.08em; line-height: 1; }
.intro-side > span { z-index: 1; margin-top: 13px; font-size: 20px; letter-spacing: .12em; }
.intro-decoration { position: absolute; top: 30px; left: 50%; z-index: 2; transform: translateX(-50%); white-space: nowrap; color: #789078; font-size: 11px; letter-spacing: .27em; text-transform: uppercase; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 30px; }
.section-heading h2, .explore-header h2 { font-size: clamp(32px, 3vw, 44px); line-height: 1.3; letter-spacing: -.04em; margin: 15px 0 0; }
.section-heading p { color: #6f7e75; font-size: 17px; line-height: 1.9; margin: 0 0 5px; }
.journey { padding: 48px 0 80px; }
.journey-map { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 22px; margin-top: 38px; position: relative; }
.journey-track { position: absolute; left: 8%; right: 8%; top: 49%; z-index: 0; border-top: 2px dashed #a7b49f; }
.map-pin { height: 315px; position: relative; z-index: 1; display: flex; flex-direction: column; align-items: flex-start; padding: 28px 30px; text-align: left; border: 0; border-radius: 34px; background: #dfe8d7; color: var(--ink); transition: transform .2s, box-shadow .2s; }
.map-pin:nth-of-type(2) { background: #e6e9dd; }
.map-pin:nth-of-type(3) { background: #e9e3ed; }
.map-pin:hover, .map-pin:focus-visible { transform: translateY(-6px); box-shadow: 0 16px 32px #314e3920; outline: 2px solid #7b9c81; outline-offset: 2px; }
.map-pin.active { box-shadow: inset 0 0 0 2px #839d83; }
.station-icon { align-self: flex-end; color: #658862; font-size: 39px; line-height: 1; }
.map-pin:nth-of-type(2) .station-icon { color: #a89c67; }
.map-pin:nth-of-type(3) .station-icon { color: #9888ad; }
.station-index { color: #73836f; font-size: 12px; font-weight: 800; letter-spacing: .15em; margin: 12px 0 18px; }
.map-pin strong { font-size: 30px; letter-spacing: -.04em; }
.map-pin small { color: #617568; font-size: 16px; line-height: 1.7; margin-top: 15px; }
.station-bottom { width: 100%; display: flex; align-items: center; justify-content: space-between; border-top: 1px solid #c9d1c1; margin-top: auto; padding-top: 17px; font-size: 16px; font-weight: 800; }
.station-bottom b { font-size: 27px; font-weight: 400; line-height: 1; }
.explore { border-top: 1px solid var(--line); padding: 52px 0 100px; }
.explore-header { display: flex; align-items: end; justify-content: space-between; gap: 20px; }
.explore-header p { color: #718076; font-size: 16px; line-height: 1.8; margin: 14px 0 0; }
.level-count { display: inline-block; vertical-align: middle; margin-left: 9px; padding: 7px 13px; border: 1px solid #c9d5c4; border-radius: 30px; color: #71846d; font-size: 15px; font-weight: 500; letter-spacing: 0; white-space: nowrap; }
.level-switch { display: flex; flex: none; gap: 5px; padding: 5px; border-radius: 40px; background: #e9eddf; }
.level-switch button { border: 0; border-radius: 30px; background: transparent; color: #697b6c; padding: 12px 15px; font-size: 14px; font-weight: 700; }
.level-switch button.selected { background: var(--green); color: white; }
.explore-tools { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin: 31px 0 23px; }
.search-wrap, .drawer-search { min-width: min(340px, 100%); height: 49px; display: flex; align-items: center; gap: 10px; padding: 0 17px; border: 1px solid #cbd4c6; border-radius: 40px; background: #fffdf8; }
.search-wrap span, .drawer-search span { color: #73896f; font-size: 27px; line-height: 1; }
.search-wrap input, .drawer-search input { flex: 1; min-width: 0; border: 0; outline: 0; background: transparent; color: var(--ink); font-size: 14px; }
.result-caption { color: #91a092; font-size: 13px; }
.world-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 21px; }
.world-card { height: 255px; display: flex; flex-direction: column; align-items: stretch; padding: 28px 29px; border: 0; border-radius: 35px; background: var(--tint); color: var(--ink); text-align: left; transition: transform .2s, box-shadow .2s; }
.world-card:hover, .world-card:focus-visible { transform: translateY(-5px); box-shadow: 0 16px 25px #47534315; outline: 2px solid var(--ink); outline-offset: 2px; }
.world-icon { align-self: flex-end; color: var(--ink); font-size: 31px; line-height: 1; }
.world-card-text { flex: 1; display: flex; flex-direction: column; }
.world-card strong { font-size: 27px; line-height: 1.3; letter-spacing: -.04em; margin: -4px 0 11px; }
.world-card small { color: #6e7b72; font-size: 15px; line-height: 1.6; }
.world-card b { border-top: 1px solid #37493b21; margin-top: auto; padding-top: 15px; font-size: 14px; }
.world-arrow { align-self: end; margin-top: -26px; font-size: 25px; line-height: 1; }
.empty-results { grid-column: 1/-1; padding: 50px 20px; border-radius: 25px; background: #e9eddf; color: #6d7d70; text-align: center; }
footer { display: flex; justify-content: space-between; gap: 30px; border-top: 1px solid var(--line); padding: 50px 0 60px; color: #7f8b7e; font-size: 15px; }
footer strong, footer span { display: block; }
footer strong { color: #6f816c; margin-bottom: 10px; }
.drawer-backdrop, .detail-backdrop { position: fixed; inset: 0; z-index: 20; background: #243a2b8a; }
.word-drawer { position: fixed; right: 0; top: 0; bottom: 0; z-index: 21; width: min(485px, 100vw); display: flex; flex-direction: column; transform: translateX(103%); transition: transform .25s; background: #f7f6f0; box-shadow: -15px 0 40px #2234292b; }
.word-drawer.open { transform: translateX(0); }
.drawer-top { display: flex; justify-content: space-between; padding: 20px 28px; }
.back-button, .close-button, .detail-close { border: 0; background: none; color: var(--green); }
.back-button { font-size: 14px; font-weight: 700; }
.close-button, .detail-close { font-size: 28px; }
.drawer-heading { padding: 13px 29px 19px; }
.drawer-heading h2 { color: var(--ink); font-size: 36px; margin: 9px 0; }
.drawer-heading p { color: #728072; font-size: 14px; margin: 0; }
.drawer-search { flex: none; min-width: auto; margin: 0 29px 20px; }
.word-list { overflow: auto; display: grid; align-content: start; gap: 11px; padding: 0 29px 30px; }
.word-item { display: flex; align-items: center; gap: 14px; padding: 17px; border: 0; border-radius: 17px; background: #e7ecdf; color: var(--ink); text-align: left; }
.word-item:nth-child(3n+2) { background: #e6e8ec; }
.word-item:nth-child(3n) { background: #f1e8d7; }
.word-item:hover { outline: 2px solid #799477; }
.word-initial { width: 43px; height: 43px; display: grid; place-items: center; border: 1px solid #afc0ab; border-radius: 50%; font-size: 21px; font-weight: 700; }
.word-item strong { font-size: 18px; }
.word-item small { display: block; color: #768678; font-size: 12px; margin-top: 3px; }
.word-item i { margin-left: auto; color: #748574; font-size: 11px; font-style: normal; white-space: nowrap; }
.detail-backdrop { z-index: 30; }
.detail-modal { position: fixed; z-index: 31; left: 50%; top: 50%; width: min(620px, calc(100vw - 28px)); overflow: hidden; opacity: 0; pointer-events: none; transform: translate(-50%, -45%) scale(.97); transition: transform .22s, opacity .22s; border-radius: 29px; background: #f7f6f0; box-shadow: 0 28px 70px #25342968; }
.detail-modal.open { opacity: 1; pointer-events: auto; transform: translate(-50%, -50%) scale(1); }
.detail-close { position: absolute; right: 20px; top: 15px; z-index: 2; }
.detail-illustration { position: relative; height: 200px; display: grid; place-items: center; overflow: hidden; background: #e4ebda; }
.detail-illustration::after { content: ""; position: absolute; bottom: -150px; width: 120%; height: 200px; border-radius: 50%; background: #c5d3b3; }
.detail-illustration #detailGlyph { z-index: 1; color: #57735c; font-size: 112px; font-weight: 800; line-height: 1; }
.story-ribbon { position: absolute; right: 23px; bottom: 17px; z-index: 2; color: #748369; font-size: 11px; letter-spacing: .18em; }
.detail-content { padding: 26px 32px 33px; }
.detail-status { display: inline-block; padding: 7px 12px; border-radius: 30px; background: #e9e2d2; color: #796a4a; font-size: 12px; }
.detail-content h2 { color: var(--ink); font-size: 47px; margin: 7px 0 0; }
.detail-content > p { color: #768479; font-size: 15px; margin: 3px 0 17px; }
.speak-button { border: 1px solid #b5c6b2; border-radius: 30px; padding: 11px 17px; background: transparent; color: var(--green); font-size: 14px; font-weight: 700; }
.story-empty { border-radius: 18px; background: #e9eddf; padding: 20px; margin-top: 26px; }
.story-empty strong { font-size: 15px; }
.story-empty p { color: #738174; font-size: 13px; line-height: 1.7; margin: 8px 0 0; }
.detail-meta { color: #9aa597; font-size: 12px; margin-top: 18px; }
.reading-progress { display: grid; grid-template-columns: 1.5fr 1fr 1fr; align-items: stretch; gap: 0; padding: 26px 30px; border-radius: 29px; background: #e8eddf; }
.progress-intro { display: flex; flex-direction: column; justify-content: center; gap: 9px; }
.progress-intro strong { color: #2c4035; font-size: 25px; letter-spacing: -.04em; }
.progress-intro small { color: #7b8a79; font-size: 12px; }
.progress-count { display: flex; flex-direction: column; justify-content: center; align-items: center; border-left: 1px solid #cbd5c7; }
.progress-count strong { color: #345e4b; font-size: 48px; line-height: 1.2; }
.progress-count span { color: #6e806e; font-size: 14px; }
@media (max-width: 1180px) {
  .brand-copy strong { font-size: 25px; }
  .site-nav { gap: 16px; font-size: 15px; }
  .site-nav .account-link { font-size: 14px; padding: 12px; }
  .intro h1 { font-size: 56px; }
  .world-card { padding: 25px; }
  .world-card strong { font-size: 24px; }
}
@media (max-width: 800px) {
  .site-shell { padding: 0 19px; }
  .site-header { height: 88px; }
  .brand-mark { font-size: 40px; }
  .brand-copy strong { font-size: 22px; }
  .brand-copy small { font-size: 8px; }
  .mobile-menu { display: block; border: 0; background: transparent; color: var(--ink); font-size: 24px; }
  .site-nav { display: none; position: absolute; z-index: 10; top: 80px; left: 15px; right: 15px; flex-direction: column; align-items: stretch; gap: 3px; padding: 18px; border: 1px solid #d7ded0; border-radius: 20px; background: #f7f6f0; box-shadow: 0 10px 25px #263a2926; }
  .site-nav.open { display: flex; }
  .site-nav > a { font-size: 16px; padding: 11px; }
  .site-nav .account-link { border-radius: 10px; }
  .intro { grid-template-columns: 1fr; min-height: 0; gap: 30px; padding: 43px 0 40px; }
  .intro h1 { font-size: clamp(40px, 10vw, 65px); margin: 15px 0; }
  .intro p { font-size: 16px; line-height: 1.9; }
  .intro-side { height: 250px; border-radius: 170px 170px 25px 25px; }
  .intro-side strong { font-size: 77px; }
  .intro-side > span { font-size: 15px; }
  .intro-sun { font-size: 50px; }
  .journey { padding: 30px 0 54px; }
  .section-heading h2, .explore-header h2 { font-size: 32px; }
  .section-heading p { font-size: 14px; }
  .journey-map { grid-template-columns: 1fr; gap: 13px; margin-top: 25px; }
  .journey-track { display: none; }
  .map-pin { height: auto; min-height: 205px; padding: 23px; }
  .station-icon { position: absolute; right: 25px; top: 20px; }
  .station-index { margin: 0 0 12px; }
  .map-pin strong { font-size: 27px; }
  .map-pin small { margin-top: 8px; }
  .station-bottom { margin-top: 22px; }
  .explore { padding: 38px 0 65px; }
  .explore-header { display: block; }
  .level-switch { width: max-content; margin-top: 21px; }
  .explore-tools { margin: 23px 0; }
  .result-caption { display: none; }
  .world-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
  .world-card { height: 205px; padding: 19px; border-radius: 23px; }
  .world-card strong { font-size: 20px; }
  .world-card small { font-size: 13px; }
  .world-card b { font-size: 12px; }
  .world-icon { font-size: 25px; }
  .reading-progress { grid-template-columns: 1fr 1fr; padding: 22px; }
  .progress-intro { grid-column: 1/-1; padding-bottom: 16px; }
  .progress-count { padding-top: 16px; border-top: 1px solid #cbd5c7; }
  .progress-count:nth-of-type(2) { border-left: 0; }
  .progress-count strong { font-size: 38px; }
  footer { font-size: 12px; }
  .footer-links { display: none; }
}
@media (max-width: 480px) {
  .section-heading { display: block; }
  .section-heading p { margin-top: 14px; }
  .world-card { height: 190px; padding: 15px; }
  .world-card strong { font-size: 18px; }
  .world-card small { font-size: 12px; }
  .world-card b { font-size: 11px; }
  .level-count { font-size: 11px; padding: 5px 9px; margin-left: 3px; }
  .level-switch button { font-size: 12px; padding: 10px; }
  .intro-link { min-width: 220px; }
  .word-item i { display: none; }
  footer > div:last-child { display: none; }
}
.world-card { height: 365px; padding: 16px 28px 25px; color: #2c4035; }
.world-image { width: 100%; height: 198px; object-fit: contain; object-position: center; display: block; margin: 0 auto 2px; filter: drop-shadow(0 6px 6px #263b2815); }
.world-card strong { margin: 0 0 7px; }
.world-card small { line-height: 1.35; }
.world-card b { padding-top: 12px; }
.site-shell { max-width: 1260px; padding: 0 40px; }
.site-header { height: 98px; gap: 32px; }
.brand { gap: 11px; }
.brand-mark { font-size: 42px; }
.brand-copy strong { font-size: 21px; letter-spacing: 1px; }
.brand-copy small { font-size: 10px; letter-spacing: 2.2px; }
.site-nav { margin-left: auto; gap: 30px; font-size: 14px; font-weight: 600; }
.site-nav .account-link { font-size: 13px; padding: 12px 18px; }
.footer-links { display: flex; gap: 20px; }
footer { font-size: 12px; }
@media (max-width: 800px) {
  .site-shell { padding: 0 18px; }
  .site-header { height: 80px; }
  .brand-mark { font-size: 35px; }
  .brand-copy strong { font-size: 18px; }
  .brand-copy small { font-size: 8px; letter-spacing: 1.5px; }
  .site-nav { margin-left: 0; }
  .footer-links { display: none; }
  .world-card { height: 285px; padding: 12px 16px 16px; }
  .world-image { height: 143px; margin-bottom: 3px; }
}
@media (max-width: 480px) {
  .world-card { height: 251px; padding: 9px 12px 13px; }
  .world-image { height: 124px; }
  .world-card strong { font-size: 17px; }
  .world-card small { font-size: 11px; }
}
.world-page { padding: 28px 0 100px; }
.world-page-back { display: flex; align-items: center; justify-content: space-between; gap: 20px; color: #748573; font-size: 13px; }
.world-page-back button { border: 0; background: transparent; color: var(--green); padding: 12px 0; font-size: 15px; font-weight: 700; }
.world-page-back button:hover { text-decoration: underline; }
.world-page-hero { display: grid; grid-template-columns: 1fr .78fr; align-items: center; gap: 34px; min-height: 345px; margin: 22px 0 62px; padding: 35px 7%; border-radius: 34px; background: var(--world-tint,#e4ebda); overflow: hidden; }
.world-page-hero h1 { margin: 14px 0 8px; font-size: clamp(43px,5vw,65px); letter-spacing: -.05em; line-height: 1.25; }
.world-page-hero p { margin: 0 0 25px; color: #647568; font-size: 18px; line-height: 1.7; }
.world-page-count { display: inline-flex; border: 1px solid #9faf9a; border-radius: 40px; padding: 10px 16px; color: #4f6c55; font-size: 14px; font-weight: 700; }
.world-page-hero img { display: block; width: 100%; max-width: 390px; max-height: 295px; object-fit: contain; justify-self: center; filter: drop-shadow(0 16px 18px #465a3822); }
.world-page-heading { display: flex; align-items: end; justify-content: space-between; gap: 26px; margin-bottom: 28px; }
.world-page-heading h2 { margin: 11px 0 7px; font-size: clamp(29px,3vw,39px); letter-spacing: -.04em; }
.world-page-heading p { margin: 0; color: #778578; font-size: 14px; line-height: 1.7; }
.word-cover-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 24px; }
.word-cover { min-width: 0; padding: 0; border: 1px solid #e0e1d8; border-radius: 27px; overflow: hidden; background: #fffdf8; text-align: left; color: var(--ink); box-shadow: 0 5px 16px #2e46320b; transition: transform .2s, box-shadow .2s; }
.word-cover:hover, .word-cover:focus-visible { transform: translateY(-5px); box-shadow: 0 15px 30px #2e463321; outline: 2px solid #799477; outline-offset: 2px; }
.cover-art { position: relative; display: grid; place-items: center; aspect-ratio: 1080 / 1922; height: auto; overflow: hidden; background: var(--cover-tint); }
.cover-art::before { content: ''; position: absolute; width: 210px; height: 210px; border-radius: 50%; background: #fffdf866; transform: translateY(17px); }
.cover-placeholder { position: relative; z-index: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; width: 100%; height: 100%; padding: 26px 20px; color: #496b51; }
.cover-letter { font-family: Georgia,serif; font-size: 104px; line-height: .9; font-weight: 700; opacity: .32; }
.cover-title { margin-top: -16px; max-width: 100%; overflow-wrap: anywhere; text-align: center; font-size: 24px; font-weight: 800; letter-spacing: -.04em; }
.cover-image { position: absolute; inset: 0; display: block; width: 100%; height: 100%; object-fit: cover; }
.cover-spark { position: absolute; z-index: 2; right: 19px; bottom: 11px; color: #fffef5; font-size: 28px; }
.cover-info { display: flex; align-items: center; justify-content: space-between; gap: 14px; padding: 21px 22px 12px; }
.cover-info strong { display: block; font-size: 23px; line-height: 1.25; overflow-wrap: anywhere; }
.cover-info small { display: block; margin-top: 6px; color: #768579; font-size: 13px; }
.cover-arrow { font-size: 24px; font-weight: 400; flex: none; }
.cover-status { display: block; margin: 0 22px 21px; padding-top: 12px; border-top: 1px solid #e9e9e1; color: #9a9c8f; font-size: 11px; }
@media (max-width: 800px) {
  .world-page { padding-top: 15px; }
  .world-page-hero { min-height: 270px; margin-bottom: 45px; padding: 25px 6%; }
  .world-page-hero img { max-height: 220px; }
  .word-cover-grid { grid-template-columns: repeat(2,minmax(0,1fr)); gap: 15px; }
  .world-page-heading { align-items: start; flex-direction: column; }
}
@media (max-width: 600px) {
  .world-page-hero { grid-template-columns: 1fr; gap: 4px; margin-top: 12px; text-align: center; }
  .world-page-hero h1 { font-size: 40px; }
  .world-page-hero img { max-height: 190px; }
  .cover-letter { font-size: 78px; }
  .cover-title { font-size: 19px; margin-top: -10px; }
  .cover-info { padding: 13px 12px 8px; }
  .cover-info strong { font-size: 19px; }
  .cover-info small { font-size: 11px; }
  .cover-status { margin: 0 12px 14px; font-size: 9px; }
}

/* —— 单词故事视频（封面取自视频最后一帧） —— */
.detail-modal { max-height: 92vh; overflow: hidden auto; }
.detail-illustration.has-video { height: auto; background: #f2ece1; }
.detail-illustration.has-video::after { display: none; }
.detail-video { position: relative; z-index: 1; display: block; width: auto; max-width: 100%; height: min(60vh, 520px); margin: 0 auto; background: #f2ece1; }
.detail-illustration.has-video .story-ribbon { display: none; }
.word-cover.has-video .cover-spark { display: none; }
.cover-play { position: absolute; z-index: 3; right: 14px; bottom: 14px; display: grid; place-items: center; width: 46px; height: 46px; border-radius: 50%; background: #fffdf8e6; color: #3f6049; font-size: 16px; box-shadow: 0 6px 16px #2e46322e; }
.word-cover.has-video .cover-status { color: #57735c; font-weight: 700; }