:root { color-scheme: light; --ink: #263d34; --muted: #607268; --paper: #f7f6f0; --line: #dcded3; --accent: #2c7058; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif; line-height: 1.7; }
a { color: inherit; }
button, input { font: inherit; }
button, a, input { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid #b75f1a; outline-offset: 5px; }
[hidden] { display: none !important; }
.masthead, main, footer { width: min(1160px, calc(100% - 64px)); margin: auto; }
.masthead { display: flex; justify-content: space-between; align-items: center; min-height: 94px; border-bottom: 1px solid var(--line); }
.brand { text-decoration: none; font-weight: 650; font-size: 20px; display: flex; align-items: center; gap: 12px; }
.brand-mark { background: var(--ink); color: var(--paper); border-radius: 12px 12px 12px 3px; padding: 0 11px; font: italic 27px/1.5 Georgia, serif; }
.catalog-link { font-size: 14px; text-decoration: none; }
.catalog-link span { margin-left: 18px; }
.intro { display: grid; grid-template-columns: 1.4fr 1fr; gap: 60px; align-items: center; padding: 72px 0 66px; }
.eyebrow { letter-spacing: .16em; font-size: 12px; color: var(--accent); margin: 0 0 16px; font-weight: 650; }
h1 { font-size: clamp(30px, 3.6vw, 47px); line-height: 1.45; letter-spacing: -.04em; margin: 0; font-weight: 650; }
h1 em { font-style: normal; color: var(--accent); }
.intro-copy { color: var(--muted); font-size: 16px; margin: 24px 0 18px; }
.intro-note { font-size: 12px; color: var(--muted); }
.notebook { position: relative; transform: rotate(3deg); padding: 22px 24px; border: 1px solid #d5dacb; background-color: #eeeee2; background-image: linear-gradient(#d8ddce66 1px, transparent 1px), linear-gradient(90deg, #d8ddce66 1px, transparent 1px); background-size: 24px 24px; border-radius: 3px; box-shadow: 8px 10px 0 #e8e8dd; }
.note-label { font-size: 12px; letter-spacing: .1em; color: var(--muted); }
.notebook svg { width: 100%; display: block; }
.notebook svg text { font: italic 24px Georgia, serif; }
.note-formula { display: block; text-align: right; font: italic 26px Georgia, serif; color: var(--accent); }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 20px; }
.section-heading .eyebrow { margin-bottom: 6px; }
h2 { margin: 0; font-size: 25px; font-weight: 650; }
#result-count { font-size: 13px; color: var(--muted); white-space: nowrap; }
.toolbar { display: flex; justify-content: space-between; gap: 20px; margin: 26px 0; align-items: center; }
.filters { display: flex; flex-wrap: wrap; gap: 8px; }
.filters button { padding: 7px 20px; border: 1px solid var(--line); border-radius: 24px; background: transparent; color: var(--muted); cursor: pointer; font-size: 14px; }
.filters button[aria-pressed="true"] { background: var(--ink); border-color: var(--ink); color: white; }
.search { display: flex; gap: 12px; align-items: center; font-size: 12px; color: var(--muted); }
.search input { min-width: 0; width: 200px; border: 1px solid var(--line); background: #fffdf8; padding: 9px 12px; border-radius: 5px; font-size: 14px; color: var(--ink); }
.lesson-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; margin-top: 26px; }
.lesson { background: #fffdf8; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; display: flex; flex-direction: column; }
.lesson-art { height: 118px; background: #e7eee6; color: #37654f; display: flex; align-items: center; justify-content: center; font: italic 28px Georgia, "STKaiti", serif; letter-spacing: .06em; border-bottom: 1px solid var(--line); }
.lesson[data-subject="chinese"] .lesson-art { background: #f1e9dc; color: #916236; font-style: normal; }
.lesson[data-subject="science"] .lesson-art { background: #e5eaf0; color: #526c88; font-size: 37px; }
.lesson-body { padding: 22px; display: flex; flex-direction: column; flex: 1; }
.lesson-meta { color: var(--muted); font-size: 11px; letter-spacing: .03em; margin: 0 0 10px; }
.lesson h3 { font-size: 18px; line-height: 1.5; margin: 0; }
.lesson-description { font-size: 14px; color: var(--muted); margin: 12px 0 24px; }
.lesson-link { margin-top: auto; display: flex; justify-content: space-between; text-decoration: none; font-size: 13px; color: var(--accent); font-weight: 650; padding-top: 13px; border-top: 1px solid var(--line); }
.lesson-link:hover { text-decoration: underline; }
.learning-note { display: flex; align-items: center; gap: 24px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); margin: 50px 0 0; padding: 24px 0; color: var(--muted); }
.learning-note > span { font: 38px Georgia, serif; color: var(--accent); }
.learning-note p { font-size: 14px; margin: 0; }
.learning-note strong { color: var(--ink); font-weight: 600; }
footer { display: flex; justify-content: space-between; gap: 20px; padding: 30px 0; font-size: 12px; color: var(--muted); }
@media (max-width: 900px) { .intro { gap: 30px; } .lesson-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } .search span { display: none; } }
@media (max-width: 600px) { .masthead, main, footer { width: calc(100% - 36px); } .masthead { min-height: 76px; } .brand { font-size: 17px; } .intro { grid-template-columns: 1fr; padding: 42px 0; gap: 30px; } .notebook { width: 80%; margin: auto; } .notebook svg { max-height: 160px; } h1 { font-size: 30px; } .intro-copy { font-size: 14px; } h2 { font-size: 22px; } .toolbar { align-items: stretch; flex-direction: column; gap: 14px; } .filters button { padding: 7px 17px; } .search input { width: 100%; } .lesson-grid { grid-template-columns: 1fr; gap: 16px; } .lesson-art { height: 96px; } .section-heading { align-items: start; flex-direction: column; gap: 0; } #result-count { margin-bottom: 0; } footer { flex-direction: column; gap: 4px; } }