:root{--bg:#f3f4f0;--paper:#fff;--ink:#18211d;--muted:#657068;--line:#d9ded9;--brand:#175743;--brand-2:#0f4434;--soft:#e9f0ec;--warn:#8b4c2e;--danger:#9d3030;--shadow:0 14px 42px rgba(28,44,35,.08);--radius:10px;--header:68px;font-family:Arial,"Noto Sans TC","PingFang TC","Microsoft JhengHei",sans-serif;color-scheme:light}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--ink);font-size:16px;line-height:1.65}a{color:inherit;text-decoration:none}button,input,select,textarea{font:inherit}button{cursor:pointer}.icon{width:20px;height:20px;fill:currentColor;flex:0 0 auto}.site-header{height:var(--header);position:sticky;top:0;z-index:40;background:rgba(255,255,255,.97);border-bottom:1px solid var(--line);backdrop-filter:blur(10px)}.header-inner{height:100%;max-width:1240px;margin:auto;padding:0 22px;display:flex;align-items:center;gap:28px}.brand{display:flex;align-items:center;gap:10px;font-weight:800;letter-spacing:-.02em;white-space:nowrap}.brand-mark{display:grid;place-items:center;width:34px;height:34px;border:1px solid var(--line);border-radius:8px;background:#fff}.brand small{display:block;font-weight:500;color:var(--muted);font-size:11px;line-height:1}.desktop-nav{margin-left:auto;display:flex;align-items:center;gap:5px}.nav-link,.nav-button{display:flex;align-items:center;gap:7px;padding:9px 11px;border:0;background:transparent;border-radius:7px;color:#334039}.nav-link:hover,.nav-button:hover,.nav-link[aria-current=page]{background:var(--soft);color:var(--brand)}.nav-group{position:relative}.dropdown{position:absolute;right:0;top:calc(100% + 8px);min-width:220px;padding:7px;background:#fff;border:1px solid var(--line);border-radius:9px;box-shadow:var(--shadow);opacity:0;visibility:hidden;transform:translateY(-5px);transition:.16s ease}.nav-group.open .dropdown{opacity:1;visibility:visible;transform:none}.dropdown a{display:flex;align-items:center;gap:9px;padding:10px;border-radius:6px}.dropdown a:hover{background:var(--soft)}.mobile-menu-button{display:none;margin-left:auto;border:1px solid var(--line);background:#fff;width:42px;height:42px;border-radius:8px;place-items:center}.mobile-panel{display:none;position:fixed;inset:var(--header) 0 auto 0;z-index:39;background:#fff;border-bottom:1px solid var(--line);padding:12px 18px 20px;box-shadow:var(--shadow)}.mobile-panel.open{display:block}.mobile-panel a{display:flex;align-items:center;gap:10px;padding:13px 4px;border-bottom:1px solid #edf0ed}.page{max-width:1180px;margin:0 auto;padding:30px 22px 72px}.page-head{display:flex;align-items:flex-start;justify-content:space-between;gap:20px;margin-bottom:22px}.eyebrow{color:var(--brand);font-size:13px;font-weight:700;letter-spacing:.08em}.page h1{margin:3px 0 6px;font-size:clamp(27px,3.2vw,42px);line-height:1.2;letter-spacing:-.035em}.lead{margin:0;color:var(--muted);max-width:720px}.hero-shell{position:relative;overflow:hidden;background:#f8f8f4;border:1px solid var(--line);border-radius:12px;min-height:172px;padding:28px 34px;margin-bottom:22px}.hero-shell:after{content:"";position:absolute;inset:0 0 0 55%;background-image:linear-gradient(90deg,#f8f8f4 0,rgba(248,248,244,.72) 24%,rgba(248,248,244,0) 66%),url("https://img.kaelith.tw/babyai/v1/lesson-workspace.webp");background-position:center right;background-size:cover;background-repeat:no-repeat;pointer-events:none;user-select:none;-webkit-user-select:none;-webkit-touch-callout:none}.hero-copy{position:relative;z-index:2;max-width:600px}.grid{display:grid;gap:18px}.grid-2{grid-template-columns:minmax(0,1fr) 340px}.card{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 3px 12px rgba(28,44,35,.035)}.card-head{padding:18px 20px;border-bottom:1px solid var(--line)}.card-head h2,.card-head h3{margin:0;font-size:19px}.card-body{padding:20px}.steps{display:flex;border-bottom:1px solid var(--line);overflow:auto;scrollbar-width:none}.step{min-width:145px;flex:1;border:0;background:#fff;padding:14px 12px;color:var(--muted);border-bottom:2px solid transparent}.step.active{color:var(--brand);border-bottom-color:var(--brand);font-weight:700}.step-panel{display:none}.step-panel.active{display:block;animation:panel-in .18s ease}.form-section{padding:22px}.form-section h2{font-size:22px;margin:0 0 4px}.form-section>p{margin:0 0 18px;color:var(--muted)}.fields{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.field.full{grid-column:1/-1}.field label,.legend{display:block;font-weight:700;font-size:14px;margin-bottom:6px}.help{display:block;color:var(--muted);font-size:12px;margin-top:5px}.control{width:100%;min-height:45px;border:1px solid #cfd5cf;border-radius:7px;padding:10px 12px;background:#fff;color:var(--ink);outline:none}.control:focus{border-color:var(--brand);box-shadow:0 0 0 3px rgba(23,87,67,.1)}textarea.control{min-height:112px;resize:vertical}.choice-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px}.choice{position:relative}.choice input{position:absolute;opacity:0}.choice span{display:flex;align-items:center;min-height:43px;padding:9px 11px;border:1px solid var(--line);border-radius:7px;background:#fff}.choice input:checked+span{border-color:var(--brand);background:var(--soft);color:var(--brand);font-weight:700}.actions{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:16px 20px;border-top:1px solid var(--line)}.action-set{display:flex;gap:8px;flex-wrap:wrap}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:42px;padding:9px 15px;border:1px solid var(--line);border-radius:7px;background:#fff;color:var(--ink);font-weight:700}.btn:hover{border-color:#aeb7b0;background:#fafbfa}.btn.primary{background:var(--brand);border-color:var(--brand);color:#fff}.btn.primary:hover{background:var(--brand-2)}.btn.danger{color:var(--danger)}.btn:disabled{opacity:.55;cursor:not-allowed}.summary-list{margin:0}.summary-list div{padding:12px 0;border-bottom:1px solid var(--line)}.summary-list dt{font-size:12px;color:var(--muted)}.summary-list dd{margin:2px 0 0;font-weight:700}.notice{padding:12px 14px;border-left:3px solid var(--brand);background:#f2f6f3;color:#3b4941}.job-bar{display:none;position:fixed;right:20px;bottom:20px;z-index:50;width:min(360px,calc(100vw - 36px));background:#18211d;color:#fff;padding:14px 16px;border-radius:9px;box-shadow:var(--shadow)}.job-bar.show{display:block}.job-bar strong{display:block}.job-bar p{margin:2px 0 8px;color:#dfe6e1;font-size:13px}.progress{height:4px;background:rgba(255,255,255,.22);overflow:hidden;border-radius:2px}.progress i{display:block;height:100%;width:34%;background:#fff;animation:progress 1.25s infinite ease-in-out}.toolbar{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:14px}.lesson-header{padding:24px}.lesson-header h1{font-size:32px}.meta{display:flex;gap:8px 18px;flex-wrap:wrap;color:var(--muted);font-size:14px}.activity{border-top:1px solid var(--line)}.activity:first-child{border-top:0}.activity-summary{width:100%;display:grid;grid-template-columns:38px 1fr auto;gap:12px;align-items:center;text-align:left;border:0;background:#fff;padding:16px 20px}.activity-summary:hover{background:#fafbf9}.number{display:grid;place-items:center;width:32px;height:32px;border:1px solid var(--line);border-radius:50%;font-weight:800}.activity-summary h3{margin:0;font-size:18px}.activity-summary small{color:var(--brand);font-weight:700}.activity-content{display:none;padding:2px 22px 24px 70px}.activity.open .activity-content{display:block}.detail-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px 26px}.detail-block.full{grid-column:1/-1}.detail-block h4{font-size:13px;margin:0 0 5px;color:#425148}.detail-block ul{margin:0;padding-left:20px}.empty{padding:50px 22px;text-align:center;color:var(--muted)}.library-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.lesson-card{padding:18px}.lesson-card h3{margin:4px 0}.lesson-card .meta{font-size:12px}.lesson-card footer{display:flex;gap:7px;flex-wrap:wrap;margin-top:16px}.tag{display:inline-block;padding:3px 7px;border-radius:4px;background:var(--soft);color:var(--brand);font-size:12px}.modal{border:0;border-radius:10px;padding:0;width:min(520px,calc(100% - 30px));box-shadow:var(--shadow)}.modal::backdrop{background:rgba(10,18,14,.42)}.modal header,.modal footer{padding:16px 18px}.modal header{border-bottom:1px solid var(--line)}.modal footer{border-top:1px solid var(--line);display:flex;justify-content:flex-end;gap:8px}.modal .modal-body{padding:18px}.guide-layout{display:grid;grid-template-columns:250px minmax(0,1fr);gap:26px}.guide-toc{position:sticky;top:94px;align-self:start}.guide-toc a{display:block;padding:8px 10px;border-left:2px solid var(--line)}.guide-toc a:hover{border-color:var(--brand);color:var(--brand)}.guide-content section{scroll-margin-top:90px;padding:22px;margin-bottom:14px;background:#fff;border:1px solid var(--line);border-radius:9px}.guide-content h2{margin-top:0}.site-footer{border-top:1px solid var(--line);background:#fff}.footer-inner{max-width:1180px;margin:auto;padding:24px 22px;display:flex;justify-content:space-between;gap:20px;color:var(--muted);font-size:13px}.decorative-bg{position:fixed;inset:auto 0 0 auto;width:420px;height:420px;background:url("https://img.kaelith.tw/babyai/v1/paper-leaves.webp") center/contain no-repeat;opacity:.16;pointer-events:none;z-index:-1;user-select:none;-webkit-touch-callout:none}
@keyframes panel-in{from{opacity:0;transform:translateY(3px)}to{opacity:1;transform:none}}@keyframes progress{0%{transform:translateX(-100%)}100%{transform:translateX(300%)}}
@media(max-width:920px){.desktop-nav{display:none}.mobile-menu-button{display:grid}.grid-2,.guide-layout{grid-template-columns:1fr}.side-summary{order:-1}.guide-toc{display:none}.library-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.hero-shell:after{opacity:.42;inset:0}.hero-copy{background:rgba(248,248,244,.86);padding:14px;border-radius:8px}.detail-grid{grid-template-columns:1fr}}
@media(max-width:620px){:root{--header:60px}.header-inner{padding:0 14px}.brand span span{display:none}.page{padding:20px 14px 58px}.page-head{display:block}.hero-shell{padding:18px;min-height:150px}.fields,.choice-grid{grid-template-columns:1fr}.actions{align-items:stretch}.actions,.action-set{flex-direction:column}.btn{width:100%}.steps{margin:0 -1px}.step{min-width:122px;font-size:13px}.form-section{padding:18px 15px}.card-body{padding:15px}.library-grid{grid-template-columns:1fr}.activity-summary{grid-template-columns:32px 1fr auto;padding:14px}.activity-content{padding:0 15px 20px}.lesson-header{padding:18px}.lesson-header h1{font-size:26px}.footer-inner{display:block}.job-bar{right:10px;bottom:10px;width:calc(100vw - 20px)}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important;scroll-behavior:auto!important}}
@media print{.site-header,.site-footer,.toolbar,.job-bar,.decorative-bg,.revision-panel{display:none!important}.page{max-width:none;padding:0}.card{border:0;box-shadow:none}.activity-content{display:block!important}.activity-summary{padding-left:0}.activity{break-inside:avoid}.detail-grid{display:block}.detail-block{margin-bottom:14px}}