:root{color-scheme:light;--green: #16a34a;--green-dark: #15803d;--green-soft: #dcfce7;--ink: #1f2937;--muted: #6b7280;--line: #e5e7eb;--bg: #f7f8fa;--surface: #ffffff;--sunken: #f1f5f9;--text-soft: #374151;--red: #dc2626;--red-soft: #fee2e2;--radius: 16px;font-family:system-ui,-apple-system,Segoe UI,Roboto,Noto Sans TC,sans-serif}:root[data-theme=dark]{color-scheme:dark;--green-soft: #14532d;--ink: #e5e7eb;--muted: #94a3b8;--line: #334155;--bg: #0f172a;--surface: #1e293b;--sunken: #334155;--text-soft: #cbd5e1;--red-soft: #4c1d1d}@media (prefers-color-scheme: dark){:root:not([data-theme=light]){color-scheme:dark;--green-soft: #14532d;--ink: #e5e7eb;--muted: #94a3b8;--line: #334155;--bg: #0f172a;--surface: #1e293b;--sunken: #334155;--text-soft: #cbd5e1;--red-soft: #4c1d1d}}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink)}.app{max-width:560px;margin:0 auto;padding:16px;padding-top:calc(16px + env(safe-area-inset-top));padding-bottom:calc(16px + env(safe-area-inset-bottom));min-height:100vh;min-height:100dvh}button{font:inherit;cursor:pointer}.btn-primary{width:100%;border:none;background:var(--green);color:#fff;font-weight:700;font-size:17px;padding:14px;border-radius:var(--radius);box-shadow:0 3px 0 var(--green-dark);transition:transform .05s,background .15s}.btn-primary:active{transform:translateY(2px);box-shadow:0 1px 0 var(--green-dark)}.btn-primary:disabled{background:#cbd5e1;box-shadow:0 3px #94a3b8;cursor:not-allowed}.btn-outline{width:100%;border:2px solid var(--line);background:var(--surface);color:var(--ink);font-weight:700;font-size:17px;padding:12px;border-radius:var(--radius);box-shadow:0 2px 0 var(--line);transition:transform .05s}.btn-outline:active{transform:translateY(2px);box-shadow:0 0 0 var(--line)}.btn-outline:disabled{opacity:.5;cursor:not-allowed}.intro-top{margin-bottom:24px}.intro-body{display:flex;flex-direction:column;gap:14px;text-align:center;padding-top:32px}.intro-track{color:var(--muted);margin:0;font-weight:600}.intro-title{font-size:28px;margin:0}.intro-sub{color:var(--muted);margin:0 0 16px}.study-count{font-weight:700;color:var(--muted);font-size:14px;min-width:48px;text-align:right}.flashcard{display:block;width:100%;min-height:320px;margin:24px 0;border:2px solid var(--line);border-radius:20px;background:var(--surface);box-shadow:0 4px 0 var(--line);padding:32px 20px;text-align:center}.flashcard-face{display:flex;flex-direction:column;gap:14px;justify-content:center;min-height:240px}.flashcard-term{font-size:36px;font-weight:800}.flashcard-pos{color:var(--muted);font-style:italic}.flashcard-hint{color:var(--muted);font-size:13px;margin-top:8px}.flashcard-zh{font-size:30px;font-weight:800;color:var(--green-dark)}.flashcard-sentence{font-size:18px;line-height:1.5}.flashcard-sentence-zh{color:var(--muted);line-height:1.5}.study-nav{display:flex;gap:12px}.study-nav .btn-outline,.study-nav .study-done{flex:1}.stats{display:flex;gap:12px;justify-content:flex-end;margin-bottom:16px}.stat{background:var(--surface);border:1px solid var(--line);border-radius:999px;padding:6px 14px;font-weight:700;font-size:15px}.review-card{width:100%;display:flex;align-items:center;gap:14px;text-align:left;background:linear-gradient(135deg,#22c55e,#16a34a);color:#fff;border:none;border-radius:var(--radius);padding:18px;margin-bottom:24px;box-shadow:0 4px 0 var(--green-dark)}.review-card.disabled{background:var(--sunken);color:var(--muted);box-shadow:0 4px 0 var(--line);cursor:not-allowed}.review-icon{font-size:28px}.review-text{display:flex;flex-direction:column}.review-text strong{font-size:18px}.review-text small{opacity:.92}.track-list{display:grid;gap:12px}.track-card{width:100%;display:flex;align-items:center;gap:12px;text-align:left;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:18px 16px;box-shadow:0 2px 0 var(--line)}.track-card-main{flex:1;display:flex;flex-direction:column;gap:8px}.track-card-main strong{font-size:17px}.track-card-main small{color:var(--muted);font-size:13px}.track-card-bar{height:8px;background:var(--sunken);border-radius:999px;overflow:hidden}.track-card-bar-fill{height:100%;background:var(--green);border-radius:999px;transition:width .3s ease}.track-card-chevron{font-size:26px;color:var(--muted);line-height:1}.trackmap-top{display:flex;align-items:center;gap:8px;margin-bottom:8px}.trackmap-title{font-size:22px;margin:0}.map-path{position:relative;display:flex;flex-direction:column;align-items:center;gap:20px;padding:14px 0}.map-path:before{content:"";position:absolute;top:24px;bottom:48px;left:50%;width:4px;transform:translate(-50%);background:repeating-linear-gradient(var(--line) 0 8px,transparent 8px 16px);z-index:0}.map-row{display:flex;flex-direction:column;align-items:center;gap:20px}.map-group{z-index:1;padding:6px 16px;border-radius:999px;background:var(--sunken);color:var(--muted);font-size:13px;font-weight:700;letter-spacing:.5px}.map-node{position:relative;z-index:1;border:none;background:none;display:flex;flex-direction:column;align-items:center;gap:8px;padding:0}.map-circle{width:76px;height:76px;border-radius:50%;display:grid;place-items:center;font-size:30px;font-weight:800;background:var(--surface);border:3px solid var(--line);box-shadow:0 4px 0 var(--line);transition:transform .06s}.map-node:not(.locked):active .map-circle{transform:translateY(2px)}.map-node.done .map-circle{background:var(--green);border-color:var(--green);color:#fff;box-shadow:0 4px 0 var(--green-dark)}.map-node.current .map-circle{background:var(--green-soft);border-color:var(--green);color:var(--green-dark);box-shadow:0 4px 0 var(--green)}.map-node.locked{cursor:not-allowed}.map-node.locked .map-circle{opacity:.6}.map-title{font-size:13px;font-weight:600;color:var(--ink);max-width:140px;text-align:center;line-height:1.3}.map-node.locked .map-title{color:var(--muted)}.tagline{text-align:center;color:var(--muted);margin-top:24px}.home-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:8px}.icon-btn{border:none;background:none;font-size:22px;padding:6px;line-height:1}.daily-ring{position:relative;width:72px;margin:4px auto 20px;text-align:center}.ring-bg{fill:none;stroke:var(--line);stroke-width:7}.ring-fg{fill:none;stroke:var(--green);stroke-width:7;stroke-linecap:round;transition:stroke-dashoffset .4s ease}.daily-ring.reached .ring-fg{stroke:var(--green)}.ring-label{position:absolute;top:22px;left:0;right:0;line-height:1}.ring-label strong{font-size:18px;color:var(--ink)}.ring-label small{display:block;font-size:11px;color:var(--muted)}.ring-caption{display:block;font-size:12px;color:var(--muted);margin-top:4px}.settings-top{display:flex;align-items:center;gap:8px;margin-bottom:20px}.settings-title{font-size:22px;margin:0}.setting-row{display:flex;align-items:center;justify-content:space-between;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:16px;margin-bottom:12px}.setting-block{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:16px;margin-bottom:12px}.setting-label{display:block;margin-bottom:10px;font-weight:600}.seg{display:flex;gap:8px}.seg-btn{flex:1;padding:10px;border:2px solid var(--line);border-radius:12px;background:var(--surface);color:var(--ink);font-weight:700}.seg-btn.active{border-color:var(--green);background:var(--green-soft);color:var(--green-dark)}.btn-danger{width:100%;border:2px solid var(--red);background:var(--surface);color:var(--red);font-weight:700;font-size:16px;padding:12px;border-radius:var(--radius);margin-top:12px}.lesson{display:flex;flex-direction:column;min-height:90vh;min-height:90dvh}.lesson-top{display:flex;align-items:center;gap:12px;margin-bottom:24px}.quit{border:none;background:none;font-size:22px;color:var(--muted);line-height:1;padding:4px;white-space:nowrap}.quit.quit-confirm{font-size:15px;font-weight:700;color:var(--red)}.progress{flex:1;height:14px;background:var(--line);border-radius:999px;overflow:hidden}.progress-fill{height:100%;background:var(--green);border-radius:999px;transition:width .25s ease}.lesson-body{flex:1}.exercise{display:flex;flex-direction:column;gap:14px}.prompt-hint{color:var(--muted);font-size:14px;margin:0}.prompt-term{font-size:28px;font-weight:800;margin:0}.prompt-sentence{font-size:17px;color:var(--text-soft);margin:0;line-height:1.5}.options{display:grid;gap:10px;margin:4px 0 8px}.option{display:flex;align-items:center;gap:12px;text-align:left;background:var(--surface);border:2px solid var(--line);border-radius:var(--radius);padding:14px 16px;font-size:17px;box-shadow:0 2px 0 var(--line)}.option-num{width:24px;height:24px;flex:none;display:grid;place-items:center;border-radius:8px;background:var(--sunken);color:var(--muted);font-size:13px;font-weight:700}.option.selected,.option.correct{border-color:var(--green);background:var(--green-soft)}.option.wrong{border-color:var(--red);background:var(--red-soft)}.spell-input{width:100%;font:inherit;font-size:18px;padding:14px 16px;border:2px solid var(--line);border-radius:var(--radius);outline:none}.spell-input:focus{border-color:var(--green)}.match-grid{display:flex;gap:12px}.match-col{flex:1;display:flex;flex-direction:column;gap:10px}.match-item{padding:16px 10px;border:2px solid var(--line);border-radius:var(--radius);background:var(--surface);font-size:16px;box-shadow:0 2px 0 var(--line);min-height:56px;transition:background .1s,border-color .1s}.match-item.sel{border-color:var(--green);background:var(--green-soft)}.match-item.done{border-color:var(--green);background:var(--green-soft);opacity:.45}.match-item.wrong{border-color:var(--red);background:var(--red-soft)}.arrange-answer{min-height:56px;display:flex;flex-wrap:wrap;gap:8px;align-content:flex-start;padding:10px;border-bottom:2px solid var(--line)}.arrange-pool{display:flex;flex-wrap:wrap;gap:8px;padding:12px 0}.token{background:var(--surface);border:2px solid var(--line);border-radius:12px;padding:10px 14px;font-size:16px;box-shadow:0 2px 0 var(--line)}.banner{position:sticky;bottom:0;margin:16px -16px -16px;padding:16px;padding-bottom:calc(16px + env(safe-area-inset-bottom));border-top-left-radius:20px;border-top-right-radius:20px}.banner.ok{background:var(--green-soft)}.banner.bad{background:var(--red-soft)}.banner-title{font-weight:800;font-size:18px;margin-bottom:4px}.banner.ok .banner-title{color:var(--green-dark)}.banner.bad .banner-title{color:var(--red)}.banner-answer{margin-bottom:10px;color:var(--text-soft)}.banner-sentence{margin-bottom:12px;font-size:14px;line-height:1.5;color:var(--text-soft)}.resume-card{border:2px solid var(--green)}.intro-words,.result-words{display:flex;flex-wrap:wrap;justify-content:center;gap:8px;margin:4px 0 20px}.word-chip{padding:5px 12px;border-radius:999px;background:var(--sunken);color:var(--text-soft);font-size:13px}.word-chip.ok{background:var(--green-soft);color:var(--green-dark)}.word-chip.bad{background:var(--red-soft);color:var(--red)}:root[data-theme=dark] .word-chip.ok,:root[data-theme=dark] .word-chip.bad{color:var(--ink)}@media (prefers-color-scheme: dark){:root:not([data-theme=light]) .word-chip.ok,:root:not([data-theme=light]) .word-chip.bad{color:var(--ink)}}@keyframes pop-in{0%{opacity:0;transform:scale(.7)}70%{transform:scale(1.06)}to{opacity:1;transform:scale(1)}}.result-title{animation:pop-in .45s ease-out}.result-cards{animation:pop-in .45s ease-out .12s backwards}.result-words{animation:pop-in .45s ease-out .24s backwards}.banner-sentence-zh{color:var(--muted)}.btn-continue{width:100%;border:none;background:var(--green);color:#fff;font-weight:700;font-size:17px;padding:14px;border-radius:var(--radius);box-shadow:0 3px 0 var(--green-dark)}.banner.bad .btn-continue{background:var(--red);box-shadow:0 3px #991b1b}.result{text-align:center;padding-top:40px;display:flex;flex-direction:column;align-items:center;gap:18px}.result-emoji{font-size:64px}.result-title{font-size:26px;margin:0}.result-cards{display:flex;gap:12px;width:100%;justify-content:center}.result-card{flex:1;max-width:150px;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:16px 8px}.result-num{font-size:22px;font-weight:800;color:var(--green-dark)}.result-label{color:var(--muted);font-size:13px;margin-top:4px}.result .btn-primary{max-width:320px;margin-top:12px}@media (min-width: 640px){.app{padding:32px 24px}}