:root{--bg:#f7f5f2;--card:#ffffff;--ink:#2b2926;--muted:#8a857d;--brand:#1f6feb;--brand-soft:#e7f0ff;--ok:#2e9e5b;--ok-soft:#e2f6e9;--err:#d64545;--err-soft:#fdeaea;--warn:#b7791f;--line:#e6e1da;--radius:16px}*{box-sizing:border-box}body,html{margin:0;padding:0}body{font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--ink);line-height:1.55}a{color:inherit;text-decoration:none}.app-shell{max-width:900px;margin:0 auto;padding:0 20px 80px}.topbar{display:flex;align-items:center;justify-content:space-between;padding:20px 0;gap:12px;flex-wrap:wrap}.brand{font-weight:800;font-size:20px;letter-spacing:-.5px}.brand span{color:var(--brand)}.nav{display:flex;gap:8px;flex-wrap:wrap}.nav a{padding:8px 14px;border-radius:999px;font-weight:600;font-size:14px;color:var(--muted);transition:.15s}.nav a.active,.nav a:hover{background:var(--card);color:var(--ink);box-shadow:0 1px 3px rgba(0,0,0,.06)}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px;box-shadow:0 1px 2px rgba(0,0,0,.04)}.section-title{font-size:22px;font-weight:800;margin:0 0 4px}.subtitle{color:var(--muted);font-size:14px;margin:0 0 18px}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));grid-gap:16px;gap:16px}.stats-row4{display:grid;grid-template-columns:repeat(4,1fr);grid-gap:14px;gap:14px}.stat-card{padding:18px 20px}@media (max-width:720px){.stats-row4{grid-template-columns:repeat(2,1fr)}}.stat{display:flex;flex-direction:column;gap:2px}.stat b{font-size:28px;font-weight:800}.stat label{color:var(--muted);font-size:13px}.stats-row{display:flex;gap:24px;flex-wrap:wrap;margin-bottom:20px}.btn{display:inline-flex;align-items:center;gap:8px;background:var(--brand);color:#fff;border:none;border-radius:12px;padding:12px 22px;font-size:16px;font-weight:700;cursor:pointer;transition:.15s}.btn:hover{filter:brightness(1.06)}.btn:disabled{opacity:.5;cursor:not-allowed}.btn.ghost{background:var(--card);color:var(--ink);border:1px solid var(--line)}.btn.ok{background:var(--ok)}.btn.big{width:100%;justify-content:center;padding:16px;font-size:18px}.list{flex-direction:column}.list,.row-item{display:flex;gap:12px}.row-item{justify-content:space-between;align-items:center;padding:12px 16px;background:var(--card);border:1px solid var(--line);border-radius:12px}.row-item .title{font-weight:700}.row-item .meta{color:var(--muted);font-size:13px}.badge{font-size:12px;font-weight:700;padding:3px 10px;border-radius:999px;background:var(--brand-soft);color:var(--brand);white-space:nowrap}.badge.ok{background:var(--ok-soft);color:var(--ok)}.badge.dim{background:var(--line);color:var(--muted)}.lesson-pick-list{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));grid-gap:10px;gap:10px}.lesson-pick{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:12px 14px;background:var(--card);border:1px solid var(--line);border-radius:12px;transition:.12s}.lesson-pick:hover{border-color:var(--brand);background:var(--brand-soft)}.wcard{padding:18px 22px 20px}.wcard-top{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.wcard-word{font-size:34px;font-weight:800;letter-spacing:-.5px;text-align:center;margin-top:12px;line-height:1.2}.wcard-meaning{text-align:center;margin:4px 0 14px}.wcard-meaning .zh{font-size:20px;font-weight:700;color:var(--brand)}.wcard-meaning .pos{font-size:13px;color:var(--muted);margin-left:8px}.wcard-example{background:var(--bg);border-radius:12px;padding:12px 16px;text-align:left;margin-bottom:14px}.wcard-example .de{font-size:15px;font-weight:500}.wcard-example .zh{font-size:13.5px;color:var(--muted);margin-top:3px}.wcard-example .phrase{font-size:13px;color:var(--muted);border-top:1px dashed var(--line);margin-top:8px;padding-top:7px}.followbar{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap;background:var(--bg);border:1px dashed var(--line);border-radius:12px;padding:10px 14px}.followbar-note{width:100%;text-align:center;font-size:12px;line-height:1.5}.btn.sm{padding:8px 14px;font-size:14px;border-radius:10px}@keyframes input-shake{0%,to{transform:translateX(0)}20%{transform:translateX(-7px)}40%{transform:translateX(6px)}60%{transform:translateX(-4px)}80%{transform:translateX(3px)}}.shake{animation:input-shake .42s ease}.input-alert{border-color:var(--warn)!important;box-shadow:0 0 0 3px rgba(183,121,31,.18)}.mini-hint{font-size:12px;color:var(--muted);margin-top:8px;text-align:center}.mini-hint.warn{color:var(--warn);font-weight:600}.wcard-nav{display:flex;gap:10px;justify-content:center;flex-wrap:wrap;margin-top:14px}.wcard-hint{text-align:center;font-size:13px;color:var(--muted);margin-top:10px}.textlink{background:none;border:none;padding:0;cursor:pointer;font-size:13px;color:var(--brand);text-decoration:underline}.cells-wrap{display:flex;gap:12px;row-gap:16px;margin:6px 0 4px}.cells-row,.cells-wrap{flex-wrap:wrap;align-items:center;justify-content:center}.cells-row{display:inline-flex;gap:5px}.cells-space{width:12px}.cell-fixed{display:inline-flex;align-items:center;justify-content:center;min-width:30px;padding:6px 2px 4px;font-size:22px;font-weight:700;border-bottom:3px solid var(--line);color:var(--ink)}.cell-blank{width:38px;height:44px;text-align:center;font-size:21px;font-weight:800;border:none;border-bottom:3px solid var(--brand);border-radius:7px;background:var(--bg);color:var(--ink);outline:none;transition:border-color .12s,box-shadow .12s,background .12s}.cell-blank.cell-active{border-bottom-color:var(--brand);box-shadow:0 3px 0 0 var(--brand)}.cell-blank.cell-right{border-bottom-color:var(--ok);background:var(--ok-soft);color:var(--ok)}.cell-blank.cell-wrong{border-bottom-color:var(--err);background:var(--err-soft);color:var(--err)}.cell-blank:disabled{opacity:1}.cells-specials{display:inline-flex;gap:6px;margin-left:4px}.cell-special{min-width:38px;height:38px;padding:0 6px;font-size:16px;font-weight:700;border:2px solid var(--line);border-radius:9px;background:var(--card);color:var(--ink);cursor:pointer}.cell-special:hover{border-color:var(--brand);color:var(--brand)}@media (max-width:600px){.cell-blank{width:32px;height:40px;font-size:18px}.cell-fixed{min-width:24px;font-size:18px}.cell-special{min-width:33px;height:33px;font-size:14px}}.quiz-q{font-size:22px;font-weight:700;margin-bottom:20px}.choices{display:grid;grid-template-columns:1fr 1fr;grid-gap:12px;gap:12px}.option{padding:16px;border:2px solid var(--line);border-radius:12px;background:var(--card);font-size:17px;font-weight:600;cursor:pointer;transition:.12s;text-align:left}.option:hover{border-color:var(--brand)}.option.correct{border-color:var(--ok);background:var(--ok-soft)}.option.wrong{border-color:var(--err);background:var(--err-soft)}.option:disabled{cursor:default;opacity:.85}.option .tag{float:right;font-size:12px;color:var(--muted);font-weight:400}.feedback{display:flex;gap:12px;align-items:center;justify-content:center;margin-top:18px}.feedback .ans{color:var(--muted);font-size:14px}.progressbar{height:8px;background:var(--line);border-radius:999px;overflow:hidden;margin:8px 0 20px}.progressbar div{height:100%;background:var(--brand);transition:width .3s}.score-big{font-size:56px;font-weight:800;text-align:center}.score-note{text-align:center;color:var(--muted);margin-bottom:24px}.weak-list{margin-top:12px}@media (max-width:600px){.choices{grid-template-columns:1fr}.wcard-word{font-size:28px}}.auth-card{max-width:420px;margin:24px auto;padding:32px 28px}.auth-form{display:grid;grid-gap:14px;gap:14px}.field{display:grid;grid-gap:6px;gap:6px;font-size:14px;font-weight:600;color:var(--muted)}.field input{padding:12px 14px;border:2px solid var(--line);border-radius:12px;font-size:16px;font-weight:500;color:var(--ink);background:var(--card);outline:none;transition:.15s}.field input:focus{border-color:var(--brand);box-shadow:0 0 0 3px var(--brand-soft)}.auth-error{background:var(--err-soft);color:var(--err);font-size:14px}.auth-error,.auth-warn{border-radius:10px;padding:10px 12px;font-weight:600}.auth-warn{background:#fff8e7;color:var(--warn);font-size:13px;line-height:1.5}.auth-switch{text-align:center;color:var(--muted);font-size:14px;margin:18px 0 0}.auth-switch a{color:var(--brand);font-weight:700}.nav-user{padding:8px 12px;border-radius:999px;font-size:14px;font-weight:700;color:var(--ink);background:var(--brand-soft);max-width:140px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.nav-btn{border:1px solid var(--line);background:var(--card);color:var(--muted);padding:8px 14px;border-radius:999px;font-weight:600;font-size:14px;cursor:pointer}.nav-btn:hover{color:var(--ink)}.nav-btn:disabled{opacity:.5;cursor:default}