:root{--primary:#6366f1;--primary-deep:#4f46e5;--primary-soft:#eef2ff;--accent:#f97316;--accent-soft:#fff7ed;--success:#16a34a;--success-soft:#f0fdf4;--danger:#dc2626;--danger-soft:#fef2f2;--warning:#d97706;--warning-soft:#fffbeb;--ink:#1e293b;--sub:#64748b;--line:#e2e8f0;--bg:#f8fafc;--card:#fff;--radius:12px;--radius-lg:20px;--shadow-sm:0 1px 2px #0f172a0f;--shadow:0 6px 24px #4f46e514;--shadow-lg:0 16px 48px #4f46e524}*{box-sizing:border-box;margin:0;padding:0}body{background:var(--bg);color:var(--ink);-webkit-font-smoothing:antialiased;font-family:Nunito,PingFang SC,Microsoft YaHei,system-ui,sans-serif;line-height:1.6}a{color:inherit;text-decoration:none}button{cursor:pointer;font-family:inherit}.container{max-width:1080px;margin:0 auto;padding:0 20px}.btn{border:none;border-radius:999px;align-items:center;gap:6px;padding:11px 20px;font-size:14px;font-weight:700;transition:all .2s;display:inline-flex}.btn-primary{background:var(--primary);color:#fff;box-shadow:var(--shadow)}.btn-primary:hover{background:var(--primary-deep);transform:translateY(-1px)}.btn-ghost{border:1.5px solid var(--line);color:var(--sub);background:0 0}.btn-ghost:hover{border-color:var(--primary);color:var(--primary)}.btn-soft{background:var(--primary-soft);color:var(--primary-deep)}.chip{background:var(--card);border:1px solid var(--line);gap:6px;padding:6px 14px;font-size:13px}.chip,.tag{border-radius:999px;align-items:center;display:inline-flex}.tag{gap:4px;padding:2px 10px;font-size:12px;font-weight:700}.topbar{z-index:50;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);border-bottom:1px solid var(--line);background:#ffffffdb;position:sticky;top:0}.topbar-inner{gap:12px;max-width:1080px;margin:0 auto;padding:14px 20px}.brand,.topbar-inner{align-items:center;display:flex}.brand{gap:10px;font-size:18px;font-weight:800}.brand .logo{background:linear-gradient(135deg,var(--primary),#8b5cf6);color:#fff;width:40px;height:40px;box-shadow:var(--shadow);border-radius:12px;justify-content:center;align-items:center;font-size:20px;display:flex}.hero{border-radius:var(--radius-lg);background:linear-gradient(135deg,#eef2ff 0,#f5f3ff 55%,#fff7ed);border:1px solid #e0e7ff;margin:28px 0 30px;padding:40px 34px;position:relative;overflow:hidden}.hero h1{letter-spacing:.3px;font-size:30px;font-weight:800}.hero p{color:var(--sub);max-width:620px;margin-top:8px}.hero-stats{flex-wrap:wrap;gap:12px;margin-top:22px;display:flex}.stat{box-shadow:var(--shadow-sm);background:#fff;border-radius:14px;align-items:center;gap:8px;padding:12px 18px;font-size:13px;font-weight:700;display:flex}.stat b{color:var(--primary-deep);font-size:17px}.section-head{justify-content:space-between;align-items:baseline;margin:8px 2px 18px;display:flex}.section-head h2{font-size:20px;font-weight:800}.section-head span{color:var(--sub);font-size:13px;font-weight:600}.book-grid{grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:18px;display:grid}.book-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius-lg);cursor:pointer;padding:24px 20px 18px;transition:all .25s;position:relative;overflow:hidden}.book-card:before{content:"";background:var(--c,var(--primary));height:4px;position:absolute;inset:0 0 auto}.book-card:hover{box-shadow:var(--shadow-lg);border-color:#c7d2fe;transform:translateY(-4px)}.book-card .cover{margin:4px 0 10px;font-size:42px;transition:all .25s;display:inline-block}.book-card:hover .cover{transform:scale(1.1)rotate(-3deg)}.book-card .name{font-size:17px;font-weight:800}.book-card .meta{color:var(--sub);margin-top:4px;font-size:12.5px;font-weight:600}.progress{background:#f1f5f9;border-radius:99px;height:8px;margin-top:14px;overflow:hidden}.progress i{background:var(--c,var(--primary));border-radius:99px;height:100%;transition:width .5s;display:block}.book-card .pct{color:var(--sub);margin-top:7px;font-size:12px;font-weight:700}.crumb{color:var(--sub);align-items:center;gap:8px;margin:22px 0 16px;font-size:13px;font-weight:600;display:flex}.crumb a{color:var(--primary-deep);cursor:pointer}.crumb a:hover{text-decoration:underline}.banner{border-radius:var(--radius-lg);color:#fff;background:linear-gradient(135deg,var(--c,var(--primary)) 0,#8b5cf6 100%);box-shadow:var(--shadow);align-items:center;gap:18px;margin-bottom:20px;padding:26px 30px;display:flex}.banner .bc{background:#ffffff2e;border-radius:16px;padding:8px;font-size:44px}.banner h2{font-size:22px;font-weight:800}.banner .sub{opacity:.9;margin-top:3px;font-size:13px;font-weight:600}.unit-tabs{flex-wrap:wrap;gap:10px;margin-bottom:20px;display:flex}.unit-tab{background:var(--card);border:1.5px solid var(--line);border-radius:var(--radius);text-align:center;min-width:88px;padding:10px 16px;font-size:14px;font-weight:700;transition:all .2s}.unit-tab small{color:var(--sub);margin-top:2px;font-size:11px;font-weight:600;display:block}.unit-tab:hover{border-color:var(--primary);transform:translateY(-2px)}.unit-tab.active{background:var(--primary);color:#fff;border-color:#0000}.unit-tab.active small{color:#ffffffd9}.unit-tab.done{background:var(--success-soft);color:var(--success);border-color:#bbf7d0}.mode-tabs{flex-wrap:wrap;gap:10px;margin:4px 0 22px;display:flex}.mode-tab{color:var(--sub);background:var(--card);border:1.5px solid var(--line);border-radius:999px;padding:10px 20px;font-size:14px;font-weight:700;transition:all .2s}.mode-tab:hover{border-color:var(--primary);color:var(--primary-deep)}.mode-tab.active{background:var(--primary);color:#fff;box-shadow:var(--shadow);border-color:#0000}.flashcard-wrap{flex-direction:column;align-items:center;padding:10px 0 26px;display:flex}.flashcard{perspective:1200px;cursor:pointer;width:min(430px,92vw);height:300px;margin-bottom:22px}.fc-inner{width:100%;height:100%;transform-style:preserve-3d;transition:transform .5s cubic-bezier(.4,.2,.2,1);position:relative}.flashcard.flipped .fc-inner{transform:rotateY(180deg)}.fc-face{backface-visibility:hidden;border-radius:var(--radius-lg);border:1.5px solid var(--line);box-shadow:var(--shadow);background:#fff;flex-direction:column;justify-content:center;align-items:center;padding:20px;display:flex;position:absolute;inset:0}.fc-face.back{background:linear-gradient(160deg,var(--primary-soft),#fff);border-color:#c7d2fe;transform:rotateY(180deg)}.fc-img{-o-object-fit:cover;object-fit:cover;border-radius:var(--radius);background:var(--primary-soft);width:150px;height:110px;margin-bottom:14px}.fc-emoji{margin-bottom:10px;font-size:64px}.fc-word{color:var(--primary-deep);font-size:36px;font-weight:800}.fc-ipa{color:var(--sub);margin-top:2px;font-size:15px;font-weight:600}.fc-cn{color:var(--primary-deep);font-size:32px;font-weight:800}.fc-pos{color:var(--primary);margin-top:6px;font-size:14px;font-weight:700}.fc-tip{color:var(--sub);margin-top:14px;font-size:13px;font-weight:600}.fc-count{color:var(--sub);margin-bottom:14px;font-size:14px;font-weight:700}.fc-nav{gap:12px;display:flex}.quiz-q{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);margin-bottom:14px;padding:20px}.quiz-q .q{margin-bottom:14px;font-size:15px;font-weight:700}.opt{border:1.5px solid var(--line);border-radius:var(--radius);cursor:pointer;margin-bottom:9px;padding:11px 14px;font-size:14px;transition:all .15s;display:block}.opt.selected,.opt:hover{border-color:var(--primary)}.opt.selected{background:var(--primary-soft);font-weight:700}.opt.correct{border-color:var(--success);background:var(--success-soft)}.opt.wrong{border-color:var(--danger);background:var(--danger-soft)}.explain{border-radius:var(--radius);background:var(--warning-soft);color:#92400e;margin-top:10px;padding:11px 13px;font-size:13.5px;display:none}.explain.show{display:block}.score-bar{border-radius:var(--radius);margin-top:16px;padding:16px 18px;font-size:15px;font-weight:700}.score-bar.good{background:var(--success-soft);color:var(--success)}.score-bar.ok{background:var(--warning-soft);color:var(--warning)}.score-bar.bad{background:var(--danger-soft);color:var(--danger)}.point-card{background:var(--card);border:1px solid var(--line);border-left:4px solid var(--primary);border-radius:var(--radius);margin-bottom:14px;padding:18px 20px}.point-card h4{color:var(--primary-deep);margin-bottom:6px;font-size:15px}.point-card .eg{background:var(--primary-soft);border-radius:var(--radius);color:var(--primary-deep);margin-top:10px;padding:10px 14px;font-weight:700}.empty{text-align:center;color:var(--sub);padding:60px 20px}.k-block{margin-bottom:30px}.k-title{align-items:baseline;gap:8px;margin-bottom:14px;font-size:18px;font-weight:800;display:flex}.k-title span{color:var(--sub);font-size:12.5px;font-weight:600}.k-sents{flex-direction:column}.k-sent,.k-sents{gap:12px;display:flex}.k-sent{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);align-items:flex-start;padding:14px 16px}.ks-en{color:var(--primary-deep);font-size:18px;font-weight:800}.ks-cn{color:var(--sub);margin-top:3px;font-size:14px}.k-points{grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:14px;display:grid}.k-point{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;position:relative;overflow:hidden}.k-point:before{content:"";background:var(--primary);width:4px;position:absolute;top:0;bottom:0;left:0}.kp-head{gap:10px;margin-bottom:8px}.kp-head,.kp-num{align-items:center;display:flex}.kp-num{background:var(--primary-soft);border-radius:8px;flex-shrink:0;justify-content:center;width:26px;height:26px;font-size:14px;font-weight:800}.kp-head h4,.kp-num{color:var(--primary-deep)}.kp-head h4{font-size:15px}.kp-body{color:var(--ink);font-size:14px;line-height:1.7}.kp-body b{color:var(--primary-deep)}.kp-eg{background:var(--primary-soft);border-radius:var(--radius);color:var(--primary-deep);align-items:center;margin-top:10px;padding:9px 12px;font-size:14px;font-weight:700}.k-words,.kp-eg{gap:8px;display:flex}.k-words{flex-wrap:wrap}.kw-chip{background:var(--card);border:1px solid var(--line);font:inherit;border-radius:999px;align-items:center;gap:8px;padding:8px 14px;transition:all .15s;display:inline-flex}.kw-chip:hover{border-color:var(--primary);background:var(--primary-soft);transform:translateY(-1px)}.kw-en{color:var(--primary-deep);font-size:14px;font-weight:700}.kw-cn{color:var(--sub);font-size:12.5px}.mini-play{border:1.5px solid var(--line);background:#fff;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:32px;height:32px;transition:all .15s;display:flex}.mini-play:hover{border-color:var(--primary);background:var(--primary-soft)}.k-goals{flex-direction:column;gap:12px;list-style:none;display:flex}.k-goal{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);align-items:flex-start;gap:14px;padding:14px 16px;transition:all .15s;display:flex}.k-goal:hover{box-shadow:var(--shadow-sm);border-color:#c7d2fe}.kg-check{background:linear-gradient(135deg,var(--primary),#8b5cf6);color:#fff;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:28px;height:28px;font-size:14px;font-weight:800;display:flex}.kg-body{flex-direction:column;gap:3px;display:flex}.kg-en{color:var(--ink);font-size:15px;font-weight:700}.kg-cn,.kg-en{line-height:1.5}.kg-cn{color:var(--sub);font-size:13.5px}.k-exprs{grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:12px;display:grid}.ke-chip{text-align:left;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);font:inherit;flex-direction:column;align-items:flex-start;gap:4px;padding:14px 16px;transition:all .15s;display:flex}.ke-chip:hover{border-color:var(--primary);background:var(--primary-soft);box-shadow:var(--shadow-sm);transform:translateY(-2px)}.ke-en{color:var(--primary-deep);font-size:16px;font-weight:800}.ke-cn{color:var(--sub);font-size:13px}.k-notes{flex-direction:column;gap:14px;display:flex}.k-note{background:var(--card);border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:var(--radius);padding:16px 18px}.kn-head{align-items:flex-start;gap:10px;display:flex}.kn-num{background:var(--accent-soft);width:26px;height:26px;color:var(--accent);border-radius:8px;flex-shrink:0;justify-content:center;align-items:center;font-size:14px;display:flex}.kn-en,.kn-num{font-weight:800}.kn-en{font-size:16px;line-height:1.5}.kn-cn,.kn-en{color:var(--ink)}.kn-cn{margin:8px 0 0 36px;line-height:1.8}.kn-cn,.kn-eg{font-size:14px}.kn-eg{background:var(--primary-soft);border-radius:var(--radius);color:var(--primary-deep);align-items:center;gap:8px;margin:10px 0 0 36px;padding:10px 12px;display:flex}.kn-eg,.kw-pos{font-weight:700}.kw-pos{color:var(--accent);background:var(--accent-soft);border-radius:999px;padding:1px 8px;font-size:11px}.kw-ipa{color:#94a3b8;font-size:12px;font-weight:600}.review-list{flex-direction:column;gap:14px;display:flex}.review-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px;transition:all .2s}.review-card.passed{background:var(--success-soft);border-color:#bbf7d0}.review-card .q{margin:12px 0;font-size:15px;font-weight:700}.review-card .opt{font-size:14px}.rc-head{gap:10px}.rc-head,.rc-num{align-items:center;display:flex}.rc-num{background:var(--primary-soft);width:26px;height:26px;color:var(--primary-deep);border-radius:8px;flex-shrink:0;justify-content:center;font-size:13px;font-weight:800}.rc-src{color:var(--sub);font-size:12px;font-weight:700}.rc-tag{color:var(--success);margin-left:auto;font-size:12px;font-weight:800}.rc-opts{flex-direction:column;display:flex}.rc-explain{border-radius:var(--radius);background:var(--warning-soft);color:#92400e;margin-top:10px;padding:10px 13px;font-size:13px}.story-stack{flex-direction:column;gap:16px;display:flex}.story-sub{color:var(--sub);margin-top:8px;font-size:14px;font-weight:800}.story-reader{background:var(--card);border:1px solid var(--line);border-radius:var(--radius-lg);padding:24px 26px}.sr-head{justify-content:space-between;align-items:flex-start;gap:16px;margin-bottom:18px;display:flex}.sr-head-text h3{color:var(--ink);font-size:20px;font-weight:800}.sr-title-cn{color:var(--sub);font-size:14px;font-weight:600}.sr-actions{flex-shrink:0;gap:10px;display:flex}.sr-body{flex-direction:column;gap:4px;display:flex}.sr-sentence{cursor:pointer;color:var(--ink);border-radius:10px;padding:9px 12px;font-size:16px;line-height:1.9;transition:background .15s;position:relative}.sr-sentence:hover{background:var(--primary-soft)}.sr-sentence.dialog{border-left:3px solid var(--accent);background:var(--accent-soft)}.sr-sentence.dialog:hover{background:#fff1e6}.sr-word{color:var(--primary-deep);background:var(--primary-soft);cursor:pointer;border-radius:6px;margin:0 1px;padding:1px 5px;font-weight:800;transition:all .15s}.sr-word:hover{background:var(--primary);color:#fff}.sr-cn{border-top:1px dashed var(--line);margin-top:18px;padding-top:16px}.sr-cn-label{color:var(--accent);letter-spacing:2px;margin-bottom:8px;font-size:12px;font-weight:800}.sr-cn p{color:var(--ink);font-size:15px;line-height:2}.sr-qa{border-top:1px solid var(--line);margin-top:20px;padding-top:16px}.sr-qa-label{color:var(--sub);margin-bottom:12px;font-size:13px;font-weight:800}.sr-q{margin-bottom:14px}.sr-q-text{margin-bottom:8px;font-size:14px;font-weight:700}.sr-q-opts{flex-wrap:wrap;gap:8px;display:flex}.sr-opt{border:1.5px solid var(--line);background:var(--card);border-radius:999px;padding:7px 14px;font-size:13px;font-weight:600;transition:all .15s}.sr-opt:hover{border-color:var(--primary)}.sr-opt.correct{border-color:var(--success);background:var(--success-soft);color:var(--success)}.sr-opt.wrong{border-color:var(--danger);background:var(--danger-soft);color:var(--danger)}.chip-dot{background:var(--danger);color:#fff;border-radius:999px;justify-content:center;align-items:center;min-width:18px;height:18px;padding:0 5px;font-size:11px;font-weight:800;line-height:1;display:inline-flex}.fc-toolbar{justify-content:space-between;gap:12px;width:min(430px,92vw);margin-bottom:14px}.fc-groups,.fc-toolbar{flex-wrap:wrap;align-items:center;display:flex}.fc-groups{gap:6px}.fc-groups-label{margin-right:2px;font-size:12px}.fc-groups-label,.fg-chip{color:var(--sub);font-weight:700}.fg-chip{border:1.5px solid var(--line);background:var(--card);border-radius:999px;padding:6px 12px;font-size:13px;transition:all .15s}.fg-chip:hover{border-color:var(--primary);color:var(--primary)}.fg-chip.active{background:var(--primary);color:#fff;border-color:#0000}.fg-chip.fg-review{background:var(--warning-soft);color:#92400e;border-color:#fde68a}.fg-chip.fg-review.active{background:var(--warning);color:#fff;border-color:#0000}.fc-group-switch{align-items:center;gap:14px;margin-bottom:14px;display:flex}.fc-group-name{color:var(--ink);font-size:14px;font-weight:800}.fc-grade{flex-wrap:wrap;justify-content:center;gap:8px;margin-top:16px;display:flex}.fgr{color:#fff;border:none;border-radius:999px;padding:9px 16px;font-size:14px;font-weight:800;transition:all .15s}.fgr:hover{transform:translateY(-1px)}.fgr-bad{background:var(--danger)}.fgr-mid{background:var(--warning)}.fgr-good{background:var(--success)}.rc-source{border-radius:999px;flex-shrink:0;padding:3px 10px;font-size:11px;font-weight:800}.rc-source.quiz{background:var(--primary-soft);color:var(--primary-deep)}.rc-source.challenge{background:var(--accent-soft);color:#c2410c}.ch-setup{flex-direction:column;gap:16px;max-width:640px;margin:0 auto;display:flex}.ch-panel{background:var(--card);border:1px solid var(--line);border-radius:var(--radius-lg);padding:22px}.ch-panel h3{margin-bottom:14px;font-size:16px;font-weight:800}.ch-modes{grid-template-columns:repeat(2,1fr);gap:10px;display:grid}.ch-mode{text-align:left;background:var(--bg);border:1.5px solid var(--line);border-radius:var(--radius);padding:14px;transition:all .15s}.ch-mode.active,.ch-mode:hover{border-color:var(--primary)}.ch-mode.active{background:var(--primary-soft)}.ch-mode-label{color:var(--ink);font-size:15px;font-weight:800;display:block}.ch-mode-desc{color:var(--sub);margin-top:2px;font-size:12px;font-weight:600;display:block}.ch-scopes{flex-wrap:wrap;gap:8px;display:flex}.ch-scope{border:1.5px solid var(--line);background:var(--card);color:var(--sub);border-radius:999px;padding:8px 16px;font-size:13px;font-weight:700;transition:all .15s}.ch-scope:hover{border-color:var(--primary);color:var(--primary)}.ch-scope.active{background:var(--primary);color:#fff;border-color:#0000}.ch-pool-info{color:var(--sub);margin-top:12px;font-size:13px;font-weight:600}.ch-hint-warn{background:var(--warning-soft);color:#92400e;border-radius:var(--radius);padding:12px 16px;font-size:14px;font-weight:600}.ch-start{justify-content:center;padding:14px;font-size:16px}.ch-result{text-align:center;padding:40px 20px}.ch-result-big{color:var(--primary-deep);font-size:56px;font-weight:800}.ch-result-sub{color:var(--sub);margin:10px 0 24px;font-size:15px;font-weight:600}.ch-result-actions{flex-wrap:wrap;justify-content:center;gap:12px;display:flex}.challenge{max-width:560px;margin:0 auto}.ch-progress{color:var(--sub);align-items:center;gap:12px;margin-bottom:18px;font-size:13px;font-weight:700;display:flex}.ch-qno,.ch-score{flex-shrink:0}.ch-score{color:var(--success)}.ch-bar{background:var(--line);flex:1;height:8px;overflow:hidden}.ch-bar,.ch-bar i{border-radius:999px}.ch-bar i{background:var(--primary);height:100%;transition:width .3s;display:block}.ch-question{background:var(--card);border:1px solid var(--line);border-radius:var(--radius-lg);text-align:center;margin-bottom:16px;padding:28px 24px}.ch-word-btn{color:var(--primary-deep);background:0 0;border:none;font-size:34px;font-weight:800}.ch-word-btn:hover{text-decoration:underline}.ch-en-target{color:var(--sub);margin-bottom:6px;font-size:13px;font-weight:700}.ch-cn{color:var(--ink);margin:6px 0;font-size:30px;font-weight:800}.ch-hint{justify-content:center;gap:10px;margin-top:8px;display:flex}.ch-pos{color:var(--primary);background:var(--primary-soft);border-radius:999px;padding:2px 8px;font-size:12px;font-weight:700}.ch-ipa{color:var(--sub);font-size:13px;font-weight:600}.ch-listen{background:var(--accent-soft);color:#c2410c;border:1.5px solid #fdba74;border-radius:999px;padding:12px 22px;font-size:16px;font-weight:800}.ch-listen:hover{background:#fff1e6}.ch-opts{flex-direction:column;gap:10px;display:flex}.ch-opt{text-align:left;background:var(--card);border:1.5px solid var(--line);border-radius:var(--radius);padding:14px 18px;font-size:15px;font-weight:600;transition:all .15s}.ch-opt:hover{border-color:var(--primary)}.ch-opt.correct{border-color:var(--success);background:var(--success-soft);color:var(--success)}.ch-opt.wrong{border-color:var(--danger);background:var(--danger-soft);color:var(--danger)}.ch-input-row{gap:10px;display:flex}.ch-input{border:1.5px solid var(--line);border-radius:var(--radius);flex:1;padding:12px 16px;font-family:inherit;font-size:16px}.ch-input:focus{border-color:var(--primary);outline:none}.ch-feedback{border-radius:var(--radius);flex-wrap:wrap;justify-content:center;align-items:center;gap:12px;margin-top:16px;padding:16px;font-size:15px;font-weight:600;display:flex}.ch-feedback.ok{background:var(--success-soft);color:#166534}.ch-feedback:not(.ok){background:var(--danger-soft);color:#991b1b}