/* Hanzi Studio v4 · Curriculum, placement, handwriting, content governance */
.v4{--v4-ink:#222741;--v4-lilac:#eeeaff;--v4-mint:#dcf8ed;--v4-edge:var(--stroke);color:var(--txt)}
.v4 *{box-sizing:border-box}.v4 h1,.v4 h2,.v4 h3,.v4 p{margin-top:0}.v4 .section-top{display:flex;align-items:flex-start;justify-content:space-between;gap:18px;flex-wrap:wrap;margin-bottom:23px}.v4 .eyebrow{color:var(--primary);text-transform:uppercase;letter-spacing:1.7px;font-size:10px;font-weight:900;margin:0 0 9px}.v4 .page-title{font-size:clamp(27px,3.5vw,39px);font-weight:900;letter-spacing:-1.6px;line-height:1.16;margin-bottom:10px}.v4 .lead{color:var(--muted);line-height:1.65;font-size:13px;max-width:720px}.v4 .surface{background:var(--surface);border:1px solid var(--v4-edge);border-radius:21px;padding:24px;box-shadow:var(--shadow)}.v4 .soft{background:var(--muted-bg);border:1px solid var(--stroke);border-radius:15px;padding:16px}.v4 .chip{border-radius:999px;padding:6px 10px;font-size:10px;line-height:1;font-weight:800;background:var(--primary-light);color:var(--primary);display:inline-block}.v4 .chip-green{background:var(--teal-light);color:var(--teal)}.v4 .chip-orange{background:var(--orange-light);color:var(--orange)}.v4 .v4-subheading{font-size:19px;font-weight:900;letter-spacing:-.4px;margin-bottom:5px}.v4 .muted{color:var(--muted);font-size:12px;line-height:1.65}.v4 .line{height:1px;background:var(--stroke);margin:18px 0}.v4 .v4-btn{display:inline-flex;align-items:center;justify-content:center;gap:9px;border-radius:12px;border:1px solid var(--stroke);background:var(--surface);padding:12px 16px;min-height:43px;color:var(--txt);font-size:12px;font-weight:800;transition:.18s}.v4 .v4-btn:hover{border-color:var(--primary);transform:translateY(-1px)}.v4 .v4-primary{background:var(--primary);color:#fff;border-color:var(--primary)}.v4 .v4-outline{border-color:var(--primary);color:var(--primary);background:var(--primary-light)}.v4 .v4-btn[disabled]{opacity:.45}.v4 .action-bar{display:flex;align-items:center;gap:9px;flex-wrap:wrap}.v4 .level-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:15px}.v4 .level-card{background:var(--surface);border:1px solid var(--stroke);border-radius:19px;padding:19px;text-align:left;min-height:194px;display:flex;flex-direction:column;gap:9px;cursor:pointer;transition:.2s;box-shadow:var(--shadow)}.v4 .level-card:hover{transform:translateY(-3px);border-color:var(--primary)}.v4 .level-card.selected{border:2px solid var(--primary);padding:18px;box-shadow:0 10px 30px #6657e71b}.v4 .level-top{display:flex;justify-content:space-between;align-items:center}.v4 .level-monogram{font-family:'Noto Sans SC','Microsoft YaHei',sans-serif;font-size:27px;font-weight:750;width:47px;height:47px;display:grid;place-items:center;color:var(--primary);border-radius:16px;background:var(--primary-light)}.v4 .level-card h3{font-size:18px;letter-spacing:-.5px;margin:4px 0 0;font-weight:900}.v4 .level-card p{font-size:11px;line-height:1.5;color:var(--muted);margin:0;min-height:27px}.v4 .level-foot{margin-top:auto;display:flex;align-items:center;justify-content:space-between;gap:8px;font-size:11px;font-weight:800}.v4 .progress-line{height:6px;border-radius:9px;background:var(--muted-bg);overflow:hidden;margin:0}.v4 .progress-line span{display:block;background:linear-gradient(90deg,var(--primary),#b69cff);height:100%;border-radius:inherit}.v4 .split{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(295px,.85fr);gap:18px}.v4 .study-card{border-radius:22px;min-height:280px;background:linear-gradient(130deg,#eee9ff,#fff 70%);display:grid;align-content:center;justify-items:center;position:relative;border:1px solid #e7e0ff;cursor:pointer;user-select:none;padding:26px;text-align:center;transition:.2s}.v4 .study-card:hover{box-shadow:0 13px 40px #8170c42b}.v4 .study-card .hanzi{font-family:'Noto Sans SC','Microsoft YaHei',sans-serif;color:#5040b6;font-size:clamp(53px,7vw,86px);font-weight:600;line-height:1.4;word-break:break-word}.v4 .study-card .pinyin{font-size:19px;color:#6755b3;letter-spacing:.3px;margin:8px 0}.v4 .study-card .meaning{font-size:22px;font-weight:800;color:#3e3b65;max-width:400px}.v4 .study-card .prompt{position:absolute;left:15px;top:14px;font-size:9px;font-weight:850;letter-spacing:1.2px;color:#9990cc;text-transform:uppercase}.v4 .study-card .flip-hint{position:absolute;bottom:16px;font-size:10px;color:#aca5cd}.v4 .big-number{font-size:31px;font-weight:900;letter-spacing:-1px}.v4 .study-controls{display:flex;justify-content:space-between;gap:7px;margin-top:15px;flex-wrap:wrap}.v4 .answer-opts{display:grid;grid-template-columns:1fr 1fr;gap:10px}.v4 .answer-opts button{text-align:left;padding:14px;border:1px solid var(--stroke);border-radius:12px;background:var(--surface);font-weight:750;min-height:60px;color:var(--txt)}.v4 .answer-opts button:hover{background:var(--muted-bg)}.v4 .answer-opts button.correct{border-color:var(--teal);background:var(--teal-light);color:#136d50}.v4 .answer-opts button.incorrect{border-color:var(--red);background:var(--red-light);color:#9b4650}.v4 .import-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.v4 input[type=file]{max-width:100%;font-size:12px}.v4 input[type=url]{width:100%;margin-bottom:11px}.v4 .stats-flex{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;align-items:center}.v4 .viz-road{background:radial-gradient(circle at 80% 20%,#dacfff,#f4f1ff 45%,#f7fbff);color:#3f3b6a;border-radius:23px;min-height:172px;padding:25px;position:relative;overflow:hidden}.v4 .viz-road::after{content:'学';position:absolute;right:5%;bottom:-45px;font-size:180px;color:#d0c8fd;line-height:1;transform:rotate(-8deg);font-weight:900}.v4 .road-copy{position:relative;z-index:1;max-width:460px}.v4 .road-copy h2{font-size:25px;letter-spacing:-.8px;margin:9px 0}.v4 .road-copy p{color:#6d6a99;font-size:12px;line-height:1.6}.v4 .lesson-meta{display:flex;gap:11px;flex-wrap:wrap;align-items:center;margin:0 0 15px}.v4 .hand-canvas{width:min(100%,340px);aspect-ratio:1;background-color:#fff;background-image:linear-gradient(45deg,transparent calc(50% - .5px),#f3eaf8 50%,transparent calc(50% + .5px)),linear-gradient(135deg,transparent calc(50% - .5px),#f3eaf8 50%,transparent calc(50% + .5px)),linear-gradient(#ede3f7,#ede3f7),linear-gradient(90deg,#ede3f7,#ede3f7);background-size:100% 100%,100% 100%,100% 1px,1px 100%;background-position:center,center,center,center;background-repeat:no-repeat;border:2px solid #d8ccff;border-radius:15px;touch-action:none;cursor:crosshair}.v4 .write-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:20px}.v4 .source-row{display:grid;grid-template-columns:minmax(0,1fr) 130px;align-items:center;gap:10px;padding:13px 0;border-bottom:1px solid var(--stroke);font-size:12px}.v4 .source-row a{color:var(--primary);font-weight:750}.v4 .source-row small{color:var(--muted)}.v4 .source-row:last-child{border:0}.v4 .result-banner{border-radius:14px;background:var(--teal-light);color:#126a52;padding:14px 18px;font-size:12px;line-height:1.5;font-weight:800}.v4 .warning-banner{border-radius:14px;background:var(--orange-light);color:#a06b27;padding:14px 18px;font-size:12px;line-height:1.5}.v4 .quiz-number{font-size:11px;color:var(--muted);font-weight:900}.v4 .quiz-question{font-size:26px;font-weight:850;line-height:1.5;margin:12px 0 18px}.v4 .report-row{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:12px 0;border-bottom:1px solid var(--stroke)}.v4 .report-row:last-child{border:none}.v4 .stack{display:grid;gap:17px}.v4 .course-badge{font-size:11px;font-weight:800;color:var(--primary)}.v4 .badge-label{color:var(--muted);font-size:11px}.v4 .fine-print{font-size:11px;color:var(--muted);line-height:1.75}.v4 a.ext{color:var(--primary);font-weight:750;text-decoration:underline;text-underline-offset:3px}
@media(max-width:1250px){.v4 .level-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:940px){.v4 .split,.v4 .write-grid{grid-template-columns:1fr}}@media(max-width:640px){.v4 .level-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.v4 .level-card{min-height:185px;padding:13px}.v4 .level-card.selected{padding:12px}.v4 .level-card h3{font-size:15px}.v4 .level-monogram{width:39px;height:39px;font-size:22px}.v4 .surface{padding:16px}.v4 .study-card{min-height:260px}.v4 .import-grid{grid-template-columns:1fr}.v4 .answer-opts{grid-template-columns:1fr}.v4 .section-top .v4-btn{width:100%}.v4 .study-controls .v4-btn{flex:1}.v4 .page-title{font-size:27px}.v4 .viz-road::after{font-size:130px}}
.v4 .study-card{width:100%}.v4 .study-card .hanzi{max-width:100%}.v4 .study-card .meaning{word-wrap:break-word}.v4 .source-row .chip{white-space:normal;line-height:1.4}@media(max-width:640px){.v4 .study-card{min-width:0}.v4 .source-row{grid-template-columns:1fr}.v4 .source-row a{display:inline-block}}
[data-theme="dark"] .v4 .study-card{background:linear-gradient(130deg,#343059,#24263e 75%);border-color:#444166}[data-theme="dark"] .v4 .study-card .hanzi,[data-theme="dark"] .v4 .study-card .pinyin{color:#c7bcff}[data-theme="dark"] .v4 .study-card .meaning{color:#f1edff}[data-theme="dark"] .v4 .viz-road{background:linear-gradient(120deg,#322b55,#26334a);color:#f2eaff}[data-theme="dark"] .v4 .viz-road .road-copy p{color:#b7bad6}