:root{--ink:#17233f;--muted:#6f7890;--line:#dce3f1;--blue:#315edb;--blue2:#6f8fe9;--paper:#fff;--soft:#f4f7ff;--teacher:#147d6e;--shadow:0 18px 55px rgba(31,52,101,.11)}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:radial-gradient(circle at 85% 4%,#e8efff 0,transparent 30%),linear-gradient(180deg,#f7f9ff,#eef3fa);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;min-height:100vh}.topbar{height:76px;padding:0 5vw;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid rgba(211,221,240,.8);background:rgba(255,255,255,.78);backdrop-filter:blur(18px)}.brand{display:flex;align-items:center;gap:11px;color:inherit;text-decoration:none}.brand>span{display:grid;width:42px;height:42px;place-items:center;border-radius:13px;background:linear-gradient(145deg,var(--blue),var(--blue2));color:#fff;font-size:20px;font-weight:900;box-shadow:0 8px 20px rgba(49,94,219,.24)}.brand strong,.brand small{display:block}.brand small{margin-top:2px;color:var(--muted);font-size:11px}.back{color:#56627a;font-size:14px;text-decoration:none}.side-rail{position:fixed;z-index:5;left:18px;top:50%;width:132px;padding:12px;border:1px solid var(--line);border-radius:20px;background:rgba(255,255,255,.94);box-shadow:var(--shadow);transform:translateY(-50%)}.side-rail>div{padding:4px 5px 10px;border-bottom:1px solid #e8ecf3}.side-rail strong,.side-rail small{display:block}.side-rail small{color:#99a1b2;font-size:8px;letter-spacing:.11em}.side-rail a{display:flex;align-items:center;gap:9px;margin-top:8px;padding:8px;border:1px solid transparent;border-radius:13px;color:#47536b;text-decoration:none}.side-rail a.active{border-color:#c8d5f5;background:#eef3ff;color:var(--blue)}.side-rail a b{display:grid;width:32px;height:32px;place-items:center;border-radius:10px;background:#e7ecf8}.side-rail a.active b{background:var(--blue);color:#fff}.side-rail a 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button.active{background:#edf3ff;color:var(--blue)}.role-tabs button.active>span{background:var(--blue);color:#fff}body.teacher-mode{--blue:#147d6e;--blue2:#43a291;--soft:#eff9f6}body.teacher-mode .role-tabs button.active{background:#eaf7f3}.workbench{display:grid;grid-template-columns:minmax(320px,.8fr) minmax(480px,1.2fr);gap:20px;margin-top:34px}.input-panel,.output-panel{padding:25px;border:1px solid var(--line);border-radius:24px;background:rgba(255,255,255,.94);box-shadow:var(--shadow)}.panel-heading{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:20px}.panel-heading>div{display:flex;align-items:center;gap:10px}.panel-heading span{color:var(--blue);font-size:11px;font-weight:900}.panel-heading h2{margin:0;font-size:19px}.panel-heading em{padding:5px 9px;border-radius:999px;background:var(--soft);color:var(--blue);font-size:10px;font-style:normal;font-weight:800}.input-panel label{display:block;margin-bottom:8px;font-size:12px;font-weight:850}.input-panel textarea{width:100%;min-height:144px;padding:16px;border:1px solid #ced8ea;border-radius:15px;outline:0;resize:vertical;color:var(--ink);font:inherit;line-height:1.65;transition:.18s}.input-panel textarea:focus{border-color:var(--blue);box-shadow:0 0 0 4px color-mix(in srgb,var(--blue) 11%,transparent)}.examples{margin:15px 0}.examples>span{display:block;margin-bottom:8px;color:var(--muted);font-size:11px}.examples>div{display:flex;flex-wrap:wrap;gap:7px}.examples button{padding:7px 9px;border:1px solid #dbe2ef;border-radius:999px;background:#f9faff;color:#59657b;font-size:10px;cursor:pointer}.examples button:hover{border-color:var(--blue);color:var(--blue)}.generate{display:flex;width:100%;align-items:center;justify-content:space-between;padding:13px 16px;border:0;border-radius:14px;background:linear-gradient(135deg,var(--blue),var(--blue2));color:#fff;font-weight:850;cursor:pointer;box-shadow:0 10px 22px color-mix(in srgb,var(--blue) 25%,transparent)}.generate b{font-size:19px}.privacy{margin:12px 0 0;color:#8a93a4;font-size:10px;line-height:1.55}.output-panel{min-height:480px}.empty{display:grid;min-height:330px;place-items:center;align-content:center;color:#9ba4b4;text-align:center}.empty span{font-size:40px}.empty strong{margin-top:9px;color:#69748a}.empty p{margin:7px 0;font-size:12px}.hidden{display:none!important}.structure-line{display:flex;gap:5px;margin-bottom:14px;overflow:hidden}.structure-line span{flex:1;height:4px;border-radius:8px;background:var(--blue);opacity:calc(.28 + var(--i)*.08)}.sections{display:grid;gap:9px}.prompt-section{display:grid;grid-template-columns:92px 1fr;gap:12px;padding:12px 14px;border:1px solid #e3e8f2;border-radius:13px;background:#fbfcff}.prompt-section strong{color:var(--blue);font-size:11px}.prompt-section p{margin:0;color:#3f4b61;font-size:12px;line-height:1.7;white-space:pre-line}.result-actions{display:flex;gap:9px;margin-top:16px}.result-actions button{padding:11px 16px;border-radius:12px;font-weight:800;cursor:pointer}.copy{flex:1;border:0;background:var(--blue);color:#fff}.plain{border:1px solid #d8dfec;background:#fff;color:#647087}.copy-status{min-height:16px;margin:8px 0 0;color:var(--blue);font-size:11px;text-align:center}.principles{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:20px}.principles article{display:flex;gap:11px;padding:16px;border:1px solid var(--line);border-radius:17px;background:rgba(255,255,255,.72)}.principles article>span{color:var(--blue);font-size:10px;font-weight:900}.principles strong{font-size:13px}.principles p{margin:4px 0 0;color:var(--muted);font-size:11px}footer{padding:21px;text-align:center;color:#8b94a5;font-size:11px}@media(max-width:1280px){.side-rail{left:9px;width:60px;padding:8px}.side-rail>div,.side-rail a span{display:none}.side-rail a{justify-content:center;padding:6px}}@media(max-width:900px){main{padding-top:40px}.workbench{grid-template-columns:1fr}.principles{grid-template-columns:1fr 1fr 1fr}}@media(max-width:680px){body{padding-bottom:68px}.topbar{height:66px;padding:0 18px}.back{font-size:12px}.side-rail{top:auto;right:12px;bottom:10px;left:12px;width:auto;display:flex;justify-content:center;gap:8px;padding:7px;transform:none}.side-rail a{width:46%;margin:0}.side-rail a span{display:block}.side-rail a b{width:28px;height:28px}main{padding:32px 14px}.hero>p:last-of-type{font-size:13px}.role-tabs{display:flex}.role-tabs button{padding:9px 12px}.role-tabs button small{display:none}.input-panel,.output-panel{padding:18px;border-radius:19px}.prompt-section{grid-template-columns:1fr;gap:5px}.principles{grid-template-columns:1fr}.result-actions{flex-direction:column}.plain{order:2}}