:root{--teal:#087a74;--mint:#a9dfd7;--bg:#edf5f6;--blue:#3f8cff;--ink:#183039;--muted:#769097}*{box-sizing:border-box}body{margin:0;font-family:"Microsoft YaHei",Arial,sans-serif;color:var(--ink);background:var(--bg)}button,input{font:inherit}.login{min-height:100vh;display:grid;grid-template-columns:42% 58%;background:white}.login-left{padding:48px 12%;position:relative;display:flex;flex-direction:column;justify-content:center}.brand{display:flex;align-items:center;gap:10px;font-size:22px;font-weight:800;color:#26373d}.brand-mark{width:45px;height:45px;border:10px solid #94c83d;border-radius:50% 50% 42% 42%;border-top-color:#f2bd32;transform:rotate(25deg)}.login h1{font-size:40px;color:var(--teal);margin:65px 0 45px}.field{width:330px;border:1px solid #d9e1e8;border-radius:5px;padding:15px 16px;margin-bottom:25px}.login-btn{width:330px;border:0;border-radius:28px;color:#fff;background:linear-gradient(90deg,#057481,#078f72);padding:14px;font-size:20px;cursor:pointer}.login-art{background:linear-gradient(135deg,rgba(9,121,118,.9),rgba(2,102,108,.95)),url('http://47.105.55.159/assets/login-bg-C9GFoUnj.png') center/cover;display:flex;align-items:center;justify-content:center;color:#d2ff91;font-size:clamp(80px,14vw,210px);font-weight:800;letter-spacing:40px}.shell{display:grid;grid-template-columns:204px 1fr;min-height:100vh}.sidebar{background:#fff;padding:34px 24px;position:sticky;top:0;height:100vh}.sidebar .brand{margin-bottom:45px;font-size:19px}.nav{display:flex;flex-direction:column;gap:18px}.nav button{border:0;background:transparent;text-align:left;padding:14px 16px;border-radius:10px;font-size:18px;font-weight:700;cursor:pointer;color:#1d292e}.nav button.active{background:#e0f5f2;color:var(--teal)}.nav-icon{display:inline-grid;place-items:center;width:28px;height:28px;margin-right:12px;color:#fff;background:#687277;border-radius:6px}.nav button.active .nav-icon{background:var(--teal)}.main{padding:22px 5vw 60px}.topbar{height:58px;display:flex;justify-content:flex-end;align-items:center}.avatar{width:34px;height:34px;border-radius:50%;background:#d5e8ff;display:grid;place-items:center;margin-right:8px}.hero{height:122px;border-radius:10px;margin:80px auto 26px;max-width:900px;background:linear-gradient(100deg,#8de2ee,#cdf8ed);display:flex;align-items:center;justify-content:center;font-size:29px;color:#177482;font-weight:800;letter-spacing:3px}.panel{max-width:900px;margin:auto}.section-title{background:var(--mint);color:#fff;font-size:20px;font-weight:800;border-radius:6px 6px 0 0;padding:10px 15px;display:flex;justify-content:space-between}.search{border:1px solid #79cfc5;border-radius:18px;background:#c9ebe7;padding:7px 14px;min-width:220px}.students,.course-grid{background:#fff;padding:20px;display:grid;grid-template-columns:repeat(3,1fr);gap:16px;border-radius:0 0 6px 6px;min-height:320px}.student,.course-card{border:1px solid #e8eef0;border-radius:9px;padding:16px;background:#fff;box-shadow:0 2px 10px #163b4510}.student{display:flex;gap:12px}.student-pic{font-size:34px}.links button{border:0;background:none;color:var(--blue);padding:4px 10px 0 0;cursor:pointer}.module-head{max-width:1000px;margin:45px auto 25px;display:flex;align-items:end;justify-content:space-between}.module-head h1{margin:0}.module-head p{color:var(--muted);margin:8px 0 0}.course-grid{max-width:1000px;margin:auto;grid-template-columns:repeat(3,1fr);background:transparent;padding:0}.course-card{cursor:pointer;transition:.2s}.course-card:hover{transform:translateY(-3px);box-shadow:0 10px 30px #17454f20}.course-cover{height:108px;border-radius:8px;background:linear-gradient(135deg,#47c6c0,#8dc7ff);display:flex;align-items:center;justify-content:center;color:white;font-size:38px}.progress{height:8px;background:#ecf0f1;border-radius:8px;overflow:hidden}.progress span{display:block;height:100%;background:#54c58b}.empty{grid-column:1/-1;text-align:center;padding:70px;color:var(--muted)}.back{border:0;background:#fff;border-radius:8px;padding:10px 15px;cursor:pointer}.units{max-width:1000px;margin:auto;display:grid;grid-template-columns:280px 1fr;gap:20px}.unit-list,.lesson{background:white;border-radius:10px;padding:18px}.unit-list button{width:100%;border:0;background:#f4f8f8;border-radius:7px;margin:5px 0;padding:11px;text-align:left;cursor:pointer}.unit-list button.active{background:#dff4ef;color:var(--teal);font-weight:700}.lesson-top{display:flex;justify-content:space-between;align-items:center}.word-row{padding:14px 6px;border-bottom:1px dashed #dfe8e9;font-size:17px;line-height:1.8}.badge{font-size:12px;background:#ebfaf5;color:#168365;border-radius:12px;padding:4px 9px}.test-card{max-width:700px;margin:80px auto;background:white;padding:40px;border-radius:16px;text-align:center}.primary{border:0;border-radius:22px;background:var(--teal);color:#fff;padding:12px 28px;cursor:pointer}.toast{position:fixed;right:25px;top:25px;background:#163b45;color:white;padding:12px 18px;border-radius:8px}@media(max-width:800px){.login{grid-template-columns:1fr}.login-art{display:none}.shell{grid-template-columns:76px 1fr}.sidebar{padding:20px 9px}.sidebar .brand span,.nav button span:last-child{display:none}.main{padding:14px}.students,.course-grid{grid-template-columns:1fr}.hero{margin-top:25px;font-size:20px}.units{grid-template-columns:1fr}}