:root{--ink:#12213a;--muted:#6c7b91;--blue:#1769e0;--blue2:#24a6df;--line:#dfe7f1;--surface:#f4f8fd;--white:#fff;--orange:#ef8d22}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Inter,Segoe UI,Arial,sans-serif;color:var(--ink);background:var(--surface);min-height:100vh}
.notes-header{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.95);backdrop-filter:blur(15px);border-bottom:1px solid var(--line);box-shadow:0 8px 25px rgba(18,33,58,.06)}
.notes-nav{width:min(1440px,calc(100% - 32px));margin:auto;min-height:72px;display:flex;align-items:center;gap:18px}
.notes-brand{display:flex;align-items:center;gap:10px;color:var(--ink);font-weight:900;text-decoration:none;white-space:nowrap}.notes-brand img{width:44px;height:44px;object-fit:contain}.notes-brand span{color:var(--blue)}
.subject-nav{display:flex;align-items:center;gap:5px;overflow-x:auto;margin-left:auto;padding:7px 0}.subject-nav a{white-space:nowrap;text-decoration:none;color:#536279;font-size:12px;font-weight:800;padding:9px 11px;border-radius:10px}.subject-nav a:hover,.subject-nav a.active{background:#eaf3ff;color:var(--blue)}
.notes-layout{display:grid;grid-template-columns:320px minmax(0,1fr);height:calc(100vh - 72px)}
.topic-panel{background:#fff;border-right:1px solid var(--line);overflow:auto;padding:22px 16px}.topic-top{display:flex;align-items:center;justify-content:space-between;gap:10px;margin:0 4px 17px}.topic-top h1{font-size:20px;letter-spacing:-.02em;margin:0}.topic-count{font-size:11px;color:var(--blue);font-weight:850;background:#eaf3ff;border-radius:999px;padding:6px 9px}
.topic-search{position:sticky;top:-22px;background:#fff;padding:0 0 13px;z-index:3}.topic-search input{width:100%;height:44px;border:1px solid var(--line);border-radius:13px;padding:0 13px 0 39px;background:#f9fbfe;outline:0;font-size:13px}.topic-search input:focus{border-color:#80b7f7;box-shadow:0 0 0 4px rgba(23,105,224,.08)}.topic-search i{position:absolute;left:14px;top:15px;color:#8795a9;font-size:13px}
.topic-list{list-style:none;padding:0;margin:0;display:grid;gap:5px}.topic-list a{display:flex;align-items:flex-start;gap:9px;padding:11px 12px;border-radius:12px;color:#4a5a72;text-decoration:none;font-size:12px;font-weight:720;line-height:1.45}.topic-list a:before{content:"";width:7px;height:7px;border-radius:50%;background:#c5d2e2;margin-top:5px;flex:0 0 7px}.topic-list a:hover{background:#f2f7fd;color:var(--blue)}.topic-list a.active{background:linear-gradient(135deg,#1769e0,#278eff);color:#fff;box-shadow:0 10px 22px rgba(23,105,224,.2)}.topic-list a.active:before{background:#fff}
.notes-main{min-width:0;overflow:auto;padding:22px}.content-shell{height:100%;min-height:650px;background:#fff;border:1px solid var(--line);border-radius:22px;overflow:hidden;box-shadow:0 18px 44px rgba(18,33,58,.08)}.content-toolbar{min-height:58px;padding:10px 16px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:12px;background:#fff}.content-title{font-size:14px;font-weight:850;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.content-actions{display:flex;gap:7px}.content-actions a,.content-actions button{border:1px solid var(--line);background:#fff;color:#4f5f76;border-radius:10px;padding:8px 11px;font-size:11px;font-weight:800;text-decoration:none;cursor:pointer}.content-actions a:hover,.content-actions button:hover{color:var(--blue);border-color:#9bc3f4;background:#f3f8ff}.note-frame{display:block;width:100%;height:calc(100% - 58px);min-height:590px;border:0;background:#fff}
.empty-notes{height:100%;min-height:520px;display:grid;place-items:center;text-align:center;padding:30px}.empty-notes div{max-width:480px}.empty-notes i{width:72px;height:72px;border-radius:23px;background:linear-gradient(135deg,#eaf3ff,#dff8fb);color:var(--blue);display:grid;place-items:center;font-size:30px;margin:0 auto 18px}.empty-notes h2{font-size:25px;margin:0 0 10px}.empty-notes p{color:var(--muted);line-height:1.75;margin:0}
.mobile-topics{display:none;border:0;background:var(--blue);color:#fff;border-radius:10px;padding:9px 12px;font-size:12px;font-weight:800}
@media(max-width:1050px){.subject-nav{display:none}.mobile-topics{display:inline-flex;margin-left:auto}.notes-layout{grid-template-columns:1fr}.topic-panel{position:fixed;left:0;top:72px;bottom:0;width:min(86vw,340px);z-index:90;transform:translateX(-105%);transition:.25s;box-shadow:18px 0 50px rgba(18,33,58,.2)}.topic-panel.open{transform:none}.notes-main{padding:12px}.content-shell{border-radius:16px}.notes-brand small{display:none}}
@media(max-width:560px){.notes-nav{width:min(100% - 20px,1440px)}.notes-brand{font-size:14px}.notes-brand img{width:39px;height:39px}.content-toolbar{align-items:flex-start}.content-title{font-size:12px}.content-actions a{display:none}.notes-main{padding:8px}.content-shell{border-radius:13px}.note-frame{min-height:calc(100vh - 150px)}}