:root{--ink:#22272b;--muted:#7a7f80;--paper:#f7f6f2;--card:#fff;--line:#e9e6df;--green:#245d4b;--lime:#dff08a;--coral:#ef876f;--violet:#8972d6;--mint:#74bca1;--blue:#6ca6d9;--shadow:0 18px 50px rgba(34,39,43,.08)}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:"DM Sans",sans-serif}.sidebar{width:246px;position:fixed;inset:0 auto 0 0;background:#f0efe9;border-right:1px solid var(--line);padding:28px 18px 20px;display:flex;flex-direction:column;z-index:20}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);font:800 20px Manrope;margin:0 10px 42px}.brand-mark{display:grid;place-items:center;width:31px;height:31px;border-radius:10px;background:var(--green);color:#fff;font-size:17px}.nav-item{border:0;background:transparent;color:#666b6b;width:100%;padding:11px 13px;border-radius:10px;text-align:left;font:600 14px "DM Sans";display:flex;align-items:center;gap:13px;cursor:pointer;margin:2px 0}.nav-item span{font-size:17px;width:19px;text-align:center}.nav-item:hover,.nav-item.active{background:#fff;color:var(--ink)}.nav-label{font-size:10px;font-weight:700;letter-spacing:1.7px;color:#a3a39e;margin:28px 13px 10px}.sidebar-bottom{margin-top:auto}.profile{border-top:1px solid #ddd9d1;margin-top:15px;padding:18px 8px 0;display:flex;gap:10px;align-items:center}.profile strong,.profile small{display:block}.profile strong{font-size:12px}.profile small{font-size:10px;color:var(--muted);margin-top:2px}.mini-avatar{width:34px;height:34px;background:var(--lime);border-radius:50%;display:grid;place-items:center;font-weight:700;font-size:11px}main{margin-left:246px;min-height:100vh}header{height:76px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 5vw;background:rgba(247,246,242,.88);backdrop-filter:blur(10px);position:sticky;top:0;z-index:10}.crumb{font-size:13px;color:var(--muted)}.header-actions{display:flex;gap:9px}.icon-button{background:#fff;border:1px solid var(--line);border-radius:10px;padding:8px 11px;color:#545959}.mobile-menu{display:none;border:0;background:none;font-size:22px}.page{max-width:1240px;margin:auto;padding:52px 5vw 80px}.hero{display:grid;grid-template-columns:1.35fr .65fr;gap:30px;align-items:stretch;margin-bottom:50px}.hero-copy{padding:22px 0}.eyebrow{font-size:11px;letter-spacing:2px;font-weight:800;color:var(--green)}h1,h2,h3{font-family:Manrope,sans-serif;margin-top:0}h1{font-size:clamp(38px,5vw,66px);line-height:1.05;letter-spacing:-3px;margin:17px 0 20px;max-width:700px}h1 em{font-style:normal;color:var(--green);position:relative}h1 em:after{content:"";height:8px;background:var(--lime);border-radius:9px;position:absolute;left:0;right:0;bottom:1px;z-index:-1}.hero-copy p{font-size:16px;line-height:1.75;color:#6e7474;max-width:580px}.primary-button,.secondary-button{border:0;border-radius:11px;padding:13px 20px;font-weight:700;cursor:pointer}.primary-button{background:var(--green);color:#fff}.secondary-button{background:#fff;border:1px solid var(--line);color:var(--ink)}.hero-actions{display:flex;gap:10px;margin-top:29px}.quote-card{background:var(--green);color:#fff;border-radius:24px;padding:35px;display:flex;flex-direction:column;justify-content:space-between;min-height:275px;position:relative;overflow:hidden}.quote-card:after{content:"✦";position:absolute;right:-10px;bottom:-45px;font-size:160px;color:rgba(255,255,255,.06)}.quote-card blockquote{font:600 21px/1.5 Manrope;margin:15px 0}.quote-card small{color:#b7d0c7}.section-head{display:flex;justify-content:space-between;align-items:end;margin-bottom:22px}.section-head h2{font-size:25px;margin-bottom:4px}.section-head p{margin:0;color:var(--muted);font-size:13px}.text-button{border:0;background:none;color:var(--green);font-weight:700;cursor:pointer}.subject-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:17px}.subject-card{background:#fff;border:1px solid var(--line);border-radius:17px;overflow:hidden;cursor:pointer;transition:.2s;box-shadow:0 2px 0 rgba(0,0,0,.01)}.subject-card:hover{transform:translateY(-5px);box-shadow:var(--shadow)}.teacher-scene{height:150px;position:relative;display:grid;place-items:center;overflow:hidden}.teacher-scene.coral{background:#fbe5de}.teacher-scene.violet{background:#e9e4f8}.teacher-scene.mint{background:#dff2e9}.teacher-scene.blue{background:#e1effa}.teacher-avatar{width:82px;height:82px;border-radius:50% 50% 45% 45%;background:#fff;display:grid;place-items:center;font:800 23px Manrope;box-shadow:0 10px 25px rgba(0,0,0,.12);position:relative}.teacher-avatar:before{content:"";position:absolute;top:-10px;width:70px;height:33px;border-radius:50% 50% 30% 30%;background:#35404a}.teacher-bubble{position:absolute;right:13px;top:13px;background:#fff;padding:7px 10px;border-radius:10px;font-size:10px;font-weight:700}.subject-info{padding:18px}.subject-code{font-size:10px;color:var(--green);font-weight:800;letter-spacing:1px}.subject-info h3{font-size:15px;line-height:1.35;margin:7px 0 13px;min-height:41px}.teacher-line{display:flex;align-items:center;justify-content:space-between;font-size:11px;color:var(--muted)}.file-count{background:#f4f3ef;border-radius:8px;padding:4px 7px}.stats-row{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:40px}.stat{padding:18px 20px;border-top:1px solid var(--line);display:flex;gap:13px;align-items:center}.stat-icon{width:38px;height:38px;border-radius:11px;background:#e8edc6;display:grid;place-items:center}.stat strong,.stat small{display:block}.stat small{color:var(--muted);font-size:11px;margin-top:2px}
.subject-hero{display:flex;align-items:center;gap:24px;margin-bottom:35px}.large-avatar{width:92px;height:92px;border-radius:23px;display:grid;place-items:center;font:800 25px Manrope}.large-avatar.coral{background:#f8d9d1}.large-avatar.violet{background:#ded6f5}.large-avatar.mint{background:#d5ede3}.large-avatar.blue{background:#d7e9f7}.subject-hero h1{font-size:38px;letter-spacing:-1.5px;margin:6px 0}.subject-hero p{color:var(--muted);margin:0}.category-tabs{display:flex;gap:8px;border-bottom:1px solid var(--line);margin-bottom:24px}.tab{border:0;background:none;padding:13px 17px;font-weight:700;color:var(--muted);cursor:pointer;border-bottom:2px solid transparent}.tab.active{color:var(--green);border-color:var(--green)}.file-list{display:grid;gap:10px}.file-card{background:#fff;border:1px solid var(--line);padding:17px 19px;border-radius:13px;display:flex;align-items:center;gap:15px;cursor:pointer;transition:.15s}.file-card:hover{border-color:#b8c9c2;transform:translateX(3px)}.file-icon{width:43px;height:43px;border-radius:11px;background:#eef3d1;display:grid;place-items:center;font-weight:800;color:var(--green);font-size:11px}.file-meta{flex:1;min-width:0}.file-meta strong{display:block;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-size:14px}.file-meta small{color:var(--muted)}.arrow{font-size:22px;color:#a7aaa9}.empty-state{text-align:center;padding:70px 20px;background:#fff;border:1px dashed #d9d5cd;border-radius:16px;color:var(--muted)}
.lesson-layout{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:22px}.lesson-panel,.chat-panel{background:#fff;border:1px solid var(--line);border-radius:18px}.lesson-panel{padding:28px;min-height:600px}.lesson-top{display:flex;justify-content:space-between;gap:15px;border-bottom:1px solid var(--line);padding-bottom:19px;margin-bottom:24px}.lesson-top h2{font-size:20px;margin:5px 0 0}.lesson-actions{display:flex;gap:6px}.lesson-actions button{border:1px solid var(--line);background:#fff;border-radius:8px;padding:8px;cursor:pointer}.lesson-content{font-size:15px;line-height:1.75}.lesson-content h1,.lesson-content h2{font-size:21px;letter-spacing:0;margin:25px 0 10px}.lesson-content h3{font-size:17px;margin:20px 0 8px}.lesson-content table{border-collapse:collapse;width:100%;margin:16px 0}.lesson-content th,.lesson-content td{border:1px solid var(--line);padding:9px;text-align:left}.lesson-content th{background:#f4f5ed}.lesson-content pre{white-space:pre-wrap;background:#f3f4f1;border-radius:10px;padding:14px}.welcome-lesson{text-align:center;padding:95px 12%;color:var(--muted)}.welcome-lesson .magic{font-size:40px}.welcome-lesson h2{color:var(--ink);margin:14px 0 10px}.chat-panel{height:670px;display:flex;flex-direction:column;overflow:hidden;position:sticky;top:98px}.chat-head{padding:18px;border-bottom:1px solid var(--line);display:flex;gap:11px;align-items:center}.chat-head .mini-avatar{background:#dff08a}.online{font-size:10px;color:#4d8a67}.chat-messages{flex:1;overflow:auto;padding:16px;display:flex;flex-direction:column;gap:12px}.message{font-size:13px;line-height:1.55;padding:11px 13px;border-radius:12px;max-width:90%}.message.ai{background:#f3f3ee;align-self:flex-start}.message.user{background:var(--green);color:#fff;align-self:flex-end}.message.error{background:#fff0ed;color:#a44332}.chat-form{border-top:1px solid var(--line);padding:12px}.quick-prompts{display:flex;gap:5px;overflow:auto;margin-bottom:8px}.quick-prompts button{white-space:nowrap;border:1px solid var(--line);background:#fff;border-radius:20px;padding:6px 9px;font-size:10px;cursor:pointer}.input-row{display:flex;gap:7px}.input-row textarea{resize:none;flex:1;border:1px solid var(--line);border-radius:10px;padding:10px;font:13px "DM Sans";height:42px}.send-button{width:42px;border:0;border-radius:10px;background:var(--green);color:#fff;font-size:18px}.loading{display:inline-flex;gap:4px}.loading i{width:6px;height:6px;background:#89918d;border-radius:50%;animation:pulse 1s infinite}.loading i:nth-child(2){animation-delay:.15s}.loading i:nth-child(3){animation-delay:.3s}@keyframes pulse{50%{opacity:.2;transform:translateY(-2px)}}.modal-backdrop{position:fixed;inset:0;background:rgba(20,27,25,.45);display:grid;place-items:center;z-index:100;padding:20px}.hidden{display:none}.modal{width:min(460px,100%);background:#fff;border-radius:20px;padding:31px;position:relative;box-shadow:var(--shadow)}.modal-close{position:absolute;right:17px;top:14px;border:0;background:none;font-size:25px;cursor:pointer}.modal h2{margin:10px 0}.modal>p{color:var(--muted);font-size:13px}.provider-choice{border:1px solid var(--line);border-radius:12px;padding:13px;display:flex;gap:10px;margin:9px 0;cursor:pointer}.provider-choice span,.provider-choice strong,.provider-choice small{display:block}.provider-choice small{color:var(--muted);margin-top:3px}.setup-note{background:#f4f5ed;padding:12px;border-radius:9px;font-size:12px;margin:16px 0}.modal-done{width:100%}@media(max-width:1050px){.subject-grid{grid-template-columns:repeat(2,1fr)}.hero{grid-template-columns:1fr}.quote-card{min-height:200px}.lesson-layout{grid-template-columns:1fr}.chat-panel{position:static;height:560px}}@media(max-width:700px){.sidebar{transform:translateX(-100%);transition:.2s}.sidebar.open{transform:none}.mobile-menu{display:block}main{margin-left:0}header{padding:0 20px}.page{padding:32px 20px}.subject-grid{grid-template-columns:1fr}.stats-row{grid-template-columns:1fr}.hero-copy{padding:0}h1{font-size:40px;letter-spacing:-2px}.subject-hero{align-items:flex-start}.subject-hero h1{font-size:27px}.large-avatar{width:70px;height:70px}.lesson-panel{padding:18px}.lesson-top{flex-direction:column}}