:root{
  --bg:#f5f7fb; --surface:#ffffff; --surface-2:#f8fafc; --text:#172033; --muted:#667085;
  --line:#e5e7eb; --line-strong:#d5dae3; --accent:#2563eb; --accent-2:#1d4ed8; --accent-soft:#eff6ff;
  --green:#0f766e; --green-soft:#ecfdf5; --amber:#b45309; --amber-soft:#fffbeb; --red:#b42318; --red-soft:#fef3f2;
  --shadow:0 10px 30px rgba(15,23,42,.06); --radius:18px; --sidebar:292px;
}
*{box-sizing:border-box} html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.55}
button,input,textarea,select{font:inherit}
a{color:inherit;text-decoration:none}

/* --- top bar --- */
.topbar{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.9);backdrop-filter:blur(14px);border-bottom:1px solid var(--line);height:72px;display:flex;align-items:center;gap:18px;padding:0 24px}
.brand{font-weight:800;letter-spacing:-.02em;white-space:nowrap}.brand small{display:block;color:var(--muted);font-size:11px;font-weight:600;letter-spacing:.08em;text-transform:uppercase}
.search-wrap{flex:1;max-width:640px;margin:auto;position:relative}
.search{width:100%;height:42px;border:1px solid var(--line);border-radius:12px;padding:0 14px 0 40px;background:var(--surface);outline:none}
.search:focus{border-color:#93c5fd;box-shadow:0 0 0 3px rgba(37,99,235,.1)}
.search-icon{position:absolute;margin:12px 0 0 14px;color:#98a2b3;font-size:15px;pointer-events:none}
.toolbar{display:flex;gap:8px;align-items:center}
.btn{border:1px solid var(--line);background:#fff;border-radius:10px;padding:9px 12px;font-weight:700;color:#344054;cursor:pointer}
.btn:hover{border-color:#bcc6d4;background:#f8fafc}
.btn.primary{background:var(--accent);border-color:var(--accent);color:#fff}
.btn.primary:hover{background:var(--accent-2)}
.btn.danger{color:var(--red)}
label.btn{cursor:pointer}

/* --- user menu --- */
.menu{position:relative}
.menu summary{list-style:none}
.menu summary::-webkit-details-marker{display:none}
.menu-panel{position:absolute;right:0;top:calc(100% + 8px);min-width:210px;background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:0 18px 44px rgba(15,23,42,.14);padding:8px;z-index:80}
.menu-user{padding:8px 10px 10px;font-size:12px;color:var(--muted);border-bottom:1px solid var(--line);margin-bottom:6px}
.menu-user b{display:block;color:var(--text);font-size:13px}
.menu-item{display:block;width:100%;text-align:left;background:none;border:0;border-radius:9px;padding:9px 10px;font-weight:700;color:#344054;cursor:pointer}
.menu-item:hover{background:#f2f4f8}
.menu-item.danger{color:var(--red)}
.menu-item.danger:hover{background:var(--red-soft)}

/* --- layout --- */
.layout{display:grid;grid-template-columns:var(--sidebar) minmax(0,1fr);min-height:calc(100vh - 72px)}
.sidebar{position:sticky;top:72px;height:calc(100vh - 72px);overflow:auto;border-right:1px solid var(--line);background:#fbfcfe;padding:20px 14px}
.side-title{font-size:12px;font-weight:800;color:#98a2b3;text-transform:uppercase;letter-spacing:.08em;margin:6px 10px 10px}
.side-title.mt{margin-top:20px}
.nav{display:flex;flex-direction:column;gap:3px}
.nav a{padding:8px 10px;border-radius:10px;font-size:13px;color:#475467;display:flex;align-items:center;gap:8px}
.nav a:hover{background:#eef2f7;color:#1d2939}
.nav a.active{background:var(--accent-soft);color:var(--accent-2);font-weight:800}
.nav .dot{width:7px;height:7px;border-radius:50%;background:#d0d5dd;flex:0 0 auto}
.nav a.done .dot{background:#10b981}
.nav .count{margin-left:auto;font-size:11px;color:#98a2b3}
.main{max-width:1050px;width:100%;margin:0 auto;padding:34px 34px 100px}

/* --- hero --- */
.hero{background:linear-gradient(145deg,#111827 0%,#1f2937 65%,#27344a 100%);color:#fff;border-radius:26px;padding:38px 40px;box-shadow:var(--shadow);margin-bottom:28px}
.eyebrow{font-size:12px;font-weight:800;letter-spacing:.12em;text-transform:uppercase;color:#93c5fd}
.hero h1{font-size:42px;line-height:1.05;letter-spacing:-.04em;margin:8px 0 12px}
.hero p{max-width:760px;color:#dbe3ef;margin:0}
.hero-grid{display:grid;grid-template-columns:1fr 320px;gap:26px;align-items:end}
.progress-panel{padding:18px;border:1px solid rgba(255,255,255,.12);background:rgba(255,255,255,.06);border-radius:18px}
.progress-label{display:flex;justify-content:space-between;font-size:12px;color:#cbd5e1;margin-bottom:8px}
.progress-track{height:10px;background:rgba(255,255,255,.1);border-radius:999px;overflow:hidden}
.progress-fill{height:100%;width:0;background:#93c5fd;border-radius:999px;transition:width .3s}
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:14px}
.stat{padding:11px 12px;border-radius:12px;background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.08)}
.stat strong{display:block;font-size:19px}
.stat span{font-size:11px;color:#bdc8d8}

.notice{display:flex;gap:12px;align-items:flex-start;padding:14px 16px;border:1px solid #dbeafe;background:#f8fbff;border-radius:14px;color:#334155;margin-bottom:28px}
.notice b{color:#1e40af}

/* --- toc --- */
.toc-section{background:#fff;border:1px solid var(--line);border-radius:20px;padding:22px;margin-bottom:30px;box-shadow:var(--shadow)}
.toc-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:8px}
.toc-item{padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:var(--surface-2);display:flex;gap:12px}
.toc-item:hover{border-color:#cbd5e1;background:#fff}
.toc-no{font-weight:800;color:var(--accent);min-width:26px}
.toc-name{font-weight:800}
.toc-sub{font-size:11px;color:var(--muted);margin-top:2px}

/* --- phases & sections --- */
.phase{margin:50px 0 18px;scroll-margin-top:92px}
.phase-label{display:inline-flex;padding:6px 10px;border-radius:999px;background:#e9eef7;color:#475467;font-size:11px;font-weight:800;letter-spacing:.09em;text-transform:uppercase}
.phase h2{font-size:31px;letter-spacing:-.03em;margin:8px 0 2px}
.phase p{color:var(--muted);margin:0}
.section{scroll-margin-top:92px;margin-bottom:50px}
.section-head{padding:24px 26px;background:#fff;border:1px solid var(--line);border-radius:22px 22px 0 0;box-shadow:var(--shadow)}
.section-kicker{display:flex;justify-content:space-between;gap:12px;align-items:center}
.section-id{font-size:12px;font-weight:800;letter-spacing:.1em;text-transform:uppercase;color:var(--accent)}
.section-progress{font-size:12px;color:var(--muted)}
.section-title{font-size:30px;letter-spacing:-.035em;margin:8px 0}
.objective{color:#475467;margin:0}
.section-example{margin-top:16px;padding:14px 16px;border-left:4px solid var(--accent);background:var(--accent-soft);border-radius:12px;color:#334155;font-size:13px}
.section-example strong{display:block;color:#1e40af;margin-bottom:4px}

/* --- tasks --- */
.tasks{padding:14px;background:#eef2f6;border:1px solid var(--line);border-top:0;border-radius:0 0 22px 22px}
.task{background:#fff;border:1px solid var(--line);border-radius:18px;margin-bottom:12px;overflow:hidden;transition:box-shadow .2s,border-color .2s}
.task:hover{box-shadow:0 8px 22px rgba(15,23,42,.05);border-color:#d6dce5}
.task.hidden{display:none}
.task-head{padding:16px 18px 12px;display:flex;gap:12px;align-items:flex-start}
.task-id{font-size:11px;font-weight:900;color:#64748b;padding-top:3px;min-width:64px}
.task-main{flex:1}
.task-title{margin:0;font-size:17px;letter-spacing:-.01em}
.task-instruction{margin:5px 0 0;color:#667085;font-size:13px}
.task-controls{display:flex;gap:5px;align-items:center;flex-wrap:wrap}
.pill{border:1px solid var(--line);background:#fff;color:#667085;border-radius:9px;padding:5px 7px;font-size:10px;font-weight:800;cursor:pointer}
.pill.active{background:#ecfdf5;border-color:#a7f3d0;color:#047857}
.pill[data-confidence="A"].active{background:#eff6ff;border-color:#bfdbfe;color:#1d4ed8}
.pill[data-confidence="B"].active{background:#f0fdf4;border-color:#bbf7d0;color:#15803d}
.pill[data-confidence="C"].active{background:#fffbeb;border-color:#fde68a;color:#a16207}
.pill[data-confidence="D"].active{background:#fef2f2;border-color:#fecaca;color:#b91c1c}
.status-btn.active{background:#eef2ff;border-color:#c7d2fe;color:#4338ca}
.task-body{padding:0 18px 18px}
.example-box{padding:14px 15px;background:#fbfcfe;border:1px solid #e6eaf0;border-radius:13px;margin:2px 0 14px}
.example-box .label{font-size:10px;font-weight:900;letter-spacing:.1em;text-transform:uppercase;color:#98a2b3;margin-bottom:5px}
.example-box p{margin:0;color:#344054;font-size:13px}
.write-label{display:flex;justify-content:space-between;align-items:center;font-size:11px;font-weight:900;letter-spacing:.08em;text-transform:uppercase;color:#667085;margin-bottom:7px}
.write-hint{font-weight:600;color:#98a2b3;letter-spacing:0;text-transform:none}
.answer{width:100%;min-height:122px;resize:vertical;border:1px solid var(--line-strong);border-radius:13px;padding:12px 13px;outline:none;background:#fff;color:#172033;line-height:1.55}
.answer:focus{border-color:#93c5fd;box-shadow:0 0 0 3px rgba(37,99,235,.08)}
.answer::placeholder{color:#a0a8b4}
.source-row{display:flex;gap:8px;align-items:center;margin-top:9px}
.source{flex:1;border:1px solid var(--line);border-radius:10px;padding:9px 11px;outline:none;background:#fff}
.source:focus{border-color:#93c5fd}
.evidence-btn{white-space:nowrap}
.extra-evidence{margin-top:8px;display:flex;flex-direction:column;gap:8px}
.extra-evidence .ev{display:flex;gap:8px}
.extra-evidence input{flex:1;border:1px solid var(--line);border-radius:10px;padding:8px 10px;outline:none}
.extra-evidence input:focus{border-color:#93c5fd}
.ev-del{border:1px solid var(--line);background:#fff;color:#98a2b3;border-radius:10px;padding:4px 9px;cursor:pointer;font-weight:800}
.ev-del:hover{color:var(--red);border-color:#fecaca;background:var(--red-soft)}
.task-meta{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-top:10px}
.saved{font-size:10px;color:#98a2b3}
.custom-badge{font-size:10px;color:var(--accent);font-weight:800}
.del-task{border:1px solid var(--line);background:#fff;color:#98a2b3;border-radius:9px;padding:5px 8px;font-size:10px;font-weight:800;cursor:pointer}
.del-task:hover{color:var(--red);border-color:#fecaca;background:var(--red-soft)}
.add-task{width:100%;border:1px dashed #cbd5e1;background:transparent;color:#64748b;border-radius:12px;padding:11px;cursor:pointer;font-weight:800}
.add-task:hover{border-color:#93c5fd;color:var(--accent);background:#f8fbff}

/* --- takeaway & appendix --- */
.takeaway{margin-top:14px;background:#fff;border:1px solid var(--line);border-radius:18px;padding:18px}
.takeaway h3{margin:0 0 10px;font-size:16px}
.takeaway-grid{display:grid;grid-template-columns:2fr 1fr;gap:10px}
.takeaway textarea,.takeaway input{width:100%;border:1px solid var(--line);border-radius:11px;padding:10px 11px;outline:none}
.takeaway textarea{min-height:92px;resize:vertical}
.takeaway textarea:focus,.takeaway input:focus{border-color:#93c5fd}
.next{margin-top:12px;display:flex;justify-content:flex-end}
.next a{font-size:12px;font-weight:800;color:var(--accent)}
.appendix{margin-top:52px}
.definition-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}
.definition{background:#fff;border:1px solid var(--line);border-radius:15px;padding:15px}
.definition b{display:block;color:var(--accent-2);margin-bottom:4px}
.source-desc{margin-bottom:8px}
.source-link{color:var(--accent);font-size:12px;font-weight:800}
.checklist{background:#fff;border:1px solid var(--line);border-radius:18px;padding:18px}
.check{display:flex;gap:10px;padding:9px 0;border-bottom:1px solid #f0f2f5}
.check:last-child{border-bottom:0}
.check input{margin-top:5px}
.app-footer{padding:30px 4px 10px;color:#98a2b3;font-size:11px}

/* --- modals & toast --- */
.modal-backdrop{position:fixed;inset:0;background:rgba(15,23,42,.48);z-index:100;display:none;align-items:center;justify-content:center;padding:20px}
.modal-backdrop.show{display:flex}
.modal{width:min(620px,100%);background:#fff;border-radius:22px;padding:24px;box-shadow:0 25px 70px rgba(0,0,0,.18);max-height:90vh;overflow:auto}
.modal h3{margin:0 0 15px}
.modal label{font-size:12px;font-weight:800;color:#475467;display:block;margin:12px 0 6px}
.modal input,.modal textarea{width:100%;border:1px solid var(--line-strong);border-radius:11px;padding:10px;outline:none}
.modal input:focus,.modal textarea:focus{border-color:#93c5fd}
.modal textarea{min-height:100px;resize:vertical}
.modal .error{color:var(--red);font-size:12px;font-weight:700;margin-top:10px;min-height:1em}
.modal-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:16px}
.toast{position:fixed;right:20px;bottom:20px;background:#101828;color:#fff;border-radius:12px;padding:10px 14px;font-size:12px;opacity:0;transform:translateY(8px);pointer-events:none;transition:.2s;z-index:120;max-width:min(420px,90vw)}
.toast.show{opacity:1;transform:none}

/* --- login --- */
.login-body{display:flex;align-items:center;justify-content:center;min-height:100vh;background:linear-gradient(160deg,#f5f7fb 0%,#e8eef7 100%);padding:20px}
.login-card{width:min(420px,100%);background:#fff;border:1px solid var(--line);border-radius:24px;box-shadow:var(--shadow);padding:34px 32px}
.login-brand{font-weight:800;font-size:20px;letter-spacing:-.02em;margin-bottom:2px}
.login-sub{color:var(--muted);font-size:13px;margin:0 0 24px}
.login-card label{font-size:12px;font-weight:800;color:#475467;display:block;margin:0 0 6px}
.login-card input{width:100%;border:1px solid var(--line-strong);border-radius:11px;padding:11px 12px;outline:none;margin-bottom:14px}
.login-card input:focus{border-color:#93c5fd;box-shadow:0 0 0 3px rgba(37,99,235,.08)}
.login-card button{width:100%;padding:12px;font-size:15px;border-radius:12px}
.login-error{background:var(--red-soft);border:1px solid #fecaca;color:var(--red);border-radius:11px;padding:10px 12px;font-size:13px;margin-bottom:14px}
.login-foot{color:#98a2b3;font-size:11px;margin-top:18px;text-align:center}

/* --- responsive & print --- */
@media(max-width:980px){.layout{grid-template-columns:1fr}.sidebar{display:none}.main{padding:20px}.hero-grid{grid-template-columns:1fr}.toc-grid{grid-template-columns:1fr}.topbar{padding:0 14px}.toolbar .btn span{display:none}.toolbar .btn{padding:9px}.stats{grid-template-columns:1fr 1fr 1fr}.menu summary span{display:none}}
@media(max-width:640px){.hero{padding:28px 22px;border-radius:22px}.hero h1{font-size:34px}.main{padding:14px}.task-head{flex-wrap:wrap}.task-id{min-width:55px}.task-controls{margin-left:auto}.takeaway-grid{grid-template-columns:1fr}.source-row{flex-direction:column;align-items:stretch}.section-title{font-size:26px}.topbar{gap:8px}.brand small{display:none}.search-wrap{max-width:none}.btn{padding:9px}}
@media print{.topbar,.sidebar,.toolbar,.search-wrap,.add-task,.modal-backdrop,.toast,.menu,.del-task,.ev-del{display:none!important}.layout{display:block}.main{max-width:none;padding:0}.hero{box-shadow:none}.task{break-inside:avoid}.answer{border-color:#999}}