:root{
  --navy:#071126;
  --navy2:#0b1733;
  --navy3:#102047;
  --brand:#ffc72c;
  --brand2:#ffe08a;
  --blue:#2563eb;
  --green:#16a34a;
  --red:#dc2626;
  --orange:#f59e0b;
  --bg:#f4f7fb;
  --surface:#ffffff;
  --surface2:#f8fbff;
  --text:#0f172a;
  --muted:#64748b;
  --line:#e5eaf3;
  --shadow:0 18px 55px rgba(15,23,42,.10);
  --radius:22px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  color:var(--text);
  background:
    radial-gradient(circle at top left, rgba(255,199,44,.26), transparent 28rem),
    radial-gradient(circle at top right, rgba(37,99,235,.13), transparent 32rem),
    var(--bg);
  font-family:Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}
a{color:inherit;text-decoration:none}
img{display:block;max-width:100%}
button,input,select,textarea{font:inherit}
button{cursor:pointer}
.container{width:min(1180px, calc(100% - 28px));margin:0 auto}
.header{
  position:sticky;top:0;z-index:50;
  background:rgba(244,247,251,.86);
  border-bottom:1px solid rgba(229,234,243,.82);
  backdrop-filter:blur(18px);
}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:12px 0}
.brand{display:flex;align-items:center;gap:11px;font-weight:1000}
.brand img{width:44px;height:44px;border-radius:15px;box-shadow:0 10px 22px rgba(15,23,42,.12)}
.brand span{display:block}
.brand small{display:block;color:var(--muted);font-weight:800;font-size:12px;margin-top:1px}
.nav{display:flex;align-items:center;gap:7px;flex-wrap:wrap;justify-content:flex-end}
.nav a,.nav button{
  border:0;background:transparent;color:#475569;font-weight:900;
  padding:9px 11px;border-radius:999px;font-size:14px
}
.nav a:hover,.nav a.active{background:#fff;color:var(--text);box-shadow:0 8px 22px rgba(15,23,42,.08)}
.menu{display:none;border:1px solid var(--line);background:#fff;border-radius:13px;padding:9px 12px;font-weight:1000}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  border:0;border-radius:15px;background:var(--navy);color:white;
  font-weight:1000;padding:12px 18px;box-shadow:0 14px 34px rgba(7,17,38,.18)
}
.btn:hover{filter:brightness(1.04)}
.btn.brand-btn{background:var(--brand);color:#111827}
.btn.secondary{background:white;color:var(--navy);border:1px solid var(--line);box-shadow:none}
.btn.ghost{background:#eef4ff;color:var(--navy);box-shadow:none}
.btn.danger{background:var(--red);color:#fff}
.btn.small{padding:9px 12px;font-size:13px;border-radius:12px}
.btn.full{width:100%}
.hero{padding:62px 0 34px}
.hero-grid{display:grid;grid-template-columns:1.06fr .94fr;gap:24px;align-items:center}
.hero h1{font-size:clamp(42px, 6vw, 76px);line-height:.98;margin:16px 0;color:var(--navy)}
h1,h2,h3,p{margin-top:0}
h2{font-size:clamp(26px, 3.3vw, 44px);line-height:1.08;color:var(--navy);margin-bottom:12px}
h3{font-size:21px;color:var(--navy);margin-bottom:10px}
p{color:var(--muted);line-height:1.72}
.lead{font-size:18px;max-width:720px}
.badge,.chip{
  display:inline-flex;align-items:center;gap:7px;border:1px solid #f4d676;background:#fff8df;
  color:#5b4100;border-radius:999px;padding:7px 11px;font-size:13px;font-weight:1000
}
.chip{padding:5px 9px;font-size:12px;margin:3px}
.chip.ok{background:#dcfce7;color:#14532d;border-color:#bbf7d0}
.chip.bad{background:#fee2e2;color:#7f1d1d;border-color:#fecaca}
.chip.warn{background:#fef3c7;color:#78350f;border-color:#fde68a}
.chip.blue{background:#dbeafe;color:#1e3a8a;border-color:#bfdbfe}
.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}
.card,.panel{
  background:rgba(255,255,255,.96);
  border:1px solid var(--line);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
}
.card{padding:24px}
.panel{padding:18px}
.card.dark{
  background:linear-gradient(135deg,var(--navy),var(--navy3));
  color:#fff;border-color:rgba(255,255,255,.12)
}
.card.dark h2,.card.dark h3{color:#fff}
.card.dark p{color:#cbd5e1}
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.grid.two{grid-template-columns:repeat(2,1fr)}
.grid.four{grid-template-columns:repeat(4,1fr)}
.grid.auto{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.section{padding:42px 0}
.section-head{max-width:790px;margin-bottom:22px}
.stat{
  background:#fff;border:1px solid var(--line);border-radius:20px;padding:18px;
  position:relative;overflow:hidden
}
.stat::after{content:"";position:absolute;right:-25px;top:-25px;width:84px;height:84px;border-radius:50%;background:rgba(255,199,44,.18)}
.stat span{display:block;color:var(--muted);font-size:13px;font-weight:900}
.stat b{display:block;margin-top:8px;font-size:30px;color:var(--navy)}
.feature-card{transition:.18s}
.feature-card:hover{transform:translateY(-4px)}
.feature-icon{
  width:46px;height:46px;border-radius:15px;background:#fff3c4;color:#1f2937;
  display:grid;place-items:center;font-weight:1000;margin-bottom:14px
}
.exam-strip{display:grid;grid-template-columns:repeat(5,1fr);gap:10px;margin-top:20px}
.exam-pill{background:#fff;border:1px solid var(--line);border-radius:16px;padding:13px;text-align:center;font-weight:1000;color:var(--navy)}
.list{display:grid;gap:12px}
.item{
  display:flex;justify-content:space-between;align-items:center;gap:14px;
  background:#fff;border:1px solid var(--line);border-radius:18px;padding:14px
}
.item strong{display:block;color:var(--navy)}
.item small{display:block;color:var(--muted);margin-top:3px}
.footer{background:var(--navy);color:#fff;margin-top:54px}
.footer-grid{display:grid;grid-template-columns:1.25fr repeat(3,1fr);gap:24px;padding:38px 0}
.footer a,.footer p{color:#cbd5e1}
.footer h3{color:#fff}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding:17px 0;color:#cbd5e1;font-size:13px}

/* App shell */
.app-shell{width:min(1240px,calc(100% - 26px));margin:0 auto;padding:20px 0 46px}
.app-layout{display:grid;grid-template-columns:260px 1fr;gap:18px}
.sidebar{
  position:sticky;top:78px;align-self:start;background:#fff;border:1px solid var(--line);
  border-radius:24px;padding:12px;box-shadow:var(--shadow)
}
.sidebar .side-title{font-size:12px;text-transform:uppercase;letter-spacing:.08em;color:#94a3b8;font-weight:1000;margin:10px 12px}
.sidebar a{display:flex;align-items:center;gap:10px;border-radius:15px;padding:12px;color:#475569;font-weight:900}
.sidebar a:hover,.sidebar a.active{background:#eef4ff;color:var(--navy)}
.app-main{min-width:0}
.top-dashboard{
  display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:16px
}
.page-title h1{font-size:34px;margin:0 0 6px;color:var(--navy)}
.page-title p{margin:0}
.mobile-bottom{display:none}
.auth-wrap{width:min(1060px,100%);margin:28px auto;display:grid;grid-template-columns:1fr 1fr;gap:18px;align-items:stretch}
.auth-hero{background:linear-gradient(135deg,var(--navy),#172554);color:#fff;border-radius:26px;padding:30px;box-shadow:var(--shadow)}
.auth-hero h1{color:#fff;font-size:42px;line-height:1.05;margin:14px 0}
.auth-hero p{color:#dbeafe}
form{display:grid;gap:13px}
label{display:block;color:#475569;font-weight:900;font-size:13px;margin-bottom:6px}
input,select,textarea{
  width:100%;border:1px solid var(--line);border-radius:14px;background:#fff;color:var(--text);
  padding:12px 13px;outline:none
}
textarea{min-height:128px;resize:vertical}
input:focus,select:focus,textarea:focus{border-color:#93b4ff;box-shadow:0 0 0 4px rgba(37,99,235,.10)}
.filterbar{display:flex;gap:10px;flex-wrap:wrap;margin:14px 0}
.filterbar input,.filterbar select{width:auto;min-width:170px;flex:1}
.quiz-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:14px}
.quiz-card{display:grid;gap:10px;background:#fff;border:1px solid var(--line);border-radius:22px;padding:18px;box-shadow:0 10px 28px rgba(15,23,42,.06)}
.quiz-card .meta{display:flex;flex-wrap:wrap;gap:4px}
.topic-card{display:flex;gap:14px;align-items:flex-start;background:#fff;border:1px solid var(--line);border-radius:20px;padding:18px}
.topic-icon{width:48px;height:48px;border-radius:16px;display:grid;place-items:center;background:#eff6ff;font-weight:1000;color:#1e3a8a}
.flashcard{
  background:linear-gradient(180deg,#fff,#f8fbff);border:1px solid var(--line);border-radius:22px;padding:20px;box-shadow:0 10px 30px rgba(15,23,42,.06)
}
.flashcard h2{font-size:32px;margin-bottom:4px}
.note-card{display:flex;justify-content:space-between;gap:14px;align-items:center;background:#fff;border:1px solid var(--line);border-radius:20px;padding:16px}
.table-wrap{overflow:auto}
table{width:100%;border-collapse:collapse;min-width:760px}
th,td{text-align:left;border-bottom:1px solid var(--line);padding:12px;vertical-align:top}
th{font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:#64748b}
td{color:#475569}
td strong{color:var(--navy)}
.toast{
  position:fixed;left:50%;bottom:22px;transform:translateX(-50%);
  background:#111827;color:#fff;border-radius:15px;padding:13px 16px;box-shadow:var(--shadow);z-index:100;
  max-width:min(92vw,620px)
}
.hidden{display:none!important}
.quiz-top{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-bottom:14px}
.timer{font-weight:1000;color:#5e4300;background:#fff4c7;border:1px solid #f3d16d;border-radius:999px;padding:9px 12px}
.quiz-layout{display:grid;grid-template-columns:1fr 300px;gap:18px}
.question-card{min-height:420px}
.option{
  width:100%;text-align:left;border:1px solid var(--line);background:#fff;border-radius:16px;padding:15px;
  font-weight:900;color:var(--navy);cursor:pointer
}
.option.selected{border-color:var(--blue);background:#eff6ff}
.option.correct{border-color:var(--green);background:#dcfce7}
.option.wrong{border-color:var(--red);background:#fee2e2}
.palette{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}
.palette button{border:1px solid var(--line);border-radius:11px;background:#fff;padding:9px 0;font-weight:1000}
.palette button.done{background:#dcfce7}.palette button.marked{background:#fef3c7}.palette button.current{outline:2px solid var(--blue)}
.progress{height:10px;background:#eef2f7;border-radius:999px;overflow:hidden;margin:12px 0 16px}
.progress span{display:block;height:100%;background:linear-gradient(90deg,var(--brand),#fb923c);width:0}
.score-circle{width:160px;height:160px;border-radius:50%;background:#fff8dc;border:2px solid #f4d16b;display:grid;place-items:center;margin:16px auto}
.score-circle b{font-size:36px;color:#5e4300}
.planner-task{display:flex;gap:10px;align-items:center;background:#fff;border:1px solid var(--line);border-radius:15px;padding:12px}
.planner-task.done{opacity:.68;text-decoration:line-through}
.code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;background:#081225;color:#e2e8f0;border-radius:16px;padding:14px;white-space:pre-wrap;overflow:auto}
.admin-hero{background:linear-gradient(135deg,#071126,#172554);color:#fff;border-radius:26px;padding:24px;box-shadow:var(--shadow)}
.admin-hero h1,.admin-hero h2,.admin-hero h3{color:#fff}.admin-hero p{color:#cbd5e1}
.quick-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:12px}
.quick-action{background:#fff;border:1px solid var(--line);border-radius:18px;padding:16px;display:block}
.quick-action b{display:block;color:var(--navy);margin-bottom:4px}
@media(max-width:960px){
  .hero-grid,.app-layout,.quiz-layout,.footer-grid,.auth-wrap{grid-template-columns:1fr}
  .grid,.grid.two,.grid.four,.exam-strip{grid-template-columns:1fr 1fr}
  .sidebar{position:static;display:none}
  .mobile-bottom{display:grid;position:fixed;left:8px;right:8px;bottom:8px;z-index:60;background:#fff;border:1px solid var(--line);box-shadow:var(--shadow);border-radius:20px;grid-template-columns:repeat(5,1fr);padding:7px}
  .mobile-bottom a{font-size:11px;text-align:center;color:#475569;font-weight:900;padding:8px 4px;border-radius:12px}
  .mobile-bottom a.active{background:#eef4ff;color:var(--navy)}
  body{padding-bottom:72px}
}
@media(max-width:720px){
  .container,.app-shell{width:min(100% - 18px, 1180px)}
  .menu{display:block}
  .nav{display:none;position:absolute;left:10px;right:10px;top:68px;background:#fff;border:1px solid var(--line);border-radius:20px;padding:10px;box-shadow:var(--shadow)}
  .nav.open{display:grid;grid-template-columns:1fr}
  .nav a,.nav button{text-align:left;border-radius:12px}
  .hero{padding:34px 0 20px}
  .grid,.grid.two,.grid.four,.exam-strip{grid-template-columns:1fr}
  .card{padding:19px;border-radius:20px}
  .item,.note-card{align-items:flex-start;flex-direction:column}
  .page-title h1{font-size:28px}
  .filterbar input,.filterbar select{width:100%;min-width:0}
}