:root{
  --bg:#f4f8ff;
  --card:#ffffff;
  --line:#dbe8ff;
  --blue:#2d7ff9;
  --blue-dark:#145cc8;
  --text:#14213d;
  --muted:#6b7a99;
  --soft:#eef5ff;
  --green:#19b46b;
  --orange:#ff9f1c;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family:Arial,Helvetica,sans-serif;
  background:linear-gradient(180deg,#f7fbff 0%,#eef5ff 100%);
  color:var(--text);
}
a{color:inherit}
.app{display:grid;grid-template-columns:260px 1fr;min-height:100vh}
.sidebar{
  background:#fff;border-right:1px solid var(--line);
  padding:28px 18px;position:sticky;top:0;height:100vh
}
.brand{font-size:18px;font-weight:800}
.brand .blue{color:var(--blue)}
.tag{color:var(--muted);font-size:13px;margin:4px 0 26px}
.nav a{
  display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);
  padding:12px 14px;border-radius:14px;margin-bottom:6px;font-weight:600
}
.nav a.active,.nav a:hover{background:var(--soft);color:var(--blue-dark)}
.pill-box{
  margin-top:26px;background:linear-gradient(180deg,#f7fbff 0%,#e9f2ff 100%);
  border:1px solid var(--line);border-radius:20px;padding:18px
}
.pill-box h3{margin:0 0 8px;font-size:18px}
.pill-box p{margin:0 0 14px;color:var(--muted);font-size:14px;line-height:1.45}
.main{padding:24px}
.topbar{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-bottom:20px}
h1{margin:0;font-size:42px;line-height:1.05}
.sub{margin-top:8px;color:var(--muted);font-size:18px}
.user{
  display:flex;align-items:center;gap:12px;background:#fff;border:1px solid var(--line);
  padding:10px 14px;border-radius:18px
}
.avatar{
  width:44px;height:44px;border-radius:50%;background:var(--soft);color:var(--blue-dark);
  display:grid;place-items:center;font-weight:800
}
.grid{display:grid;grid-template-columns:2fr 1fr;gap:20px}
.card{
  background:var(--card);border:1px solid var(--line);border-radius:24px;padding:22px;
  box-shadow:0 8px 30px rgba(45,127,249,.06)
}
.hero{
  display:grid;grid-template-columns:1.1fr .9fr;align-items:center;gap:14px;min-height:250px;
  background:linear-gradient(135deg,#fff 0%,#eef5ff 100%)
}
.eyebrow{
  color:var(--blue);font-size:12px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;
  margin-bottom:10px
}
.hero h2{font-size:44px;margin:0 0 10px}
.hero p{font-size:21px;line-height:1.45;color:var(--muted);margin:0 0 18px;max-width:440px}
button,.btn{
  background:linear-gradient(180deg,#3690ff 0%,#2d7ff9 100%);
  color:#fff;border:none;border-radius:14px;padding:14px 18px;font-size:17px;font-weight:700;
  cursor:pointer;box-shadow:0 8px 18px rgba(45,127,249,.2);text-decoration:none;display:inline-block
}
.btn.secondary, .secondary{
  background:#fff;color:var(--blue-dark);border:1px solid var(--line);box-shadow:none
}
.math-visual{display:grid;place-items:center;min-height:180px;position:relative}
.disc{
  width:280px;height:120px;border-radius:999px;background:radial-gradient(circle at 50% 20%,#fff 0%,#ddebff 80%);
  border:1px solid #cfe1ff;box-shadow:0 15px 30px rgba(45,127,249,.12);position:absolute;bottom:18px
}
.nums{
  position:relative;display:flex;gap:18px;flex-wrap:wrap;justify-content:center;max-width:260px;
  font-size:64px;color:#76adff;font-weight:900;text-shadow:0 2px 0 #fff,0 8px 18px rgba(45,127,249,.15)
}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:20px}
.stat{
  background:#fff;border:1px solid var(--line);border-radius:20px;padding:18px;
  box-shadow:0 6px 16px rgba(45,127,249,.04)
}
.stat .big{font-size:34px;font-weight:800;margin:8px 0 6px}
.bar{height:8px;background:#eaf2ff;border-radius:999px;overflow:hidden;margin-top:12px}
.fill{height:100%;background:var(--blue);border-radius:999px}
.fill.green{background:var(--green)}
.fill.orange{background:var(--orange)}
.section-title{display:flex;justify-content:space-between;align-items:center;margin:26px 0 14px}
.section-title h3{margin:0;font-size:34px}
.section-title a{color:var(--blue);text-decoration:none;font-weight:700}
.topic-head,.topic-row{display:grid;grid-template-columns:2fr 1fr 1fr 140px;gap:14px;align-items:center}
.topic-head{
  padding:0 8px 12px;color:var(--muted);text-transform:uppercase;letter-spacing:.06em;
  font-size:12px;font-weight:700
}
.topic-row{padding:16px 8px;border-top:1px solid #edf3ff}
.topic-name{font-weight:700;font-size:24px;margin-bottom:4px}
.topic-desc{color:var(--muted);font-size:15px}
.mini-bar{height:8px;background:#eaf2ff;border-radius:999px;overflow:hidden;margin-top:8px;max-width:120px}
.chips{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-top:18px}
.chip{background:#fff;border:1px solid var(--line);border-radius:18px;padding:16px;min-height:108px}
.chip h4{margin:0 0 6px;font-size:22px}
.chip p{margin:0;color:var(--muted);font-size:15px;line-height:1.4}
.center{text-align:center}
.timer-num{font-size:72px;color:var(--blue);text-align:center;font-weight:800;letter-spacing:-2px;margin:10px 0 8px}
.timer-actions{display:grid;gap:10px;margin-top:12px}
.ring-wrap{display:flex;justify-content:space-between;align-items:center;gap:16px}
.ring{width:92px;height:92px;border-radius:50%;background:conic-gradient(var(--blue) 0 250deg,#dce9ff 250deg 360deg);display:grid;place-items:center}
.ring:before{content:"";width:68px;height:68px;border-radius:50%;background:#fff;display:block}
.muted{color:var(--muted)}
.good{color:var(--green);font-weight:700}
.warn{color:var(--orange);font-weight:700}
input, select{
  width:100%;border:1px solid #cfe1ff;border-radius:12px;padding:13px 14px;font-size:18px;outline:none;background:#fff
}
.practice-row{display:grid;grid-template-columns:1fr 160px 160px;gap:12px;align-items:end;margin-top:18px}
.price-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.price-card{position:relative}
.badge{
  position:absolute;top:16px;right:16px;background:var(--soft);color:var(--blue-dark);
  padding:6px 10px;border-radius:999px;font-size:12px;font-weight:700
}
.price{font-size:40px;font-weight:800;margin:12px 0}
.checklist{padding-left:18px;color:var(--muted);line-height:1.6}
.hero-home{
  display:grid;grid-template-columns:1.2fr .8fr;gap:24px;align-items:center;margin-bottom:20px
}
.hero-card{
  background:linear-gradient(135deg,#fff 0%,#eaf3ff 100%);border:1px solid var(--line);border-radius:28px;padding:30px
}
.hero-card h2{font-size:52px;margin:0 0 12px}
.hero-card p{font-size:22px;color:var(--muted);line-height:1.5}
.list-card{display:grid;gap:14px}
.list-item{
  display:flex;justify-content:space-between;gap:20px;padding:16px;border-radius:18px;background:#fff;border:1px solid var(--line)
}
.footer{
  margin-top:24px;color:var(--muted);font-size:14px;text-align:center;padding-bottom:10px
}
.table-lite{width:100%;border-collapse:collapse}
.table-lite th,.table-lite td{padding:14px 10px;border-bottom:1px solid #edf3ff;text-align:left}
.table-lite th{color:var(--muted);font-size:12px;text-transform:uppercase;letter-spacing:.06em}
.quiz-head{display:flex;justify-content:space-between;align-items:center;gap:16px;flex-wrap:wrap}
.big-number{font-size:58px;font-weight:800}
@media (max-width:1200px){
  .stats,.price-grid{grid-template-columns:repeat(2,1fr)}
  .chips{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:980px){
  .app{grid-template-columns:1fr}
  .sidebar{position:relative;height:auto;border-right:none;border-bottom:1px solid var(--line)}
  .main{padding:18px}
  .grid,.hero,.hero-home,.price-grid{grid-template-columns:1fr}
  .stats{grid-template-columns:1fr 1fr}
  .chips{grid-template-columns:1fr 1fr}
  .practice-row{grid-template-columns:1fr}
  h1{font-size:32px}
  .hero h2,.hero-card h2{font-size:36px}
  .section-title h3{font-size:28px}
}
@media (max-width:620px){
  .stats,.chips,.price-grid{grid-template-columns:1fr}
  .topic-head{display:none}
  .topic-row{grid-template-columns:1fr}
}