:root{
  --bg:#f6f7fb;
  --card:#ffffff;
  --text:#182033;
  --muted:#667085;
  --primary:#8f1717;
  --primary2:#c0392b;
  --line:#e6e9f2;
  --shadow:0 18px 50px rgba(24,32,51,.10);
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,system-ui,Arial,sans-serif}
h1,h2,h3{font-family:Montserrat,Inter,sans-serif;margin:0 0 12px}
.container{width:min(1120px,92%);margin:auto}
.hero{padding:54px 0;background:linear-gradient(135deg,#5d0c0c,#9e1d1d 55%,#d24534);color:#fff}
.hero-grid{display:grid;grid-template-columns:1fr 260px;gap:28px;align-items:center}
.hero h1{font-size:clamp(34px,5vw,60px);font-weight:900;letter-spacing:-1.5px}
.hero p{font-size:18px;line-height:1.7;max-width:690px;opacity:.94}
.badge{display:inline-flex;padding:8px 13px;border-radius:999px;background:rgba(255,255,255,.16);border:1px solid rgba(255,255,255,.24);font-weight:800;font-size:13px;text-transform:uppercase;letter-spacing:.6px;margin-bottom:14px}
.hero-card{background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.28);border-radius:24px;padding:26px;text-align:center;box-shadow:var(--shadow)}
.hero-card strong{display:block;font-size:58px;font-family:Montserrat;font-weight:900}.hero-card span{font-weight:700}
.main-panel{padding:34px 0 60px}.filters{display:grid;grid-template-columns:1.4fr .8fr .8fr;gap:14px;margin-bottom:22px}
input,select,textarea{width:100%;border:1px solid var(--line);border-radius:14px;padding:14px 15px;font:inherit;background:#fff;color:var(--text);outline:none}textarea{resize:vertical}input:focus,select:focus,textarea:focus{border-color:var(--primary);box-shadow:0 0 0 4px rgba(143,23,23,.10)}
.exercise-list{display:grid;gap:18px}.exercise-card{background:var(--card);border:1px solid var(--line);border-radius:22px;padding:24px;box-shadow:var(--shadow)}
.exercise-top{display:grid;grid-template-columns:52px 1fr;gap:16px;align-items:start}.number{display:grid;place-items:center;width:52px;height:52px;border-radius:16px;background:#fff0ef;color:var(--primary);font-weight:900;font-family:Montserrat;font-size:24px}.tags{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:7px}.tags span{font-size:12px;font-weight:800;color:var(--primary);background:#fff0ef;border:1px solid #ffd6d1;padding:6px 10px;border-radius:999px}.exercise-card h2{font-size:22px}.statement,.solution-box{line-height:1.75;font-size:16px}.solution-btn,.primary,.ghost,.danger{border:0;border-radius:14px;padding:12px 16px;font-weight:800;cursor:pointer;font-family:Inter}.solution-btn,.primary{background:linear-gradient(135deg,var(--primary),var(--primary2));color:#fff}.solution-btn{margin:18px 0 0}.solution-box{margin-top:16px;background:#fff8e8;border:1px solid #ffe0a3;border-left:6px solid #f0a500;border-radius:16px;padding:18px}.empty{text-align:center;color:var(--muted);padding:22px}.footer{padding:28px 0;border-top:1px solid var(--line);color:var(--muted);background:#fff}
.login-screen{min-height:100vh;display:grid;place-items:center;background:linear-gradient(135deg,#5d0c0c,#a82020)}.login-card{width:min(430px,92%);background:#fff;border-radius:26px;padding:30px;box-shadow:var(--shadow)}.login-card .badge,.admin-header .badge{background:#fff0ef;color:var(--primary);border-color:#ffd6d1}.login-card h1{font-size:32px}.login-card p,.hint{color:var(--muted);line-height:1.6}.login-card button{width:100%;margin-top:12px}.error{color:#b42318;display:block;margin-top:12px;font-weight:700}.admin-panel{padding:34px 0 60px}.admin-header{display:flex;justify-content:space-between;gap:20px;align-items:flex-start;margin-bottom:22px}.admin-header h1{font-size:38px}.admin-actions{display:flex;gap:10px;flex-wrap:wrap}.admin-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px}.form-card{background:#fff;border:1px solid var(--line);border-radius:24px;padding:24px;box-shadow:var(--shadow)}label{display:block;font-weight:800;margin:14px 0 6px}.form-actions,.item-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:16px}.ghost{background:#f1f3f8;color:var(--text);text-decoration:none;display:inline-flex;align-items:center}.danger{background:#ffe9e8;color:#b42318}.admin-list{display:grid;gap:12px;margin-top:14px}.admin-item{border:1px solid var(--line);border-radius:16px;padding:14px;display:flex;justify-content:space-between;gap:12px;align-items:center}.admin-item small{display:block;color:var(--muted);margin-top:4px}hr{border:0;border-top:1px solid var(--line);margin:22px 0}
@media(max-width:820px){.hero-grid,.filters,.admin-grid{grid-template-columns:1fr}.admin-header{display:block}.admin-actions{margin-top:12px}.hero-card{text-align:left}.exercise-top{grid-template-columns:1fr}.number{width:44px;height:44px;font-size:20px}.admin-item{display:block}.item-actions{margin-top:12px}}

.hint-login{display:block;margin-top:12px;color:#667085;text-align:center}

.exercise-image{margin:16px 0 4px;background:#fff;border:1px solid var(--line);border-radius:18px;padding:10px;overflow:hidden}
.exercise-image img{display:block;max-width:100%;height:auto;margin:auto;border-radius:12px}
.exercise-image figcaption{font-size:12px;color:var(--muted);text-align:center;margin-top:8px}
.solution-box .exercise-image{background:#fffdf5}
.label-hint{font-weight:600;color:var(--muted);font-size:12px}
.small-hint{font-size:13px;margin-top:8px}