:root{
  --teal-deep:#1F4D52;
  --teal-dark:#327C84;
  --teal:#45ACB7;
  --gold:#F5B942;
  --gold-dark:#C9871F;
  --ink:#132625;
  --paper:#FAF8F1;
  --line:#E4DFCC;
  --muted:#6B7A77;
  --red:#C1443C;
  --green:#2E7D5E;
}
*{ box-sizing:border-box; }
html,body{ margin:0; padding:0; }
body{
  background:var(--paper);
  color:var(--ink);
  font-family:'Inter',sans-serif;
  min-height:100vh;
  -webkit-font-smoothing:antialiased;
}
a{ color:var(--teal-deep); }
h1,h2,h3{ font-family:'Space Grotesk',sans-serif; color:var(--ink); margin:0 0 6px; }

.site-nav{
  display:flex; align-items:center; justify-content:space-between; gap:20px;
  padding:16px 32px; background:rgba(250,248,241,0.92); backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line); position:sticky; top:0; z-index:20;
}
.nav-brand{ font-family:'Space Grotesk',sans-serif; font-weight:600; font-size:16px; color:var(--teal-deep); text-decoration:none; }
.nav-links{ display:flex; gap:6px; list-style:none; margin:0; padding:0; flex-wrap:wrap; }
.nav-links a{ font-family:'Space Grotesk',sans-serif; font-weight:600; font-size:13.5px; color:var(--teal-deep); text-decoration:none; padding:8px 14px; border-radius:10px; }
.nav-links a:hover{ background:rgba(69,172,183,0.12); }
.nav-links a.active{ background:var(--teal-deep); color:#fff; }

.wrap{ max-width:760px; margin:0 auto; padding:40px 20px 80px; }

.card{ background:#fff; border:1px solid var(--line); border-radius:18px; padding:28px 30px; box-shadow:0 16px 40px rgba(18,63,59,0.06); margin-bottom:22px; }

label{ display:block; font-family:'Space Grotesk',sans-serif; font-weight:600; font-size:13.5px; margin:14px 0 6px; }
input[type=text],input[type=email],input[type=password],input[type=number],select{
  width:100%; padding:11px 14px; border-radius:10px; border:1px solid var(--line);
  font-family:'Inter',sans-serif; font-size:15px; background:var(--paper);
}

.btn{
  font-family:'Space Grotesk',sans-serif; font-weight:600; font-size:15px; padding:12px 22px; border-radius:12px;
  background:var(--teal-deep); color:#fff; border:none; text-decoration:none; display:inline-flex; align-items:center; gap:8px; cursor:pointer;
  box-shadow:0 4px 0 var(--teal-dark);
}
.btn:active{ transform:translateY(2px); box-shadow:0 2px 0 var(--teal-dark); }
.btn.gold{ background:var(--gold-dark); box-shadow:0 4px 0 #A5690E; }
.btn.ghost{ background:#fff; color:var(--teal-deep); border:2px solid var(--line); box-shadow:none; }

.error{ background:#FBEAE8; border:1px solid #F1CFCA; color:var(--red); padding:12px 16px; border-radius:12px; margin-bottom:14px; font-size:14px; }
.success{ background:#EAF5EC; border:1px solid #CFE6D6; color:var(--green); padding:12px 16px; border-radius:12px; margin-bottom:14px; font-size:14px; }

.points-chip{ font-family:'JetBrains Mono',monospace; font-weight:600; background:#FDF3E1; color:var(--gold-dark); border:1px solid #F3DFAE; border-radius:10px; padding:6px 12px; display:inline-block; }

.student-row{ display:flex; justify-content:space-between; align-items:center; gap:12px; padding:14px 0; border-bottom:1px solid var(--line); flex-wrap:wrap; }
.student-row:last-child{ border-bottom:none; }

.week-title{ margin:34px 0 12px; }
.challenge-grid{ display:grid; grid-template-columns:repeat(auto-fit,minmax(200px,1fr)); gap:14px; }
.challenge-card{ border:1px solid var(--line); border-radius:16px; padding:18px; background:#fff; }
.challenge-card.done{ opacity:0.85; }
.difficulty-tag{ font-family:'JetBrains Mono',monospace; font-size:11px; text-transform:uppercase; letter-spacing:.06em; padding:4px 8px; border-radius:8px; display:inline-block; margin-bottom:8px; }
.difficulty-tag.easy{ background:#EAF5EC; color:var(--green); }
.difficulty-tag.medium{ background:#FDF3E1; color:var(--gold-dark); }
.difficulty-tag.hard{ background:#FBEAE8; color:var(--red); }

table{ width:100%; border-collapse:collapse; font-size:14px; }
th,td{ text-align:left; padding:10px 8px; border-bottom:1px solid var(--line); }
th{ font-family:'Space Grotesk',sans-serif; font-size:12.5px; color:var(--muted); text-transform:uppercase; letter-spacing:.04em; }

.subtle{ color:var(--muted); font-size:13.5px; margin:4px 0 0; }
.status-pending{ color:var(--gold-dark); font-weight:600; }
.status-fulfilled{ color:var(--green); font-weight:600; }
.status-denied{ color:var(--red); font-weight:600; }

@media (max-width:480px){
  .card{ padding:20px; }
  .site-nav{ padding:12px 16px; flex-direction:column; align-items:stretch; gap:8px; }
}