:root {
  --orange: #f07119;
  --blue: #3B4893;
  --sky: #498FC3;
  --white: #ffffff;
  --ink: #182033;
  --muted: #65718a;
  --line: #dfe5ef;
  --soft: #f6f8fb;
  --success: #178a56;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
body { margin: 0; color: var(--ink); background: var(--white); }
a { color: inherit; text-decoration: none; }
main { min-height: 100vh; }
.topbar {
  position: sticky; top: 0; z-index: 10; display: flex; align-items: center; justify-content: space-between;
  gap: 20px; padding: 14px clamp(18px, 4vw, 56px); background: rgba(255,255,255,.94); border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}
.brand { font-weight: 900; font-size: 1.25rem; color: var(--blue); }
.brand span { color: var(--orange); }
.topbar nav { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; color: var(--muted); font-weight: 700; }
.button {
  display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: 0 18px; border: 0; border-radius: 8px;
  background: var(--orange); color: var(--white); font-weight: 800; cursor: pointer; box-shadow: 0 8px 18px rgba(240,113,25,.22);
}
.button.secondary { background: var(--blue); box-shadow: 0 8px 18px rgba(59,72,147,.18); }
.button.small { min-height: 36px; padding: 0 13px; font-size: .92rem; }
.hero {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(260px, 380px); gap: 36px; align-items: center;
  padding: clamp(44px, 8vw, 86px) clamp(18px, 5vw, 72px); background: linear-gradient(135deg, #fff 0%, #f7fbff 58%, #fff4ec 100%);
}
.hero h1, .page-header h1 { margin: 0; max-width: 840px; font-size: clamp(2rem, 5vw, 4.4rem); line-height: 1.02; color: var(--blue); letter-spacing: 0; }
.hero p, .page-header p, .section-head p { max-width: 760px; color: var(--muted); font-size: 1.06rem; line-height: 1.7; }
.eyebrow, .status { display: inline-flex; width: fit-content; padding: 6px 10px; border-radius: 999px; background: #fff0e6; color: var(--orange); font-weight: 900; text-transform: uppercase; font-size: .74rem; }
.status-success { background: #eefaf5; color: var(--success); }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 24px; }
.hero-panel { min-height: 240px; display: grid; place-content: center; text-align: center; border-radius: 8px; color: var(--white); background: linear-gradient(135deg, var(--blue), var(--sky)); }
.hero-panel strong { font-size: clamp(2.2rem, 5vw, 4rem); }
.hero-panel span { font-weight: 800; }
.stats-grid, .admin-grid, .challenge-grid {
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; padding: 24px clamp(18px, 5vw, 72px);
}
.stats-grid article, .admin-grid article, .challenge-card, .side-panel, .form-card, .row-card, .notice, .objective-list article {
  border: 1px solid var(--line); border-radius: 8px; background: var(--white); padding: 18px;
}
.stats-grid strong { display: block; font-size: 1.9rem; color: var(--blue); }
.stats-grid span, small, dt { color: var(--muted); }
.section { padding: 34px clamp(18px, 5vw, 72px); }
.section-head { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 18px; }
h2 { color: var(--blue); margin: 0 0 14px; font-size: 1.35rem; }
h3 { margin: 12px 0 8px; color: var(--ink); }
.challenge-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); padding: 0; }
.challenge-card p { color: var(--muted); line-height: 1.55; }
.challenge-card dl { display: grid; gap: 8px; margin: 18px 0; }
.challenge-card dl div { display: flex; justify-content: space-between; gap: 12px; }
.split { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(280px, .9fr); gap: 24px; align-items: start; }
.leaderboard { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.leaderboard li, .publication-list a, .publication-card, .timeline li {
  display: flex; justify-content: space-between; gap: 14px; padding: 12px 14px; border: 1px solid var(--line); border-radius: 8px; background: var(--soft);
}
.publication-list { display: grid; gap: 10px; }
.publication-list a { display: grid; }
.publication-list strong { color: var(--blue); }
.publication-card { display: grid; justify-content: stretch; }
.publication-card.ready { background: #eefaf5; border-color: rgba(23,138,86,.35); }
.publication-card.pending { background: #fff8ef; border-color: rgba(240,113,25,.3); }
.publication-card a { overflow-wrap: anywhere; color: var(--blue); font-weight: 800; }
.publication-card .button { justify-self: start; }
.page-header { padding: 46px clamp(18px, 5vw, 72px) 24px; background: var(--soft); }
.page-header.compact h1 { font-size: clamp(1.8rem, 3vw, 3rem); }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin: 10px 0 24px; }
.tags span { padding: 8px 11px; border-radius: 999px; color: var(--blue); background: #edf5fb; font-weight: 800; }
.objective-list, .stack { display: grid; gap: 12px; }
.objective-list article { display: flex; justify-content: space-between; align-items: center; }
.objective-list article.done { border-color: rgba(23,138,86,.35); background: #eefaf5; }
.form-shell { padding: 30px clamp(18px, 5vw, 72px); max-width: 880px; }
.form-card { display: grid; gap: 16px; }
label, fieldset { display: grid; gap: 7px; font-weight: 800; color: var(--blue); border: 0; padding: 0; margin: 0; }
input, textarea { width: 100%; border: 1px solid var(--line); border-radius: 8px; padding: 12px 13px; font: inherit; color: var(--ink); background: var(--white); }
.form-note { margin: 0; padding: 12px 14px; border: 1px solid var(--line); border-radius: 8px; background: var(--soft); color: var(--muted); line-height: 1.5; }
.check { display: flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 700; }
.check input { width: auto; }
.row-card { display: grid; gap: 4px; }
.row-card strong { color: var(--orange); }
.notice.read { opacity: .72; }
.timeline { display: grid; gap: 10px; padding-left: 0; list-style: none; }
.admin-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.flash { margin: 16px clamp(18px, 5vw, 72px); padding: 12px 16px; border-radius: 8px; background: #fff4ec; color: #863900; font-weight: 700; }
.flash.success { background: #eefaf5; color: var(--success); border: 1px solid rgba(23,138,86,.25); }
.flash.error { background: #fff4ec; color: #863900; border: 1px solid rgba(240,113,25,.25); }
.login-shell { min-height: calc(100vh - 70px); display: grid; place-items: center; padding: 48px 18px; background: linear-gradient(135deg, #f7fbff, #fff4ec); }
.login-panel { width: min(100%, 560px); display: grid; gap: 18px; padding: clamp(24px, 5vw, 42px); border: 1px solid var(--line); border-radius: 8px; background: rgba(255,255,255,.94); box-shadow: 0 22px 60px rgba(59,72,147,.12); }
.login-panel h1 { margin: 0; color: var(--blue); font-size: clamp(2rem, 4vw, 3.2rem); line-height: 1.05; }
.login-panel p { margin: 0; color: var(--muted); line-height: 1.65; }
.login-note { font-size: .94rem; }

@media (max-width: 920px) {
  .hero, .split, .admin-grid { grid-template-columns: 1fr; }
  .stats-grid, .challenge-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 620px) {
  .topbar { align-items: flex-start; flex-direction: column; }
  .stats-grid, .challenge-grid { grid-template-columns: 1fr; }
  .section-head { display: block; }
  .leaderboard li { display: grid; }
}