:root {
  --bg: #0f1117;
  --surface: #1a1d2e;
  --surface2: #242740;
  --border: #2e3250;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --success: #22c55e;
  --danger: #ef4444;
  --warning: #f59e0b;
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --radius: 10px;
  --font: 'Segoe UI', system-ui, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  min-height: 100vh;
  font-size: 15px;
  line-height: 1.6;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Layout */
.page-center {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  width: 100%;
  max-width: 440px;
}

.card-wide { max-width: 900px; }

.logo {
  font-size: 2rem;
  text-align: center;
  margin-bottom: 8px;
}

h1 { font-size: 1.6rem; font-weight: 700; }
h2 { font-size: 1.25rem; font-weight: 600; margin-bottom: 16px; }
h3 { font-size: 1rem; font-weight: 600; color: var(--text-muted); margin-bottom: 12px; }

/* Nav */
nav {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-brand { font-weight: 700; font-size: 1.1rem; }
.nav-links { display: flex; gap: 24px; align-items: center; }
.nav-links a { color: var(--text-muted); font-size: 0.9rem; }
.nav-links a.active, .nav-links a:hover { color: var(--text); }

main { padding: 32px 24px; max-width: 1000px; margin: 0 auto; }

/* Forms */
.form-group { margin-bottom: 18px; }
label { display: block; font-size: 0.85rem; color: var(--text-muted); margin-bottom: 6px; font-weight: 500; }

input, select {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  padding: 10px 14px;
  font-size: 0.95rem;
  font-family: var(--font);
  transition: border-color 0.15s;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--primary);
}

select option { background: var(--surface); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 6px;
  border: none;
  font-size: 0.95rem;
  font-family: var(--font);
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, opacity 0.15s;
}

.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-hover); }
.btn-success { background: var(--success); color: #fff; }
.btn-danger { background: var(--danger); color: #fff; }
.btn-secondary { background: var(--surface2); color: var(--text); }
.btn-secondary:hover { background: var(--border); }
.btn-full { width: 100%; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-sm { padding: 6px 12px; font-size: 0.8rem; }

/* Alerts */
.alert {
  padding: 12px 16px;
  border-radius: 6px;
  font-size: 0.9rem;
  margin-bottom: 16px;
}
.alert-error { background: rgba(239,68,68,0.15); border: 1px solid rgba(239,68,68,0.4); color: #fca5a5; }
.alert-success { background: rgba(34,197,94,0.15); border: 1px solid rgba(34,197,94,0.4); color: #86efac; }
.alert-info { background: rgba(59,130,246,0.15); border: 1px solid rgba(59,130,246,0.4); color: #93c5fd; }

/* Table */
.table-wrap { overflow-x: auto; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

th {
  text-align: left;
  padding: 10px 14px;
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 1px solid var(--border);
}

td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
}

tr:last-child td { border-bottom: none; }
tr:hover td { background: var(--surface2); }

.rank-1 td:first-child { color: #fbbf24; font-weight: 700; }
.rank-2 td:first-child { color: #94a3b8; font-weight: 700; }
.rank-3 td:first-child { color: #cd7c32; font-weight: 700; }

.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 500;
}
.badge-green { background: rgba(34,197,94,0.2); color: #86efac; }
.badge-yellow { background: rgba(245,158,11,0.2); color: #fcd34d; }
.badge-red { background: rgba(239,68,68,0.2); color: #fca5a5; }

/* Grid for group predictions */
.groups-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.group-card {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
}

.group-card h3 { color: var(--primary); margin-bottom: 10px; }

.group-row { display: flex; flex-direction: column; gap: 8px; }
.group-row .form-group { margin-bottom: 0; }

/* Deadline banner */
.deadline-banner {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 18px;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.9rem;
}

.deadline-banner.locked {
  border-color: rgba(239,68,68,0.4);
  background: rgba(239,68,68,0.1);
}

/* Section separator */
.section { margin-bottom: 40px; }

/* Language toggle */
.lang-btn {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  cursor: pointer;
  font-size: 0.8rem;
  font-family: var(--font);
  padding: 4px 10px;
  transition: background 0.15s;
}
.lang-btn:hover { background: var(--border); }

/* Spinner */
.spinner {
  width: 20px; height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  display: inline-block;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* Responsive */
@media (max-width: 600px) {
  main { padding: 16px; }
  .card { padding: 24px 20px; }
  .groups-grid { grid-template-columns: 1fr; }
}