:root {
  --bg-main: #f5f7fb;
  --bg-card: #ffffff;
  --border: #e5e7eb;

  --text-main: #0f172a;
  --text-muted: #6b7280;

  --primary: #2563eb;

  --leetcode: #00af9b;
  --codechef: #7b5c3e;
  --codeforces: #318ce7;
  --gfg: #2f8d46;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
}

/* ---------- LAYOUT ---------- */

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 16px;
}

.section {
  margin-bottom: 48px;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

/* ---------- NAVBAR ---------- */

.navbar {
  background-color: var(--bg-card);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
}

.nav-links a {
  margin-left: 24px;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 500;
}

.nav-links a:hover {
  color: var(--primary);
}

/* ---------- HERO ---------- */

.hero {
  text-align: center;
  margin: 40px 0 48px;
}

.hero h1 {
  font-size: 2.25rem;
  font-weight: 700;
}

.hero p {
  margin-top: 8px;
  color: var(--text-muted);
}

/* ---------- LOADING ---------- */

.loading {
  padding: 24px;
  text-align: center;
  color: var(--text-muted);
}

/* ---------- FOOTER ---------- */

.footer {
  text-align: center;
  padding: 32px 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* ---------- RESPONSIVE ---------- */

@media (max-width: 768px) {
  .nav-links a {
    margin-left: 12px;
    font-size: 0.9rem;
  }

  .hero h1 {
    font-size: 1.8rem;
  }
}

/* ---------- REGISTER BUTTONS ---------- */

.register-btn {
  display: inline-block;
  margin-top: 12px;
  padding: 8px 14px;
  background-color: var(--primary);
  color: white;
  text-decoration: none;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 500;
}

.register-btn:hover {
  opacity: 0.9;
}

.register-link {
  display: inline-block;
  margin-top: 8px;
  font-size: 0.85rem;
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
}

.register-link:hover {
  text-decoration: underline;
}

.register-link.small {
  font-size: 0.8rem;
}