* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: #0d1117;
  color: #e6edf3;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.topnav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
  border-bottom: 1px solid #30363d;
}

.brand {
  font-weight: 800;
  font-size: 20px;
  color: #3fa9f5;
  text-decoration: none;
}

.nav-links a {
  color: #c9d1d9;
  text-decoration: none;
  margin-left: 18px;
  font-size: 14px;
}

.nav-links a:hover { color: #ffffff; }

.nav-user {
  margin-left: 18px;
  color: #ffd23f;
  font-size: 14px;
}

.page {
  max-width: 640px;
  margin: 40px auto;
  padding: 0 20px;
}

.card {
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 12px;
  padding: 28px 32px;
}

.card h1 {
  margin-top: 0;
  font-size: 24px;
}

label {
  display: block;
  margin: 14px 0 6px;
  font-size: 13px;
  color: #8b949e;
}

input[type="text"],
input[type="email"],
input[type="password"] {
  width: 100%;
  padding: 10px 12px;
  border-radius: 6px;
  border: 1px solid #30363d;
  background: #0d1117;
  color: #e6edf3;
  font-size: 15px;
}

button, .btn {
  display: inline-block;
  margin-top: 20px;
  width: 100%;
  padding: 12px;
  border: none;
  border-radius: 6px;
  background: #3fa9f5;
  color: #0d1117;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  text-align: center;
  text-decoration: none;
}

button:hover, .btn:hover { background: #5fb8f7; }

.error {
  background: rgba(245, 87, 63, 0.15);
  border: 1px solid #f5573f;
  color: #ffb4a8;
  padding: 10px 14px;
  border-radius: 6px;
  font-size: 14px;
  margin-top: 14px;
}

.hint {
  margin-top: 14px;
  font-size: 13px;
  color: #8b949e;
  text-align: center;
}

.hint a { color: #3fa9f5; }

table {
  width: 100%;
  border-collapse: collapse;
}

table th, table td {
  text-align: left;
  padding: 8px 10px;
  border-bottom: 1px solid #30363d;
  font-size: 14px;
}

table th {
  color: #8b949e;
  font-weight: 600;
  font-size: 12px;
  text-transform: uppercase;
}

.rank-1 { color: #ffd23f; font-weight: 700; }