:root {
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #1f2937;
  --accent: #0f766e;
  --accent-hover: #115e59;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(150deg, #eef2ff 0%, var(--bg) 60%, #ecfeff 100%);
  color: var(--text);
}

.container {
  max-width: 640px;
  width: 100%;
  padding: 32px;
  border-radius: 16px;
  background: var(--card);
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
}

h1 {
  margin-top: 0;
  margin-bottom: 12px;
}

p {
  line-height: 1.6;
  margin-bottom: 20px;
}

.btn {
  display: inline-block;
  padding: 10px 14px;
  border-radius: 10px;
  text-decoration: none;
  color: #ffffff;
  background: var(--accent);
  transition: background 0.2s ease;
}

.btn:hover {
  background: var(--accent-hover);
}

footer {
  margin-top: 16px;
  text-align: center;
}