:root {
  --bg: #f3f5f7;
  --surface: #ffffff;
  --line: #d7dde4;
  --text: #1a2330;
  --muted: #5f6b7a;
  --accent: #0f766e;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
}

.container {
  width: min(1080px, 92vw);
  margin: 0 auto;
}

.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header .container {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 0;
}

.site-header h1 {
  margin: 0;
  font-size: 20px;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 10px;
  background: #fff;
}

main {
  padding: 20px 0 40px;
}

section,
form,
ul {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
}

ul {
  list-style: none;
  margin: 10px 0 0;
  padding: 14px;
}

li + li {
  margin-top: 8px;
}

input,
select,
textarea,
button {
  font: inherit;
}

button {
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  border-radius: 6px;
  padding: 8px 14px;
  cursor: pointer;
}

.messages {
  padding: 0;
  margin: 0 0 12px;
}

.messages li {
  background: #ecfeff;
  border: 1px solid #67e8f9;
  border-radius: 8px;
  padding: 8px 12px;
}