:root {
  --brand: #0b6efd;
  --muted: #6b7280;
  --card: #ffffff;
  --bg: linear-gradient(180deg, #f7fbff 0%, #eef6ff 100%);
  --glass: rgba(255, 255, 255, 0.7);
  --radius: 12px;
  --gap: 16px;
  --maxw: 1100px;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  background: var(--bg);
  color: #0f1724;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.45;
}

.wrap {
  max-width: var(--maxw);
  margin: 32px auto;
  padding: 24px;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  width: 52px;
  height: 52px;
  border-radius: var(--radius);
  background: var(--brand);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-size: 18px;
  position: relative;
  overflow: hidden;
}

.logo::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.15) 0%, rgba(255, 255, 255, 0) 60%);
}

.brand-name {
  font-weight: 700;
  font-size: 20px;
  color: var(--brand);
}

.brand-sub {
  color: var(--muted);
  font-size: 13px;
}

nav a {
  margin-left: 14px;
  color: var(--muted);
  text-decoration: none;
  font-weight: 600;
}

nav a.active {
  color: var(--brand);
}

/* ===== 可选补充：表单与按钮（登录/注册页复用） ===== */
form {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 320px;
  margin-top: 24px;
}

input {
  padding: 10px 12px;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  font-size: 15px;
  outline: none;
  transition: border 0.2s;
}

input:focus {
  border-color: var(--brand);
  box-shadow: 0 0 0 2px rgba(11, 110, 253, 0.15);
}

button {
  background: var(--brand);
  color: #fff;
  border: none;
  padding: 10px 14px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}

button:hover {
  background: #0a5bdc;
}

#msg {
  margin-top: 8px;
  font-size: 14px;
  color: var(--muted);
}

.center-page {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 80vh;
}