:root {
  --ink: #101828;
  --muted: #667085;
  --line: #e7edf5;
  --blue: #2764e8;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 18% 16%, rgba(39, 100, 232, .1), transparent 30%),
    linear-gradient(180deg, #f8fbff 0%, #fff 100%);
}

a { color: inherit; text-decoration: none; }

.nav {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, .9);
  backdrop-filter: blur(16px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 850;
}

.logo {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  box-shadow: 0 8px 20px rgba(39, 100, 232, .18);
}

.nav-link {
  color: #344054;
  font-size: 14px;
  font-weight: 750;
}

.shell {
  min-height: calc(100vh - 64px);
  display: grid;
  place-items: center;
  padding: 52px 18px;
}

.auth-card {
  width: min(100%, 420px);
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(255, 255, 255, .94);
  box-shadow: 0 28px 90px rgba(16, 24, 40, .1);
  padding: 28px;
}

h1 {
  margin: 0;
  font-size: 30px;
  line-height: 1.25;
}

.copy {
  margin: 10px 0 24px;
  color: var(--muted);
  line-height: 1.7;
}

form {
  display: grid;
  gap: 14px;
}

label {
  display: grid;
  gap: 7px;
  color: #344054;
  font-size: 14px;
  font-weight: 750;
}

input {
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 12px;
  color: var(--ink);
  font: inherit;
  background: #fff;
}

button {
  min-height: 44px;
  border: 0;
  border-radius: 8px;
  color: #fff;
  background: linear-gradient(135deg, #2764e8, #1d4ed8);
  box-shadow: 0 14px 30px rgba(39, 100, 232, .22);
  font: inherit;
  font-weight: 850;
  cursor: pointer;
}

button:disabled {
  cursor: not-allowed;
  opacity: .65;
}

.switch {
  margin-top: 16px;
  color: var(--muted);
  text-align: center;
  font-size: 14px;
}

.switch a { color: var(--blue); font-weight: 850; }

.message {
  display: none;
  margin-top: 16px;
  padding: 12px;
  border-radius: 8px;
  line-height: 1.6;
  font-size: 14px;
}

.message.show { display: block; }
.message.ok { background: #ecfdf3; color: #027a48; }
.message.error { background: #fff1f3; color: #b42318; }