:root {
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --text: #172033;
  --muted: #667085;
  --line: #dbe3ef;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: "Microsoft YaHei UI", "Segoe UI", Arial, sans-serif;
  background:
    linear-gradient(120deg, rgba(37, 99, 235, 0.08), rgba(15, 23, 42, 0.04)),
    #f5f7fb;
}

.login-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.login-card {
  width: min(420px, 100%);
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  box-shadow: 0 24px 70px rgba(15, 23, 42, 0.12);
}

.brand-mark {
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: #172033;
  color: #fff;
  font-weight: 800;
  letter-spacing: 0;
}

h1 {
  margin: 18px 0 8px;
  font-size: 25px;
}

p {
  margin: 0 0 26px;
  color: var(--muted);
  line-height: 1.6;
  font-size: 14px;
}

form {
  display: grid;
  gap: 16px;
}

.mode-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 18px;
  border-radius: 8px;
  background: #f1f5f9;
  padding: 4px;
}

.mode {
  height: 36px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: #475467;
  font-size: 14px;
  font-weight: 700;
}

.mode.active {
  background: #fff;
  color: var(--blue);
  box-shadow: 0 1px 4px rgba(15, 23, 42, 0.12);
}

.login-mode {
  display: grid;
  gap: 16px;
}

.hidden {
  display: none !important;
}

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

input {
  width: 100%;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 12px;
  font: inherit;
  outline: none;
}

input:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

button {
  height: 42px;
  border: 0;
  border-radius: 8px;
  background: var(--blue);
  color: #fff;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

button:hover {
  background: var(--blue-dark);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.68;
}

.message {
  min-height: 20px;
  color: #b42318;
  font-size: 13px;
}