:root {
  --ink: #1D2129;
  --muted: #86909C;
  --water: #165DFF;
  --water-deep: #0E42B3;
  --line: #E5E6EB;
  --soft: #F5F7FA;
  --font: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --serif: "Noto Serif SC", "Songti SC", serif;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font);
  color: var(--ink);
  min-height: 100vh;
  background:
    linear-gradient(160deg, #E8F3FF 0%, #F5F7FA 45%, #fff 100%);
}
.auth-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px 16px;
}
.auth-card {
  width: 100%;
  max-width: 420px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 28px 28px 22px;
  box-shadow: 0 16px 40px rgba(22, 93, 255, 0.08);
}
.auth-card-wide { max-width: 640px; }
.auth-brand a {
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 700;
  color: var(--water-deep);
  text-decoration: none;
}
.auth-brand p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 13px;
}
.auth-tabs {
  display: flex;
  gap: 8px;
  margin: 22px 0 16px;
  border-bottom: 1px solid var(--line);
}
.auth-tabs a {
  flex: 1;
  text-align: center;
  padding: 10px 6px;
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
}
.auth-tabs a.is-active {
  color: var(--water);
  font-weight: 600;
  border-bottom-color: var(--water);
}
.auth-hint {
  margin: 0 0 14px;
  padding: 10px 12px;
  background: var(--soft);
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
  border-radius: 8px;
}
.auth-form label {
  display: block;
  margin: 10px 0 6px;
  font-size: 13px;
  color: var(--muted);
}
.auth-form input,
.auth-form select {
  width: 100%;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 12px;
  font: inherit;
}
.auth-form input:focus,
.auth-form select:focus {
  outline: none;
  border-color: var(--water);
  box-shadow: 0 0 0 3px rgba(22, 93, 255, 0.12);
}
.auth-btn {
  width: 100%;
  margin-top: 18px;
  height: 44px;
  border: 0;
  border-radius: 8px;
  background: var(--water);
  color: #fff;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
.auth-btn:hover { background: var(--water-deep); }
.auth-btn:disabled { opacity: 0.6; cursor: not-allowed; }
.auth-foot {
  margin-top: 16px;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-size: 13px;
  color: var(--muted);
}
.auth-foot a { color: var(--water); text-decoration: none; }
.auth-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px 14px;
}
.auth-grid .span-2 { grid-column: 1 / -1; }
@media (max-width: 640px) {
  .auth-grid { grid-template-columns: 1fr; }
  .auth-grid .span-2 { grid-column: auto; }
}
.auth-captcha-row,
.auth-sms-row {
  display: flex;
  gap: 10px;
  align-items: center;
}
.auth-captcha-row input,
.auth-sms-row input { flex: 1; }
.auth-captcha-row img {
  height: 42px;
  width: 120px;
  border-radius: 8px;
  border: 1px solid var(--line);
  cursor: pointer;
  flex-shrink: 0;
}
.auth-sms-btn {
  height: 42px;
  padding: 0 14px;
  border: 1px solid var(--water);
  border-radius: 8px;
  background: #fff;
  color: var(--water);
  font: inherit;
  font-size: 13px;
  cursor: pointer;
  white-space: nowrap;
  flex-shrink: 0;
}
.auth-sms-btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  border-color: var(--line);
  color: var(--muted);
}