:root {
  --page: #f7f7f4;
  --surface: #ffffff;
  --text: #1b1f1d;
  --muted: #7c8781;
  --line: #e2e6e1;
  --accent: #216f5c;
  --accent-strong: #185948;
  --soft: #e7f2ed;
  --danger: #b94949;
  --shadow: 0 24px 70px rgba(25, 43, 35, .1);
}
* { box-sizing: border-box; }
html, body { min-height: 100%; }
body {
  margin: 0;
  min-height: 100dvh;
  display: grid;
  place-items: center;
  padding: 24px;
  color: var(--text);
  background: radial-gradient(circle at 50% -15%, rgba(33,111,92,.12), transparent 42%), var(--page);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Microsoft YaHei", sans-serif;
}
.auth-card {
  width: min(430px, 100%);
  border: 1px solid var(--line);
  border-radius: 26px;
  background: color-mix(in srgb, var(--surface) 95%, transparent);
  padding: 30px;
  box-shadow: var(--shadow);
}
.brand { display: flex; align-items: center; gap: 12px; margin-bottom: 28px; }
.brand-mark {
  width: 44px; height: 44px; display: grid; place-items: center;
  border-radius: 14px; background: var(--accent); color: #fff; font-weight: 800;
  box-shadow: 0 8px 20px rgba(33,111,92,.2);
}
.brand strong { display: block; font-size: 1rem; }
.brand small { color: var(--muted); font-size: .75rem; }
h1 { margin: 0 0 8px; font-size: 1.55rem; letter-spacing: -.03em; }
.intro { margin: 0 0 24px; color: var(--muted); font-size: .85rem; line-height: 1.6; }
.field { display: grid; gap: 7px; margin-bottom: 15px; }
.field label { font-size: .78rem; color: var(--muted); }
.field input {
  width: 100%; height: 46px; border: 1px solid var(--line); border-radius: 12px;
  padding: 0 13px; background: #fbfcfa; color: var(--text); outline: none;
}
.field input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(33,111,92,.08); }
.submit {
  width: 100%; height: 47px; border: 0; border-radius: 12px; margin-top: 5px;
  background: var(--accent); color: #fff; font-weight: 750; cursor: pointer;
}
.submit:hover { background: var(--accent-strong); }
.alert { display: none; margin-bottom: 16px; border-radius: 11px; padding: 10px 12px; background: #fbe9e8; color: var(--danger); font-size: .8rem; line-height: 1.5; }
.alert.show { display: block; }
.footer-link { margin: 19px 0 0; text-align: center; color: var(--muted); font-size: .78rem; }
.footer-link a { color: var(--accent); text-decoration: none; font-weight: 650; }
.note { margin-top: 18px; border-radius: 12px; background: var(--soft); color: var(--accent-strong); padding: 11px 12px; font-size: .74rem; line-height: 1.55; }
@media (prefers-color-scheme: dark) {
  :root { --page:#111613; --surface:#19201d; --text:#edf3ef; --muted:#87938d; --line:#2b3530; --soft:#1e3a31; --accent:#2a8069; --accent-strong:#62b99d; }
  .field input { background:#151b18; }
}