:root {
  --bg: #f4f6f9;
  --surface: #ffffff;
  --ink: #0f172a;
  --text: #334155;
  --muted: #64748b;
  --accent: #1e40af;
  --accent-hover: #1e3a8a;
  --gold: #b08d2e;
  --border: #cbd5e1;
  --border-soft: #e2e8f0;
  --error: #b91c1c;
  --ring: rgba(30, 64, 175, .2);
  --serif: "Source Han Serif SC", "Noto Serif SC", "SimSun", "宋体", serif;
  --sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, sans-serif;
}

* { box-sizing: border-box; }
html, body { min-height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.6;
}
.topbar {
  height: 4px;
  background: var(--ink);
  border-bottom: 1px solid var(--gold);
}
.login-shell {
  width: min(100% - 32px, 440px);
  margin: 0 auto;
  padding: 64px 0 32px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 28px;
}
.logo {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border: 2px solid var(--gold);
  border-radius: 8px;
  background: var(--ink);
  color: var(--gold);
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 700;
}
.brand h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: 23px;
  letter-spacing: 1px;
}
.brand p {
  margin: 2px 0 0;
  color: var(--muted);
  font-size: 13px;
}
.login-panel {
  position: relative;
  padding: 32px;
  border: 1px solid var(--border-soft);
  border-radius: 10px;
  background: var(--surface);
  box-shadow: 0 1px 3px rgba(15, 23, 42, .07);
}
.login-panel::before {
  content: "";
  position: absolute;
  inset: -1px auto auto 32px;
  width: 56px;
  height: 2px;
  background: var(--gold);
}
.panel-heading { margin-bottom: 24px; }
.eyebrow {
  margin: 0 0 4px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .12em;
}
.panel-heading h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: 24px;
  line-height: 1.35;
}
.panel-heading > p:last-child {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
}
.field { margin-bottom: 18px; }
.field label {
  display: block;
  margin-bottom: 6px;
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
}
input {
  width: 100%;
  min-height: 46px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 7px;
  background: var(--surface);
  color: var(--ink);
  font: inherit;
}
input:hover { border-color: #94a3b8; }
input:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
input[aria-invalid="true"] { border-color: var(--error); }
.password-field { position: relative; }
.password-field input { padding-right: 68px; }
.password-field button {
  position: absolute;
  inset: 3px 3px 3px auto;
  min-width: 58px;
  border: 0;
  border-radius: 5px;
  background: transparent;
  color: var(--accent);
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}
.password-field button:hover { background: #eff6ff; }
.form-error {
  margin: -4px 0 16px;
  padding: 10px 12px;
  border: 1px solid #fecaca;
  border-radius: 7px;
  background: #fef2f2;
  color: var(--error);
  font-size: 13px;
}
.submit-btn {
  width: 100%;
  min-height: 46px;
  border: 1px solid var(--accent);
  border-radius: 7px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}
.submit-btn:hover:not(:disabled) { background: var(--accent-hover); }
.submit-btn:disabled { cursor: wait; opacity: .72; }
.loading-text { display: none; }
.submit-btn.busy > span:first-child { display: none; }
.submit-btn.busy .loading-text { display: inline; }
footer {
  padding-top: 20px;
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}
@media (max-width: 480px) {
  .login-shell { padding-top: 36px; }
  .login-panel { padding: 24px 20px; }
  .login-panel::before { left: 20px; }
  input { font-size: 16px; }
}
@media (forced-colors: active) {
  .login-panel::before { background: CanvasText; }
}