:root {
  --navy: #082a47;
  --navy-deep: #051d31;
  --blue: #1769aa;
  --cyan: #78d2df;
  --ink: #172536;
  --muted: #68788a;
  --line: #dce4eb;
  --paper: #f6f8fa;
}

* { box-sizing: border-box; }
html, body { min-height: 100%; }
body {
  margin: 0;
  font-family: "Microsoft YaHei UI", "PingFang SC", system-ui, sans-serif;
  color: var(--ink);
  background: var(--paper);
}
button, input { font: inherit; }

.cover-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(0, 1.42fr) minmax(390px, .78fr);
}

.cover-visual {
  position: relative;
  min-height: 100vh;
  overflow: hidden;
  isolation: isolate;
  padding: clamp(42px, 6vw, 88px);
  color: #fff;
  background:
    radial-gradient(circle at 78% 15%, rgba(97, 202, 213, .22), transparent 30%),
    linear-gradient(138deg, #0b3859 0%, #082c49 46%, #051d31 100%);
}
.cover-visual::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -2;
  background: linear-gradient(115deg, transparent 0 58%, rgba(255,255,255,.035) 58% 72%, transparent 72%);
}
.visual-grid {
  position: absolute;
  inset: 0;
  z-index: -1;
  opacity: .18;
  background-image:
    linear-gradient(rgba(255,255,255,.14) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.14) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: linear-gradient(to bottom, #000, transparent 72%);
}
.city-lines { position: absolute; inset: 0; width: 100%; height: 100%; z-index: -1; }
.river { fill: none; stroke: url(#river); stroke-width: 22; stroke-linecap: round; }
.river-two { stroke-width: 15; opacity: .72; }
.mountains { fill: url(#mountain); }
.district-nodes circle { fill: #e8c77a; stroke: rgba(255,255,255,.8); stroke-width: 2; }
.district-nodes path { fill: none; stroke: rgba(255,255,255,.2); stroke-width: 1.5; stroke-dasharray: 5 8; }

.cover-brand { display: flex; align-items: flex-start; gap: 28px; max-width: 720px; }
.brand-mark {
  flex: 0 0 auto;
  width: 78px;
  height: 78px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255,255,255,.42);
  border-radius: 24px 8px 24px 8px;
  background: rgba(255,255,255,.09);
  box-shadow: inset 0 0 0 6px rgba(255,255,255,.035), 0 18px 44px rgba(0,0,0,.18);
  backdrop-filter: blur(10px);
}
.brand-mark span { font-family: "STKaiti", "KaiTi", serif; font-size: 42px; line-height: 1; }
.department { margin: 4px 0 24px; color: #a8dce2; font-size: 14px; letter-spacing: .14em; }
.cover-brand h1 { margin: 0; font-size: clamp(44px, 5vw, 76px); line-height: 1.09; letter-spacing: .025em; }
.cover-intro { max-width: 610px; margin: 30px 0 0; color: rgba(255,255,255,.72); font-size: 17px; line-height: 1.9; }

.cover-metrics {
  position: absolute;
  left: clamp(42px, 6vw, 88px);
  right: clamp(42px, 6vw, 88px);
  bottom: clamp(38px, 6vw, 72px);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid rgba(255,255,255,.2);
}
.cover-metrics article { padding: 24px 24px 0 0; }
.cover-metrics strong { display: block; font-size: clamp(20px, 2vw, 30px); font-weight: 650; letter-spacing: .02em; }
.cover-metrics span { display: block; margin-top: 8px; color: rgba(255,255,255,.58); font-size: 13px; }

.login-panel {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(32px, 6vw, 78px);
  background: linear-gradient(150deg, #fff 0%, #f6f8fa 100%);
}
.login-card { width: min(100%, 430px); margin: auto; }
.mobile-brand { display: none; }
.eyebrow { margin: 0 0 18px; color: var(--blue); font-size: 12px; font-weight: 800; letter-spacing: .19em; }
.login-card h2 { margin: 0; color: var(--ink); font-size: clamp(34px, 4vw, 48px); font-weight: 660; letter-spacing: -.025em; }
.login-copy { margin: 18px 0 42px; color: var(--muted); font-size: 15px; line-height: 1.75; }
form label { display: block; margin-bottom: 10px; font-size: 14px; font-weight: 700; }
.password-field { position: relative; }
.password-field input {
  width: 100%;
  height: 58px;
  padding: 0 72px 0 17px;
  border: 1px solid var(--line);
  border-radius: 12px;
  outline: none;
  color: var(--ink);
  background: #fff;
  box-shadow: 0 10px 30px rgba(26, 54, 78, .045);
  transition: border-color .2s, box-shadow .2s;
}
.password-field input:focus { border-color: #5d9dc9; box-shadow: 0 0 0 4px rgba(23,105,170,.09), 0 12px 34px rgba(26,54,78,.07); }
.password-field button {
  position: absolute;
  top: 50%; right: 13px;
  transform: translateY(-50%);
  border: 0;
  padding: 7px 8px;
  color: var(--blue);
  background: transparent;
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
}
.login-message { min-height: 24px; margin: 8px 2px 4px; color: #b43c32; font-size: 13px; }
.login-button {
  width: 100%; height: 58px;
  display: flex; align-items: center; justify-content: space-between;
  margin-top: 4px; padding: 0 20px;
  border: 0; border-radius: 12px;
  color: #fff; background: var(--navy);
  box-shadow: 0 16px 34px rgba(8,42,71,.19);
  cursor: pointer; font-weight: 750;
  transition: transform .2s, background .2s, box-shadow .2s;
}
.login-button:hover { transform: translateY(-1px); background: #0c3d65; box-shadow: 0 18px 38px rgba(8,42,71,.24); }
.login-button:disabled { cursor: wait; opacity: .66; transform: none; }
.login-button i { font-style: normal; font-size: 21px; }
.security-note {
  display: flex; gap: 12px; align-items: flex-start;
  margin-top: 32px; padding-top: 24px;
  border-top: 1px solid var(--line); color: var(--muted);
}
.security-note > span { margin-top: 4px; color: #2b9a71; font-size: 9px; }
.security-note p { margin: 0; font-size: 12px; line-height: 1.65; }
.security-note strong { color: #405264; font-size: 13px; }
.login-panel footer { width: min(100%, 430px); margin: 50px auto 0; color: #9aa6b2; font-size: 11px; }

@media (max-width: 900px) {
  .cover-shell { grid-template-columns: 1fr; }
  .cover-visual { min-height: 37vh; padding: 34px 28px 95px; }
  .brand-mark { width: 58px; height: 58px; border-radius: 18px 7px 18px 7px; }
  .brand-mark span { font-size: 31px; }
  .department { margin: 2px 0 14px; }
  .cover-brand h1 { font-size: 38px; }
  .cover-intro { display: none; }
  .cover-metrics { left: 28px; right: 28px; bottom: 22px; }
  .cover-metrics article { padding-top: 15px; }
  .cover-metrics strong { font-size: 17px; }
  .cover-metrics span { font-size: 11px; }
  .login-panel { min-height: 63vh; padding: 46px 28px 34px; }
  .login-card { width: min(100%, 520px); }
  .login-panel footer { width: min(100%, 520px); }
}

@media (max-width: 560px) {
  .cover-visual { min-height: 25vh; padding: 26px 22px; }
  .cover-brand { display: none; }
  .cover-metrics { display: none; }
  .login-panel { min-height: 75vh; justify-content: flex-start; padding: 34px 22px 24px; }
  .mobile-brand { display: flex; align-items: center; gap: 12px; margin-bottom: 45px; }
  .mobile-mark { width: 42px; height: 42px; display: grid; place-items: center; border-radius: 13px 5px 13px 5px; color: #fff; background: var(--navy); font-family: "STKaiti", "KaiTi", serif; font-size: 24px; }
  .mobile-brand strong, .mobile-brand small { display: block; }
  .mobile-brand strong { font-size: 15px; }
  .mobile-brand small { margin-top: 3px; color: var(--muted); font-size: 11px; }
  .login-copy { margin-bottom: 30px; }
  .login-panel footer { margin-top: 36px; }
}