:root {
  --navy-950: #061829;
  --navy-900: #08223a;
  --navy-800: #0b3152;
  --blue-600: #176ea6;
  --cyan-400: #63cad4;
  --gold-400: #d7b66b;
  --ink: #172536;
  --muted: #657588;
  --line: #dce5ec;
  --paper: #f5f8fa;
}

* { 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(--navy-950);
}
button, input { font: inherit; }

.cover-shell {
  position: relative;
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(0, 1.16fr) minmax(420px, .84fr);
  overflow: hidden;
  background:
    radial-gradient(circle at 15% 12%, rgba(64, 156, 183, .24), transparent 31%),
    radial-gradient(circle at 75% 78%, rgba(35, 99, 139, .18), transparent 28%),
    linear-gradient(135deg, #082943 0%, #071f36 46%, #051727 100%);
}
.cover-shell::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .18;
  background-image:
    linear-gradient(rgba(255,255,255,.10) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.10) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: linear-gradient(105deg, #000 0 54%, transparent 78%);
}
.ambient { position: absolute; border: 1px solid rgba(111, 206, 216, .16); border-radius: 50%; pointer-events: none; }
.ambient-one { width: 580px; height: 580px; left: -220px; bottom: -300px; box-shadow: 0 0 0 80px rgba(83,177,193,.025), 0 0 0 170px rgba(83,177,193,.018); }
.ambient-two { width: 420px; height: 420px; left: 43%; top: -270px; box-shadow: 0 0 0 65px rgba(83,177,193,.022); }

.system-intro {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: clamp(34px, 4.8vw, 72px) clamp(38px, 6vw, 96px);
  color: #fff;
}
.brand-bar { display: flex; align-items: center; gap: 14px; }
.brand-mark {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255,255,255,.34);
  border-radius: 15px 5px 15px 5px;
  background: rgba(255,255,255,.09);
  box-shadow: inset 0 0 0 4px rgba(255,255,255,.025);
  font-family: "STKaiti", "KaiTi", serif;
  font-size: 29px;
}
.brand-copy strong, .brand-copy span { display: block; }
.brand-copy strong { font-size: 18px; letter-spacing: .08em; }
.brand-copy span { margin-top: 4px; color: rgba(255,255,255,.54); font-size: 11px; letter-spacing: .08em; }

.intro-main { width: min(100%, 720px); margin: auto 0; padding: 54px 0 42px; }
.overline { margin: 0 0 18px; color: #82d8df; font-size: 11px; font-weight: 800; letter-spacing: .23em; }
.intro-main h1 { margin: 0; font-size: clamp(42px, 5vw, 68px); line-height: 1.12; letter-spacing: .02em; }
.intro-copy { width: min(100%, 650px); margin: 24px 0 0; color: rgba(255,255,255,.68); font-size: 16px; line-height: 1.85; }

.feature-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; margin-top: 42px; }
.feature-grid article {
  min-height: 82px;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 15px 17px;
  border: 1px solid rgba(255,255,255,.105);
  border-radius: 14px;
  background: rgba(255,255,255,.045);
  backdrop-filter: blur(8px);
}
.feature-icon {
  flex: 0 0 auto;
  width: 35px;
  height: 35px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  color: #a8e2e5;
  background: rgba(99,202,212,.13);
  font-size: 13px;
  font-weight: 800;
}
.feature-grid strong, .feature-grid small { display: block; }
.feature-grid strong { font-size: 13px; }
.feature-grid small { margin-top: 5px; color: rgba(255,255,255,.48); font-size: 11px; line-height: 1.45; }

.coverage { display: flex; gap: clamp(34px, 5vw, 76px); padding-top: 22px; border-top: 1px solid rgba(255,255,255,.13); }
.coverage article { min-width: 104px; }
.coverage strong, .coverage span { display: block; }
.coverage strong { font-size: 22px; font-weight: 680; letter-spacing: .03em; }
.coverage span { margin-top: 6px; color: rgba(255,255,255,.48); font-size: 11px; }

.access-panel {
  position: relative;
  z-index: 2;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(30px, 4vw, 58px);
  background: linear-gradient(160deg, rgba(255,255,255,.99), rgba(246,249,251,.98));
  box-shadow: -30px 0 80px rgba(0,0,0,.08);
}
.login-card { width: min(100%, 430px); margin: auto; }
.mobile-brand { display: none; }
.access-label { display: flex; align-items: center; gap: 8px; margin: 0 0 20px; color: var(--blue-600); font-size: 12px; font-weight: 800; letter-spacing: .12em; }
.access-label i { width: 7px; height: 7px; border-radius: 50%; background: #2ca178; box-shadow: 0 0 0 4px rgba(44,161,120,.10); }
.login-card h2 { margin: 0; color: var(--ink); font-size: clamp(34px, 3.5vw, 46px); line-height: 1.15; letter-spacing: -.025em; }
.login-copy { margin: 17px 0 34px; color: var(--muted); font-size: 14px; line-height: 1.75; }
form label { display: block; margin-bottom: 9px; color: #314356; font-size: 13px; font-weight: 750; }
.password-field { position: relative; }
.password-field input {
  width: 100%;
  height: 56px;
  padding: 0 72px 0 17px;
  border: 1px solid var(--line);
  border-radius: 12px;
  outline: none;
  color: var(--ink);
  background: #fff;
  box-shadow: 0 10px 26px rgba(24,52,75,.045);
  transition: border-color .2s, box-shadow .2s;
}
.password-field input:focus { border-color: #5c9fc8; box-shadow: 0 0 0 4px rgba(23,110,166,.09), 0 12px 28px rgba(24,52,75,.07); }
.password-field button {
  position: absolute;
  top: 50%;
  right: 12px;
  transform: translateY(-50%);
  border: 0;
  padding: 7px 8px;
  color: var(--blue-600);
  background: transparent;
  cursor: pointer;
  font-size: 12px;
  font-weight: 750;
}
.login-message { min-height: 22px; margin: 7px 2px 3px; color: #b23e35; font-size: 12px; }
.login-button {
  width: 100%;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 19px;
  border: 0;
  border-radius: 12px;
  color: #fff;
  background: linear-gradient(135deg, #0b3152, #0b446d);
  box-shadow: 0 15px 32px rgba(8,42,71,.19);
  cursor: pointer;
  font-weight: 760;
  transition: transform .2s, box-shadow .2s, filter .2s;
}
.login-button:hover { transform: translateY(-1px); filter: brightness(1.05); box-shadow: 0 18px 36px rgba(8,42,71,.24); }
.login-button:disabled { cursor: wait; transform: none; filter: none; opacity: .86; }
.login-button i { font-style: normal; font-size: 20px; }

.loading-panel { display: none; margin-top: 18px; padding: 14px 15px 13px; border: 1px solid #dce8ee; border-radius: 12px; background: #f7fafb; }
.loading-panel.is-visible { display: block; }
.loading-head { display: flex; justify-content: space-between; gap: 15px; color: #31475b; font-size: 12px; }
.loading-head strong { font-weight: 760; }
.loading-head span { color: var(--blue-600); font-variant-numeric: tabular-nums; }
.progress-track { height: 5px; margin-top: 10px; overflow: hidden; border-radius: 999px; background: #e3ebef; }
.progress-track i { display: block; width: 0; height: 100%; border-radius: inherit; background: linear-gradient(90deg, #1972aa, #63cad4); transition: width .25s ease; }
.loading-panel p { margin: 9px 0 0; color: #7a8998; font-size: 11px; line-height: 1.55; }

.access-note { display: flex; align-items: flex-start; gap: 11px; margin-top: 28px; padding-top: 22px; border-top: 1px solid var(--line); color: var(--muted); }
.access-note > span { width: 19px; height: 19px; display: grid; place-items: center; flex: 0 0 auto; border-radius: 50%; color: #2b956f; background: rgba(43,149,111,.10); font-size: 11px; font-weight: 800; }
.access-note p { margin: 0; font-size: 11px; line-height: 1.65; }
.access-note strong { color: #405264; font-size: 12px; }
.access-panel footer { width: min(100%, 430px); margin: 38px auto 0; color: #9ba8b4; font-size: 10px; letter-spacing: .05em; }

@media (max-width: 980px) {
  .cover-shell { grid-template-columns: minmax(0, 1fr) minmax(390px, .88fr); }
  .system-intro { padding: 38px; }
  .feature-grid { grid-template-columns: 1fr; margin-top: 30px; }
  .feature-grid article:nth-child(n+3) { display: none; }
  .coverage { gap: 30px; }
}

@media (max-width: 760px) {
  .cover-shell { display: block; min-height: 100vh; background: linear-gradient(145deg, #082b47, #061b2e); }
  .system-intro { min-height: 185px; padding: 28px 24px; }
  .brand-bar, .intro-copy, .feature-grid, .coverage { display: none; }
  .intro-main { margin: auto 0 0; padding: 35px 0 5px; }
  .overline { margin-bottom: 10px; font-size: 9px; }
  .intro-main h1 { font-size: 31px; }
  .access-panel { min-height: calc(100vh - 185px); justify-content: flex-start; padding: 34px 24px 28px; border-radius: 24px 24px 0 0; box-shadow: 0 -20px 60px rgba(0,0,0,.12); }
  .login-card { width: min(100%, 500px); }
  .mobile-brand { display: flex; align-items: center; gap: 11px; margin-bottom: 34px; }
  .mobile-brand > span { width: 40px; height: 40px; display: grid; place-items: center; border-radius: 12px 4px 12px 4px; color: #fff; background: var(--navy-800); font-family: "STKaiti", "KaiTi", serif; font-size: 23px; }
  .mobile-brand strong, .mobile-brand small { display: block; }
  .mobile-brand strong { font-size: 14px; }
  .mobile-brand small { margin-top: 3px; color: var(--muted); font-size: 10px; }
  .access-label { margin-bottom: 14px; }
  .login-card h2 { font-size: 33px; }
  .login-copy { margin-bottom: 28px; }
  .access-panel footer { width: min(100%, 500px); margin-top: 30px; }
}

@media (max-height: 720px) and (min-width: 761px) {
  .system-intro { padding-top: 28px; padding-bottom: 28px; }
  .intro-main { padding: 30px 0 24px; }
  .intro-main h1 { font-size: 48px; }
  .intro-copy { margin-top: 16px; }
  .feature-grid { margin-top: 24px; }
  .feature-grid article { min-height: 70px; }
  .coverage { padding-top: 16px; }
  .access-panel { padding-top: 28px; padding-bottom: 28px; }
}