:root {
  --night: #12201d;
  --night-soft: #1b2d29;
  --paper: #f3efe5;
  --paper-bright: #fffdf7;
  --ink: #19231f;
  --muted: #737a73;
  --mint: #77e0bc;
  --signal: #f3b544;
  --danger: #b63d35;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: "Bahnschrift", "Microsoft YaHei", sans-serif;
}

.login-shell {
  display: grid;
  grid-template-columns: minmax(440px, 1.08fr) minmax(430px, .92fr);
  min-height: 100vh;
}

.signal-panel {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 100vh;
  padding: clamp(34px, 5vw, 72px);
  overflow: hidden;
  isolation: isolate;
  color: #f5f2e8;
  background:
    radial-gradient(circle at 72% 34%, rgba(119, 224, 188, .12), transparent 19rem),
    linear-gradient(145deg, #182a26 0%, #101b19 68%);
}

.grid {
  position: absolute;
  inset: 0;
  z-index: -2;
  opacity: .18;
  background-image:
    linear-gradient(rgba(255,255,255,.12) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.12) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(to bottom right, #000, transparent 75%);
}

.signal-panel::after {
  content: "";
  position: absolute;
  width: 430px;
  height: 430px;
  right: -170px;
  bottom: -160px;
  border-radius: 50%;
  background: var(--signal);
  opacity: .95;
  z-index: -1;
}

.brand-mark { display: flex; align-items: center; gap: 13px; font: 700 17px/1 Georgia, serif; letter-spacing: .12em; }
.brand-mark span { display: grid; place-items: center; width: 47px; height: 47px; border: 1px solid rgba(255,255,255,.72); }
.brand-mark i { display: block; width: 58px; height: 1px; background: var(--mint); }

.signal-copy { max-width: 720px; margin: auto 0; padding: 70px 0; }
.overline, .step { color: var(--mint); font-size: 11px; font-weight: 800; letter-spacing: .2em; }
.signal-copy h1 {
  margin: 24px 0 22px;
  font: 400 clamp(45px, 6.2vw, 88px)/1.05 "Bodoni 72", "STSong", Georgia, serif;
  letter-spacing: -.045em;
}
.intro { max-width: 440px; color: rgba(245,242,232,.68); font-size: 15px; line-height: 1.8; }

.telemetry { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; max-width: 600px; border-top: 1px solid rgba(255,255,255,.18); padding-top: 20px; }
.telemetry div { display: grid; gap: 6px; }
.telemetry span { color: rgba(255,255,255,.42); font-size: 9px; letter-spacing: .18em; }
.telemetry strong { font: 600 11px/1 monospace; color: var(--mint); }

.orbit { position: absolute; border: 1px solid rgba(119,224,188,.22); border-radius: 50%; z-index: -1; animation: breathe 6s ease-in-out infinite; }
.orbit-one { width: 430px; height: 430px; right: -50px; top: 17%; }
.orbit-two { width: 310px; height: 310px; right: 10px; top: 23%; animation-delay: -2s; }

.form-panel { display: grid; place-items: center; padding: 48px clamp(28px, 6vw, 92px); background: var(--paper); }
.form-wrap { width: min(100%, 480px); animation: arrive .65s cubic-bezier(.2,.75,.25,1) both; }
.mobile-brand { display: none; }
.step { color: #2d7663; margin: 0 0 22px; }
.form-wrap h2 { margin: 0; font: 400 clamp(38px, 5vw, 58px)/1.08 "Bodoni 72", "STSong", Georgia, serif; letter-spacing: -.035em; }
.hint { color: var(--muted); font-size: 14px; line-height: 1.7; margin: 15px 0 38px; }
.login-form label { display: block; margin: 23px 0 9px; color: #59625d; font-size: 12px; font-weight: 700; letter-spacing: .04em; }
.field { display: flex; align-items: center; border-bottom: 1px solid #aeb2a9; transition: border-color .2s ease; }
.field:focus-within { border-color: #237d65; }
.field-index { width: 42px; color: #969b94; font: 10px/1 monospace; }
.field input { flex: 1; width: 100%; padding: 15px 0; border: 0; outline: 0; background: transparent; color: var(--ink); font: 16px/1.4 "Bahnschrift", "Microsoft YaHei", sans-serif; }
.field input::placeholder { color: #a4a8a1; }
.reveal { border: 0; padding: 10px 0 10px 14px; background: transparent; color: #37715f; cursor: pointer; font-weight: 700; }
.submit-button { display: flex; align-items: center; justify-content: space-between; width: 100%; margin-top: 38px; padding: 18px 19px 18px 22px; border: 0; background: var(--night); color: #fff; cursor: pointer; font: 700 14px/1 "Bahnschrift", "Microsoft YaHei", sans-serif; transition: transform .2s ease, background .2s ease; }
.submit-button:hover { transform: translateY(-2px); background: #20473d; }
.submit-button:focus-visible { outline: 3px solid rgba(35,125,101,.3); outline-offset: 3px; }
.arrow { display: grid; place-items: center; width: 31px; height: 31px; border-radius: 50%; background: var(--mint); color: var(--night); font-size: 17px; }
.security-note { display: flex; align-items: center; gap: 9px; margin-top: 22px; color: #80867f; font-size: 11px; line-height: 1.5; }
.security-note i { flex: none; width: 6px; height: 6px; border-radius: 50%; background: #45a582; box-shadow: 0 0 0 4px rgba(69,165,130,.12); }
.error-message { display: flex; align-items: center; gap: 10px; margin: -18px 0 28px; padding: 12px 14px; border-left: 3px solid var(--danger); background: rgba(182,61,53,.08); color: #8c2d28; font-size: 13px; }
.error-message span { display: grid; place-items: center; width: 20px; height: 20px; border: 1px solid currentColor; border-radius: 50%; font-weight: 800; }

@keyframes arrive { from { opacity: 0; transform: translateY(18px); } to { opacity: 1; transform: translateY(0); } }
@keyframes breathe { 50% { transform: scale(1.045); opacity: .55; } }
@media (prefers-reduced-motion: reduce) { * { animation: none !important; transition: none !important; } }

@media (max-width: 900px) {
  .login-shell { grid-template-columns: 1fr; }
  .signal-panel { display: none; }
  .form-panel { min-height: 100vh; }
  .mobile-brand { display: flex; align-items: center; gap: 11px; margin-bottom: 64px; color: #406057; font: 700 13px/1 Georgia, serif; letter-spacing: .07em; }
  .mobile-brand span { display: grid; place-items: center; width: 38px; height: 38px; border: 1px solid #517369; }
}

@media (max-width: 520px) {
  .form-panel { align-items: start; padding: 30px 22px 40px; }
  .form-wrap { margin-top: 0; }
  .mobile-brand { margin-bottom: 68px; }
  .hint { margin-bottom: 30px; }
}