:root {
  color-scheme: dark;
  --night: #050c14;
  --panel: rgba(7, 28, 41, .86);
  --line: rgba(70, 211, 255, .24);
  --cyan: #46d3ff;
  --amber: #ffc95c;
  --text: #edf9ff;
  --muted: #7895a6;
  --danger: #ff756d;
  font-family: Inter, "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 18% 14%, rgba(9, 89, 128, .24), transparent 30rem),
    radial-gradient(circle at 82% 86%, rgba(15, 82, 106, .17), transparent 36rem),
    var(--night);
}

button,
input { font: inherit; }

button { cursor: pointer; }

button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.login-shell {
  position: relative;
  isolation: isolate;
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(330px, 460px);
  align-items: center;
  gap: clamp(48px, 9vw, 160px);
  padding: clamp(32px, 7vw, 110px);
  overflow: hidden;
}

.ambient-grid {
  position: absolute;
  z-index: -1;
  inset: 0;
  opacity: .22;
  background-image:
    linear-gradient(rgba(70, 211, 255, .11) 1px, transparent 1px),
    linear-gradient(90deg, rgba(70, 211, 255, .11) 1px, transparent 1px);
  background-size: 52px 52px;
  mask-image: linear-gradient(115deg, #000, transparent 72%);
  transform: perspective(720px) rotateX(64deg) scale(1.55) translateY(24%);
  transform-origin: bottom;
}

.identity { max-width: 680px; }

.system-mark {
  width: 66px;
  height: 66px;
  position: relative;
  display: grid;
  place-items: center;
  margin-bottom: 36px;
  border: 1px solid var(--line);
  transform: rotate(30deg);
}

.system-mark::before,
.system-mark::after {
  content: "";
  position: absolute;
  inset: 8px;
  border: 1px solid rgba(70, 211, 255, .38);
}

.system-mark::after { inset: 17px; }

.system-mark span {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 16px var(--amber);
}

.system-mark span:nth-child(2) { transform: translate(13px, -9px); }
.system-mark span:nth-child(3) { transform: translate(-13px, 9px); }

.eyebrow,
.card-kicker {
  margin: 0;
  color: var(--cyan);
  font-size: .76rem;
  font-weight: 700;
  letter-spacing: .2em;
}

.identity h1 {
  margin: 14px 0 16px;
  font-size: clamp(3rem, 6.5vw, 6.4rem);
  font-weight: 650;
  line-height: .98;
  letter-spacing: -.055em;
}

.subtitle {
  margin: 0;
  color: var(--muted);
  font-size: clamp(1rem, 1.5vw, 1.25rem);
  letter-spacing: .08em;
}

.login-card {
  position: relative;
  display: grid;
  gap: 12px;
  padding: clamp(28px, 4vw, 48px);
  border: 1px solid var(--line);
  background: var(--panel);
  box-shadow: 0 30px 90px rgba(0, 0, 0, .38);
  backdrop-filter: blur(18px);
  opacity: .72;
  transition: opacity 180ms ease;
}

.login-card.ready { opacity: 1; }

.login-card::before,
.login-card::after {
  content: "";
  position: absolute;
  width: 38px;
  height: 38px;
  border-color: var(--cyan);
}

.login-card::before {
  top: -1px;
  left: -1px;
  border-top: 2px solid;
  border-left: 2px solid;
}

.login-card::after {
  right: -1px;
  bottom: -1px;
  border-right: 2px solid;
  border-bottom: 2px solid;
}

.login-card header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 22px;
}

.signal {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 18px var(--amber);
}

.login-card h2 {
  margin: 3px 0 0;
  font-size: 1.75rem;
}

.login-card label {
  margin-top: 7px;
  color: #a8c0ce;
  font-size: .86rem;
}

.login-card input {
  width: 100%;
  min-height: 52px;
  padding: 0 15px;
  border: 1px solid rgba(119, 176, 200, .28);
  border-radius: 3px;
  color: var(--text);
  background: rgba(1, 11, 18, .62);
}

.login-card input:hover { border-color: rgba(70, 211, 255, .5); }

.password-field { position: relative; }

.password-field input { padding-right: 70px; }

.password-toggle {
  position: absolute;
  top: 50%;
  right: 8px;
  min-height: 36px;
  padding: 0 9px;
  border: 0;
  color: var(--cyan);
  background: transparent;
}

.submit {
  min-height: 52px;
  margin-top: 10px;
  border: 1px solid rgba(255, 201, 92, .65);
  border-radius: 3px;
  color: #161206;
  background: linear-gradient(100deg, #ffc95c, #f3ae39);
  font-weight: 750;
  letter-spacing: .12em;
}

.submit:hover { filter: brightness(1.08); }
.submit:disabled { cursor: wait; opacity: .62; }

.error {
  min-height: 24px;
  margin: 2px 0 0;
  color: var(--danger);
  font-size: .9rem;
}

.session-status {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: .8rem;
  text-align: center;
}

@media (max-width: 820px) {
  .login-shell {
    grid-template-columns: 1fr;
    align-content: center;
    gap: 48px;
  }

  .identity h1 { font-size: clamp(3rem, 14vw, 5rem); }
  .system-mark { margin-bottom: 24px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}