:root {
  color-scheme: dark;
  --ink: #edf5ff;
  --muted: #9db0d0;
  --line: rgba(133, 178, 240, 0.3);
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body {
  min-height: 100vh;
  color: var(--ink);
  font-family: "Segoe UI", Arial, sans-serif;
  background:
    radial-gradient(circle at 12% 12%, rgba(90, 73, 160, 0.32), transparent 34%),
    radial-gradient(circle at 90% 5%, rgba(31, 119, 162, 0.3), transparent 34%),
    linear-gradient(145deg, #060916, #111a35 55%, #0a2440);
}

.auth-shell {
  width: min(1040px, calc(100% - 32px));
  min-height: 100vh;
  margin: auto;
  padding: 48px 0;
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(340px, .85fr);
  gap: 56px;
  align-items: center;
}

.logo { width: 68px; height: 68px; object-fit: contain; }
.home-link { display: inline-flex; border-radius: 12px; }
.home-link:focus-visible { outline: 3px solid rgba(87, 216, 197, .45); outline-offset: 4px; }
.eyebrow, .form-kicker {
  margin: 22px 0 8px;
  color: #78d6dc;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .16em;
}
h1 { margin: 0; max-width: 650px; font-size: clamp(2.2rem, 5vw, 4.5rem); line-height: 1.02; letter-spacing: -.04em; }
.lead { max-width: 580px; color: #bdcbe3; font-size: 1.05rem; line-height: 1.65; }
.intro-panel ul { margin: 24px 0 0; padding-left: 20px; color: #c8d5e9; line-height: 1.9; }
.intro-panel li::marker { color: #57d8c5; }
.guardrail {
  max-width: 610px;
  margin-top: 24px;
  padding: 16px 18px;
  border: 1px solid rgba(87, 216, 197, 0.35);
  border-radius: 14px;
  background: rgba(9, 75, 71, 0.25);
}
.guardrail strong, .guardrail span { display: block; }
.guardrail span { margin-top: 5px; color: #bce7e3; font-size: 13px; line-height: 1.5; }

.auth-card {
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: rgba(9, 18, 40, .78);
  box-shadow: 0 28px 80px rgba(0, 0, 0, .38);
  backdrop-filter: blur(16px);
}
.tabs { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; padding: 5px; border-radius: 12px; background: rgba(5, 13, 29, .76); }
.tab {
  border: 0;
  border-radius: 9px;
  padding: 10px;
  color: var(--muted);
  background: transparent;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}
.tab.is-active { color: #edf9ff; background: linear-gradient(135deg, rgba(80, 124, 199, .7), rgba(38, 145, 147, .65)); }
.auth-form { display: grid; gap: 16px; margin-top: 24px; }
.auth-form[hidden] { display: none !important; }
.auth-form h2 { margin: 2px 0 0; font-size: 1.45rem; }
.form-kicker { margin: 0; font-size: 9px; }
label { display: grid; gap: 7px; color: #c5d3e8; font-size: 13px; font-weight: 650; }
input {
  width: 100%;
  border: 1px solid rgba(143, 181, 238, .32);
  border-radius: 10px;
  padding: 12px 13px;
  color: var(--ink);
  background: rgba(5, 13, 28, .82);
  font: inherit;
}
input:focus { outline: 3px solid rgba(87, 216, 197, .15); border-color: #57d8c5; }
small { color: var(--muted); font-weight: 400; }
.terms-check {
  grid-template-columns: auto 1fr;
  align-items: start;
  gap: 9px;
  color: #aebfda;
  font-weight: 400;
  line-height: 1.45;
}
.terms-check input { width: 17px; height: 17px; margin: 2px 0 0; accent-color: #57d8c5; }
.terms-check a { color: #8de6df; }
.primary-btn {
  margin-top: 4px;
  border: 0;
  border-radius: 11px;
  padding: 13px;
  color: #07191b;
  background: linear-gradient(135deg, #57d8c5, #8ce99a);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}
.primary-btn:disabled { opacity: .55; cursor: wait; }
.message { min-height: 20px; margin: 16px 0 0; color: #ffc9c7; font-size: 13px; }

@media (max-width: 820px) {
  .auth-shell { grid-template-columns: 1fr; gap: 34px; padding: 28px 0 48px; }
  h1 { font-size: clamp(2.2rem, 11vw, 3.7rem); }
}