:root {
  color-scheme: light;
  --ink: #171717;
  --muted: #777773;
  --paper: #f5f5f2;
  --line: rgba(23, 23, 23, .16);
  --soft-line: rgba(23, 23, 23, .08);
}

* { box-sizing: border-box; }
html { min-width: 320px; background: var(--paper); }
body {
  min-height: 100vh;
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

a { color: inherit; text-decoration: none; }
.shell {
  width: min(100% - 48px, 720px);
  min-height: 100vh;
  margin: 0 auto;
  padding: 32px 0;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .08em;
}
.brand-mark {
  display: inline-block;
  width: 15px;
  height: 15px;
  border: 1.5px solid var(--ink);
  border-radius: 50%;
  position: relative;
  overflow: hidden;
}
.brand-mark::after {
  content: "";
  position: absolute;
  width: 15px;
  height: 15px;
  top: -4px;
  left: 4px;
  border-radius: 50%;
  background: var(--paper);
}
.access-card {
  max-width: 520px;
  margin: clamp(120px, 20vh, 220px) auto 0;
  padding: 40px;
  border: 1px solid var(--soft-line);
  border-radius: 24px;
  background: rgba(255, 255, 253, .68);
}
.eyebrow {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 11px;
  letter-spacing: .2em;
}
h1 {
  margin: 0;
  font-size: clamp(30px, 5vw, 48px);
  font-weight: 500;
  letter-spacing: -.06em;
}
.description {
  margin: 18px 0 32px;
  color: var(--muted);
  line-height: 1.8;
}
label {
  display: block;
  margin-bottom: 10px;
  font-size: 13px;
  color: var(--muted);
}
input {
  width: 100%;
  height: 52px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  color: var(--ink);
  font: inherit;
  letter-spacing: .08em;
}
input:focus { outline: 2px solid var(--ink); outline-offset: 2px; }
button {
  width: 100%;
  height: 52px;
  margin-top: 16px;
  border: 0;
  border-radius: 12px;
  background: var(--ink);
  color: #fff;
  font: inherit;
  cursor: pointer;
}
button:disabled { cursor: wait; opacity: .55; }
.error {
  min-height: 24px;
  margin: 14px 0 0;
  color: #a24438;
  font-size: 13px;
}
@media (max-width: 640px) {
  .shell { width: min(100% - 32px, 720px); padding-top: 24px; }
  .access-card { margin-top: 96px; padding: 28px 22px; }
}