:root {
  color-scheme: light;
  --paper: #f4efe4; --card: #fbf9f4; --ink: #1d1b17; --ink-2: #4a463e; --muted: #7a7366; --clay: #d97757; --red: #b3372a;
  font: 15px/1.6 -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
}
* { box-sizing: border-box; }
body {
  min-height: 100svh; margin: 0; display: grid; place-items: center; padding: 24px;
  background: radial-gradient(circle at 1px 1px, rgba(29, 27, 23, .09) 1px, transparent 1.3px) 0 0 / 9px 9px, var(--paper);
}
main {
  width: 100%; max-width: 400px;
  background: var(--card); border: 3px solid var(--ink); border-radius: 2px;
  box-shadow: 8px 8px 0 var(--ink);
  padding: 32px 30px 22px;
}
.mark {
  width: 50px; height: 50px; display: grid; place-items: center; margin-bottom: 20px;
  font: 900 24px/1 ui-monospace, "SF Mono", Menlo, monospace; color: var(--ink); background: var(--clay);
  clip-path: polygon(50% 0, 61% 26%, 90% 10%, 76% 39%, 100% 50%, 76% 61%, 90% 90%, 61% 74%, 50% 100%, 39% 74%, 10% 90%, 24% 61%, 0 50%, 24% 39%, 10% 10%, 39% 26%);
}
.eyebrow { margin: 0; font: 700 11px ui-monospace, "SF Mono", Menlo, monospace; letter-spacing: .16em; color: var(--muted); }
h1 { font: 900 34px/1.2 "Songti SC", "STSong", "Noto Serif CJK SC", "Source Han Serif SC", Georgia, serif; margin: 6px 0 6px; }
.description { font-size: 14px; color: var(--ink-2); margin: 0 0 26px; }
label { display: block; font-size: 13.5px; font-weight: 700; margin-bottom: 7px; }
input {
  width: 100%; border: 2px solid var(--ink); border-radius: 2px; background: #fff;
  padding: 12px 13px; font-size: 17px; outline: none;
}
input:focus { box-shadow: 3px 3px 0 var(--clay); }
button {
  width: 100%; margin-top: 16px; display: flex; justify-content: space-between; align-items: center;
  font: 700 15px/1.2 inherit; color: var(--ink); background: var(--clay);
  border: 2px solid var(--ink); border-radius: 2px; padding: 13px 16px;
  box-shadow: 3px 3px 0 var(--ink); cursor: pointer;
  transition: transform .06s, box-shadow .06s;
}
button:hover { background: #e2866a; }
button:active:not(:disabled) { transform: translate(3px, 3px); box-shadow: none; }
button:disabled { opacity: .6; cursor: wait; }
#error { min-height: 22px; font-size: 13.5px; font-weight: 700; color: var(--red); margin: 12px 0 4px; }
footer { border-top: 2px dashed #d9d0bf; padding-top: 14px; font: 11px ui-monospace, "SF Mono", Menlo, monospace; letter-spacing: .06em; color: var(--muted); }