:root {
  --bg: #16182a;
  --bg-2: #1e2136;
  --card: #232741;
  --ink: #e8e9f2;
  --muted: #9aa0b8;
  --accent: #ecc954;
  --accent-2: #7cc7ff;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(0, 0, 0, .35);
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: radial-gradient(1200px 600px at 20% -10%, var(--bg-2), var(--bg) 60%);
  color: var(--ink);
  font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
.top {
  display: grid;
  grid-template-columns: 48px 1fr;
  grid-template-rows: auto auto;
  column-gap: 14px;
  align-items: center;
  padding: 36px 24px 12px;
  max-width: 760px;
  width: 100%;
  margin: 0 auto;
}
.top img { grid-row: 1 / span 2; border-radius: 12px; }
.top h1 { margin: 0; font-size: 28px; letter-spacing: .3px; }
.top .tag { margin: 0; color: var(--muted); font-size: 14px; }
main {
  flex: 1;
  width: 100%;
  max-width: 760px;
  margin: 0 auto;
  padding: 12px 24px 40px;
  display: grid;
  gap: 18px;
}
.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px 24px;
  border: 1px solid rgba(255, 255, 255, .04);
}
.card h2 { margin: 0 0 10px; font-size: 18px; color: var(--accent); }
.card p { margin: 0 0 10px; }
.seq {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 20px;
  letter-spacing: 1px;
  color: var(--accent-2);
  word-break: break-all;
}
form { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-top: 8px; }
label { color: var(--muted); font-size: 14px; }
input {
  flex: 1 1 160px;
  background: var(--bg);
  color: var(--ink);
  border: 1px solid rgba(255, 255, 255, .12);
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 16px;
}
input:focus { outline: none; border-color: var(--accent-2); box-shadow: 0 0 0 3px rgba(124, 199, 255, .2); }
button {
  background: var(--accent);
  color: #1b1c22;
  border: 0;
  border-radius: 10px;
  padding: 10px 16px;
  font-weight: 600;
  cursor: pointer;
}
button:hover { filter: brightness(1.06); }
button:active { transform: translateY(1px); }
.muted { color: var(--muted); font-size: 14px; }
.ok { color: #7ee2a8; }
.bad { color: #ff8b8b; }
.list { margin: 8px 0 0; padding-left: 20px; color: var(--muted); }
.list li { margin: 4px 0; }
.foot { text-align: center; color: var(--muted); font-size: 13px; padding: 18px 24px 28px; }
.foot a { color: var(--muted); }
@media (max-width: 480px) {
  .top { padding-top: 24px; }
  .top h1 { font-size: 22px; }
  .card { padding: 18px; }
}