:root {
  --bg: #1a1d23;
  --card: #242933;
  --text: #e8eaed;
  --muted: #9aa0a6;
  --line: #3c4250;
  --accent: #6b9bd1;
  --accent-press: #5a86b8;
  --err: #e8b4b4;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background:
    radial-gradient(1200px 600px at 20% 0%, #2a3344 0%, transparent 55%),
    radial-gradient(900px 500px at 90% 100%, #2c2438 0%, transparent 50%),
    var(--bg);
  color: var(--text);
}
.card {
  width: min(92vw, 380px);
  padding: 2rem 1.75rem 1.5rem;
  background: color-mix(in srgb, var(--card) 92%, black);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: 0 18px 50px rgba(0,0,0,.35);
}
h1 {
  margin: 0 0 .35rem;
  font-size: 1.55rem;
  font-weight: 650;
  letter-spacing: .04em;
}
.tag {
  margin: 0 0 1.4rem;
  color: var(--muted);
  font-size: .9rem;
}
label {
  display: block;
  margin-bottom: .9rem;
}
label span {
  display: block;
  margin-bottom: .35rem;
  color: var(--muted);
  font-size: .85rem;
}
input {
  width: 100%;
  padding: .7rem .8rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #1b1f27;
  color: var(--text);
  font-size: 1rem;
}
input:focus {
  outline: 2px solid color-mix(in srgb, var(--accent) 55%, transparent);
  border-color: var(--accent);
}
button {
  width: 100%;
  margin-top: .35rem;
  padding: .75rem 1rem;
  border: 0;
  border-radius: 8px;
  background: var(--accent);
  color: #0f141a;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
}
button:hover { background: var(--accent-press); }
.msg {
  margin: 1rem 0 0;
  padding: .7rem .8rem;
  border-radius: 8px;
  background: rgba(180, 70, 70, .15);
  color: var(--err);
  font-size: .88rem;
  line-height: 1.45;
}
.foot {
  margin: 1.25rem 0 0;
  color: var(--muted);
  font-size: .78rem;
  text-align: center;
}