:root {
  --bg: #020507;
  --panel: #04090d;
  --line: #123;
  --cyan: #3fe0ff;
  --dim: #6b8a99;
  --text: #dfeef5;
  --err: #ff3b6b;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at 50% 0%, #06131b 0%, var(--bg) 70%);
  color: var(--text);
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  padding: 24px;
}

.box {
  width: 100%;
  max-width: 440px;
  text-align: center;
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 40px 32px;
  border-radius: 8px;
}

.logo { width: 220px; max-width: 80%; height: auto; margin-bottom: 20px; }

h1 { font-size: 22px; margin: 0 0 8px; letter-spacing: .04em; }

.sub { color: var(--dim); font-size: 14px; line-height: 1.5; margin: 0 0 24px; }

form { display: flex; flex-direction: column; gap: 12px; }

input[type=text] {
  padding: 12px 14px;
  font-size: 15px;
  background: #061019;
  border: 1px solid var(--line);
  border-radius: 5px;
  color: var(--text);
  text-align: center;
  letter-spacing: .04em;
}
input[type=text]:focus { outline: none; border-color: var(--cyan); }

.btn, button {
  display: inline-block;
  padding: 13px 18px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .04em;
  color: #021016;
  background: var(--cyan);
  border: none;
  border-radius: 5px;
  cursor: pointer;
  text-decoration: none;
}
.btn:hover, button:hover { filter: brightness(1.1); }

.err {
  color: var(--err);
  font-size: 14px;
  margin: 0 0 16px;
}

.foot { margin: 24px 0 0; font-size: 13px; color: var(--dim); }
.foot a { color: var(--cyan); text-decoration: none; }