* {
  box-sizing: border-box;
}
body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background:
    radial-gradient(900px 500px at 50% -10%, rgba(79, 140, 255, 0.18), transparent), #0b1220;
  color: #e8edf7;
}
.box {
  background: linear-gradient(180deg, #131c2e, #1a2540);
  border: 1px solid #26324d;
  border-radius: 16px;
  padding: 34px 30px;
  width: 320px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  text-align: center;
}
.ball {
  font-size: 40px;
}
h1 {
  font-size: 20px;
  margin: 10px 0 4px;
}
p {
  color: #9aa7c2;
  font-size: 13px;
  margin: 0 0 22px;
}
input {
  width: 100%;
  padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid #26324d;
  background: #0e1626;
  color: #e8edf7;
  font-size: 15px;
  margin-bottom: 12px;
}
input:focus {
  outline: 2px solid #4f8cff;
  outline-offset: 1px;
}
button {
  width: 100%;
  padding: 12px;
  border-radius: 10px;
  border: 0;
  background: #4f8cff;
  color: #fff;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
}
button:hover {
  filter: brightness(1.08);
}
.err {
  color: #ff8080;
  font-size: 13px;
  margin-bottom: 12px;
  display: none;
}
.err.show {
  display: block;
}