:root {
  color-scheme: dark;
  --ink: #f2f0f7;
  --muted: #aaa6b4;
  --paper: #0b0b10;
  --line: #35323f;
  --green: #a77cff;
  --green-soft: #2b213e;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 18% 15%, rgba(117, 72, 181, .25), transparent 34%),
    radial-gradient(circle at 82% 78%, rgba(83, 50, 128, .18), transparent 30%),
    var(--paper);
  color: var(--ink);
  font: 15px/1.5 Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

main {
  width: min(420px, calc(100% - 32px));
  background: #17171e;
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 36px;
  box-shadow: 0 26px 75px rgba(0, 0, 0, .52);
}

.mark {
  display: grid;
  place-items: center;
  width: 54px;
  height: 54px;
  margin-bottom: 18px;
  border-radius: 15px;
  background: var(--green-soft);
  color: var(--green);
  font: 700 29px/1 Georgia, serif;
}

h1 {
  margin: 0 0 2px;
  font: 600 31px/1.15 Georgia, serif;
}

p { margin: 0 0 22px; color: var(--muted); }
.subtitle { margin-bottom: 18px; color: var(--green); font-size: 12px; }
label { display: block; margin-bottom: 7px; font-weight: 650; }

input {
  width: 100%;
  border: 1px solid #45404f;
  border-radius: 11px;
  padding: 12px 13px;
  color: var(--ink);
  background: #0f0f14;
  font: inherit;
}

input:focus {
  outline: 3px solid rgba(167, 124, 255, .15);
  border-color: var(--green);
}

button {
  width: 100%;
  margin-top: 13px;
  border: 0;
  border-radius: 11px;
  padding: 12px;
  background: var(--green);
  color: #130d1f;
  font: 650 15px system-ui, sans-serif;
  cursor: pointer;
}

button:hover { background: #bd9aff; }

.error {
  color: #ffaba4;
  background: #3b2024;
  border-radius: 9px;
  padding: 9px 11px;
  margin-bottom: 13px;
}