:root {
  color-scheme: light;
  --page: #f5f7fb;
  --surface: #ffffff;
  --surface-soft: #f7f9fc;
  --text: #121a2a;
  --muted: #7b879c;
  --line: #e2e7f0;
  --primary: #4169e1;
  --primary-hover: #3158cc;
  --danger: #c83f46;
  --danger-bg: #fff1f2;
  --shadow: 0 24px 70px rgba(25, 38, 68, .12);
}

* { box-sizing: border-box; }

html, body { min-height: 100%; }

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 18% 12%, rgba(65, 105, 225, .09), transparent 30rem),
    radial-gradient(circle at 86% 90%, rgba(105, 78, 214, .07), transparent 32rem),
    var(--page);
  font: 15px/1.45 Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.login-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 32px 20px;
}

.login-card {
  width: min(100%, 430px);
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: color-mix(in srgb, var(--surface) 96%, transparent);
  box-shadow: var(--shadow);
}

.login-brand {
  display: flex;
  align-items: center;
  gap: 13px;
  margin-bottom: 38px;
}

.login-brand img {
  display: block;
  width: 52px;
  height: 52px;
  border-radius: 14px;
  box-shadow: 0 8px 20px rgba(20, 25, 38, .16);
}

.login-brand span { display: grid; gap: 1px; }
.login-brand strong { font-size: 20px; letter-spacing: -.02em; }
.login-brand small { color: var(--muted); font-size: 12px; letter-spacing: .08em; }

form { display: grid; }
label { margin: 0 0 7px; font-size: 13px; font-weight: 650; }
input {
  width: 100%;
  height: 48px;
  margin: 0 0 18px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 11px;
  outline: none;
  color: var(--text);
  background: var(--surface-soft);
  font: inherit;
  transition: border-color .15s ease, box-shadow .15s ease, background-color .15s ease;
}

input:hover { border-color: #cbd3e1; }
input:focus {
  border-color: var(--primary);
  background: var(--surface);
  box-shadow: 0 0 0 3px rgba(65, 105, 225, .13);
}

button {
  height: 48px;
  margin-top: 4px;
  border: 0;
  border-radius: 11px;
  color: #fff;
  background: var(--primary);
  font: inherit;
  font-weight: 750;
  cursor: pointer;
  box-shadow: 0 8px 18px rgba(65, 105, 225, .22);
  transition: transform .12s ease, background-color .15s ease, box-shadow .15s ease;
}

button:hover { background: var(--primary-hover); box-shadow: 0 10px 22px rgba(65, 105, 225, .28); }
button:active { transform: translateY(1px); }
button:focus-visible { outline: 3px solid rgba(65, 105, 225, .25); outline-offset: 2px; }

.login-error {
  margin: -8px 0 20px;
  padding: 11px 13px;
  border: 1px solid color-mix(in srgb, var(--danger) 30%, transparent);
  border-radius: 10px;
  color: var(--danger);
  background: var(--danger-bg);
  font-size: 13px;
}

.login-note {
  margin: 22px 0 0;
  color: var(--muted);
  text-align: center;
  font-size: 12px;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --page: #0d1117;
    --surface: #151b25;
    --surface-soft: #101620;
    --text: #f2f5fa;
    --muted: #8d99ad;
    --line: #293345;
    --primary: #6d85f7;
    --primary-hover: #7f95ff;
    --danger: #ff858b;
    --danger-bg: #351d22;
    --shadow: 0 24px 80px rgba(0, 0, 0, .42);
  }
  body {
    background:
      radial-gradient(circle at 18% 12%, rgba(78, 105, 224, .12), transparent 30rem),
      radial-gradient(circle at 86% 90%, rgba(77, 59, 159, .11), transparent 32rem),
      var(--page);
  }
  .login-card { background: color-mix(in srgb, var(--surface) 96%, transparent); }
  input:hover { border-color: #3a475c; }
}

@media (max-width: 520px) {
  .login-shell { padding: 18px; }
  .login-card { padding: 26px 22px; border-radius: 18px; }
  .login-brand { margin-bottom: 30px; }
  h1 { font-size: 25px; }
}

@media (prefers-reduced-motion: reduce) {
  input, button { transition: none; }
}