:root {
  --login-bg: #f2f5fb;
  --login-surface: #ffffff;
  --login-surface-2: #eef2f7;
  --login-border: #dce4ef;
  --login-text: #172033;
  --login-muted: #6d788a;
  --login-primary: #4f6fe8;
  --login-primary-hover: #405dcd;
  --login-primary-soft: rgba(79,111,232,.14);
  --login-shadow: 0 28px 70px rgba(25,38,70,.14);
}
html[data-theme="dark"] {
  color-scheme: dark;
  --login-bg: #101620;
  --login-surface: #19212d;
  --login-surface-2: #202a38;
  --login-border: #303c4d;
  --login-text: #edf2fa;
  --login-muted: #a6b1c2;
  --login-primary: #7da0ff;
  --login-primary-hover: #91b0ff;
  --login-primary-soft: rgba(125,160,255,.16);
  --login-shadow: 0 30px 80px rgba(0,0,0,.36);
}
html, body { min-height: 100%; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 32px 18px;
  color: var(--login-text);
  background:
    radial-gradient(circle at 15% 20%, var(--login-primary-soft), transparent 34%),
    radial-gradient(circle at 85% 80%, rgba(69,190,160,.08), transparent 30%),
    var(--login-bg);
}
.login-theme-wrap { position: fixed; top: 18px; right: 18px; }
.theme-toggle {
  display: inline-flex; align-items: center; gap: .5rem;
  height: 42px; padding: 0 .8rem;
  border: 1px solid var(--login-border); border-radius: 11px;
  color: var(--login-text); background: var(--login-surface);
  font-weight: 650; cursor: pointer;
  box-shadow: 0 5px 18px rgba(0,0,0,.06);
}
.theme-toggle:hover { background: var(--login-surface-2); }
.theme-toggle svg { width:18px; height:18px; }
.form-signin {
  width: min(100%, 450px);
  padding: 34px;
  margin: auto;
  text-align: left;
  background: var(--login-surface);
  border: 1px solid var(--login-border);
  border-radius: 24px;
  box-shadow: var(--login-shadow);
}
.login-brand { display:flex; align-items:center; gap:16px; margin-bottom:28px; }
.login-logo {
  width: 58px; height: 58px; object-fit: contain;
  padding: 8px; border-radius: 16px;
  background: var(--login-primary-soft);
}
.login-title { margin:0 0 3px; font-size:1.55rem; font-weight:780; letter-spacing:-.025em; }
.login-subtitle { margin:0; color:var(--login-muted); }
.form-floating { margin-bottom: 12px; }
.form-floating > .form-control {
  height: 58px;
  color: var(--login-text);
  background: var(--login-surface-2);
  border: 1px solid var(--login-border);
  border-radius: 13px;
}
.form-floating > .form-control:focus {
  color: var(--login-text);
  background: var(--login-surface);
  border-color: var(--login-primary);
  box-shadow: 0 0 0 .22rem var(--login-primary-soft);
}
.form-floating > label { color: var(--login-muted); }
.btn-primary {
  min-height: 50px;
  margin-top: 6px;
  border: 0;
  border-radius: 13px;
  background: var(--login-primary);
  font-weight: 720;
}
.btn-primary:hover { background: var(--login-primary-hover); }
.alert { border-radius: 12px; }
.login-footer { margin: 24px 0 0; text-align:center; color:var(--login-muted); font-size:.85rem; }
@media (max-width: 520px) {
  body { padding: 20px 12px; }
  .form-signin { padding: 24px 20px; border-radius: 20px; }
  .login-theme-wrap { top: 10px; right: 10px; }
}