:root { color-scheme: light; }
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: #1e293b;
  /* 設定画面（#screen-settings）と同じ配色に合わせる */
  background:
    radial-gradient(820px 560px at 8% 0%, rgba(124, 58, 237, 0.42), transparent 58%),
    radial-gradient(760px 560px at 95% 6%, rgba(14, 165, 233, 0.40), transparent 55%),
    radial-gradient(900px 680px at 78% 102%, rgba(244, 114, 182, 0.30), transparent 58%),
    radial-gradient(720px 560px at 22% 108%, rgba(34, 211, 238, 0.28), transparent 56%),
    linear-gradient(160deg, #eef2ff, #fdf2ff);
}
.login-card {
  width: min(92vw, 380px);
  padding: 32px 28px 28px;
  text-align: center;
  background: rgba(255, 255, 255, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.66);
  border-radius: 20px;
  box-shadow: 0 20px 60px rgba(40, 50, 80, 0.18);
  backdrop-filter: blur(10px);
}
.login-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 12px;
  color: #5b3aa6;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.66);
  backdrop-filter: blur(10px);
  margin-bottom: 16px;
}
.login-card h1 {
  margin: 0 0 4px;
  font-size: 1.6rem;
  font-weight: 800;
  background: linear-gradient(90deg, #7c3aed, #0ea5e9);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.login-sub { margin: 0 0 22px; color: #475569; font-size: 0.92rem; }
.login-card form { text-align: left; }
.login-card label { display: block; margin-bottom: 14px; }
.login-card label span { display: block; margin-bottom: 6px; font-size: 0.85rem; color: #5b6577; font-weight: 700; }
.login-card input {
  width: 100%;
  padding: 11px 12px;
  border-radius: 11px;
  border: 1px solid rgba(71, 85, 105, 0.32);
  background: rgba(255, 255, 255, 0.88);
  color: #1e293b;
  font-size: 1rem;
}
.login-card input:focus { outline: none; border-color: #7c3aed; box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.12); }
#login-submit {
  width: 100%;
  margin-top: 6px;
  padding: 12px;
  border: 0;
  border-radius: 11px;
  background: linear-gradient(135deg, #7c3aed, #0ea5e9);
  color: #fff;
  font-size: 1rem;
  font-weight: 800;
  cursor: pointer;
}
#login-submit:hover { filter: brightness(1.06); }
#login-submit:disabled { opacity: 0.6; cursor: progress; }
.login-error {
  margin: 14px 0 0;
  padding: 10px 12px;
  border-radius: 8px;
  background: rgba(192, 57, 43, 0.10);
  border: 1px solid rgba(192, 57, 43, 0.4);
  color: #c0392b;
  font-size: 0.9rem;
}