:root {
  color: #e9f0f8;
  background: #0b1220;
  font-family: Inter, "Noto Sans TC", "Microsoft JhengHei", system-ui, sans-serif;
  font-synthesis: none;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-width: 320px;
  min-height: 100dvh;
  background:
    radial-gradient(circle at 20% 15%, rgba(45, 124, 255, 0.24), transparent 34rem),
    radial-gradient(circle at 90% 85%, rgba(55, 210, 184, 0.14), transparent 30rem),
    #0b1220;
}

.login-shell {
  min-height: 100dvh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.login-card {
  width: min(100%, 420px);
  padding: clamp(28px, 7vw, 44px);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 24px;
  background: rgba(17, 28, 47, 0.9);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.36);
  backdrop-filter: blur(18px);
}

.brand-mark {
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  color: white;
  background: linear-gradient(135deg, #2d7cff, #22bfa7);
  font-weight: 800;
  letter-spacing: -0.04em;
}

.eyebrow {
  margin: 24px 0 8px;
  color: #7faeff;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.16em;
}

h1 { margin: 0; font-size: clamp(1.65rem, 5vw, 2.1rem); }
.description { margin: 10px 0 28px; color: #aebbd0; line-height: 1.6; }
form { display: grid; gap: 10px; }
label { margin-top: 8px; color: #cbd6e5; font-size: 0.9rem; font-weight: 650; }

input {
  width: 100%;
  min-height: 48px;
  border: 1px solid #34445e;
  border-radius: 12px;
  padding: 0 14px;
  color: white;
  background: #0d1728;
  font: inherit;
  outline: none;
}

input:focus { border-color: #5c95ff; box-shadow: 0 0 0 3px rgba(45, 124, 255, 0.2); }

button {
  min-height: 50px;
  margin-top: 8px;
  border: 0;
  border-radius: 13px;
  color: white;
  background: linear-gradient(135deg, #2d7cff, #1aa68f);
  font: inherit;
  font-weight: 750;
  cursor: pointer;
}

button:disabled { cursor: wait; opacity: 0.7; }
.message { min-height: 1.35em; margin: 4px 0 0; color: #ff9e9e; font-size: 0.9rem; }

@media (max-width: 480px) {
  .login-shell { padding: 14px; }
  .login-card { border-radius: 19px; }
}