:root {
  --bg-top: #dbeafe;
  --bg-bottom: #f0f9ff;
  --card: #ffffff;
  --text: #0c4a6e;
  --text-muted: #0369a1;
  --border: #bae6fd;
  --accent: #0284c7;
  --accent-hover: #0369a1;
  --error-bg: #fef2f2;
  --error-text: #b91c1c;
  --shadow: 0 20px 50px rgba(14, 116, 144, 0.12);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Ubuntu, sans-serif;
  color: var(--text);
  background: linear-gradient(165deg, var(--bg-top) 0%, var(--bg-bottom) 45%, #ffffff 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.login-shell {
  width: 100%;
  max-width: 420px;
}

.login-card {
  background: var(--card);
  border-radius: 16px;
  padding: 2.25rem 2rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.login-brand {
  text-align: center;
  margin-bottom: 1.75rem;
}

.login-brand h1 {
  margin: 0 0 0.35rem;
  font-size: 1.5rem;
  font-weight: 650;
  letter-spacing: -0.02em;
  color: var(--text);
}

.login-brand p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-muted);
}

.field {
  margin-bottom: 1.15rem;
}

.field label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--text);
}

.field input {
  width: 100%;
  padding: 0.65rem 0.85rem;
  font-size: 1rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #f8fcff;
  color: var(--text);
  transition: border-color 0.15s, box-shadow 0.15s;
}

.field input::placeholder {
  color: #94a3b8;
}

.field input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.2);
  background: #fff;
}

.btn-primary {
  width: 100%;
  margin-top: 0.5rem;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.15s, transform 0.05s;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-primary:active {
  transform: scale(0.99);
}

.btn-primary:disabled {
  opacity: 0.65;
  cursor: not-allowed;
}

.message {
  margin-top: 1rem;
  padding: 0.65rem 0.85rem;
  border-radius: 10px;
  font-size: 0.9rem;
  display: none;
}

.message.visible {
  display: block;
}

.message.error {
  background: var(--error-bg);
  color: var(--error-text);
  border: 1px solid #fecaca;
}

.message.success {
  background: #ecfdf5;
  color: #047857;
  border: 1px solid #a7f3d0;
}