:root {
  --bg-gradient: linear-gradient(145deg, #f5f7fb, #e8ecf6);
  --card-bg: #ffffff;
  --shadow: 0 24px 48px rgba(15, 23, 42, 0.12);
  --text: #1f2937;
  --muted: #6b7280;
  --accent: #3b82f6;
  --accent-strong: #2563eb;
  --border: #d1d5db;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: var(--bg-gradient);
  color: var(--text);
}

.login-card {
  width: min(360px, 90vw);
  padding: 36px 32px;
  border-radius: 18px;
  background: var(--card-bg);
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.login-card h1 {
  margin: 0;
  font-size: 24px;
  font-weight: 700;
}

.login-card form {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.login-card label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  color: var(--text);
  font-weight: 600;
}

.login-card input {
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  font-size: 14px;
  font-family: inherit;
}

.login-card input:focus {
  outline: none;
  border-color: var(--accent-strong);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
  background: #fff;
}

.primary-btn {
  margin-top: 8px;
  padding: 12px 16px;
  border-radius: 12px;
  border: none;
  font-size: 15px;
  font-weight: 600;
  color: #fff;
  cursor: pointer;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  box-shadow: 0 12px 24px rgba(37, 99, 235, 0.25);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.primary-btn:hover {
  transform: translateY(-1px);
}

.tips {
  text-align: center;
  color: var(--muted);
  margin: 0;
}

.tips a {
  color: var(--accent-strong);
  text-decoration: none;
}

.toast {
  text-align: center;
  color: #fff;
  background: rgba(239, 68, 68, 0.92);
  border-radius: 24px;
  padding: 8px 16px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease;
  transform: translateY(8px);
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}