html, body {
  height: 100%;
}
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background: #f7f9fb;
}
main {
  flex: 1 0 auto;
}
footer {
  flex-shrink: 0;
  background: #f8f9fa;
  border-top: 1px solid #e9ecef;
}
.navbar-brand {
  font-weight: 700;
  letter-spacing: .5px;
}
h1, h2, h3, h4, h5 {
  font-family: 'Inter', 'Segoe UI', Arial, sans-serif;
  font-weight: 700;
}
a {
  color: #276ef1;
  text-decoration: none;
  transition: color .2s;
}
a:hover {
  color: #174ea6;
  text-decoration: underline;
}
.card {
  border-radius: 1rem;
  box-shadow: 0 2px 10px 0 rgba(40,60,100,0.04);
}


/* Сделать ссылки в dropdown белыми для тёмной навигации */
.navbar-dark .dropdown-menu {
  background: #23272b; /* тёмный фон */
}
.navbar-dark .dropdown-menu .dropdown-item {
  color: #fff;
  transition: background .15s, color .15s;
}
.navbar-dark .dropdown-menu .dropdown-item:hover,
.navbar-dark .dropdown-menu .dropdown-item:focus {
  color: #212529;
  background-color: #fff;
}