html {
  font-size: 14px;
}

@media (min-width: 768px) {
  html {
    font-size: 16px;
  }
}

.btn:focus, .btn:active:focus, .btn-link.nav-link:focus, .form-control:focus, .form-check-input:focus {
  box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem #258cfb;
}

body {
    /*    background-image: url('/background.jpg');
    background-size: auto;
    background-position: center;*/
    background-color: #e5e7e8;
    display: flex;
    flex-direction: column;
}
/* Header Area */
.navbar {
    background-color: #000;
    color: #fff;
    border: 1px solid #fff;
}

.navbar-collapse .navbar-nav > li > a {
    color: #fff;
}

.navbar-default .navbar-brand {
    color: #fff;
}

/* Container Area */
.jumbotron {
    color: #2c3e50;
    background-color: #ecf0f1;
    border: 1px solid #D6DBDF;
    margin-top: 10px;
}
main {
    flex: 1; /* ana içerik alanı tüm boşluğu kaplar */
}
footer {
    margin-top: auto; /* footer'ı alta iter */
}