body {
    background: #ffffff;
    color: #1a1a1a;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
}

h1, h2 {
    color: #1a1a1a;
}

.btn-primary {
    background-color: #1a1a1a;
    border-color: #1a1a1a;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background-color: #333;
    border-color: #333;
}

.form-control {
    background-color: #fff;
    border: 1px solid #e0e0e0;
    color: #1a1a1a;
}

.form-control::placeholder {
    color: #999;
}

.form-control:focus {
    background-color: #fff;
    border-color: #1a1a1a;
}

.card {
    background-color: #fff;
    border: 1px solid #e8e8e8;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
    transition: all 0.3s ease;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.card-title {
    color: #1a1a1a;
    font-weight: bold;
}

.card-text {
    color: #555;
}

.text-muted {
    color: #999 !important;
}

.list-group-item {
    background-color: #fff;
    border-bottom: 1px solid #f0f0f0;
    color: #1a1a1a;
    transition: all 0.3s ease;
}

.list-group-item:hover {
    background-color: #fafafa;
}

.preview-toggle {
    cursor: pointer;
    transition: all 0.3s ease;
}

.preview-toggle:hover {
    color: #1a1a1a;
}

.preview-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease-out;
}

.preview-content.show {
    max-height: 500px;
}


.card-1, .card-2, .card-3, .card-4 {
    border-left: 3px solid #e8e8e8;
}

.card-1:hover {
    border-left-color: #1a1a1a;
}

.card-2:hover {
    border-left-color: #1a1a1a;
}

.card-3:hover {
    border-left-color: #1a1a1a;
}

.card-4:hover {
    border-left-color: #1a1a1a;
}

.preview-toggle {
    background: #f5f5f5;
    padding: 5px 10px;
    border-radius: 4px;
    display: inline-block;
}