:root {
    --main-bg-color: white;
    --main-box-shadow: rgba(0, 0, 0, 0.1);
    --main-border-radius: 8px;
    --heading-font-size: 2.5em;
    --paragraph-line-height: 1.6;
    --register-btn-bg-color: #3f8ce3;
    --register-btn-bg-hover-color: #71acd4;
    --register-btn-text-color: white;
}

main {
    padding: 2rem;
    max-width: 900px;
    margin: 0 auto;
    background: var(--main-bg-color);
    box-shadow: 0 2px 10px var(--main-box-shadow);
    border-radius: var(--main-border-radius);
}

main h1 {
    font-size: var(--heading-font-size);
    margin-bottom: 10px;
}

main p {
    line-height: var(--paragraph-line-height);
    margin: 15px 0;
}

/* Welcome Section */
.welcome-section {
    margin-bottom: 3rem;
}

.welcome-section p {
    color: #495057;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.registerBtn {
    display: inline-block;
    background-color: #0d6efd;
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: background-color 0.3s ease;
    margin-top: 1rem;
}

.registerBtn:hover {
    background-color: #0b5ed7;
    color: white;
    text-decoration: none;
}

/* Statistics Section */
.section-title {
    color: #212529;
    font-weight: 700;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid #e9ecef;
}

/* Statistics Cards */
.stat-card {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border: none;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    height: 100%;
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

.stat-card .card-body {
    padding: 1.5rem;
}

.stat-card .card-title {
    color: #495057;
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.stat-card .card-text {
    color: #212529;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.stat-card .card-text.small {
    color: #6c757d;
    font-size: 0.875rem;
    font-weight: 400;
}

/* Structure Distribution */
.structure-item {
    background: white;
    border-radius: 5px;
    padding: 0.75rem;
    margin-bottom: 0.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.structure-name {
    color: #495057;
    font-size: 0.875rem;
    font-weight: 500;
}

.structure-count {
    color: #0d6efd;
    font-size: 0.875rem;
    font-weight: 600;
    background: #e7f1ff;
    padding: 0.25rem 0.5rem;
    border-radius: 3px;
}

/* Main Content */
.display-4 {
    color: #212529;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.lead {
    color: #6c757d;
    font-size: 1.25rem;
}

/* About Card */
.card {
    border: none;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.card-body {
    padding: 2rem;
}

.card-title {
    color: #212529;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

.card-text {
    color: #495057;
    line-height: 1.6;
    margin-bottom: 1rem;
}

/* Register Button */
.btn-primary {
    background-color: #0d6efd;
    border: none;
    border-radius: 5px;
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    transition: background-color 0.3s ease;
}

.btn-primary:hover {
    background-color: #0b5ed7;
}