:root {
    --primary-blue: #1e88e5;
    --secondary-blue: #64b5f6;
    --dark-blue: #0d47a1;
    --light-blue: #bbdefb;
}

body {
    background-color: #f5f5f5;
    font-family: "Microsoft YaHei", sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.navbar {
    background-color: var(--primary-blue);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.navbar-brand {
    color: white !important;
    font-weight: bold;
}

.card {
    border: none;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    margin-bottom: 1rem;
}

.btn-primary {
    background-color: var(--primary-blue);
    border-color: var(--primary-blue);
}

.btn-primary:hover {
    background-color: var(--dark-blue);
    border-color: var(--dark-blue);
}

.message-card {
    border-left: 4px solid var(--primary-blue);
}

.private-message {
    border-left: 4px solid var(--secondary-blue);
}

.avatar-upload {
    position: relative;
    max-width: 200px;
    margin: 20px auto;
}

.avatar-preview {
    width: 192px;
    height: 192px;
    border-radius: 50%;
    overflow: hidden;
    border: 6px solid var(--light-blue);
}

.footer {
    margin-top: auto;
    background-color: #f8f9fa;
    padding: 1rem 0;
}

.notice-card {
    background-color: var(--light-blue);
    border-radius: 0.5rem;
    padding: 1rem;
    margin-bottom: 1rem;
}

.pagination .page-link {
    color: var(--primary-blue);
}

.pagination .active .page-link {
    background-color: var(--primary-blue);
    border-color: var(--primary-blue);
}

.table th {
    background-color: #f8f9fa;
}

.modal-header {
    background-color: var(--primary-blue);
    color: white;
}

.modal-header .btn-close {
    filter: brightness(0) invert(1);
}

.badge.bg-secondary {
    background-color: #5a6268 !important;
}

.badge.bg-orange {
    background-color: #ff6b00 !important;
    color: #fff !important;
}