/* Basic Reset & Typography */
:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --dark-bg: #212529;
    --white: #fff;
    --border-color: #dee2e6;
}

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    color: var(--text-color);
    background-color: var(--light-bg);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease, text-decoration 0.3s ease;
}

a:hover {
    color: #0056b3;
    text-decoration: underline;
}

ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 10px 20px;
    border-radius: 5px;
    font-weight: bold;
    text-align: center;
    cursor: pointer;
    border: none;
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

.btn-primary:hover {
    background-color: #0056b3;
}

.btn-secondary {
    background-color: var(--secondary-color);
    color: var(--white);
}

.btn-secondary:hover {
    background-color: #5a6268;
}

/* Header & Footer Common Styles */
.main-header, .main-footer {
    background-color: var(--dark-bg);
    color: var(--white);
}

.main-header .container, .main-footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.main-header .social-links a,
.main-footer .social-links a,
.footer-social-links a {
    color: var(--white);
    font-size: 1.2em;
    margin-left: 10px;
    transition: color 0.3s ease;
}

.main-header .social-links a:hover,
.main-footer .social-links a:hover,
.footer-social-links a:hover {
    color: var(--primary-color);
}

/* Utility Classes */
.row {
    display: flex;
    flex-wrap: wrap;
    margin: -15px; /* Compensate for padding in columns */
}

.col-md-2, .col-md-3, .col-md-6 {
    padding: 15px;
    box-sizing: border-box;
}

@media (min-width: 768px) {
    .col-md-2 { flex: 0 0 16.666667%; max-width: 16.666667%; }
    .col-md-3 { flex: 0 0 25%; max-width: 25%; }
    .col-md-6 { flex: 0 0 50%; max-width: 50%; }
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    border: 0;
}
/* 移动端内容区防溢出（系统追加，请勿删除） */
@media (max-width: 768px) {
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}