/* General Setup / 基础设置 */
body {
    font-family: sans-serif;
    margin: 0;
    background-color: #f0f2f5;
    color: #1a1a1b;
}

/* Hidden Logic / 逻辑隐藏 */
.menu-state-hidden {
    display: none;
}

/* Header Styling / 头部样式 */
.site-header {
    background: #ffffff;
    padding: 1rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

/* Desktop Navigation / 桌面端导航 */
.nav-links {
    list-style: none;
    display: flex;
    gap: 2rem;
    margin: 0;
    padding: 0;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
}

/* Burger Icon Design / 汉堡图标设计 */
.burger-label {
    display: none; /* Hidden on desktop / 桌面端隐藏 */
    cursor: pointer;
    width: 30px;
    height: 20px;
    position: relative;
}

.burger-line, .burger-line::before, .burger-line::after {
    content: "";
    display: block;
    width: 100%;
    height: 3px;
    background: #333;
    position: absolute;
    transition: 0.3s;
}

.burger-line { top: 50%; transform: translateY(-50%); }
.burger-line::before { top: -8px; }
.burger-line::after { top: 8px; }

/* MOBILE STYLES / 移动端样式 */
@media (max-width: 768px) {
    .burger-label {
        display: block;
    }

    .mobile-nav {
        position: fixed;
        top: 60px; /* Header height */
        right: -100%; /* Off-canvas / 移出屏幕 */
        width: 250px;
        height: calc(100vh - 60px);
        background: #ffffff;
        box-shadow: -2px 0 5px rgba(0,0,0,0.1);
        transition: right 0.4s cubic-bezier(0.17, 0.67, 0.83, 0.67);
    }

    .nav-links {
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
    }

    /* THE MAGIC: If checkbox is checked, move menu into view */
    /* 核心逻辑：如果复选框被勾选，将菜单移入视野 */
    .menu-state-hidden:checked ~ .site-header .mobile-nav {
        right: 0;
    }

    /* Burger animation to 'X' / 汉堡图标变为“X” */
    .menu-state-hidden:checked ~ .site-header .burger-line {
        background: transparent;
    }
    .menu-state-hidden:checked ~ .site-header .burger-line::before {
        top: 0;
        transform: rotate(45deg);
    }
    .menu-state-hidden:checked ~ .site-header .burger-line::after {
        top: 0;
        transform: rotate(-45deg);
    }
}

/* Explanation UI / 说明界面 */
.explanation-container {
    padding: 2rem 5%;
    max-width: 900px;
    margin: auto;
}

.info-box {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    margin-top: 2rem;
}

.warning-text {
    background: #fff4e5;
    color: #663c00;
    padding: 1rem;
    border-left: 5px solid #ffa117;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

/* Explanation Block Styling / 说明板块样式 */
.responsiveness-explanation {
    margin-top: 40px;
    padding: 25px;
    background-color: #ffffff;
    border: 1px solid #e1e4e8;
    border-radius: 8px;
    border-left: 5px solid #2c3e50;
}

.explanation-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

.lang-block h3 {
    margin-top: 0;
    color: #2c3e50;
    font-size: 1.1rem;
}

.lang-block ul {
    padding-left: 20px;
    font-size: 0.9rem;
}

/* Responsive adjustment for the explanation text / 说明文字的响应式调整 */
@media (max-width: 600px) {
    .explanation-content {
        grid-template-columns: 1fr;
    }
}

/* SEO Insight Box Styling / SEO 见解区块样式 */
.seo-insight-box {
    max-width: 1000px;
    margin: 2rem auto;
    padding: 2rem;
    background: #ffffff;
    border-radius: 12px;
    border: 1px solid #e2e8f0; /* Matches your border-gray */
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.seo-insight-box h2 {
    color: #2563eb; /* Matches your accent-blue */
    font-size: 1.5rem;
    margin-top: 0;
    margin-bottom: 1.5rem;
    border-bottom: 2px solid #f1f5f9;
    padding-bottom: 0.5rem;
}

.insight-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.seo-insight-box article h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: #0f172a;
}

.seo-insight-box p {
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 1rem;
    color: #1e293b;
}

.seo-insight-box p[lang="zh"] {
    color: #64748b;
    font-size: 0.9rem;
    border-left: 3px solid #eff6ff;
    padding-left: 1rem;
}

@media (max-width: 768px) {
    .insight-grid { grid-template-columns: 1fr; }
}

/* Footer Styling */
.pattern-footer {
    max-width: 1000px;
    margin: 4rem auto;
    padding: 2rem 1rem;
    text-align: center;
}

.back-nav a {
    color: var(--accent-blue);
    text-decoration: none;
    font-weight: 600;
}

.corporate-links {
    margin-top: 2rem;
    font-size: 0.9rem;
    color: #64748b;
}

.corporate-links a {
    color: var(--accent-blue);
    text-decoration: none;
}

@media (max-width: 768px) {
    .insight-grid { grid-template-columns: 1fr; }
}