/* General Styling / 基础样式 */
body {
    font-family: system-ui, -apple-system, sans-serif;
    background-color: #f4f4f9;
    color: #333;
    line-height: 1.6;
    padding: 2rem;
}

.container {
    max-width: 750px;
    margin: 0 auto;
}

/* THE LOGIC / 核心逻辑 */
.toggle-input {
    display: none; /* Hide the checkbox / 隐藏复选框 */
}

.expandable-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    position: relative;
}

/* Content Control / 内容控制 */
.more-text {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.5s cubic-bezier(0, 1, 0, 1), opacity 0.3s ease;
}

/* THE MAGIC: When checked, expand / 核心魔力：选中时展开 */
.toggle-input:checked ~ .content-body .more-text {
    max-height: 1000px; /* Large enough value / 足够大的数值 */
    opacity: 1;
    transition: max-height 0.5s cubic-bezier(1, 0, 1, 0), opacity 0.5s ease;
}

/* Button Styling / 按钮样式 */
.read-more-label {
    display: inline-block;
    margin-top: 15px;
    color: #2563eb;
    font-weight: 600;
    cursor: pointer;
    text-decoration: underline;
}

/* Dynamic Text via CSS / 通过 CSS 实现动态文字 */
.read-more-label::before {
    content: attr(data-more);
}

.toggle-input:checked ~ .read-more-label::before {
    content: attr(data-less);
}

/* Gradient Overlay / 渐变遮罩 (Optional visual polish) */
.content-body {
    position: relative;
}

.toggle-input:not(:checked) ~ .content-body::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 50px;
    background: linear-gradient(transparent, white);
}

/* SEO Explanation / SEO 说明板块 */
.seo-explanation {
    margin-top: 3rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    border-top: 2px solid #ddd;
    padding-top: 2rem;
}

@media (max-width: 600px) {
    .seo-explanation {
        grid-template-columns: 1fr;
    }
}

/* SEO Insight Box Styling / SEO 见解区块样式 */
.seo-insight-box {
    margin: 3rem 0;
    padding: 2.5rem;
    background: #ffffff;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}

.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;
    text-align: left;
}

.insight-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
}

.seo-insight-box article h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: #1e293b;
}

.seo-insight-box p {
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 1.2rem;
    color: #475569;
}

.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; }
}