:root {
    --primary-color: #4a8bf5;
    --primary-hover: #357ae8;
    --bg-light: #f5f7fa;
    --text-main: #333333;
    --text-muted: #666666;
    --border-color: #ebeef5;
    --border-radius: 8px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
    background-color: #f7f8fa;
    color: var(--text-main);
    line-height: 1.6;
}

a { text-decoration: none; color: inherit; }

.navbar {
    background-color: #ffffff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 15px;
}

.logo { font-size: 20px; font-weight: bold; color: var(--primary-color); display: flex; align-items: center; gap: 8px; }
.nav-links { display: flex; gap: 30px; }
.nav-links a { font-size: 16px; padding: 10px 0; border-bottom: 2px solid transparent; transition: all 0.3s; }
.nav-links a:hover, .nav-links a.active { color: var(--primary-color); border-bottom-color: var(--primary-color); }

.page-header {
    background: linear-gradient(135deg, #4a8bf5 0%, #2b68c9 100%);
    padding: 40px 20px;
    text-align: center;
    color: #fff;
}

.page-header h1 { font-size: 28px; margin-bottom: 10px; font-weight: 500; }
.page-header p { font-size: 15px; opacity: 0.9; }

.main-container {
    max-width: 1200px;
    margin: 40px auto;
    padding: 0 15px;
    min-height: 50vh;
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.faq-item {
    background-color: #fff;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 10px rgba(0,0,0,0.02);
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item:hover {
    border-color: #c6d9f9;
    box-shadow: 0 4px 12px rgba(74, 139, 245, 0.08);
}

.faq-question {
    padding: 20px;
    font-size: 16px;
    font-weight: 500;
    color: var(--text-main);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    user-select: none;
    background-color: #fff;
}

.faq-question:hover { color: var(--primary-color); }

.faq-icon {
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s ease;
    color: #999;
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
    color: var(--primary-color);
}

.faq-item.active .faq-question {
    color: var(--primary-color);
    border-bottom: 1px dashed var(--border-color);
}

.faq-answer-wrapper {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0, 1, 0, 1);
    background-color: #fafbfc;
}

.faq-item.active .faq-answer-wrapper {
    max-height: 1000px;
    transition: max-height 0.4s ease-in-out;
}

.faq-answer {
    padding: 20px;
    font-size: 15px;
    color: var(--text-muted);
    line-height: 1.8;
}

.highlight { color: #e6a23c; font-weight: bold; }

.footer { background: #333; color: #999; text-align: center; padding: 30px 20px; margin-top: 40px; font-size: 14px; }