/* --- 全局样式与字体 --- */
:root {
    --primary-color: #4A90E2;
    --dark-color: #2c3e50;
    --light-color: #ffffff;
    --gray-color: #7f8c8d;
    --bg-color: #f7f9fc;
}

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;700;900&display=swap');

body {
    font-family: 'Inter', 'Helvetica Neue', 'Hiragino Sans GB', 'WenQuanYi Micro Hei', 'Microsoft YaHei', sans-serif;
    margin: 0;
    line-height: 1.7;
    color: var(--dark-color);
    background-color: var(--light-color);
    scroll-behavior: smooth;
}

/* --- 容器与布局 --- */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

section {
    padding: 80px 0;
}

/* --- 导航栏 --- */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    padding: 20px 0;
    z-index: 1000;
    transition: all 0.3s ease-in-out;
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.navbar.scrolled {
    padding: 15px 0;
}
.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.logo {
    font-size: 24px;
    font-weight: 900;
    color: var(--primary-color);
    text-decoration: none;
}
.nav-links {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 30px;
    align-items: center;
}
.nav-links a {
    text-decoration: none;
    color: var(--dark-color);
    font-weight: 500;
    transition: color 0.3s ease;
}
.nav-links a:hover {
    color: var(--primary-color);
}

/* --- 英雄区域 (Hero Section) --- */
.hero {
    background-color: var(--bg-color);
    text-align: center;
    padding-top: 140px;
}
.hero h1 {
    font-size: 48px;
    font-weight: 900;
    margin-bottom: 20px;
    line-height: 1.2;
}
.hero .slogan {
    font-size: 20px;
    color: var(--gray-color);
    margin-bottom: 40px;
}
.cta-button {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--light-color);
    padding: 15px 30px;
    font-size: 18px;
    font-weight: 700;
    border-radius: 50px;
    text-decoration: none;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.4);
}
.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.5);
}

/* --- 演示区域 --- */
.demo-gif-container {
    width: 100%;
    max-width: 800px;
    margin: 40px auto 0;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
    overflow: hidden;
    border: 1px solid #e0e0e0;
}
.demo-gif-container img,
.demo-gif-container video {
    width: 100%;
    display: block;
}

/* --- Section 标题 --- */
.section-title {
    text-align: center;
    font-size: 36px;
    font-weight: 900;
    margin-bottom: 60px;
}

/* --- 安装区域 --- */
#install {
    background-color: var(--bg-color);
}
.install-steps {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 40px;
}
.step {
    text-align: center;
    max-width: 300px;
}
.step-number {
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    color: var(--light-color);
    border-radius: 50%;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 20px;
}
.step p {
    font-size: 16px;
    color: var(--gray-color);
}
.bookmarklet-button {
    display: inline-block;
    padding: 12px 24px;
    background-color: #2ecc71;
    color: var(--light-color);
    border-radius: 8px;
    font-weight: 700;
    cursor: grab;
    user-select: none;
    border: 2px dashed #27ae60;
    transition: all 0.3s ease;
    animation: pulse 2s infinite;
    text-decoration: none;
}
.bookmarklet-button:hover {
    background-color: #27ae60;
    transform: scale(1.05);
}
@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(46, 204, 113, 0.7); }
    70% { box-shadow: 0 0 0 15px rgba(46, 204, 113, 0); }
    100% { box-shadow: 0 0 0 0 rgba(46, 204, 113, 0); }
}
.mobile-note {
    text-align: center;
    margin-top: 40px;
    font-size: 14px;
    color: var(--gray-color);
}

/* --- 通用卡片网格布局 --- */
.grid-layout {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}
.card {
    background-color: var(--light-color);
    padding: 30px;
    border-radius: 12px;
    text-align: left;
    box-shadow: 0 5px 25px rgba(0,0,0,0.07);
    transition: all 0.3s ease;
}
.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.1);
}
.card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 10px;
    margin-top: 0;
}
.card p {
    font-size: 15px;
    color: var(--gray-color);
}
.card h3 a {
    color: var(--dark-color);
    text-decoration: none;
}
.card h3 a:hover {
    color: var(--primary-color);
}
.read-more {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}
.read-more:hover {
    text-decoration: underline;
}

/* --- FAQ Section --- */
.faq-item {
    background-color: #fff;
    margin-bottom: 15px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.faq-question {
    width: 100%;
    background: none;
    border: none;
    padding: 20px;
    font-size: 18px;
    font-weight: 500;
    text-align: left;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.faq-answer {
    padding: 0 20px 20px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, padding 0.3s ease-out;
}
.faq-answer p {
    margin: 0;
    color: var(--gray-color);
    border-top: 1px solid #f0f0f0;
    padding-top: 15px;
}
.faq-item.active .faq-answer {
    max-height: 200px; /* Adjust as needed */
}
.faq-question .icon { transition: transform 0.3s ease; }
.faq-item.active .icon { transform: rotate(45deg); }

/* --- 页脚 --- */
.footer {
    background-color: var(--dark-color);
    color: #bdc3c7;
    text-align: center;
    padding: 40px 0;
}
.footer p { margin: 0; }
.footer a {
    color: #ffffff;
    text-decoration: none;
}
.footer a:hover {
    color: var(--primary-color);
}

@media (max-width: 768px) {
    .hero h1 { font-size: 36px; }
    .hero .slogan { font-size: 18px; }
    .section-title { font-size: 28px; }
    .install-steps { flex-direction: column; align-items: center; }
    .nav-links { display: none; } /* Hide nav links on mobile for simplicity */
}

/* --- AI Browser Advertisement Slide-in --- */
.ai-browser-ad {
    position: fixed;
    bottom: 20px;
    right: -400px;
    width: 350px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    z-index: 10000;
    transition: right 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    font-family: 'Inter', sans-serif;
}

.ai-browser-ad.show {
    right: 20px;
}

.ad-content {
    padding: 24px;
    position: relative;
    color: white;
}

.ad-close {
    position: absolute;
    top: 12px;
    right: 12px;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    font-size: 24px;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.3s ease;
    line-height: 1;
}

.ad-close:hover {
    background: rgba(255, 255, 255, 0.3);
}

.ad-header {
    display: flex;
    align-items: center;
    margin-bottom: 16px;
}

.ad-logo {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    margin-right: 12px;
    object-fit: cover;
}

.ad-badge {
    background: #ff6b6b;
    color: white;
    font-size: 12px;
    font-weight: 700;
    padding: 4px 8px;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.ad-title {
    font-size: 18px;
    font-weight: 700;
    margin: 0 0 8px 0;
    line-height: 1.3;
    color: white;
}

.ad-description {
    font-size: 14px;
    margin: 0 0 16px 0;
    opacity: 0.9;
    line-height: 1.4;
}

.ad-cta {
    display: inline-block;
    background: rgba(255, 255, 255, 0.95);
    color: #667eea;
    text-decoration: none;
    padding: 12px 20px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s ease;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.ad-cta:hover {
    background: white;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

/* Mobile responsiveness */
@media (max-width: 768px) {
    .ai-browser-ad {
        width: 300px;
        bottom: 15px;
        right: -320px;
    }

    .ai-browser-ad.show {
        right: 15px;
    }

    .ad-content {
        padding: 20px;
    }

    .ad-title {
        font-size: 16px;
    }

    .ad-description {
        font-size: 13px;
    }

    .ad-cta {
        padding: 10px 16px;
        font-size: 13px;
    }
}