/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: #333;
    line-height: 1.6;
    background: linear-gradient(135deg, #a1c4fd 0%, #c2e9fb 100%);
    background-attachment: fixed;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* 蓝天白云动态背景 */
.clouds {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
}

.cloud {
    position: absolute;
    background: #fff;
    border-radius: 50%;
    filter: blur(10px);
    opacity: 0.6;
    animation: float 20s infinite linear;
}

.cloud:nth-child(1) { width: 100px; height: 40px; top: 10%; left: -100px; animation-duration: 25s; }
.cloud:nth-child(2) { width: 150px; height: 60px; top: 30%; left: -150px; animation-duration: 35s; animation-delay: 5s; }
.cloud:nth-child(3) { width: 80px; height: 30px; top: 50%; left: -80px; animation-duration: 20s; animation-delay: 10s; }
.cloud:nth-child(4) { width: 200px; height: 80px; top: 70%; left: -200px; animation-duration: 45s; animation-delay: 15s; }

@keyframes float {
    0% { transform: translateX(0); }
    100% { transform: translateX(calc(100vw + 200px)); }
}

/* 导航栏 */
header {
    padding: 20px 0;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: #1e88e5;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo svg {
    width: 32px;
    height: 32px;
    fill: #1e88e5;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 100px 20px;
}

.hero h1 {
    font-size: 48px;
    color: #0d47a1;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(255,255,255,0.8);
}

.hero p {
    font-size: 20px;
    color: #424242;
    max-width: 600px;
    margin: 0 auto 40px;
}

.cta-button {
    display: inline-block;
    padding: 15px 40px;
    font-size: 20px;
    font-weight: bold;
    color: white;
    background: linear-gradient(45deg, #1e88e5, #42a5f5);
    border-radius: 50px;
    text-decoration: none;
    box-shadow: 0 4px 15px rgba(30, 136, 229, 0.4);
    transition: all 0.3s ease;
    animation: breathe 2s infinite alternate;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(30, 136, 229, 0.6);
}

@keyframes breathe {
    0% { transform: scale(1); box-shadow: 0 0 10px rgba(30, 136, 229, 0.4); }
    100% { transform: scale(1.05); box-shadow: 0 0 20px rgba(30, 136, 229, 0.8); }
}

/* 特性区 */
.features {
    padding: 60px 0;
}

.section-title {
    text-align: center;
    font-size: 32px;
    color: #0d47a1;
    margin-bottom: 40px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background: rgba(255, 255, 255, 0.9);
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card h3 {
    color: #1e88e5;
    margin-bottom: 15px;
}

/* 文章列表区 */
.articles-section {
    padding: 60px 0;
    background: rgba(255,255,255,0.5);
}

.article-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.article-item {
    background: #fff;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.article-item a {
    color: #333;
    text-decoration: none;
    font-weight: bold;
    font-size: 18px;
    display: block;
    margin-bottom: 10px;
    transition: color 0.3s;
}

.article-item a:hover {
    color: #1e88e5;
}

.article-item p {
    font-size: 14px;
    color: #666;
}

/* 文章详情页 */
.article-detail {
    background: rgba(255, 255, 255, 0.9);
    padding: 40px;
    border-radius: 15px;
    margin: 40px auto;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.article-detail h1 {
    color: #0d47a1;
    margin-bottom: 20px;
    border-bottom: 2px solid #e0e0e0;
    padding-bottom: 10px;
}

.article-detail h2 {
    color: #1e88e5;
    margin: 25px 0 15px;
}

.article-detail p {
    margin-bottom: 15px;
    font-size: 16px;
}

.article-detail a {
    color: #1e88e5;
    text-decoration: none;
}

.article-detail a:hover {
    text-decoration: underline;
}

/* 用户评价 */
.reviews {
    padding: 60px 0;
}

.review-slider {
    display: flex;
    overflow-x: auto;
    gap: 20px;
    padding-bottom: 20px;
    scrollbar-width: thin;
}

.review-card {
    min-width: 300px;
    background: #fff;
    padding: 20px;
    border-radius: 15px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
}

.reviewer {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
}

.avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: #e0e0e0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: #666;
}

.stars {
    color: #ffd700;
}

/* FAQ */
.faq {
    padding: 60px 0;
    background: rgba(255,255,255,0.5);
}

.faq-item {
    background: #fff;
    margin-bottom: 10px;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.faq-question {
    padding: 20px;
    cursor: pointer;
    font-weight: bold;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255,255,255,0.9);
}

.faq-question::after {
    content: '+';
    font-size: 20px;
    color: #1e88e5;
}

.faq-item.active .faq-question::after {
    content: '-';
}

.faq-answer {
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
    color: #555;
}

.faq-item.active .faq-answer {
    padding: 20px;
    max-height: 500px;
}

/* Footer */
footer {
    background: #0d47a1;
    color: #fff;
    padding: 40px 0 20px;
    text-align: center;
}

footer a {
    color: #90caf9;
    text-decoration: none;
    margin: 0 10px;
}

footer a:hover {
    color: #fff;
}

.footer-links {
    margin-bottom: 20px;
}

/* 定价区 */
.pricing {
    padding: 60px 0;
}
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    align-items: stretch;
}
.pricing-card {
    background: #1a1b26;
    color: #fff;
    padding: 40px 30px;
    border-radius: 12px;
    position: relative;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
    overflow: hidden;
    text-align: left;
    display: flex;
    flex-direction: column;
}
.pricing-card:hover {
    transform: translateY(-10px);
}
.pricing-card.recommended {
    border: 2px solid #8e2de2;
}
.ribbon {
    position: absolute;
    right: -30px;
    top: 20px;
    background: #a855f7;
    color: #fff;
    padding: 5px 40px;
    transform: rotate(45deg);
    font-size: 14px;
    font-weight: bold;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}
.pricing-card h3 {
    font-size: 18px;
    margin-bottom: 20px;
    color: #fff;
}
.pricing-card .price {
    font-size: 48px;
    font-weight: bold;
    margin-bottom: 30px;
}
.pricing-card .price span {
    font-size: 16px;
    font-weight: normal;
    color: #94a1b2;
}
.pricing-card ul {
    list-style: none;
    margin-bottom: 40px;
    flex-grow: 1;
}
.pricing-card ul li {
    margin-bottom: 15px;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: #a9b1d6;
}
.pricing-card ul li svg {
    width: 16px;
    height: 16px;
    fill: #0ea5e9;
    flex-shrink: 0;
}
.pricing-card .btn {
    display: block;
    width: 100%;
    text-align: center;
    padding: 15px;
    border-radius: 8px;
    font-weight: bold;
    text-decoration: none;
    transition: all 0.3s;
}
.pricing-card .btn-primary {
    background: linear-gradient(90deg, #8b5cf6, #0ea5e9);
    color: #fff;
}
.pricing-card .btn-primary:hover {
    opacity: 0.9;
    box-shadow: 0 5px 15px rgba(139, 92, 246, 0.4);
}
.pricing-card .btn-secondary {
    background: #2a2c3f;
    color: #fff;
}
.pricing-card .btn-secondary:hover {
    background: #363952;
}