/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #000000;
    --secondary-color: #333333;
    --text-color: #666666;
    --light-gray: #f5f5f5;
    --border-color: #e0e0e0;
    --white: #ffffff;
    --link-color: #0066cc;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    line-height: 1.8;
    color: var(--primary-color);
    background-color: var(--white);
    font-size: 16px;
}

.container {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 60px;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--white);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 60px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.nav-brand {
    font-size: 18px;
    font-weight: normal;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    color: var(--secondary-color);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: var(--link-color);
}

/* 首屏 */
.hero {
    position: relative;
    min-height: 400px;
    display: flex;
    align-items: center;
    overflow: hidden;
    background-color: var(--white);
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    cursor: pointer;
}

.hero-background img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    object-position: center;
    background-color: #ffffff;
    pointer-events: auto;
}

.hero-overlay {
    position: relative;
    z-index: 2;
    width: 100%;
    background: transparent;
    padding: 60px 0;
    transform: translateY(-32px);
    pointer-events: none;
}

.hero-overlay .container {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    pointer-events: none;
}

.hero-content {
    max-width: 700px;
    text-align: left;
    padding-left: 180px;
    pointer-events: auto;
}

.hero-title {
    font-size: 64px;
    font-weight: 700;
    margin-bottom: 20px;
    letter-spacing: -1px;
    color: var(--white);
    text-shadow: 2px 2px 8px rgba(0, 0, 0, 0.8);
}

.hero-subtitle {
    font-size: 28px;
    color: var(--white);
    margin-bottom: 30px;
    font-weight: 400;
    text-shadow: 1px 1px 6px rgba(0, 0, 0, 0.8);
}

.hero-description {
    font-size: 18px;
    color: var(--white);
    line-height: 2;
    margin-bottom: 40px;
    text-shadow: 1px 1px 6px rgba(0, 0, 0, 0.8);
}

.hero-cta {
    margin-top: 40px;
}

/* 白色按钮样式 */
.btn-primary-white {
    display: inline-block;
    padding: 14px 40px;
    text-decoration: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s ease;
    background-color: var(--white);
    color: var(--primary-color);
    border: 2px solid var(--white);
}

.btn-primary-white:hover {
    background-color: transparent;
    color: var(--white);
    border-color: var(--white);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(255, 255, 255, 0.3);
}

/* 按钮样式 */
.btn-primary,
.btn-secondary {
    display: inline-block;
    padding: 14px 40px;
    text-decoration: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background-color: var(--primary-color);
    color: var(--white);
}

.btn-primary:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
    background-color: var(--white);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: var(--white);
}

/* 分隔线 */
.divider {
    height: 1px;
    background-color: var(--border-color);
    max-width: 1500px;
    margin: 0 auto;
}

/* 功能模块 */
.features {
    background-color: var(--white);
}

.feature-item {
    padding: 80px 0;
}

/* 白色背景 */
.feature-item.bg-white {
    background-color: var(--white);
}

/* 黑色渐变背景 */
.feature-item.bg-black {
    background: linear-gradient(to right, rgba(0, 0, 0, 0.7) 0%, rgba(0, 0, 0, 0.4) 60%, transparent 100%);
}

.feature-item.bg-black .feature-title {
    color: var(--white);
}

.feature-item.bg-black .feature-description {
    color: #cccccc;
}

/* 淡蓝色渐变背景 */
.feature-item.bg-blue {
    background: linear-gradient(to right, rgba(173, 216, 230, 0.8) 0%, rgba(173, 216, 230, 0.5) 60%, rgba(173, 216, 230, 0.2) 100%);
}

.feature-item.bg-blue .feature-title {
    color: var(--primary-color);
}

.feature-item.bg-blue .feature-description {
    color: var(--secondary-color);
}

/* 淡黄色渐变背景 */
.feature-item.bg-yellow {
    background: linear-gradient(to right, rgba(255, 250, 205, 0.9) 0%, rgba(255, 250, 205, 0.6) 60%, rgba(255, 250, 205, 0.3) 100%);
}

.feature-item.bg-yellow .feature-title {
    color: var(--primary-color);
}

.feature-item.bg-yellow .feature-description {
    color: var(--secondary-color);
}

.feature-item .container {
    display: flex;
    align-items: stretch;
    gap: 80px;
}

.feature-content {
    flex: 0 0 calc(66.67% / 2.5);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.feature-content.center {
    text-align: center;
    margin: 0 auto;
}

.feature-title {
    font-size: 36px;
    font-weight: 600;
    margin-bottom: 30px;
    color: var(--primary-color);
}

.feature-description {
    font-size: 16px;
    color: var(--text-color);
    line-height: 2;
}

.feature-image {
    flex: 1;
    overflow: hidden;
    display: flex;
    align-items: center;
}

.feature-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
    transition: transform 0.3s ease;
}

.feature-image:hover img {
    transform: scale(1.02);
}

.more-features {
    padding: 100px 0;
}

.more-features .container {
    display: block;
    text-align: center;
}

/* 全屏背景功能模块 */
.feature-fullscreen {
    position: relative;
    min-height: 500px;
    display: flex;
    align-items: center;
    overflow: hidden;
    padding: 0 !important;
}

.feature-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.feature-background img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.feature-overlay {
    position: relative;
    z-index: 2;
    width: 100%;
    background: linear-gradient(to right, rgba(255, 255, 255, 0.95) 0%, rgba(255, 255, 255, 0.85) 50%, rgba(255, 255, 255, 0.5) 100%);
    padding: 80px 0;
}

.feature-fullscreen .feature-content {
    max-width: 700px;
}

.feature-fullscreen .feature-title {
    color: var(--primary-color);
    text-shadow: 1px 1px 3px rgba(255, 255, 255, 0.8);
}

.feature-fullscreen .feature-description {
    color: var(--secondary-color);
    text-shadow: 1px 1px 2px rgba(255, 255, 255, 0.8);
}

/* 下载区域 */
.download {
    padding: 100px 0;
    text-align: center;
}

.section-title {
    font-size: 42px;
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.section-subtitle {
    font-size: 18px;
    color: var(--text-color);
    margin-bottom: 60px;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
    max-width: 700px;
    margin: 0 auto;
}

.download-single {
    max-width: 500px;
    margin: 0 auto;
}

.download-item {
    padding: 40px 30px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.download-item:hover {
    border-color: var(--primary-color);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
    transform: translateY(-4px);
}

.download-item h3 {
    font-size: 24px;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.download-item p {
    font-size: 14px;
    color: var(--text-color);
    margin-bottom: 25px;
}

/* 关于我们 */
.about {
    padding: 100px 0;
    text-align: center;
}

.about-text {
    font-size: 16px;
    color: var(--text-color);
    line-height: 2.2;
    max-width: 700px;
    margin: 30px auto 0;
}

/* 页脚 */
.footer {
    padding: 40px 0;
    text-align: center;
    background-color: var(--light-gray);
    margin-top: 60px;
}

.footer p {
    font-size: 14px;
    color: var(--text-color);
    margin: 5px 0;
}

.footer a {
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer a:hover {
    color: var(--link-color);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container,
    .nav-container {
        padding: 0 20px;
    }

    .nav-brand {
        font-size: 16px;
    }

    .nav-links {
        gap: 15px;
    }

    .nav-links a {
        font-size: 13px;
    }

    .hero {
        min-height: 270px;
    }

    .hero-overlay {
        padding: 30px 0;
        background: transparent;
    }

    .hero-content {
        text-align: center;
        max-width: 100%;
        padding-left: 20px;
        padding-right: 20px;
    }

    .hero-title {
        font-size: 36px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

    .hero-description {
        font-size: 14px;
    }

    .feature-item {
        padding: 60px 0;
    }

    .feature-item .container {
        flex-direction: column !important;
        gap: 40px;
    }

    .feature-fullscreen {
        min-height: 400px;
    }

    .feature-overlay {
        padding: 60px 0;
        background: rgba(255, 255, 255, 0.9);
    }

    .feature-fullscreen .feature-content {
        text-align: center;
        max-width: 100%;
    }

    .feature-title {
        font-size: 28px;
    }

    .feature-description {
        font-size: 14px;
    }

    .section-title {
        font-size: 32px;
    }

    .section-subtitle {
        font-size: 16px;
    }

    .download-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .download-item {
        padding: 30px 20px;
    }

    .about-text {
        font-size: 14px;
    }
}

@media (max-width: 480px) {
    .hero {
        min-height: 400px;
    }

    .hero-title {
        font-size: 28px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

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

    .feature-title {
        font-size: 24px;
    }

    .section-title {
        font-size: 26px;
    }

    .nav-links {
        gap: 10px;
    }

    .nav-links a {
        font-size: 12px;
    }
}

/* 图片浏览弹窗 */
.modal {
    display: none;
    position: fixed;
    z-index: 9999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.9);
    animation: fadeIn 0.3s ease;
}

.modal-content {
    display: block;
    max-width: 90%;
    max-height: 90%;
    margin: auto;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: zoomIn 0.3s ease;
}

.modal-close {
    position: absolute;
    top: 30px;
    right: 50px;
    color: #fff;
    font-size: 50px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s ease;
    z-index: 10000;
}

.modal-close:hover {
    color: #ccc;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes zoomIn {
    from { transform: translate(-50%, -50%) scale(0.8); }
    to { transform: translate(-50%, -50%) scale(1); }
}

/* 图片可点击样式 */
.feature-image img,
.hero-background img {
    cursor: pointer;
}

.feature-image img:hover {
    opacity: 0.9;
}

/* 滚动动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-item {
    animation: fadeInUp 0.6s ease-out;
}