/* ===== 全局样式重置 ===== */
.main-content * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* 主色调 */
    --primary-color: #c60908;
    --primary-dark: #c0392b;
    --primary-light: #ec7063;

    /* 辅助色 */
    --secondary-color: #000;
    --secondary-dark: #333;

    /* 中性色 */
    --text-dark: #333;
    --text-medium: #555;
    --text-light: #7f8c8d;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --border-color: #e0e0e0;

    /* 功能色 */
    --warning-color: #f39c12;
    --success-color: #27ae60;

    /* 阴影 */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.2);

    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;

    /* 过渡 */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    /*font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;*/
    /*font-size: 16px;*/
    /*line-height: 1.7;*/
    /*color: var(--text-dark);*/
    background-color: var(--bg-light);
}

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

.flex-row { display: flex;   gap: 20px;   }
.flex-5{flex:5}
 
/* ===== 主内容区域 ===== */
.main-content {
    padding: 20px 0;
    min-height: 60vh;
}

.content-section {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    padding: 30px;
    margin-bottom: 30px;
    scroll-margin-top: 100px;
}

.section-title {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 25px;
    padding-bottom: 15px;
    border-bottom: 3px solid var(--primary-color);
    position: relative;
    line-height: 1.3;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 100px;
    height: 3px;
    background: var(--secondary-color);
}

.section-content {
    color: var(--text-medium);
}

.section-content p {
    margin-bottom: 10px;
}

.intro-text {
    font-size: 1.1rem;
    color: var(--text-dark);
    font-weight: 500;
}

/* ===== 子章节 ===== */
.subsection {
    margin-top: 30px;
    padding: 25px;
    background: var(--bg-light);
    border-radius: var(--radius-md);
    /*border-left: 4px solid var(--primary-color);*/
    /*border-left: 4px solid var(--primary-light);*/
}

.subsection h3 {
    font-size: 1.2rem;
    color: var(--text-dark);
    margin-bottom: 15px;
}

.subsection h4 {
    font-size: 1.15rem;
    color: var(--secondary-dark);
    margin: 20px 0 10px 0;
}

.subsection h5 {
    font-size: 1.1rem;
    color: #444;
    margin: 20px 0 10px 0;
}

/* ===== 视频区域 ===== */
.video-section {
    margin: 20px 0 0;
}

.video-section h3 {
    font-size: 1.2rem;
    color: var(--text-dark);
    margin-bottom: 15px;
}

.video-wrapper {
    position: relative;
    background: var(--text-dark);
    border-radius: var(--radius-md);
    overflow: hidden;
    aspect-ratio: 16 / 9;
    max-width: 800px;
}

.video-wrapper video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: none;
}

.video-wrapper video.has-source {
    display: block;
}

.video-placeholder {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    color: white;
    text-align: center;
    padding: 20px;
}

.placeholder-icon {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    margin-bottom: 20px;
    box-shadow: var(--shadow-lg);
    /*padding-left: 5px;*/
}

.video-placeholder p {
    margin: 5px 0;
}

.placeholder-hint {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-top: 10px;
}

/* ===== 图片画廊 ===== */
.image-gallery {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 25px;
    margin: 25px 0;
}

.image-gallery.single {
    grid-template-columns: 1fr;
    max-width: 700px;
}

.gallery-item {
    background: white;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition-normal);
}

.gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.gallery-item img {
    width: 100%;
    height: auto;
    display: block;
    aspect-ratio: 4 / 3;
    object-fit: contain;
}
.single-video img{
    aspect-ratio: 16 / 9;
    object-fit: contain;
}
.single-video .video-wrapper{
    border-radius: 0px;
}
.gallery-item figcaption {
    padding: 15px;
    font-size: 0.95rem;
    color: var(--text-medium);
    text-align: center;
    background: var(--bg-light);
    border-top: 1px solid var(--border-color);
}

/* ===== 信息卡片 ===== */
.info-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 25px 0;
}

.grid-3{
    grid-template-columns: repeat(3, 1fr);
}

.card {
    background: white;
    border-radius: var(--radius-md);
    padding: 20px;
    box-shadow: var(--shadow-sm);
    /*border-top: 4px solid var(--primary-color);*/
    border-top: 4px solid var(--primary-light);
}

.card h4 {
    font-size: 1.1rem;
    color: var(--secondary-dark);
    margin: 0px;
    margin-bottom: 10px;
}

.card p {
    font-size: 0.95rem;
    color: var(--text-medium);
    margin: 0;
}

/* ===== 应用场所网格 ===== */
.application-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin: 30px 0;
}

.grid-4{
    grid-template-columns: repeat(4, 1fr);
}

.application-item {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 25px 20px;
    border-radius: var(--radius-md);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition-normal);
}

.application-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.app-icon {
    font-size: 2.5rem;
    margin-bottom: 10px;
    line-height: 1.6;
}

.application-item span {
    font-size: 1rem;
    font-weight: 500;
}

.water-mist-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    /*min-height: 140px;*/
}

.grid-4 .application-item{
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    /*min-height: 140px;*/
}

.app-icon-wrapper {
    width: 48px;
    height: 48px;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.app-icon-svg {
    width: 100%;
    height: 100%;
    color: white;
    transition: var(--transition-normal);
}

/* ===== 响应式设计 ===== */

/* 平板设备 */
@media (max-width: 992px) {
     

    .content-section {
        padding: 30px 25px;
    }

    .section-title {
        /*font-size: .34rem;*/
    }

    .image-gallery {
        grid-template-columns: 1fr;
    }

    .application-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}
/*@media (max-width:1200px){*/
/*    .main-content{*/
/*        padding: 20px 0;*/
/*    }*/

/*    .content-section {*/
/*        padding: 25px 20px;*/
/*        margin-bottom: 25px;*/
/*    }*/

/*    .section-title {*/
/*        font-size: .34rem;*/
/*    }*/

/*    .subsection {*/
/*        padding: 20px 15px;*/
/*        margin-top: 20px;*/
/*    }*/
/*    .section-content{*/
/*        font-size:.26rem;*/
/*    }*/
/*    .subsection h3 {*/
/*        font-size: .26rem;*/
/*    }*/
/*    .subsection h4{*/
/*        font-size: .26rem;*/
/*    }*/
/*    .intro-text{*/
/*        font-size: .26rem;*/
/*    }*/
/*    .flex-row {*/
/*        gap: 0px;*/
/*        flex-direction: column;*/
/*    }*/
/*    .video-section h3{*/
/*        font-size: .26rem;*/
/*    }*/
/*    .placeholder-icon {*/
/*        width: 60px;*/
/*        height: 60px;*/
/*        font-size: .3rem;*/
/*    }*/
/*    .info-cards {*/
/*        grid-template-columns: 1fr;*/
/*    }*/
/*    .card h4{*/
/*        font-size: .26rem;*/
/*    }*/
/*    .card p{*/
/*        font-size: .25rem;*/
/*    }*/
    
/*    .gallery-item figcaption{*/
/*        font-size: .25rem;*/
/*    }*/
/*    .application-grid {*/
/*        grid-template-columns: repeat(2, 1fr);*/
/*        margin: 15px 0;*/
/*    }*/
/*    .application-item{*/
/*        padding: 15px 20px;*/
/*    }*/
/*    .application-item span{*/
/*        font-size: .25rem;*/
/*    }*/
/*    .app-icon{*/
/*        font-size: .5rem;*/
/*    }*/
/*}*/
/* 手机设备 */
@media (max-width: 768px) {
    .main-content{
        padding: 20px 0;
    }

    .content-section {
        padding: 25px 20px;
        margin-bottom: 25px;
    }

    .section-title {
        font-size: .34rem;
    }

    .subsection {
        padding: 20px 15px;
        margin-top: 20px;
    }
    .section-content{
        font-size:.26rem;
    }
    .subsection h3 {
        font-size: .26rem;
    }
    .subsection h4{
        font-size: .26rem;
    }
    .intro-text{
        font-size: .26rem;
    }
    .flex-row {
        gap: 0px;
        flex-direction: column;
    }
    .video-section h3{
        font-size: .26rem;
    }
    .placeholder-icon {
        width: 60px;
        height: 60px;
        font-size: .3rem;
    }
    .info-cards {
        grid-template-columns: 1fr;
    }
    .card h4{
        font-size: .26rem;
    }
    .card p{
        font-size: .25rem;
    }
    
    .gallery-item figcaption{
        font-size: .25rem;
    }
    .application-grid {
        grid-template-columns: repeat(2, 1fr);
        margin: 15px 0;
    }
    .application-item{
        padding: 15px 20px;
    }
    .application-item span{
        font-size: .25rem;
    }
    .app-icon{
        font-size: .5rem;
    }
}

/* 小屏手机 */
@media (max-width: 480px) {
     

    .content-section {
        padding: 20px 15px;
    }

    .section-title {
        font-size: .3rem;
        padding-bottom:10px;
        margin-bottom: 20px;
    }

    .subsection h3 {
        font-size: .26rem;
    }
    
    .video-wrapper {
        aspect-ratio: 16 / 10;
    }

    .placeholder-icon {
        width: 60px;
        height: 60px;
        font-size: .3rem;
    }
}

/* ===== 打印样式 ===== */
@media print {
    .main-header,
    .back-to-top,
    .video-placeholder {
        display: none;
    }

    .content-section {
        box-shadow: none;
        border: 1px solid var(--border-color);
    }

    .hero {
        background: var(--bg-light);
        color: var(--text-dark);
        padding: 60px 0 30px;
    }
}