/* ------------------------ 通用字体和颜色变量 ------------------------------------- */

    :root {

        --primary-color: #0f403f;

        --text-color-light: #ffffff;

    }



    body, h1, h2, h3, p, ul, li {

        margin: 0;

        padding: 0;

        box-sizing: border-box;

    }



    body {

        font-family: Arial, "Helvetica Neue", Helvetica, sans-serif;

        color: #333;

    }



    /* 容器居中与内边距 */

    .section-container {

        max-width: 1400px;

        margin: 0 auto;

        padding: 20px 20px;

    }



    /* ------------------------ 1. Banner 样式 ------------------------------------- */

    .banner-container {

        position: relative;

        width: 100%;

        min-height: 250px;

        color: #ffffff;

        overflow: hidden;

    }



    .banner-container::before {

        content: '';

        position: absolute;

        top: 0;

        left: 0;

        width: 100%;

        height: 100%;

        background-color: rgba(0, 0, 0, 0.2);

        z-index: 1;

        pointer-events: none;

    }



    .banner-image {

        display: block;

        width: 100%;

        height: auto;

        min-height: 250px;

        max-height: 600px;

        object-fit: cover;

        object-position: center;

    }



    .banner-text {

        position: absolute;

        top: 50%;

        left: 50%;

        transform: translate(-50%, -50%);

        z-index: 2;

        max-width: 95%;

        padding: 1rem 1%;

        text-align: center;

    }



    .banner-text h1 {

        color: #ffffff;

        font-size: clamp(28px, 2.5vw, 36px);

        font-weight: 700;

        line-height: 1.3;

    }



    /* ------------------------ 2. 核心内容结构 ------------------------------------- */

    .page-title {

        text-align: center;

        font-size: 28px !important;

        font-weight: 700;

        margin-bottom: 20px;

    }



    /* 四列图标区域 */

    .three-column-grid {

        display: flex;

        justify-content: center;

        gap: 30px;

        padding: 40px 0;

        margin-bottom: 30px;

        border-top: 1px solid #eee;

        border-bottom: 1px solid #eee;

        flex-wrap: wrap; /* 允许换行以容纳四个项目 */

    }



    .column-item {

        flex: 1;

        max-width: 25%; /* 调整为四列布局 */

        min-width: 200px; /* 防止在 PC 上太窄 */

        text-align: center;

    }



    .column-item img {

        width: 50px;

        height: 50px;

        margin-bottom: 10px;

    }



    .column-item h3 {

        font-size: 18px;

        font-weight: 700;

        margin-bottom: 10px;

        color: var(--primary-color);

    }



    .column-item p {

        font-size: 18px;

        line-height: 1.5;

        color: #999;

        text-align: left;

    }



    /* 内容图文混合部分 */

    .story-content-grid {

        display: flex;

        gap: 40px;

        align-items: center;

        padding: 30px 0;

    }



    .story-text-wrapper {

        flex: 1;

        max-width: 50%;

    }



    .story-image-wrapper {

        flex: 1;

        max-width: 50%;

        overflow: hidden;

    }



    .story-image {

        display: block;

        width: 100%;

        height: auto;

        object-fit: cover;

        border-radius: 8px;

    }



    .material-title {

        font-size: 28px !important;

        font-weight: 700;

        color: #333;

        margin-bottom: 20px;

    }



    .story-paragraph {

        font-size: 18px;

        line-height: 1.7;

        color: #666;

        margin-bottom: 20px;

    }



    /* 按钮样式 */

    .banner-btn {

        display: inline-block;

        padding: 10px 25px;

        font-size: 18px;

        font-weight: 600;

        text-align: center;

        text-decoration: none;

        border-radius: 4px;

        cursor: pointer;

        transition: background-color 0.3s ease, border-color 0.3s ease;

        line-height: 1.5;

        margin-top: 10px;

    }



    .banner-btn.btn-primary {

        background-color: var(--primary-color);

        color: var(--text-color-light);

        border: 2px solid var(--primary-color);

    }

    .banner-btn.btn-primary:hover {

        background-color: #0c3332;

        border-color: #0c3332;

    }



    /* RPET 生产流程图样式 */

    .process-flow-grid {

        display: flex;

        flex-wrap: wrap;

        justify-content: space-between;

        align-items: flex-start;

        gap: 10px;

        padding: 30px 0;

    }



    .process-step-item {

        flex: 0 0 calc(16.66% - 10px);

        max-width: calc(16.66% - 10px);

        text-align: center;

        position: relative;

        padding-bottom: 20px;

        box-sizing: border-box;

        display: flex;

        flex-direction: column;

        align-items: center;

    }



    .process-step-item img {

        width: 100%;

        max-width: 90%;

        height: auto;

        object-fit: cover;

        margin-bottom: 10px;

        border-radius: 4px;

        display: block;

        margin-left: auto;

        margin-right: auto;

    }



    .process-step-content {

        max-width: 190px;

        margin: 0 auto;

        text-align: left;

        padding: 0 5px;

    }



    .process-step-content h3 {

        font-size: 18px;

        font-weight: 700;

        color: var(--primary-color);

        margin-bottom: 5px;

    }



    .process-step-content p {

        font-size: 16px;

        line-height: 1.4;

        color: #666;

    }



    .process-step-arrow {

        position: absolute;

        top: 75px;

        right: -18px;

        transform: translateY(-50%);

        width: 25px;

        height: 25px;

        color: #999;

        display: flex;

        align-items: center;

        justify-content: center;

        z-index: 10;

    }

    .process-step-arrow svg {

        width: 100%;

        height: 100%;

        fill: currentColor;

    }



    .process-step-item:last-child .process-step-arrow {

        display: none;

    }



    /* RPET 产品展示样式 */

    .custom-capabilities-section {

        background-color: #f5f5f5;

        padding: 30px 10px;

        text-align: center;

    }



    .section-title {

        font-size: 28px;

        font-weight: bold;

        color: #333;

        margin-bottom: 40px;

    }



    .capabilities-container {

        display: flex;

        flex-wrap: wrap;

        justify-content: center;

        gap: 30px;

        max-width: 1200px;

        margin: 0 auto;

    }



    .capability-item {

        /* PC 端：每排 3 个 */

        width: calc((100% - 2 * 30px) / 3);

        max-width: 380px;

        background-color: #f5f5f5;

        padding: 0px;

        border-radius: 8px;

        text-align: left;

    }



    .capability-image {

        margin-bottom: 20px;

    }



    .capability-image img {

        width: 100%;

        height: auto;

        display: block;

        border-radius: 4px;

    }



    .capability-title {

        font-size: 18px;

        font-weight: bold;

        color: #333;

        margin-bottom: 10px;

    }



    .button-container {

        margin-top: 30px;

    }



    .custom-button {

        display: inline-block;

        padding: 12px 30px;

        background-color: #2a494a;

        color: #fff;

        text-decoration: none;

        border-radius: 5px;

        font-size: 16px;

        font-weight: 500;

        transition: background-color 0.3s ease;

        border: none;

        cursor: pointer;

    }



    .custom-button:hover {

        background-color: #3e6d6e;

    }



    /* 证书认证版块样式 */

    .certification-section {

        background-color: #ffffff;

        padding: 60px 20px;

        font-family: Arial, "Helvetica Neue", Helvetica, sans-serif;

        text-align: center;

    }



    .cert-grid {

        max-width: 1400px;

        margin: 0 auto;

        display: flex;

        flex-wrap: wrap;

        justify-content: space-between;

        gap: 30px;

    }



    .cert-item {

        /* PC 端：每行 4 个 */

        flex: 0 0 calc(25% - 22.5px);

        max-width: calc(25% - 22.5px);

        text-align: left;

    }



    .cert-image-wrapper {

        margin-bottom: 20px;

        border: 1px solid #e0e0e0;

        padding: 10px;

    }



    .cert-image {

        display: block;

        width: 100%;

        height: auto;

    }



    .cert-title {

        font-weight: bold;

        line-height: 1.4;

    }



    .cert-description {

        font-size: 14px;

        color: #7f8c8d;

        line-height: 1.6;

    }





    /* ------------------------ 3. 响应式设计 ------------------------------------- */



    @media (max-width: 900px) {

        .three-column-grid {

            /* 关键修改：使四个图标垂直堆叠，占据更宽空间 */

            flex-direction: column; 

            align-items: center; /* 居中对齐 */

            gap: 20px;

        }

        .column-item {

            /* 关键修改：移动端全宽，并限制最大宽度以保持可读性 */

            width: 100%; 

            flex: none;

            max-width: 400px; /* 限制最大宽度 */

        }



        .story-content-grid {

            flex-direction: column;

            gap: 25px;

            padding: 20px 0;

        }



        .story-text-wrapper, .story-image-wrapper {

            max-width: 100%;

            width: 100%;

        }



        /* 移动端流程图调整 */

        .process-flow-grid {

            flex-direction: column;

            align-items: center;

            gap: 20px;

        }



        .process-step-item {

            flex: 0 0 100%;

            max-width: 300px;

            display: flex;

            flex-direction: column;

            text-align: center;

            align-items: center;

            padding-bottom: 20px;

        }



        .process-step-item img {

            width: 100%;

            max-width: 100%;

            margin-bottom: 15px;

            margin-left: auto;

            margin-right: auto;

        }



        .process-step-content {

            text-align: center;

            max-width: 100%;

            margin: 0 auto;

            padding: 0;

        }



        .process-step-arrow {

            top: auto;

            bottom: 0px;

            left: 50%;

            right: auto;

            transform: translateX(-50%) rotate(90deg);

            width: 20px;

            height: 20px;

            color: var(--primary-color);

        }



        .process-flow-grid .process-step-item:last-child {

            padding-bottom: 0;

        }

    }



    @media (max-width: 768px) {

        .capabilities-container {

            flex-direction: column;

            gap: 20px;

            padding: 0 5px;

        }



        .capability-item {

            max-width: 100%;

            width: 100%;

        }



        /* 证书部分平板/手机布局 */

        .cert-item {

            flex: 0 0 calc(50% - 15px); /* 平板：两列 */

            max-width: calc(50% - 15px);

        }

    }



    @media (max-width: 600px) {

        .section-container {

            padding: 20px 5px;

        }

        .page-title {

            font-size: 24px;

            margin-bottom: 15px;

        }

        .story-paragraph {

            font-size: 16px;

        }

        .story-content-grid .banner-btn {

            display: block;

            width: 86%;

            text-align: center;

        }

        .cert-item {

            flex: 0 0 100%; /* 手机：一列 */

            max-width: 100%;

        }

    }



    /* PC 端流程图箭头保持水平 */

    @media (min-width: 901px) {

        .process-step-arrow {

            transform: translateY(-50%) rotate(0deg);

            right: -18px;

            color: #999;

            width: 25px;

            height: 25px;

            top: 105px;

        }

    }