/* 全局变量与重置 */
:root {
    --color-primary-dark: #164782;
    --color-primary: #2367b2;
    --color-accent-blue: #3482d8;
    --color-dark-bg: #192838;
    --color-text-dark: #222831;
    --color-text-light: #ffffff;
    --color-text-gray: #606873;
    --color-border-gray: #dee2e6;
    --container-max: 1260px;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Roboto', Arial, Helvetica, sans-serif;
    color: var(--color-text-dark);
    line-height: 1.55;
    overflow-x: hidden;
}
ul {
    list-style: none;
}
a {
    text-decoration: none;
    color: inherit;
}
img {
    max-width: 100%;
    display: block;
}
.container {
    width: 92%;
    max-width: var(--container-max);
    margin: 0 auto;
}
.text--blue {
    color: var(--color-accent-blue);
}
.section-head {
    text-align: center;
    margin-bottom: 48px;
}
.section-head h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--color-dark-bg);
    text-transform: uppercase;
}
.section-head__divider {
    width: 45px;
    height: 3px;
    background: var(--color-primary);
    display: block;
    margin: 10px auto 0;
}

/* 按钮 BEM 
.btn {
    display: inline-block;
    padding: 11px 22px;
    border-radius: 2px;
    font-weight: 600;
    font-size: 14px;
    text-transform: uppercase;
    border: none;
    cursor: pointer;
    transition: all 0.25s ease;
}
.btn--primary {
    background-color: var(--color-primary);
    color: #fff;
}
.btn--primary:hover {
    background-color: var(--color-primary-dark);
}
.btn--outline {
    background: transparent;
    color: var(--color-primary-dark);
    border: 2px solid var(--color-primary);
}
.btn--outline:hover {
    background: var(--color-primary);
    color: white;
}
.btn--full {
    width: 100%;
}

*/


/* header 头部模块 *
.header {
    background: #fff;
    box-shadow: 0 1px 4px rgba(0,0,0,0.08);
    position: sticky;
    top: 0;
    z-index: 999;
}
.header__inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 0;
}
.header__logo {
    display: flex;
    align-items: center;
    gap: 10px;
}
.header__logo-icon {
    font-size: 28px;
    color: var(--color-primary-dark);
}
.header__logo-text strong {
    display: block;
    font-size: 18px;
    letter-spacing: 0.5px;
    color: var(--color-dark-bg);
}
.header__logo-text span {
    font-size: 11px;
    letter-spacing: 1px;
    color: var(--color-text-gray);
}
.header__nav {
    display: flex;
    align-items: center;
    gap: 28px;
}
.header__menu {
    display: flex;
    gap: 26px;
}
.header__menu-link {
    font-size: 14px;
    font-weight: 500;
    text-transform: uppercase;
    color: var(--color-dark-bg);
}
.header__menu-link--active {
    color: var(--color-primary);
}
.header__mobile-btn {
    display: none;
    border: none;
    background: none;
    font-size: 24px;
}

*/








/* Hero模块 */
.hero {
    position: relative;
    min-height: 620px;
    display: flex;
    align-items: center;
    color: white;
}
.hero__bg {
    position: absolute;
    inset: 0;
    background: url("../images/banner.jpg") center center / cover no-repeat;
}
.hero__bg::after {
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.42);
}
.hero__content {
    position: relative;
    z-index: 2;
}
.hero__text h1 {
    font-size: 42px;
    line-height: 1.2;
    margin-bottom: 20px;
}
.hero__text p {
    font-size: 16px;
    max-width: 520px;
    margin-bottom: 30px;
}
.hero__btns {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}
.hero__dots {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 2;
}
.hero__dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255,255,255,0.45);
}
.hero__dot--active {
    background: #ffffff;
}

/* Feature特性栏 */
.feature {
    background: var(--color-dark-bg);
    color: #fff;
    padding: 36px 0;
}
.feature__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.feature__item {
    display: flex;
    gap: 14px;
}
.feature__icon {
    font-size: 32px;
    margin-top: 4px;
}
.feature__desc h4 {
    font-size: 14px;
    margin-bottom: 6px;
    text-transform: uppercase;
}
.feature__desc p {
    font-size: 13px;
    color: #c7cfd8;
}

/* 应用场景 app-section */
.app-section {
    padding: 64px 0;
    background: #f8f9fa;
}
.app-section__grid {
    display: grid;
    grid-template-columns: repeat(5,1fr);
    gap: 20px;
}
.app-card {
    background: #fff;
    border-radius: 4px;
    overflow: hidden;
    position: relative;
    box-shadow: 0 2px 8px rgba(0,0,0,0.07);
}
.app-card__img img {
    width: 100%;
    height: 180px;
    object-fit: cover;
}
.app-card__circle-icon {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    background: var(--color-primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    position: absolute;
    top: 150px;
    left: 50%;
    transform: translateX(-50%);
    border: 4px solid white;
}
.app-card__body {
    padding: 34px 14px 20px;
    text-align: center;
}
.app-card__body h4 {
    font-size: 15px;
    text-transform: uppercase;
    margin-bottom: 10px;
}
.app-card__body p {
    font-size: 13px;
    color: var(--color-text-gray);
    margin-bottom: 12px;
}
.app-card__link {
    font-size: 12px;
    color: var(--color-primary);
    font-weight: 600;
    text-transform: uppercase;
}

/* advantage-section优势 */
.advantage-section {
    padding: 60px 0;
}
.advantage-section__grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 22px;
    text-align: center;
}
.advantage-item__icon {
    font-size: 34px;
    color: var(--color-primary);
    margin-bottom: 12px;
}
.advantage-item h4 {
    font-size: 14px;
    text-transform: uppercase;
    margin-bottom: 8px;
}
.advantage-item p {
    font-size: 13px;
    color: var(--color-text-gray);
}

/* cta-section联系区块 */
.cta-section {
    padding: 64px 0;
    background: var(--color-dark-bg);
    color: white;
    background-image: linear-gradient(rgba(25,40,56,0.88), rgba(25,40,56,0.88)), url("https://picsum.photos/id/1043/1920/800");
    background-size: cover;
    background-position: center;
}
.cta-section__wrap {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: start;
}
.cta-section__text h2 {
    font-size: 32px;
    line-height: 1.3;
    margin-bottom: 16px;
}
.cta-section__text p {
    margin-bottom: 26px;
    color: #c8d1db;
}
.cta-form {
    display: flex;
    flex-direction: column;
    gap: 14px;
}
.cta-form__row--2col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap:14px;
}
.cta-form__field input,
.cta-form__field textarea {
    width: 100%;
    padding:11px 14px;
    border: none;
    border-radius: 2px;
    font-size:14px;
}
.cta-form__field textarea {
    resize: vertical;
}

/* footer页脚 */
.footer {
    background:#0f1a26;
    color:#b8c2cc;
    padding:50px 0 24px;
}
.footer__inner {
    display: grid;
    grid-template-columns:2.2fr repeat(3,1fr);
    gap:32px;
    margin-bottom:36px;
}
.footer__logo {
    display:flex;
    align-items:center;
    gap:10px;
    margin-bottom:14px;
}
.footer__logo-icon {
    font-size:28px;
    color: var(--color-primary-dark);
}
.footer__logo-text strong {
    display:block;
    font-size:18px;
    color:#fff;
}
.footer__logo-text span {
    font-size:11px;
    color:#b8c2cc;
}
.footer__col h4 {
    color:#fff;
    font-size:16px;
    margin-bottom:16px;
    text-transform:uppercase;
}
.footer__list-item {
    margin-bottom:8px;
    font-size:14px;
}
.footer__list-item a:hover {
    color:var(--color-accent-blue);
}
.footer__bottom {
    border-top:1px solid #283849;
    padding-top:18px;
    font-size:13px;
}

/* 响应式 */
@media(max-width:1100px) {
    .app-section__grid {
        grid-template-columns: repeat(3,1fr);
    }
    .advantage-section__grid {
        grid-template-columns: repeat(3,1fr);
    }
}
@media(max-width:920px) {
    .header__menu {
        display: none;
    }
    .header__mobile-btn {
        display:block;
    }
    .feature__grid {
        grid-template-columns: repeat(2,1fr);
    }
    .cta-section__wrap {
        grid-template-columns: 1fr;
    }
    .footer__inner {
        grid-template-columns: repeat(2,1fr);
    }
}
@media(max-width:640px) {
    .hero__text h1 {
        font-size:30px;
    }
    .app-section__grid {
        grid-template-columns: 1fr;
    }
    .advantage-section__grid {
        grid-template-columns: 1fr;
    }
    .feature__grid {
        grid-template-columns: 1fr;
    }
    .cta-form__row--2col {
        grid-template-columns: 1fr;
    }
    .footer__inner {
        grid-template-columns: 1fr;
    }
    .hero {
        min-height:500px;
    }
}