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

:root {
    --page: #f4f6fb;
    --surface: #ffffff;
    --ink: #182238;
    --muted: #6b778c;
    --accent: #5b5ce2;
    --accent-dark: #4648bd;
    --hero: #10182c;
    --line: #dbe2ee;
    --shadow: 0 18px 48px rgba(18, 28, 52, 0.1);
    --shadow-hover: 0 24px 56px rgba(18, 28, 52, 0.16);
    --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
    line-height: 1.6;
    color: var(--ink);
    background-color: var(--page);
}

.container {
    width: min(1180px, calc(100% - 48px));
    margin: 0 auto;
}

a {
    text-decoration: none;
    color: var(--ink);
    transition: color 160ms var(--ease), background-color 160ms var(--ease), border-color 160ms var(--ease), transform 160ms var(--ease), box-shadow 160ms var(--ease);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

.btn {
    display: inline-block;
    background-color: var(--accent);
    color: #fff;
    padding: 12px 22px;
    border: 1px solid transparent;
    border-radius: 10px;
    font-weight: 600;
    letter-spacing: 0.2px;
    transition: background-color 160ms var(--ease), transform 160ms var(--ease), box-shadow 160ms var(--ease);
}

.btn:hover {
    background-color: var(--accent-dark);
    transform: translateY(-2px);
    box-shadow: 0 12px 24px rgba(91, 92, 226, 0.24);
}

.section-title {
    text-align: left;
    margin-bottom: 32px;
}

.section-title h2 {
    font-size: clamp(1.8rem, 3.4vw, 2.5rem);
    font-weight: 700;
    letter-spacing: -0.04em;
    margin-bottom: 14px;
    position: relative;
    display: block;
}

.underline {
    height: 4px;
    width: 48px;
    background-color: var(--accent);
    border-radius: 999px;
}

/* 头部导航 */
header {
    background-color: rgba(255, 255, 255, 0.92);
    border-bottom: 1px solid rgba(219, 226, 238, 0.9);
    box-shadow: 0 8px 24px rgba(18, 28, 52, 0.06);
    backdrop-filter: blur(14px);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    min-height: 76px;
}

.logo h1 {
    font-size: 20px;
    font-weight: 700;
    color: var(--ink);
    letter-spacing: -0.03em;
}

nav ul {
    display: flex;
}

nav ul li {
    margin-left: 28px;
}

nav ul li a {
    font-size: 16px;
    color: var(--muted);
    font-weight: 600;
    padding: 8px 0;
    position: relative;
}

nav ul li a:hover,
nav ul li a.active {
    color: var(--ink);
}

nav ul li a:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent);
    transition: width 0.3s ease;
}

nav ul li a:hover:after,
nav ul li a.active:after {
    width: 100%;
}

.mobile-menu-btn {
    display: none;
    cursor: pointer;
    font-size: 24px;
    color: var(--ink);
}

/* 轮播图 */
.banner {
    height: min(680px, calc(100svh - 76px));
    min-height: 560px;
    position: relative;
    overflow: hidden;
    margin-top: 76px;
    background-color: var(--hero);
}

.slider {
    height: 100%;
    position: relative;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 700ms var(--ease);
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    display: flex;
    align-items: flex-end;
    justify-content: flex-start;
    text-align: left;
    padding: 72px max(24px, calc((100vw - 1180px) / 2)) 84px;
}

.slide:nth-child(1) {
    background-image: linear-gradient(90deg, rgba(16, 24, 44, 0.9) 0%, rgba(16, 24, 44, 0.58) 44%, rgba(16, 24, 44, 0.16) 100%), url('../images/banner1.jpg');
}

.slide:nth-child(2) {
    background-image: linear-gradient(90deg, rgba(16, 24, 44, 0.9) 0%, rgba(16, 24, 44, 0.58) 44%, rgba(16, 24, 44, 0.16) 100%), url('../images/banner2.jpg');
}

.slide.current {
    opacity: 1;
}

.slide .content {
    width: min(680px, 100%);
    background-color: rgba(16, 24, 44, 0.72);
    padding: clamp(28px, 4vw, 48px);
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: 20px;
    text-align: left;
    box-shadow: 0 24px 64px rgba(4, 9, 24, 0.28);
    backdrop-filter: blur(10px);
    transform: translateY(20px);
    opacity: 0;
    animation: slideUp 700ms var(--ease) 180ms forwards;
}

@keyframes slideUp {
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.slide .content h2 {
    font-size: clamp(2.3rem, 6vw, 4.8rem);
    line-height: 1.08;
    margin-bottom: 20px;
    color: #fff;
    letter-spacing: -0.06em;
}

.slide .content p {
    max-width: 560px;
    color: rgba(255, 255, 255, 0.78);
    font-size: 17px;
    line-height: 1.9;
    margin-bottom: 28px;
}

.controls {
    position: absolute;
    top: 50%;
    width: 100%;
    display: flex;
    justify-content: space-between;
    padding: 0 max(24px, calc((100vw - 1280px) / 2));
    transform: translateY(-50%);
    pointer-events: none;
}

.controls button {
    width: 44px;
    height: 44px;
    background-color: rgba(255, 255, 255, 0.12);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.32);
    cursor: pointer;
    padding: 0;
    border-radius: 50%;
    font-size: 18px;
    transition: background-color 160ms var(--ease), transform 160ms var(--ease);
    pointer-events: auto;
}

.controls button:hover {
    background-color: rgba(255, 255, 255, 0.24);
    transform: scale(1.06);
}

/* 公司简介 */
.about-preview {
    padding: clamp(80px, 10vw, 128px) 0;
    background-color: var(--page);
}

.about-content {
    display: grid;
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: clamp(32px, 6vw, 88px);
    align-items: center;
}

.about-text {
    max-width: 620px;
}

.about-text p {
    color: var(--muted);
    font-size: 17px;
    line-height: 1.9;
    margin-bottom: 28px;
}

.about-image {
    min-width: 0;
}

.about-image img {
    display: block;
    width: 100%;
    aspect-ratio: 4 / 3;
    object-fit: cover;
    border: 1px solid var(--line);
    border-radius: 22px;
    box-shadow: var(--shadow);
    max-width: 100%;
    transition: transform 280ms var(--ease), box-shadow 280ms var(--ease);
}

.about-image img:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

/* 关于我们页 */
.about-section {
    min-height: calc(100vh - 76px);
    padding: 148px 0 104px;
    background-color: var(--page);
}

.about-full {
    max-width: 880px;
    margin: 0 auto;
    padding: clamp(32px, 5vw, 56px);
    background-color: var(--surface);
    border: 1px solid var(--line);
    border-radius: 22px;
    box-shadow: var(--shadow);
}

.about-full p {
    color: var(--muted);
    font-size: 17px;
    line-height: 2;
    margin-bottom: 26px;
}

.about-full p:last-child {
    margin-bottom: 0;
}

/* 我们的优势 */
.advantages {
    padding: 80px 0;
    background-color: #f9f9f9;
}

.advantage-items {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}

.advantage-item {
    flex-basis: calc(25% - 30px);
    background-color: #fff;
    padding: 30px 20px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    margin-bottom: 30px;
}

.advantage-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.advantage-item .icon {
    font-size: 40px;
    color: #1e88e5;
    margin-bottom: 20px;
}

.advantage-item h3 {
    font-size: 20px;
    margin-bottom: 15px;
}

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

/* 底部信息 */
footer {
    background-color: var(--hero);
    color: #fff;
    padding: 72px 0 24px;
}

.footer-content {
    display: grid;
    grid-template-columns: minmax(0, 1.35fr) repeat(2, minmax(0, 0.72fr));
    gap: 48px;
    margin-bottom: 56px;
}

.footer-logo h2 {
    font-size: 22px;
    margin-bottom: 14px;
    color: #fff;
    letter-spacing: -0.03em;
}

.footer-logo p {
    font-size: 14px;
    line-height: 1.9;
    color: rgba(255, 255, 255, 0.62);
}

.footer-contact h3 {
    font-size: 18px;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
}

.footer-contact h3:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background-color: var(--accent);
}

.footer-contact p {
    margin-bottom: 10px;
    color: rgba(255, 255, 255, 0.64);
}

.footer-contact p i {
    margin-right: 10px;
    color: #8b8cf2;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
}

.icp {
    margin-left: 10px;
}

/* 响应式设计 */
@media screen and (max-width: 992px) {
    .advantage-item {
        flex-basis: calc(50% - 20px);
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .about-text {
        max-width: none;
    }

    .about-image {
        max-width: 720px;
    }
}

@media screen and (max-width: 768px) {
    .container {
        width: calc(100% - 32px);
    }

    .mobile-menu-btn {
        display: block;
    }

    nav {
        position: absolute;
        top: 76px;
        left: 0;
        width: 100%;
        background-color: rgba(255, 255, 255, 0.98);
        border-bottom: 1px solid var(--line);
        box-shadow: 0 12px 24px rgba(18, 28, 52, 0.08);
        padding: 0;
        max-height: 0;
        overflow: hidden;
        transition: max-height 260ms var(--ease);
    }

    nav.active {
        max-height: 300px;
    }

    nav ul {
        flex-direction: column;
        padding: 20px 0;
    }

    nav ul li {
        margin: 0;
        text-align: center;
    }

    nav ul li a {
        display: block;
        padding: 10px;
    }

    .banner {
        height: min(620px, calc(100svh - 76px));
        min-height: 520px;
        margin-top: 76px;
    }

    .slide {
        padding: 32px 24px 48px;
    }

    .slide .content {
        padding: 24px;
        border-radius: 16px;
    }

    .about-section {
        padding: 120px 0 72px;
    }

    .about-full {
        padding: 28px 22px;
    }

    .about-full p {
        font-size: 15px;
        line-height: 1.9;
    }

    .slide .content {
        padding: 20px;
    }

    .slide .content h2 {
        font-size: 28px;
    }

    .slide .content p {
        font-size: 16px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
        margin-bottom: 40px;
    }
}

@media screen and (max-width: 576px) {
    .advantage-item {
        flex-basis: 100%;
    }

    .banner {
        height: 520px;
        min-height: 520px;
    }

    .section-title h2 {
        font-size: 2rem;
    }

    .slide .content h2 {
        font-size: 2.2rem;
    }

    .slide .content p {
        font-size: 15px;
    }

    .controls {
        padding: 0 16px;
    }

    .controls button {
        width: 38px;
        height: 38px;
        font-size: 16px;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
    }
}