/* ===== Reset & Base ===== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-primary: #1a73e8;
    --color-primary-dark: #1557b0;
    --color-primary-light: #e8f0fe;
    --color-text: #333333;
    --color-text-light: #666666;
    --color-text-lighter: #999999;
    --color-bg: #ffffff;
    --color-bg-alt: #f8f9fa;
    --color-bg-dark: #1a1f36;
    --color-bg-footer: #0f1419;
    --color-border: #e0e0e0;
    --color-white: #ffffff;
    --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.12);
    --radius: 8px;
    --radius-lg: 12px;
    --transition: 0.3s ease;
    --container-max: 1200px;
    --header-height: 72px;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-main);
    font-size: 16px;
    line-height: 1.7;
    color: var(--color-text);
    background: var(--color-bg);
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Header ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
    transition: var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow-sm);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    font-size: 32px;
    color: var(--color-primary);
    line-height: 1;
}

.logo-text h1 {
    font-size: 22px;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: 0.5px;
}

.logo-subtitle {
    font-size: 11px;
    color: var(--color-text-lighter);
    letter-spacing: 2px;
    text-transform: uppercase;
    font-weight: 500;
}

.nav ul {
    display: flex;
    gap: 8px;
}

.nav ul li a {
    display: block;
    padding: 8px 20px;
    font-size: 15px;
    font-weight: 500;
    color: var(--color-text-light);
    border-radius: 6px;
    transition: var(--transition);
}

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

/* Menu Toggle (Mobile) */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    z-index: 1001;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: var(--transition);
}

/* ===== Hero ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1a1f36 0%, #2c3e6b 40%, #1a73e8 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 50%, rgba(255, 255, 255, 0.05) 0%, transparent 50%),
                radial-gradient(circle at 70% 30%, rgba(26, 115, 232, 0.15) 0%, transparent 50%),
                radial-gradient(circle at 50% 80%, rgba(255, 255, 255, 0.03) 0%, transparent 50%);
    animation: heroBgFloat 20s ease-in-out infinite;
}

@keyframes heroBgFloat {
    0%, 100% { transform: translate(0, 0) rotate(0deg); }
    33% { transform: translate(2%, 1%) rotate(0.5deg); }
    66% { transform: translate(-1%, -2%) rotate(-0.5deg); }
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' xmlns='http://www.w3.org/2000/svg'%3E%3Cdefs%3E%3Cpattern id='grid' width='60' height='60' patternUnits='userSpaceOnUse'%3E%3Cpath d='M 60 0 L 0 0 0 60' fill='none' stroke='rgba(255,255,255,0.04)' stroke-width='1'/%3E%3C/pattern%3E%3C/defs%3E%3Crect width='100%25' height='100%25' fill='url(%23grid)'/%3E%3C/svg%3E");
    opacity: 0.5;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: var(--color-white);
    padding-top: var(--header-height);
}

.hero-title {
    font-size: clamp(36px, 6vw, 56px);
    font-weight: 800;
    letter-spacing: 2px;
    margin-bottom: 24px;
    animation: fadeInUp 0.8s ease-out;
}

.hero-desc {
    font-size: clamp(16px, 2vw, 18px);
    line-height: 1.9;
    color: rgba(255, 255, 255, 0.8);
    max-width: 700px;
    margin: 0 auto 40px;
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-btns {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease-out 0.4s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    padding: 14px 36px;
    font-size: 16px;
    font-weight: 600;
    border-radius: 8px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: var(--transition);
}

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

.btn-primary:hover {
    background: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(26, 115, 232, 0.35);
}

.btn-outline {
    background: transparent;
    color: var(--color-white);
    border-color: rgba(255, 255, 255, 0.5);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--color-white);
    transform: translateY(-2px);
}

.btn-block {
    display: block;
    width: 100%;
    text-align: center;
}

/* ===== Sections ===== */
.section {
    padding: 100px 0;
}

.section.business,
.section.contact {
    background: var(--color-bg-alt);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 3px;
    color: var(--color-primary);
    text-transform: uppercase;
    margin-bottom: 12px;
    padding: 4px 12px;
    background: var(--color-primary-light);
    border-radius: 4px;
}

.section-title {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 16px;
}

.section-desc {
    font-size: 17px;
    color: var(--color-text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== About ===== */
.about-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.about-card {
    text-align: center;
    padding: 40px 30px;
    background: var(--color-white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    transition: var(--transition);
}

.about-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.about-icon {
    font-size: 48px;
    color: var(--color-primary);
    margin-bottom: 20px;
    line-height: 1;
}

.about-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--color-text);
}

.about-card p {
    font-size: 15px;
    color: var(--color-text-light);
    line-height: 1.8;
}

/* ===== Business ===== */
.business-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}

.business-card {
    background: var(--color-white);
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    border: 1px solid var(--color-border);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.business-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--color-primary);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

.business-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.business-card:hover::before {
    transform: scaleX(1);
}

.business-card-icon {
    font-size: 42px;
    margin-bottom: 16px;
    line-height: 1;
}

.business-card h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--color-text);
}

.business-card p {
    font-size: 14px;
    color: var(--color-text-light);
    line-height: 1.8;
}

/* ===== Advantage ===== */
.advantage-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.advantage-item {
    display: flex;
    gap: 24px;
    align-items: flex-start;
}

.advantage-num {
    flex-shrink: 0;
    font-size: 56px;
    font-weight: 800;
    color: var(--color-primary);
    opacity: 0.15;
    line-height: 1;
    min-width: 70px;
}

.advantage-item h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--color-text);
}

.advantage-item p {
    font-size: 15px;
    color: var(--color-text-light);
    line-height: 1.8;
}

/* ===== Contact ===== */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 50px;
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-info-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.contact-icon {
    font-size: 28px;
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary-light);
    border-radius: 12px;
    line-height: 1;
}

.contact-info-item h4 {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 4px;
}

.contact-info-item p {
    font-size: 15px;
    color: var(--color-text-light);
}

/* Form */
.contact-form {
    background: var(--color-white);
    padding: 40px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.form-group {
    margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    font-size: 15px;
    font-family: var(--font-main);
    border: 2px solid var(--color-border);
    border-radius: var(--radius);
    outline: none;
    transition: var(--transition);
    resize: vertical;
    background: var(--color-bg-alt);
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--color-primary);
    background: var(--color-white);
    box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.1);
}

/* ===== Footer ===== */
.footer {
    background: var(--color-bg-footer);
    color: rgba(255, 255, 255, 0.8);
    padding-top: 70px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    padding-bottom: 50px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-col h4 {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: 20px;
}

.footer-col p {
    font-size: 14px;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.6);
}

.footer-col ul li {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: 10px;
    transition: var(--transition);
    cursor: default;
}

.footer-col ul li:hover {
    color: var(--color-white);
}

.footer-bottom {
    padding: 30px 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
    margin-bottom: 8px;
}

.beian a {
    color: rgba(255, 255, 255, 0.5);
    font-size: 14px;
    transition: var(--transition);
}

.beian a:hover {
    color: var(--color-primary);
    text-decoration: underline;
}

/* ===== Responsive ===== */
@media (max-width: 992px) {
    .about-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
        margin: 0 auto;
    }

    .advantage-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }

    .nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--color-white);
        padding: var(--header-height) 30px 30px;
        box-shadow: var(--shadow-lg);
        transition: 0.4s ease;
    }

    .nav.active {
        right: 0;
    }

    .nav ul {
        flex-direction: column;
        gap: 4px;
    }

    .nav ul li a {
        padding: 14px 16px;
        font-size: 16px;
    }

    .section {
        padding: 70px 0;
    }

    .hero {
        min-height: 80vh;
    }

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

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
}

@media (max-width: 480px) {
    .hero-btns {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 280px;
        text-align: center;
    }

    .contact-form {
        padding: 24px;
    }

    .advantage-item {
        flex-direction: column;
        gap: 10px;
    }
}