/* ==============================
   企业级AI服务官网 - 白色淡蓝商务风格
   ============================== */

:root {
    --blue-50: #EFF6FF;
    --blue-100: #DBEAFE;
    --blue-200: #BFDBFE;
    --blue-300: #93C5FD;
    --blue-400: #60A5FA;
    --blue-500: #3B82F6;
    --blue-600: #2563EB;
    --blue-700: #1D4ED8;
    --blue-800: #1E40AF;
    --blue-900: #1E3A5F;

    --gray-50: #F9FAFB;
    --gray-100: #F3F4F6;
    --gray-200: #E5E7EB;
    --gray-300: #D1D5DB;
    --gray-400: #9CA3AF;
    --gray-500: #6B7280;
    --gray-600: #4B5563;
    --gray-700: #374151;
    --gray-800: #1F2937;
    --gray-900: #111827;

    --bg-primary: #FFFFFF;
    --bg-secondary: #F8FAFF;
    --text-primary: #1F2937;
    --text-secondary: #4B5563;
    --text-muted: #6B7280;
    --accent: var(--blue-600);
    --accent-light: var(--blue-50);
    --border: #E5E7EB;

    --radius: 12px;
    --radius-sm: 8px;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.08);
    --shadow-card: 0 2px 8px rgba(37, 99, 235, 0.06), 0 1px 3px rgba(0, 0, 0, 0.04);
}

*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: var(--text-primary);
    background: var(--bg-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.hide-mobile {
    display: inline;
}

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.88);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s, box-shadow 0.3s;
}

.navbar.scrolled {
    border-bottom-color: var(--border);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 18px;
    font-weight: 700;
    color: var(--blue-700);
    letter-spacing: -0.5px;
}

.logo-icon {
    font-size: 20px;
    color: var(--blue-500);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 36px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    transition: color 0.2s;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--blue-500);
    transition: width 0.2s;
    border-radius: 1px;
}

.nav-links a:hover {
    color: var(--blue-600);
}

.nav-links a:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 1px;
    transition: 0.3s;
}

/* ===== Hero ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    overflow: hidden;
    background: linear-gradient(165deg, #FFFFFF 0%, var(--blue-50) 40%, var(--blue-100) 100%);
}

.hero-bg {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(59, 130, 246, 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(59, 130, 246, 0.04) 1px, transparent 1px);
    background-size: 60px 60px;
}

.hero-glow {
    position: absolute;
    top: -20%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.08) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-content {
    position: relative;
    z-index: 1;
    padding: 120px 0 80px;
    text-align: center;
}

.hero-badge {
    display: inline-block;
    padding: 6px 20px;
    background: rgba(37, 99, 235, 0.08);
    color: var(--blue-700);
    border-radius: 24px;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 28px;
    border: 1px solid rgba(37, 99, 235, 0.12);
}

.hero h1 {
    font-size: clamp(36px, 5vw, 56px);
    font-weight: 800;
    line-height: 1.2;
    color: var(--gray-900);
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.gradient-text {
    background: linear-gradient(135deg, var(--blue-600), var(--blue-400));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 18px;
    color: var(--text-muted);
    margin-bottom: 40px;
    line-height: 1.7;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 64px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.25s;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--blue-600);
    color: #fff;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
    background: var(--blue-700);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    color: var(--blue-600);
    border: 1.5px solid var(--blue-200);
}

.btn-outline:hover {
    background: var(--blue-50);
    border-color: var(--blue-300);
}

.btn-full {
    width: 100%;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 64px;
}

.stat {
    text-align: center;
}

.stat-num {
    font-size: 40px;
    font-weight: 800;
    color: var(--blue-600);
}

.stat-suffix {
    font-size: 24px;
    font-weight: 700;
    color: var(--blue-500);
}

.stat-label {
    display: block;
    font-size: 14px;
    color: var(--text-muted);
    margin-top: 4px;
}

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

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

.section-tag {
    display: inline-block;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 2px;
    color: var(--blue-500);
    margin-bottom: 12px;
}

.section-header h2 {
    font-size: 32px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.section-header p {
    font-size: 16px;
    color: var(--text-muted);
}

/* ===== 核心服务 ===== */
.services {
    background: var(--bg-primary);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.service-card {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px 24px;
    transition: all 0.3s;
}

.service-card:hover {
    border-color: var(--blue-200);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.service-icon {
    width: 48px;
    height: 48px;
    color: var(--blue-500);
    margin-bottom: 20px;
}

.service-icon svg {
    width: 100%;
    height: 100%;
}

.service-card h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.service-card p {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.7;
    margin-bottom: 16px;
}

.service-features {
    list-style: none;
}

.service-features li {
    font-size: 13px;
    color: var(--text-secondary);
    padding: 4px 0;
    padding-left: 16px;
    position: relative;
}

.service-features li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--blue-200);
    transform: translateY(-50%);
}

/* ===== 解决方案 ===== */
.solutions {
    background: var(--bg-secondary);
}

.solutions-list {
    max-width: 800px;
    margin: 0 auto;
}

.solution-item {
    display: flex;
    align-items: flex-start;
    gap: 28px;
    padding: 32px 0;
    border-bottom: 1px solid var(--border);
    transition: all 0.3s;
}

.solution-item:last-child {
    border-bottom: none;
}

.solution-item:hover {
    padding-left: 12px;
}

.solution-num {
    font-size: 40px;
    font-weight: 800;
    color: var(--blue-100);
    line-height: 1;
    flex-shrink: 0;
    min-width: 60px;
    transition: color 0.3s;
}

.solution-item:hover .solution-num {
    color: var(--blue-300);
}

.solution-body h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 8px;
}

.solution-body p {
    font-size: 15px;
    color: var(--text-muted);
    line-height: 1.7;
}

.solution-arrow {
    font-size: 20px;
    color: var(--blue-300);
    flex-shrink: 0;
    align-self: center;
    transition: transform 0.3s, color 0.3s;
}

.solution-item:hover .solution-arrow {
    transform: translateX(6px);
    color: var(--blue-500);
}

/* ===== 优势 ===== */
.advantages {
    background: var(--bg-primary);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.advantage-card {
    background: var(--bg-secondary);
    border-radius: var(--radius);
    padding: 32px 28px;
    transition: all 0.3s;
    border: 1px solid transparent;
}

.advantage-card:hover {
    background: var(--blue-50);
    border-color: var(--blue-100);
}

.advantage-icon {
    font-size: 28px;
    margin-bottom: 16px;
}

.advantage-card h4 {
    font-size: 17px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 8px;
}

.advantage-card p {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.7;
}

/* ===== 联系我们 ===== */
.contact {
    background: var(--bg-secondary);
}

.contact-wrapper {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-desc {
    font-size: 16px;
    color: var(--text-muted);
    line-height: 1.8;
}

.contact-form {
    background: var(--bg-primary);
    border-radius: var(--radius);
    padding: 40px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 16px;
}

.form-group {
    margin-bottom: 16px;
}

.form-row .form-group {
    margin-bottom: 0;
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 6px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    color: var(--text-primary);
    background: var(--bg-primary);
    transition: border-color 0.2s, box-shadow 0.2s;
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--blue-400);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--gray-300);
}

.form-group textarea {
    resize: vertical;
}

.contact-info {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 32px;
}

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

.contact-item-icon {
    width: 44px;
    height: 44px;
    background: var(--blue-50);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    flex-shrink: 0;
}

.contact-item h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.contact-item p {
    font-size: 14px;
    color: var(--text-muted);
}

/* ===== 页脚 ===== */
.footer {
    background: var(--gray-900);
    padding: 40px 0 32px;
}

.footer-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
}

.footer .logo {
    color: #fff;
}

.footer .logo-icon {
    color: var(--blue-400);
}

.footer-links {
    display: flex;
    gap: 28px;
}

.footer-links a {
    font-size: 13px;
    color: var(--gray-400);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: #fff;
}

.footer-copyright {
    text-align: right;
}

.footer-copyright p {
    font-size: 12px;
    color: var(--gray-500);
    line-height: 1.8;
}

.footer-copyright a {
    color: var(--gray-400);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-copyright a:hover {
    color: var(--blue-300);
}

/* ===== 动画 ===== */
.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

@media (max-width: 768px) {
    .hide-mobile {
        display: none;
    }

    /* 移动端导航 */
    .nav-toggle {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(12px);
        flex-direction: column;
        align-items: center;
        padding: 24px 0;
        gap: 20px;
        border-bottom: 1px solid var(--border);
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all 0.3s;
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
    }

    .hero h1 {
        font-size: 32px;
    }

    .hero-desc {
        font-size: 16px;
    }

    .hero-stats {
        gap: 32px;
    }

    .stat-num {
        font-size: 30px;
    }

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

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

    .solution-item {
        flex-direction: column;
        gap: 12px;
    }

    .solution-arrow {
        display: none;
    }

    .contact-wrapper {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .contact-form {
        padding: 24px;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .footer-container {
        flex-direction: column;
        text-align: center;
    }

    .footer-copyright {
        text-align: center;
    }

    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
    }

    .section {
        padding: 64px 0;
    }

    .section-header h2 {
        font-size: 26px;
    }
}

@media (max-width: 480px) {
    .hero-stats {
        flex-direction: column;
        gap: 20px;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .hero-buttons .btn {
        width: 100%;
        max-width: 280px;
    }
}