/* ========================================
   北京博为思创科技有限公司 - 官网样式
   ======================================== */

/* CSS Variables */
:root {
    --primary-color: #0066cc;
    --primary-dark: #004c99;
    --primary-light: #3399ff;
    --secondary-color: #ff6600;
    --text-dark: #333333;
    --text-gray: #666666;
    --text-light: #999999;
    --bg-light: #f5f7fa;
    --bg-white: #ffffff;
    --border-color: #e1e5eb;
    --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 5px 20px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
    --max-width: 1200px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

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

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 30px;
    font-size: 16px;
    font-weight: 500;
    text-align: center;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: var(--bg-white);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-light), var(--primary-color));
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.btn-secondary {
    background: transparent;
    color: var(--bg-white);
    border: 2px solid var(--bg-white);
}

.btn-secondary:hover {
    background: var(--bg-white);
    color: var(--primary-color);
}

/* ========================================
   Header & Navigation
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 70px;
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-light);
    z-index: 1000;
    transition: var(--transition);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: var(--bg-white);
    font-size: 24px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
}

.logo-text {
    font-size: 22px;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-list {
    display: flex;
    gap: 40px;
}

.nav-list a {
    position: relative;
    font-size: 16px;
    color: var(--text-dark);
    padding: 5px 0;
}

.nav-list a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-list a:hover::after,
.nav-list a.active::after {
    width: 100%;
}

.nav-list a:hover,
.nav-list a.active {
    color: var(--primary-color);
}

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

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: var(--transition);
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #001f3f 0%, #003366 50%, #0066cc 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.05" d="M0,160L48,176C96,192,192,224,288,213.3C384,203,480,149,576,149.3C672,149,768,203,864,218.7C960,235,1056,213,1152,181.3C1248,149,1344,107,1392,85.3L1440,64L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
    background-size: cover;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 20% 50%, rgba(0, 102, 204, 0.3) 0%, transparent 50%),
                radial-gradient(circle at 80% 50%, rgba(0, 76, 153, 0.3) 0%, transparent 50%);
}

.hero-content {
    position: relative;
    z-index: 10;
    text-align: center;
    color: var(--bg-white);
    padding: 0 20px;
    max-width: 900px;
}

.hero-title {
    font-size: 56px;
    font-weight: 700;
    margin-bottom: 24px;
    letter-spacing: 2px;
}

.hero-title .highlight {
    color: #66b3ff;
    text-shadow: 0 0 30px rgba(102, 179, 255, 0.5);
}

.hero-subtitle {
    font-size: 18px;
    line-height: 1.8;
    margin-bottom: 40px;
    opacity: 0.9;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    color: var(--bg-white);
    opacity: 0.7;
}

.scroll-arrow {
    width: 24px;
    height: 40px;
    border: 2px solid var(--bg-white);
    border-radius: 12px;
    position: relative;
}

.scroll-arrow::after {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--bg-white);
    border-radius: 2px;
    animation: scrollBounce 2s infinite;
}

@keyframes scrollBounce {
    0%, 100% { top: 8px; opacity: 1; }
    50% { top: 20px; opacity: 0.3; }
}

/* ========================================
   Stats Section
   ======================================== */
.stats {
    background: var(--bg-white);
    padding: 60px 0;
    margin-top: -60px;
    position: relative;
    z-index: 20;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    background: var(--bg-white);
    border-radius: 12px;
    padding: 40px;
    box-shadow: var(--shadow-medium);
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1;
}

.stat-unit {
    font-size: 24px;
    font-weight: 600;
    color: var(--primary-color);
}

.stat-label {
    display: block;
    margin-top: 10px;
    font-size: 16px;
    color: var(--text-gray);
}

/* ========================================
   Section Header
   ======================================== */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 6px 16px;
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-color);
    background: rgba(0, 102, 204, 0.1);
    border-radius: 20px;
    margin-bottom: 16px;
    letter-spacing: 2px;
}

.section-title {
    font-size: 36px;
    color: var(--text-dark);
    margin-bottom: 16px;
}

.section-desc {
    font-size: 18px;
    color: var(--text-gray);
}

/* ========================================
   About Section
   ======================================== */
.about {
    padding: 100px 0;
    background: var(--bg-light);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text p {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-gray);
    margin-bottom: 20px;
}

.about-text p:first-child {
    font-size: 18px;
    color: var(--text-dark);
}

.about-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.feature-item {
    background: var(--bg-white);
    padding: 30px;
    border-radius: 12px;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
}

.feature-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.feature-icon svg {
    width: 30px;
    height: 30px;
    color: var(--bg-white);
}

.feature-item h3 {
    font-size: 20px;
    margin-bottom: 10px;
    color: var(--text-dark);
}

.feature-item p {
    font-size: 14px;
    color: var(--text-gray);
    line-height: 1.6;
}

/* ========================================
   Services Section
   ======================================== */
.services {
    padding: 100px 0;
    background: var(--bg-white);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.service-card {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 40px 30px;
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
    transform: scaleX(0);
    transition: var(--transition);
}

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

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-medium);
    border-color: transparent;
}

.service-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, rgba(0, 102, 204, 0.1), rgba(0, 102, 204, 0.05));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
}

.service-icon svg {
    width: 40px;
    height: 40px;
    color: var(--primary-color);
}

.service-card h3 {
    font-size: 22px;
    margin-bottom: 12px;
    color: var(--text-dark);
}

.service-card > p {
    font-size: 14px;
    color: var(--text-gray);
    margin-bottom: 20px;
    line-height: 1.6;
}

.service-list {
    text-align: left;
}

.service-list li {
    font-size: 14px;
    color: var(--text-gray);
    padding: 8px 0;
    border-bottom: 1px dashed var(--border-color);
    position: relative;
    padding-left: 20px;
}

.service-list li:last-child {
    border-bottom: none;
}

.service-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

/* ========================================
   Solutions Section
   ======================================== */
.solutions {
    padding: 100px 0;
    background: var(--bg-light);
}

.solutions-tabs {
    background: var(--bg-white);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-light);
}

.tab-buttons {
    display: flex;
    background: var(--bg-light);
    border-bottom: 1px solid var(--border-color);
}

.tab-btn {
    flex: 1;
    padding: 20px;
    font-size: 16px;
    font-weight: 500;
    color: var(--text-gray);
    background: transparent;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.tab-btn::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--primary-color);
    transform: scaleX(0);
    transition: var(--transition);
}

.tab-btn:hover {
    color: var(--primary-color);
}

.tab-btn.active {
    color: var(--primary-color);
    background: var(--bg-white);
}

.tab-btn.active::after {
    transform: scaleX(1);
}

.tab-contents {
    padding: 40px;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.solution-detail h3 {
    font-size: 26px;
    margin-bottom: 16px;
    color: var(--text-dark);
}

.solution-detail > p {
    font-size: 16px;
    color: var(--text-gray);
    line-height: 1.8;
    margin-bottom: 30px;
}

.solution-features {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.solution-features li {
    background: var(--bg-light);
    padding: 16px 20px;
    border-radius: 8px;
    font-size: 15px;
    color: var(--text-dark);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.solution-features li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 4px;
    height: 100%;
    background: var(--primary-color);
}

/* ========================================
   Cases Section
   ======================================== */
.cases {
    padding: 100px 0;
    background: var(--bg-white);
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.case-card {
    background: var(--bg-white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
}

.case-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-medium);
}

.case-image {
    height: 220px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    position: relative;
    overflow: hidden;
}

.case-overlay {
    position: absolute;
    bottom: 20px;
    left: 20px;
}

.case-category {
    display: inline-block;
    padding: 6px 14px;
    background: rgba(255, 255, 255, 0.9);
    color: var(--primary-color);
    font-size: 13px;
    font-weight: 500;
    border-radius: 20px;
}

.case-info {
    padding: 30px;
}

.case-info h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--text-dark);
}

.case-info p {
    font-size: 14px;
    color: var(--text-gray);
    line-height: 1.6;
    margin-bottom: 16px;
}

.case-link {
    font-size: 14px;
    color: var(--primary-color);
    font-weight: 500;
}

.case-link:hover {
    color: var(--primary-dark);
}

/* ========================================
   Partners Section
   ======================================== */
.partners {
    padding: 80px 0;
    background: var(--bg-light);
}

.partners-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 30px;
}

.partner-item {
    background: var(--bg-white);
    padding: 30px 20px;
    border-radius: 12px;
    text-align: center;
    transition: var(--transition);
}

.partner-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

.partner-logo {
    height: 60px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
}

.partner-logo span {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: 2px;
}

.partner-logo small {
    font-size: 10px;
    color: var(--text-light);
    margin-top: 4px;
}

.partner-name {
    font-size: 13px;
    color: var(--text-gray);
}

/* ========================================
   Contact Section
   ======================================== */
.contact {
    padding: 100px 0;
    background: var(--bg-white);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 60px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.info-item {
    display: flex;
    gap: 20px;
    padding: 24px;
    background: var(--bg-light);
    border-radius: 12px;
    transition: var(--transition);
}

.info-item:hover {
    background: rgba(0, 102, 204, 0.05);
}

.info-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.info-icon svg {
    width: 24px;
    height: 24px;
    color: var(--bg-white);
}

.info-content h4 {
    font-size: 16px;
    color: var(--text-dark);
    margin-bottom: 6px;
}

.info-content p {
    font-size: 14px;
    color: var(--text-gray);
}

.contact-form {
    background: var(--bg-light);
    padding: 40px;
    border-radius: 16px;
}

.contact-form h3 {
    font-size: 24px;
    margin-bottom: 30px;
    color: var(--text-dark);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

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

.form-group label {
    display: block;
    font-size: 14px;
    color: var(--text-dark);
    margin-bottom: 8px;
    font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    font-size: 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-white);
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.btn-submit {
    width: 100%;
    padding: 16px;
    font-size: 16px;
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background: linear-gradient(135deg, #001f3f 0%, #003366 100%);
    color: var(--bg-white);
    padding: 60px 0 0;
}

.footer-top {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: 60px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand .logo {
    margin-bottom: 20px;
}

.footer-brand .logo-icon {
    background: rgba(255, 255, 255, 0.1);
}

.footer-brand .logo-text {
    color: var(--bg-white);
}

.footer-brand p {
    font-size: 14px;
    line-height: 1.8;
    opacity: 0.8;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.link-column h4 {
    font-size: 18px;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
}

.link-column h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background: var(--primary-light);
}

.link-column ul li {
    margin-bottom: 12px;
}

.link-column ul li a,
.link-column ul li {
    font-size: 14px;
    opacity: 0.8;
    transition: var(--transition);
}

.link-column ul li a:hover {
    opacity: 1;
    color: var(--primary-light);
}

.footer-bottom {
    text-align: center;
    padding: 24px 0;
    font-size: 14px;
    opacity: 0.7;
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 44px;
    }

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

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

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

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

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

    .partners-grid {
        grid-template-columns: repeat(3, 1fr);
    }

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

    .footer-top {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .nav-list {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: var(--bg-white);
        flex-direction: column;
        gap: 0;
        padding: 20px 0;
        box-shadow: var(--shadow-medium);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

    .nav-list.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-list li {
        text-align: center;
    }

    .nav-list a {
        display: block;
        padding: 15px 20px;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

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

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

    .hero-buttons {
        flex-direction: column;
        gap: 15px;
    }

    .stats {
        margin-top: 0;
        padding: 40px 0;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        padding: 30px 20px;
        gap: 30px;
    }

    .stat-number {
        font-size: 36px;
    }

    .section-title {
        font-size: 28px;
    }

    .about,
    .services,
    .solutions,
    .cases,
    .contact {
        padding: 60px 0;
    }

    .about-features {
        grid-template-columns: 1fr;
    }

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

    .tab-buttons {
        flex-direction: column;
    }

    .solution-features {
        grid-template-columns: 1fr;
    }

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

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

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

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

@media (max-width: 480px) {
    .hero-title {
        font-size: 28px;
    }

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

    .stat-item {
        padding: 20px 0;
        border-bottom: 1px solid var(--border-color);
    }

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

    .about-features {
        grid-template-columns: 1fr;
    }

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

/* ========================================
   Animation Classes
   ======================================== */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.animate-on-scroll.animated {
    opacity: 1;
    transform: translateY(0);
}