/* 皓航科技 - 纯黑白配色 · 优化间距 */
:root {
    --black: #000;
    --white: #fff;
    --gray-1: #0a0a0a;
    --gray-2: #1a1a1a;
    --gray-3: #333;
    --gray-4: #666;
    --gray-5: #999;
    --gray-6: #ccc;
    --gray-7: #e5e5e5;
    --gray-8: #f5f5f5;
    --gray-9: #fafafa;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
    font-family: -apple-system, "PingFang SC", "Helvetica Neue", "Microsoft YaHei", sans-serif;
    color: var(--black);
    background: var(--white);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

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

/* ===== Header ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(0, 0, 0, 0.95);
    backdrop-filter: blur(12px);
    transition: var(--transition);
    border-bottom: 1px solid var(--gray-2);
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    text-decoration: none;
    display: flex;
    flex-direction: column;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--white);
    letter-spacing: 2px;
    line-height: 1.2;
}

.logo-sub {
    font-size: 9px;
    color: var(--gray-5);
    letter-spacing: 1px;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 32px;
}

.main-nav a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 14px;
    font-weight: 400;
    transition: var(--transition);
}

.main-nav a:hover { color: var(--white); }

.nav-cta {
    padding: 10px 24px;
    background: var(--white);
    color: var(--black) !important;
    border-radius: 2px;
    font-weight: 500;
}

.nav-cta:hover {
    background: var(--gray-7);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--white);
}

.mobile-nav {
    display: none;
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--black);
    padding: 32px 24px;
    flex-direction: column;
    gap: 0;
    z-index: 999;
    border-top: 1px solid var(--gray-2);
}

.mobile-nav.active { display: flex; }

.mobile-nav a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 16px;
    padding: 16px 0;
    border-bottom: 1px solid var(--gray-2);
}

/* ===== Hero ===== */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: var(--black);
}

.hero-video-wrap {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
}

.hero-video-wrap video {
    width: 100%; height: 100%;
    object-fit: cover;
}

.hero-overlay {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(0, 0, 0, 0.6);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
    padding: 0 24px;
}

.hero-title {
    font-size: 64px;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 24px;
    letter-spacing: 8px;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--gray-5);
    margin-bottom: 16px;
    letter-spacing: 4px;
    font-weight: 300;
}

.hero-desc {
    font-size: 16px;
    color: var(--gray-6);
    margin-bottom: 48px;
    line-height: 2;
    font-weight: 300;
}

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

.btn {
    display: inline-block;
    padding: 14px 36px;
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    letter-spacing: 1px;
}

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

.btn-primary:hover {
    background: var(--gray-7);
}

.btn-outline {
    background: transparent;
    color: var(--white);
    border: 1px solid rgba(255, 255, 255, 0.4);
}

.btn-outline:hover {
    border-color: var(--white);
    background: rgba(255, 255, 255, 0.05);
}

.btn-dark {
    background: var(--black);
    color: var(--white);
}

.btn-dark:hover {
    background: var(--gray-3);
}

.btn-sm {
    padding: 12px 28px;
    font-size: 13px;
}

.btn-full { width: 100%; }

.hero-scroll-hint {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
    color: var(--gray-5);
    font-size: 12px;
    letter-spacing: 2px;
}

.scroll-arrow {
    width: 1px;
    height: 48px;
    background: var(--gray-5);
    margin: 12px auto 0;
    animation: scrollLine 2s infinite;
}

@keyframes scrollLine {
    0%, 100% { opacity: 0.3; transform: scaleY(0.5); }
    50% { opacity: 1; transform: scaleY(1); }
}

/* ===== 通用区块 ===== */
.section {
    padding: 120px 0;
}

.section-dark {
    background: var(--black);
    color: var(--white);
}

.section-gray {
    background: var(--gray-9);
}

.section-header {
    text-align: center;
    margin-bottom: 80px;
}

.section-header h2 {
    font-size: 36px;
    font-weight: 700;
    letter-spacing: 2px;
    margin-bottom: 20px;
}

.section-header p {
    font-size: 16px;
    color: var(--gray-4);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.8;
}

.section-dark .section-header p {
    color: var(--gray-5);
}

/* ===== 业务服务 ===== */
.services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1px;
    background: var(--gray-7);
    border: 1px solid var(--gray-7);
}

.service-card {
    padding: 56px 32px;
    background: var(--white);
    text-decoration: none;
    color: var(--black);
    transition: var(--transition);
    display: block;
}

.service-card:hover {
    background: var(--black);
    color: var(--white);
}

.service-card h3 {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 20px;
    letter-spacing: 1px;
}

.service-card p {
    font-size: 15px;
    line-height: 1.8;
    color: var(--gray-4);
}

.service-card:hover p {
    color: var(--gray-5);
}

/* ===== 产品分类 ===== */
.category-tabs {
    display: flex;
    justify-content: center;
    gap: 0;
    margin-bottom: 80px;
    border-bottom: 1px solid var(--gray-7);
}

.category-tab {
    padding: 20px 48px;
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    color: var(--gray-5);
    font-size: 15px;
    cursor: pointer;
    transition: var(--transition);
    letter-spacing: 1px;
}

.category-tab:hover { color: var(--black); }

.category-tab.active {
    color: var(--black);
    border-bottom-color: var(--black);
}

.product-section.hidden { display: none; }

/* ===== 产品卡片 ===== */
.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.product-card {
    background: var(--white);
    border: 1px solid var(--gray-7);
    transition: var(--transition);
}

.product-card:hover {
    border-color: var(--black);
}

.product-img {
    height: 280px;
    overflow: hidden;
    background: var(--gray-9);
}

.product-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
    filter: grayscale(20%);
}

.product-card:hover .product-img img {
    transform: scale(1.03);
    filter: grayscale(0%);
}

.product-info {
    padding: 40px 32px;
}

.product-info h3 {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 12px;
}

.product-info > p {
    color: var(--gray-4);
    font-size: 15px;
    margin-bottom: 24px;
    line-height: 1.6;
}

.product-info ul {
    list-style: none;
    margin-bottom: 32px;
}

.product-info li {
    padding: 10px 0;
    color: var(--gray-4);
    font-size: 14px;
    border-bottom: 1px solid var(--gray-8);
}

.product-info li:before {
    content: '—';
    margin-right: 12px;
    color: var(--gray-6);
}

/* ===== 呼叫无人机 ===== */
.drone-service {
    padding: 120px 0;
    background: var(--black);
    color: var(--white);
}

.service-content {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.service-content h2 {
    font-size: 36px;
    margin-bottom: 24px;
    letter-spacing: 2px;
}

.service-content > p {
    font-size: 16px;
    color: var(--gray-5);
    margin-bottom: 64px;
    line-height: 2;
}

.service-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: var(--gray-3);
    margin-bottom: 64px;
    border: 1px solid var(--gray-3);
}

.sf-item {
    padding: 48px 32px;
    background: var(--black);
}

.sf-item h4 {
    font-size: 18px;
    margin-bottom: 16px;
    font-weight: 600;
    letter-spacing: 1px;
}

.sf-item p {
    color: var(--gray-5);
    font-size: 15px;
    line-height: 1.8;
}

/* ===== 关于我们 ===== */
.about-section {
    padding: 120px 0;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text h2 {
    font-size: 36px;
    margin-bottom: 40px;
    letter-spacing: 2px;
}

.about-text p {
    font-size: 16px;
    color: var(--gray-4);
    line-height: 2;
    margin-bottom: 24px;
}

.about-stats {
    display: flex;
    gap: 80px;
    margin-top: 64px;
    padding-top: 64px;
    border-top: 1px solid var(--gray-7);
}

.about-stats > div { text-align: left; }

.about-stats strong {
    display: block;
    font-size: 42px;
    color: var(--black);
    font-weight: 700;
    margin-bottom: 8px;
}

.about-stats span {
    color: var(--gray-5);
    font-size: 14px;
    letter-spacing: 1px;
}

/* ===== 联系我们 ===== */
.contact-section {
    padding: 120px 0;
    background: var(--gray-9);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 80px;
    max-width: 1000px;
    margin: 0 auto;
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.form-group label {
    font-size: 14px;
    color: var(--gray-4);
    letter-spacing: 1px;
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 14px 18px;
    background: var(--white);
    border: 1px solid var(--gray-7);
    color: var(--black);
    font-size: 15px;
    font-family: inherit;
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--black);
}

.form-group textarea { resize: vertical; }

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 40px;
    padding-top: 8px;
}

.ci-item h4 {
    font-size: 14px;
    color: var(--gray-5);
    margin-bottom: 10px;
    letter-spacing: 1px;
    font-weight: 400;
    text-transform: uppercase;
}

.ci-item p {
    color: var(--black);
    font-size: 16px;
    line-height: 1.6;
}

/* ===== Footer ===== */
.footer {
    background: var(--black);
    color: var(--white);
    padding: 80px 0 40px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 48px;
    margin-bottom: 64px;
}

.footer-col h4 {
    font-size: 14px;
    margin-bottom: 24px;
    color: var(--gray-5);
    letter-spacing: 2px;
    font-weight: 400;
    text-transform: uppercase;
}

.footer-col a {
    display: block;
    color: rgba(255, 255, 255, 0.6);
    text-decoration: none;
    font-size: 15px;
    margin-bottom: 14px;
    transition: var(--transition);
}

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

.footer-bottom {
    padding-top: 40px;
    border-top: 1px solid var(--gray-2);
    text-align: center;
}

.footer-bottom p {
    color: var(--gray-5);
    font-size: 14px;
    margin-bottom: 10px;
}

.footer-bottom a {
    color: var(--gray-5);
    text-decoration: none;
}

.footer-bottom a:hover { color: var(--white); }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .services-grid { grid-template-columns: repeat(2, 1fr); }
    .products-grid { grid-template-columns: repeat(2, 1fr); gap: 32px; }
    .service-features { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
    
    .hero-title { font-size: 48px; letter-spacing: 6px; }
    .section-header h2 { font-size: 32px; }
    
    .section { padding: 96px 0; }
    .drone-service { padding: 96px 0; }
    .about-section { padding: 96px 0; }
    .contact-section { padding: 96px 0; }
    
    .section-header { margin-bottom: 64px; }
    .category-tabs { margin-bottom: 64px; }
}

@media (max-width: 768px) {
    .main-nav { display: none; }
    .mobile-menu-btn { display: flex; }

    .hero { min-height: 100vh; }
    .hero-title { font-size: 36px; letter-spacing: 4px; }
    .hero-subtitle { font-size: 15px; }
    .hero-desc { font-size: 15px; }
    .hero-btns { flex-direction: column; align-items: center; }
    .hero-btns .btn { width: 220px; text-align: center; }

    .section { padding: 72px 0; }
    .drone-service { padding: 72px 0; }
    .about-section { padding: 72px 0; }
    .contact-section { padding: 72px 0; }
    
    .section-header { margin-bottom: 48px; }
    .section-header h2 { font-size: 28px; }
    
    .services-grid { grid-template-columns: 1fr; }
    .service-card { padding: 40px 28px; }

    .products-grid { grid-template-columns: 1fr; gap: 32px; }
    .service-features { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; gap: 40px; }

    .contact-wrapper { grid-template-columns: 1fr; gap: 56px; }
    .form-row { grid-template-columns: 1fr; }

    .about-stats { flex-direction: column; gap: 32px; }

    .category-tabs { flex-wrap: wrap; margin-bottom: 48px; }
    .category-tab { padding: 16px 32px; font-size: 14px; }
}