/* ===== 九天技术 - 公共样式 ===== */
/* 红黄色系：#cc2200 中国红 | #e6a800 金黄 | #991a00 深红 | #fff8f0 暖白底 */

:root {
    --red: #cc2200;
    --red-dark: #991a00;
    --red-light: #ff4433;
    --gold: #e6a800;
    --gold-light: #f0c040;
    --bg: #ffffff;
    --bg-warm: #fff8f0;
    --bg-dark: #1a0a00;
    --text: #2c2c2c;
    --text-light: #666;
    --text-muted: #999;
    --border: #f0e6d0;
    --shadow: 0 4px 20px rgba(204,34,0,0.08);
    --shadow-hover: 0 8px 30px rgba(204,34,0,0.15);
    --radius: 12px;
    --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, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.7;
    overflow-x: hidden;
}

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

a { color: var(--red); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--red-dark); }

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

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}
.navbar.scrolled {
    box-shadow: 0 2px 20px rgba(0,0,0,0.08);
}
.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}
.navbar .logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--red);
}
.navbar .logo img { height: 40px; }

.nav-menu { display: flex; align-items: center; gap: 8px; list-style: none; }
.nav-menu a {
    display: block;
    padding: 8px 16px;
    color: var(--text);
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: 8px;
    transition: var(--transition);
}
.nav-menu a:hover,
.nav-menu a.active {
    color: var(--red);
    background: rgba(204,34,0,0.06);
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 8px;
}
.hamburger span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}
.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }

/* ===== 页面头部 Banner ===== */
.page-banner {
    padding: 140px 0 60px;
    background: linear-gradient(135deg, var(--bg-warm) 0%, #fff 100%);
    text-align: center;
    position: relative;
    overflow: hidden;
}
.page-banner::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(230,168,0,0.08) 0%, transparent 70%);
    border-radius: 50%;
}
.page-banner h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 16px;
}
.page-banner p {
    font-size: 1.1rem;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== Section 通用 ===== */
.section { padding: 80px 0; }
.section.bg { background: var(--bg-warm); }
.section-title {
    text-align: center;
    margin-bottom: 48px;
}
.section-title h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 12px;
}
.section-title .bar {
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--red), var(--gold));
    border-radius: 2px;
    margin: 0 auto 16px;
}
.section-title p {
    color: var(--text-light);
    font-size: 1rem;
}

/* ===== 按钮 ===== */
.btn {
    display: inline-block;
    padding: 14px 32px;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
    border: none;
}
.btn-primary {
    background: linear-gradient(135deg, var(--red), var(--red-dark));
    color: #fff;
    box-shadow: 0 4px 15px rgba(204,34,0,0.3);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(204,34,0,0.4);
    color: #fff;
}
.btn-gold {
    background: linear-gradient(135deg, var(--gold), var(--gold-light));
    color: #fff;
    box-shadow: 0 4px 15px rgba(230,168,0,0.3);
}
.btn-gold:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(230,168,0,0.4);
    color: #fff;
}
.btn-outline {
    background: transparent;
    color: var(--red);
    border: 2px solid var(--red);
}
.btn-outline:hover {
    background: var(--red);
    color: #fff;
}

/* ===== 卡片 ===== */
.card {
    background: #fff;
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border);
}
.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}
.card-icon {
    width: 64px;
    height: 64px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 20px;
    background: linear-gradient(135deg, rgba(204,34,0,0.1), rgba(230,168,0,0.1));
    color: var(--red);
}
.card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text);
}
.card p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ===== 网格 ===== */
.grid-2 { display: grid; grid-template-columns: repeat(2,1fr); gap: 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(3,1fr); gap: 24px; }
.grid-4 { display: grid; grid-template-columns: repeat(4,1fr); gap: 24px; }

/* ===== 页脚 ===== */
.site-footer {
    background: var(--bg-dark);
    color: rgba(255,255,255,0.7);
    padding: 60px 0 0;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-about h3 {
    color: #fff;
    font-size: 1.3rem;
    margin-bottom: 16px;
}
.footer-about p { line-height: 1.8; font-size: 0.9rem; }
.footer-links h4,
.footer-contact h4 {
    color: #fff;
    font-size: 1rem;
    margin-bottom: 16px;
}
.footer-links ul { list-style: none; }
.footer-links li { margin-bottom: 10px; }
.footer-links a { color: rgba(255,255,255,0.6); font-size: 0.9rem; }
.footer-links a:hover { color: var(--gold); }
.footer-contact p { font-size: 0.9rem; margin-bottom: 8px; }
.footer-contact i { color: var(--gold); margin-right: 8px; }
.footer-bottom {
    text-align: center;
    padding: 24px 0;
    font-size: 0.85rem;
    color: rgba(255,255,255,0.4);
}

/* ===== 回到顶部 ===== */
.back-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--red), var(--gold));
    color: #fff;
    border: none;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    box-shadow: 0 4px 15px rgba(204,34,0,0.3);
    z-index: 999;
    transition: var(--transition);
}
.back-top:hover { transform: translateY(-3px); }
.back-top.show { display: flex; }

/* ===== 动画 ===== */
.fade-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .grid-4 { grid-template-columns: repeat(2,1fr); }
    .footer-grid { grid-template-columns: repeat(2,1fr); }
}
@media (max-width: 768px) {
    .hamburger { display: flex; }
    .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 16px;
        box-shadow: 0 8px 30px rgba(0,0,0,0.1);
        border-top: 1px solid var(--border);
    }
    .nav-menu.active { display: flex; }
    .nav-menu a { padding: 12px 16px; }
    .page-banner h1 { font-size: 1.8rem; }
    .section { padding: 50px 0; }
    .section-title h2 { font-size: 1.6rem; }
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .hero { flex-direction: column; text-align: center; }
    .hero-image { margin-top: 30px; }
    .detail-row { flex-direction: column !important; }
    .detail-row .detail-img { width: 100% !important; }
    .timeline::before { left: 20px !important; }
    .timeline-item .timeline-dot { left: 14px !important; }
    .timeline-item .timeline-body { margin-left: 50px !important; }
}