/* ===== 致简科技 全站公共样式 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --primary: #E31B23;
    --primary-dark: #C4171E;
    --primary-light: #FF3B44;
    --bg-dark: #0A1628;
    --bg-dark-2: #0F1E35;
    --bg-section: #F7F8FA;
    --bg-white: #FFFFFF;
    --text-primary: #1A1A2E;
    --text-secondary: #4A5568;
    --text-light: #A0AEC0;
    --text-white: #FFFFFF;
    --border: #E2E8F0;
    --gradient-primary: linear-gradient(135deg, #E31B23 0%, #FF6B6B 100%);
    --gradient-dark: linear-gradient(180deg, #0A1628 0%, #1A2A4A 100%);
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.12);
    --shadow-lg: 0 8px 40px rgba(0,0,0,0.16);
    --shadow-glow: 0 0 30px rgba(227,27,35,0.3);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --max-width: 1200px;
    --nav-height: 72px;
}

html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    background: var(--bg-white);
}

a { text-decoration: none; color: inherit; transition: color 0.3s; }
img { max-width: 100%; display: block; }
ul { list-style: none; }
button { border: none; cursor: pointer; font-family: inherit; }

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

/* ===== Navigation ===== */
.nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    height: var(--nav-height);
    display: flex; align-items: center;
    transition: all 0.3s ease;
}
.nav--transparent { background: transparent; }
.nav--solid { background: rgba(10,22,40,0.95); backdrop-filter: blur(12px); box-shadow: 0 2px 20px rgba(0,0,0,0.3); }

.nav .container {
    display: flex; align-items: center; justify-content: space-between; width: 100%;
}
.nav__logo { display: flex; align-items: center; gap: 10px; }
.nav__logo img { height: 38px; width: auto; }
.nav__logo-text { color: var(--text-white); font-size: 18px; font-weight: 700; letter-spacing: 1px; }

.nav__menu { display: flex; align-items: center; gap: 36px; }
.nav__link {
    color: rgba(255,255,255,0.8); font-size: 15px; font-weight: 500;
    position: relative; transition: color 0.3s;
}
.nav__link:hover, .nav__link--active { color: var(--text-white); }
.nav__link::after {
    content: ''; position: absolute; bottom: -4px; left: 0; width: 0; height: 2px;
    background: var(--primary); transition: width 0.3s;
}
.nav__link:hover::after, .nav__link--active::after { width: 100%; }

.nav__cta {
    background: var(--primary); color: var(--text-white);
    padding: 10px 24px; border-radius: var(--radius-xl);
    font-size: 14px; font-weight: 600;
    transition: all 0.3s;
}
.nav__cta:hover { background: var(--primary-dark); transform: translateY(-1px); box-shadow: var(--shadow-glow); }

.nav__mobile-btn {
    display: none; background: none; color: white; font-size: 24px;
    width: 40px; height: 40px; align-items: center; justify-content: center;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 14px 32px; border-radius: var(--radius-xl);
    font-size: 15px; font-weight: 600; transition: all 0.3s;
}
.btn--primary { background: var(--primary); color: white; }
.btn--primary:hover { background: var(--primary-dark); transform: translateY(-2px); box-shadow: var(--shadow-glow); }
.btn--outline {
    background: transparent; color: white;
    border: 1.5px solid rgba(255,255,255,0.3);
}
.btn--outline:hover { border-color: white; background: rgba(255,255,255,0.05); }

/* ===== Section Headers ===== */
.section-header { text-align: center; margin-bottom: 64px; }
.section-tag {
    display: inline-block; color: var(--primary); font-size: 14px;
    font-weight: 600; letter-spacing: 2px; text-transform: uppercase;
    margin-bottom: 12px;
}
.section-title {
    font-size: 36px; font-weight: 800; color: var(--text-primary);
    margin-bottom: 16px;
}
.section-desc { font-size: 16px; color: var(--text-secondary); max-width: 600px; margin: 0 auto; }

/* ===== Page Banner (子页面通用Banner) ===== */
.page-banner {
    padding: calc(var(--nav-height) + 80px) 0 80px;
    background: var(--gradient-dark);
    text-align: center;
    position: relative;
    overflow: hidden;
}
.page-banner__bg-grid {
    position: absolute; inset: 0;
    background-image:
        linear-gradient(rgba(227,27,35,0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(227,27,35,0.05) 1px, transparent 1px);
    background-size: 60px 60px;
}
.page-banner__bg-glow {
    position: absolute; width: 500px; height: 500px; border-radius: 50%;
    background: radial-gradient(circle, rgba(227,27,35,0.15) 0%, transparent 70%);
    top: 50%; left: 50%; transform: translate(-50%, -50%);
}
.page-banner .container { position: relative; z-index: 1; }
.page-banner h1 {
    font-size: 40px; font-weight: 800; color: white; margin-bottom: 16px;
}
.page-banner h1 span {
    background: var(--gradient-primary); -webkit-background-clip: text;
    -webkit-text-fill-color: transparent; background-clip: text;
}
.page-banner__subtitle {
    font-size: 17px; color: rgba(255,255,255,0.6); max-width: 600px; margin: 0 auto;
}
.page-banner__breadcrumb {
    margin-top: 20px; font-size: 14px; color: rgba(255,255,255,0.4);
}
.page-banner__breadcrumb a { color: rgba(255,255,255,0.6); }
.page-banner__breadcrumb a:hover { color: white; }

/* ===== Article Content (子页面正文) ===== */
.article {
    padding: 80px 0;
    background: var(--bg-white);
}
.article .container {
    max-width: 860px;
}
.article h2 {
    font-size: 28px; font-weight: 800; color: var(--text-primary);
    margin: 40px 0 20px; padding-left: 16px;
    border-left: 4px solid var(--primary);
}
.article h2:first-child { margin-top: 0; }
.article h3 {
    font-size: 20px; font-weight: 700; color: var(--text-primary);
    margin: 28px 0 12px;
}
.article p {
    font-size: 16px; color: var(--text-secondary); line-height: 2;
    margin-bottom: 16px;
}
.article ul { margin: 16px 0 24px 0; padding-left: 8px; }
.article ul li {
    font-size: 15px; color: var(--text-secondary); line-height: 2;
    padding-left: 24px; position: relative;
}
.article ul li::before {
    content: ''; position: absolute; left: 0; top: 12px;
    width: 8px; height: 8px; border-radius: 50%;
    background: var(--primary);
}
.article strong { color: var(--text-primary); font-weight: 700; }

/* ===== Feature Cards (子页面特色卡片) ===== */
.features {
    padding: 80px 0;
    background: var(--bg-section);
}
.features__grid {
    display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px;
}
.feature-card {
    background: white; border-radius: var(--radius-lg);
    padding: 36px 28px; transition: all 0.4s;
    border: 1px solid transparent; position: relative; overflow: hidden;
}
.feature-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: var(--gradient-primary); transform: scaleX(0);
    transition: transform 0.4s; transform-origin: left;
}
.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}
.feature-card:hover::before { transform: scaleX(1); }
.feature-card__num {
    font-size: 36px; font-weight: 800; color: var(--primary);
    opacity: 0.15; position: absolute; top: 16px; right: 20px;
}
.feature-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 12px; position: relative; }
.feature-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.8; }

/* ===== CTA Section ===== */
.cta {
    padding: 100px 0; background: var(--gradient-dark);
    text-align: center; position: relative; overflow: hidden;
}
.cta__bg-glow {
    position: absolute; width: 500px; height: 500px; border-radius: 50%;
    background: radial-gradient(circle, rgba(227,27,35,0.2) 0%, transparent 70%);
    top: 50%; left: 50%; transform: translate(-50%, -50%);
}
.cta .container { position: relative; z-index: 1; }
.cta h2 {
    font-size: 36px; font-weight: 800; color: white; margin-bottom: 16px;
}
.cta p {
    font-size: 16px; color: rgba(255,255,255,0.6); margin-bottom: 36px;
}
.cta__actions { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }
.cta__actions .btn { cursor: default; }
.cta__phone {
    font-size: 28px; font-weight: 800; color: var(--primary-light);
    margin-bottom: 28px; letter-spacing: 2px;
}

/* ===== Footer ===== */
.footer {
    background: #060D18; padding: 60px 0 30px; color: rgba(255,255,255,0.6);
}
.footer .container {
    display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px;
}
.footer__brand img { height: 36px; margin-bottom: 16px; }
.footer__brand p { font-size: 14px; line-height: 1.8; margin-bottom: 16px; }
.footer__social { display: flex; gap: 12px; }
.footer__social a {
    width: 36px; height: 36px; border-radius: 50%;
    background: rgba(255,255,255,0.08); display: flex;
    align-items: center; justify-content: center;
    font-size: 14px; transition: all 0.3s;
}
.footer__social a:hover { background: var(--primary); color: white; }

.footer h4 {
    color: white; font-size: 15px; font-weight: 600; margin-bottom: 20px;
}
.footer ul li { margin-bottom: 10px; }
.footer ul li a { font-size: 14px; transition: color 0.3s; }
.footer ul li a:hover { color: var(--primary-light); }

.footer__bottom {
    margin-top: 40px; padding-top: 24px;
    border-top: 1px solid rgba(255,255,255,0.08);
    display: flex; justify-content: space-between; align-items: center;
    font-size: 13px; flex-wrap: wrap; gap: 12px;
}

/* ===== Mobile Menu ===== */
.mobile-menu {
    display: none; position: fixed; inset: 0; z-index: 999;
    background: rgba(10,22,40,0.98); backdrop-filter: blur(20px);
    flex-direction: column; align-items: center; justify-content: center; gap: 32px;
}
.mobile-menu.active { display: flex; }
.mobile-menu a {
    color: white; font-size: 20px; font-weight: 600;
    transition: color 0.3s;
}
.mobile-menu a:hover { color: var(--primary-light); }
.mobile-menu__close {
    position: absolute; top: 20px; right: 24px;
    background: none; color: white; font-size: 28px;
}

/* ===== Scroll to Top ===== */
.scroll-top {
    position: fixed; bottom: 30px; right: 30px; z-index: 998;
    width: 44px; height: 44px; border-radius: 50%;
    background: var(--primary); color: white;
    display: flex; align-items: center; justify-content: center;
    font-size: 18px; box-shadow: var(--shadow-md);
    opacity: 0; visibility: hidden; transition: all 0.3s;
}
.scroll-top.visible { opacity: 1; visibility: visible; }
.scroll-top:hover { transform: translateY(-3px); box-shadow: var(--shadow-glow); }

/* ===== Floating Phone ===== */
.float-phone {
    position: fixed; bottom: 84px; right: 30px; z-index: 998;
    width: 48px; height: 48px; border-radius: 50%;
    background: var(--primary); color: white;
    display: flex; align-items: center; justify-content: center;
    box-shadow: var(--shadow-md); text-decoration: none;
    transition: all 0.3s;
}
.float-phone::before {
    content: ''; position: absolute; inset: -2px; border-radius: 50%;
    border: 2px solid var(--primary);
    animation: phone-pulse 2s infinite;
}
@keyframes phone-pulse {
    0% { transform: scale(1); opacity: 0.8; }
    100% { transform: scale(1.6); opacity: 0; }
}
.float-phone:hover {
    transform: translateY(-3px); box-shadow: var(--shadow-glow);
    background: var(--primary-dark);
}
.float-phone svg { width: 22px; height: 22px; position: relative; z-index: 1; }

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

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .features__grid { grid-template-columns: repeat(2, 1fr); }
    .footer .container { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
    .nav__menu, .nav__cta { display: none; }
    .nav__mobile-btn { display: flex; }
    .page-banner h1 { font-size: 28px; }
    .page-banner__subtitle { font-size: 14px; }
    .article h2 { font-size: 22px; }
    .features__grid { grid-template-columns: 1fr; }
    .footer .container { grid-template-columns: 1fr; }
    .footer__bottom { flex-direction: column; text-align: center; }
}