/* ===== 全局重置与变量 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root { --primary: #1a1a2e; --accent: #e94560; --gold: #f5a623; --light: #f8f9fa; --dark: #0f0f1a; --text: #e0e0e0; --card-bg: #16213e; --shadow: 0 8px 32px rgba(0,0,0,0.3); --radius: 16px; --transition: 0.3s ease; --bg-gradient: linear-gradient(135deg, #0f0f1a 0%, #1a1a2e 50%, #16213e 100%); --glass-bg: rgba(255,255,255,0.06); --glass-border: rgba(255,255,255,0.1); }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif; background: var(--dark); color: var(--text); line-height: 1.7; overflow-x: hidden; }
body.light { --dark: #f0f2f5; --primary: #ffffff; --text: #1a1a2e; --card-bg: #ffffff; --shadow: 0 4px 20px rgba(0,0,0,0.08); --bg-gradient: linear-gradient(135deg, #e0e5ec 0%, #f0f2f5 50%, #ffffff 100%); --glass-bg: rgba(0,0,0,0.04); --glass-border: rgba(0,0,0,0.08); }
h1, h2, h3, h4, h5, h6 { line-height: 1.3; color: #fff; }
body.light h1, body.light h2, body.light h3, body.light h4, body.light h5, body.light h6 { color: #1a1a2e; }
a { color: var(--gold); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent); }

/* ===== 容器与布局 ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section { padding: 80px 0; }
.section-title { font-size: 2.2rem; text-align: center; margin-bottom: 60px; position: relative; }
.section-title::after { content: ''; display: block; width: 80px; height: 4px; background: var(--accent); margin: 16px auto 0; border-radius: 2px; }
.card { background: var(--card-bg); border-radius: var(--radius); padding: 32px; box-shadow: var(--shadow); transition: transform var(--transition), box-shadow var(--transition); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); border: 1px solid var(--glass-border); }
.card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(0,0,0,0.4); }
.btn { display: inline-block; padding: 14px 36px; background: linear-gradient(135deg, var(--accent), #c0392b); color: #fff; border: none; border-radius: 50px; font-size: 1rem; font-weight: 600; cursor: pointer; transition: var(--transition); text-align: center; }
.btn:hover { transform: scale(1.05); box-shadow: 0 8px 24px rgba(233,69,96,0.4); color: #fff; }
.btn-outline { background: transparent; border: 2px solid var(--gold); color: var(--gold); }
.btn-outline:hover { background: var(--gold); color: #1a1a2e; }
.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 32px; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 32px; }
.grid-4 { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 24px; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.text-center { text-align: center; }
.mt-2 { margin-top: 20px; }
.mb-2 { margin-bottom: 20px; }
.gap-1 { gap: 12px; }
.badge { display: inline-block; padding: 6px 16px; background: var(--accent); color: #fff; border-radius: 50px; font-size: 0.8rem; font-weight: 600; }
.badge-gold { background: var(--gold); color: #1a1a2e; }
img { max-width: 100%; height: auto; display: block; }

/* ===== Header / 导航 ===== */
header { position: sticky; top: 0; z-index: 1000; background: rgba(26,26,46,0.95); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-bottom: 1px solid rgba(255,255,255,0.06); }
body.light header { background: rgba(255,255,255,0.9); border-bottom: 1px solid rgba(0,0,0,0.06); }
header .container { display: flex; align-items: center; justify-content: space-between; padding: 12px 20px; }
header .logo { font-size: 1.6rem; font-weight: 800; color: #fff; display: flex; align-items: center; gap: 10px; }
body.light header .logo { color: #1a1a2e; }
header nav { display: flex; gap: 28px; align-items: center; }
header nav a { color: var(--text); font-weight: 500; position: relative; padding-bottom: 4px; }
header nav a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: var(--gold); transition: width var(--transition); }
header nav a:hover::after, header nav a.active::after { width: 100%; }
#themeToggle { background: none; border: none; color: var(--gold); font-size: 1.3rem; cursor: pointer; padding: 4px 8px; transition: transform 0.3s; }
#themeToggle:hover { transform: rotate(20deg); }
#mobileMenuBtn { display: none; background: none; border: none; color: #fff; font-size: 1.8rem; cursor: pointer; }
body.light #mobileMenuBtn { color: #1a1a2e; }
#mobileMenu { display: none; background: var(--primary); padding: 20px; border-top: 1px solid rgba(255,255,255,0.06); }
body.light #mobileMenu { background: #fff; border-top: 1px solid rgba(0,0,0,0.06); }
#mobileMenu nav { display: flex; flex-direction: column; gap: 16px; }

/* ===== Hero Section ===== */
.hero { padding: 100px 0 80px; background: var(--bg-gradient); position: relative; overflow: hidden; }
.hero::before { content: ''; position: absolute; top: -50%; left: -20%; width: 70%; height: 120%; background: radial-gradient(circle, rgba(233,69,96,0.15) 0%, transparent 70%); pointer-events: none; animation: pulseGlow 6s ease-in-out infinite; }
@keyframes pulseGlow { 0%, 100% { opacity: 0.6; transform: scale(1); } 50% { opacity: 1; transform: scale(1.05); } }
.hero .container { position: relative; z-index: 1; }
.hero-content { max-width: 720px; margin: 0 auto; text-align: center; }
.hero h1 { font-size: 3.2rem; font-weight: 800; margin-bottom: 20px; background: linear-gradient(135deg, #f5a623, #e94560); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; animation: fadeInUp 1s ease; }
.hero p { font-size: 1.2rem; color: #b0b0b0; margin-bottom: 32px; line-height: 1.8; animation: fadeInUp 1.2s ease; }
body.light .hero p { color: #666; }
@keyframes fadeInUp { from { opacity: 0; transform: translateY(30px); } to { opacity: 1; transform: translateY(0); } }

/* ===== About Section ===== */
#about .card ul { list-style: none; display: flex; flex-direction: column; gap: 12px; }
#about .card ul li strong { color: var(--gold); }

/* ===== Services Section ===== */
#services { background: var(--primary); }
#services .card { text-align: center; }
#services .card div:first-child { font-size: 3rem; margin-bottom: 16px; transition: transform 0.3s; }
#services .card:hover div:first-child { transform: scale(1.2) rotate(5deg); }

/* ===== Advantages Section ===== */
#advantages .card { text-align: center; }
#advantages .card div:first-child { font-size: 2.5rem; margin-bottom: 12px; }

/* ===== Insights Section ===== */
#insights { background: var(--primary); }
#insights .card article h3 { font-size: 1.2rem; margin-bottom: 8px; }
#insights .card .meta { color: #999; font-size: 0.85rem; margin-bottom: 8px; }
#insights .card a { display: inline-block; margin-top: 12px; color: var(--accent); font-weight: 500; }
#insights .card a:hover { text-decoration: underline; }

/* ===== HowTo Section ===== */
.howto-step { display: flex; gap: 20px; align-items: flex-start; }
.howto-step .step-num { background: var(--accent); color: #fff; width: 40px; height: 40px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 800; flex-shrink: 0; }
.howto-step h3 { font-size: 1.2rem; margin-bottom: 6px; }

/* ===== FAQ Section ===== */
#faq { background: var(--primary); }
.faq-item { margin-bottom: 12px; cursor: pointer; transition: background 0.3s; }
.faq-item:hover { background: rgba(255,255,255,0.03); }
.faq-item .faq-header { display: flex; justify-content: space-between; align-items: center; }
.faq-item .faq-header h3 { font-size: 1.1rem; margin: 0; }
.faq-item .faq-icon { font-size: 1.5rem; transition: transform 0.3s; }
.faq-item.open .faq-icon { transform: rotate(45deg); }
.faq-item .faq-answer { margin-top: 12px; display: none; }

/* ===== Contact Section ===== */
#contact .card h3 { font-size: 1.3rem; margin-bottom: 16px; }

/* ===== Footer ===== */
footer { background: #0a0a14; padding: 40px 0 20px; border-top: 1px solid rgba(255,255,255,0.06); }
body.light footer { background: #e0e5ec; border-top: 1px solid rgba(0,0,0,0.06); }
footer h4 { color: var(--gold); margin-bottom: 16px; }
footer ul { list-style: none; display: flex; flex-direction: column; gap: 8px; font-size: 0.9rem; }
footer ul li a { color: #888; transition: color 0.3s; }
footer ul li a:hover { color: var(--gold); }
footer .footer-bottom { text-align: center; padding-top: 20px; border-top: 1px solid rgba(255,255,255,0.06); font-size: 0.85rem; color: #666; }
body.light footer .footer-bottom { border-top: 1px solid rgba(0,0,0,0.06); }

/* ===== Back to Top Button ===== */
#backToTop { position: fixed; bottom: 30px; right: 30px; width: 48px; height: 48px; border-radius: 50%; background: var(--accent); color: #fff; border: none; font-size: 1.5rem; cursor: pointer; display: none; align-items: center; justify-content: center; box-shadow: 0 4px 16px rgba(233,69,96,0.4); z-index: 999; transition: transform 0.3s, box-shadow 0.3s; }
#backToTop:hover { transform: translateY(-4px); box-shadow: 0 8px 24px rgba(233,69,96,0.6); }

/* ===== Scroll Animation ===== */
.card { opacity: 0; transform: translateY(20px); transition: opacity 0.6s ease, transform 0.6s ease; }
.card.visible { opacity: 1; transform: translateY(0); }

/* ===== Responsive ===== */
@media (max-width: 768px) { 
    .section { padding: 48px 0; } 
    .section-title { font-size: 1.6rem; } 
    .card { padding: 24px; } 
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } 
    header nav { display: none; } 
    #mobileMenuBtn { display: block; } 
    .hero { padding: 60px 0 40px; } 
    .hero h1 { font-size: 2rem; } 
    .hero p { font-size: 1rem; } 
    #backToTop { bottom: 20px; right: 20px; width: 40px; height: 40px; font-size: 1.2rem; }
}
@media (max-width: 480px) { 
    .container { padding: 0 16px; } 
    .section-title { font-size: 1.4rem; margin-bottom: 40px; } 
    .card { padding: 20px; } 
    .btn { padding: 12px 28px; font-size: 0.9rem; } 
    .hero h1 { font-size: 1.6rem; } 
    .hero p { font-size: 0.9rem; } 
}

/* ===== Glassmorphism Enhancements ===== */
.glass { background: var(--glass-bg); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border: 1px solid var(--glass-border); }

/* ===== Gradient Text Utility ===== */
.gradient-text { background: linear-gradient(135deg, #f5a623, #e94560); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }

/* ===== Smooth Scroll ===== */
html { scroll-behavior: smooth; }

/* ===== Focus Styles ===== */
a:focus-visible, button:focus-visible { outline: 2px solid var(--gold); outline-offset: 4px; }

/* ===== Selection ===== */
::selection { background: var(--accent); color: #fff; }