/* reset & base */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif; line-height: 1.6; color: #1a1a2e; background: #f0f2f5; transition: background 0.3s, color 0.3s; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; height: auto; display: block; }

/* layout */
header { position: sticky; top: 0; z-index: 100; background: rgba(255,255,255,0.85); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); box-shadow: 0 2px 20px rgba(0,0,0,0.06); transition: background 0.3s; }
nav { max-width: 1200px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; padding: 0.8rem 1.5rem; }
.logo a { font-size: 1.4rem; font-weight: 700; background: linear-gradient(135deg, #1a5276, #2e86c1); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; letter-spacing: 1px; }
.nav-menu { display: flex; gap: 1.2rem; flex-wrap: wrap; }
.nav-menu a { font-size: 0.95rem; padding: 0.4rem 0; position: relative; color: #1a1a2e; transition: color 0.3s; }
.nav-menu a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: linear-gradient(90deg, #1a5276, #2e86c1); transition: width 0.3s; }
.nav-menu a:hover { color: #1a5276; }
.nav-menu a:hover::after { width: 100%; }

/* main content */
main { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }
section { margin: 4rem 0; opacity: 0; transform: translateY(30px); animation: fadeUp 0.7s ease forwards; }
@keyframes fadeUp { to { opacity: 1; transform: translateY(0); } }
section:nth-child(2) { animation-delay: 0.1s; }
section:nth-child(3) { animation-delay: 0.2s; }
section:nth-child(4) { animation-delay: 0.3s; }
section:nth-child(5) { animation-delay: 0.4s; }
section:nth-child(6) { animation-delay: 0.5s; }
section:nth-child(7) { animation-delay: 0.6s; }
section:nth-child(8) { animation-delay: 0.7s; }
section:nth-child(9) { animation-delay: 0.8s; }
section:nth-child(10) { animation-delay: 0.9s; }
section:nth-child(11) { animation-delay: 1.0s; }

/* hero banner */
#hero { text-align: center; padding: 5rem 2rem; border-radius: 24px; background: linear-gradient(135deg, #1a5276 0%, #2e86c1 50%, #85c1e9 100%); color: #fff; position: relative; overflow: hidden; box-shadow: 0 20px 40px -12px rgba(26,82,118,0.3); }
#hero::before { content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%; background: radial-gradient(circle at 30% 40%, rgba(255,255,255,0.15) 0%, transparent 60%); pointer-events: none; }
#hero h1 { font-size: 2.4rem; font-weight: 700; margin-bottom: 1rem; text-shadow: 0 2px 10px rgba(0,0,0,0.1); }
#hero p { font-size: 1.2rem; max-width: 700px; margin: 0 auto; opacity: 0.9; }

/* cards for sections */
section:not(#hero) h2 { font-size: 2rem; margin-bottom: 1.5rem; color: #1a5276; position: relative; display: inline-block; }
section:not(#hero) h2::after { content: ''; display: block; width: 50px; height: 3px; background: linear-gradient(90deg, #1a5276, #2e86c1); margin-top: 0.5rem; border-radius: 2px; }
section:not(#hero) h3 { font-size: 1.3rem; margin: 1.2rem 0 0.6rem; color: #2c3e50; }
section:not(#hero) p { margin-bottom: 0.8rem; color: #2c3e50; }

/* glass card style for content sections */
#about, #products, #solutions, #cases, #reviews, #news, #faq, #howto, #contact, #team {
    background: rgba(255,255,255,0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 20px;
    padding: 2rem 2.5rem;
    box-shadow: 0 8px 32px rgba(0,0,0,0.04);
    border: 1px solid rgba(255,255,255,0.3);
    transition: transform 0.3s, box-shadow 0.3s;
}
#about:hover, #products:hover, #solutions:hover, #cases:hover, #reviews:hover, #news:hover, #faq:hover, #howto:hover, #contact:hover, #team:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(0,0,0,0.08);
}

/* news articles */
#news article { padding: 1rem 0; border-bottom: 1px solid rgba(0,0,0,0.06); transition: background 0.2s; border-radius: 12px; padding: 0.8rem 1rem; }
#news article:hover { background: rgba(26,82,118,0.04); }
#news article h3 { margin: 0 0 0.3rem; font-size: 1.1rem; }
#news article p { font-size: 0.9rem; color: #555; }

/* faq */
#faq h3 { cursor: default; }
#faq p { margin-left: 0.5rem; }

/* footer */
footer { background: rgba(255,255,255,0.85); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-top: 1px solid rgba(0,0,0,0.05); padding: 2rem 1.5rem; text-align: center; margin-top: 3rem; }
footer nav { display: flex; justify-content: center; gap: 1.2rem; flex-wrap: wrap; margin-bottom: 1rem; }
footer nav a { font-size: 0.9rem; color: #1a5276; transition: color 0.3s; }
footer nav a:hover { color: #2e86c1; }
footer p { font-size: 0.85rem; color: #555; margin: 0.3rem 0; }
footer a { color: #1a5276; }
footer a:hover { text-decoration: underline; }

/* responsive */
@media (max-width: 768px) {
    nav { flex-direction: column; gap: 0.6rem; padding: 0.6rem 1rem; }
    .nav-menu { gap: 0.6rem; justify-content: center; }
    .nav-menu a { font-size: 0.85rem; }
    #hero { padding: 3rem 1rem; }
    #hero h1 { font-size: 1.8rem; }
    #hero p { font-size: 1rem; }
    section:not(#hero) h2 { font-size: 1.6rem; }
    #about, #products, #solutions, #cases, #reviews, #news, #faq, #howto, #contact, #team { padding: 1.5rem 1rem; }
    footer nav { gap: 0.8rem; }
}

/* dark mode */
@media (prefers-color-scheme: dark) {
    body { background: #0f172a; color: #e2e8f0; }
    header { background: rgba(15,23,42,0.85); box-shadow: 0 2px 20px rgba(0,0,0,0.3); }
    .nav-menu a { color: #e2e8f0; }
    .nav-menu a:hover { color: #85c1e9; }
    section:not(#hero) h2 { color: #85c1e9; }
    section:not(#hero) h3 { color: #cbd5e1; }
    section:not(#hero) p { color: #cbd5e1; }
    #about, #products, #solutions, #cases, #reviews, #news, #faq, #howto, #contact, #team {
        background: rgba(30,41,59,0.7);
        border-color: rgba(255,255,255,0.08);
    }
    #news article { border-color: rgba(255,255,255,0.06); }
    #news article:hover { background: rgba(133,193,233,0.06); }
    footer { background: rgba(15,23,42,0.85); border-top-color: rgba(255,255,255,0.05); }
    footer p { color: #94a3b8; }
    footer nav a { color: #85c1e9; }
    footer nav a:hover { color: #b3d9f2; }
    footer a { color: #85c1e9; }
    #hero { background: linear-gradient(135deg, #0b2a40 0%, #1a5276 50%, #2e86c1 100%); }
}