/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 70px; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: #1a1a2e;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

/* === Layout === */
.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }
.container-sm { max-width: 760px; }
.section { padding: 80px 0; }
.section-alt { background: #f6f8fc; }
.section-title { text-align: center; font-size: 2rem; font-weight: 700; margin-bottom: 12px; }
.section-desc { text-align: center; color: #555; font-size: 1.1rem; margin-bottom: 48px; }

.grid { display: grid; gap: 28px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

/* === Header === */
.header {
    position: fixed; top: 0; left: 0; width: 100%; z-index: 100;
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    transition: box-shadow .3s;
}
.header.scrolled { box-shadow: 0 1px 8px rgba(0,0,0,.08); }
.nav {
    display: flex; align-items: center; justify-content: space-between;
    height: 64px;
}
.nav-brand { display: flex; align-items: center; gap: 10px; }
.nav-name { font-size: 1.25rem; font-weight: 700; color: #1843ff; }
.nav-links { display: flex; gap: 32px; }
.nav-links a { font-size: .95rem; color: #333; transition: color .2s; }
.nav-links a:hover { color: #1843ff; }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; flex-direction: column; gap: 5px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: #333; border-radius: 2px; transition: .3s; }

/* === Buttons === */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 10px 24px; border-radius: 8px; font-size: .95rem; font-weight: 600;
    background: linear-gradient(135deg, #3e76ff, #1843ff); color: #fff;
    border: none; cursor: pointer; transition: transform .15s, box-shadow .2s;
}
.btn:hover { transform: translateY(-1px); box-shadow: 0 4px 16px rgba(24,67,255,.3); }
.btn-sm { padding: 7px 18px; font-size: .85rem; }
.btn-lg { padding: 14px 32px; font-size: 1.05rem; }
.btn-outline { background: transparent; color: #1843ff; border: 2px solid #1843ff; }
.btn-outline:hover { background: rgba(24,67,255,.06); box-shadow: none; transform: none; }
.btn-white { background: #fff; color: #1843ff; }
.btn-white:hover { box-shadow: 0 4px 16px rgba(0,0,0,.15); }
.btn-block { display: flex; justify-content: center; width: 100%; }

/* === Hero === */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(160deg, #e8efff 0%, #f0f4ff 40%, #fff 100%);
    text-align: center;
}
.hero h1 {
    font-size: 3rem; font-weight: 800;
    background: linear-gradient(135deg, #1843ff, #3e76ff);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 20px;
}
.hero-sub { font-size: 1.2rem; color: #444; max-width: 560px; margin: 0 auto 36px; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-note { margin-top: 24px; font-size: .85rem; color: #888; }

/* === Cards === */
.card {
    background: #fff; border-radius: 12px; padding: 32px 28px;
    border: 1px solid #eee; transition: box-shadow .25s, transform .25s;
}
.card:hover { box-shadow: 0 8px 30px rgba(24,67,255,.08); transform: translateY(-4px); }
.card-icon { color: #1843ff; margin-bottom: 16px; }
.card h3 { font-size: 1.15rem; margin-bottom: 8px; }
.card p { color: #555; font-size: .95rem; }

/* === Steps === */
.step { text-align: center; }
.step-num {
    display: inline-flex; align-items: center; justify-content: center;
    width: 56px; height: 56px; border-radius: 50%;
    background: linear-gradient(135deg, #3e76ff, #1843ff);
    color: #fff; font-size: 1.5rem; font-weight: 700; margin-bottom: 18px;
}
.step h3 { font-size: 1.15rem; margin-bottom: 8px; }
.step p { color: #555; font-size: .95rem; max-width: 300px; margin: 0 auto; }

/* === Pricing === */
.pricing-grid { max-width: 700px; margin: 0 auto; }
.price-card {
    background: #fff; border-radius: 16px; padding: 36px 32px;
    border: 2px solid #eee; text-align: center; position: relative;
}
.price-card.featured { border-color: #1843ff; }
.price-badge {
    position: absolute; top: -14px; left: 50%; transform: translateX(-50%);
    background: linear-gradient(135deg, #3e76ff, #1843ff); color: #fff;
    font-size: .8rem; font-weight: 600; padding: 4px 20px; border-radius: 20px;
}
.price-card h3 { font-size: 1.3rem; margin-bottom: 8px; }
.price-amount { font-size: 2rem; font-weight: 800; color: #1843ff; margin-bottom: 24px; }
.price-features { margin-bottom: 28px; }
.price-features li { padding: 6px 0; font-size: .95rem; color: #333; }
.price-features li.disabled { color: #bbb; text-decoration: line-through; }
.price-features li strong { color: #1843ff; }

/* === FAQ === */
.faq-list { display: flex; flex-direction: column; gap: 12px; }
.faq-item {
    background: #fff; border-radius: 10px; border: 1px solid #e8e8e8;
    overflow: hidden; transition: box-shadow .2s;
}
.faq-item[open] { box-shadow: 0 2px 12px rgba(0,0,0,.05); }
.faq-item summary {
    padding: 18px 24px; font-weight: 600; font-size: 1rem; cursor: pointer;
    list-style: none; display: flex; align-items: center; justify-content: space-between;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; font-size: 1.4rem; color: #1843ff; transition: transform .2s; }
.faq-item[open] summary::after { content: "\2212"; }
.faq-item p { padding: 0 24px 18px; color: #555; font-size: .95rem; }

/* === CTA === */
.section-cta {
    background: linear-gradient(135deg, #1843ff, #3e76ff);
    color: #fff; text-align: center; padding: 72px 0;
}
.section-cta h2 { font-size: 2rem; margin-bottom: 10px; }
.section-cta p { font-size: 1.1rem; opacity: .9; margin-bottom: 32px; }
.cta-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* === Footer === */
.footer { padding: 32px 0; border-top: 1px solid #eee; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 16px; }
.footer-brand { display: flex; align-items: center; gap: 8px; font-weight: 700; color: #1843ff; }
.footer-links { display: flex; gap: 24px; }
.footer-links a { font-size: .9rem; color: #666; transition: color .2s; }
.footer-links a:hover { color: #1843ff; }
.footer-copy { font-size: .8rem; color: #999; }

/* === Responsive === */
@media (max-width: 768px) {
    .grid-3 { grid-template-columns: 1fr; }
    .grid-2 { grid-template-columns: 1fr; }
    .hero h1 { font-size: 2rem; }
    .hero-sub { font-size: 1rem; }
    .section { padding: 56px 0; }
    .section-title { font-size: 1.6rem; }

    .nav-links {
        display: none; position: absolute; top: 64px; left: 0; width: 100%;
        flex-direction: column; background: #fff; padding: 16px 24px;
        box-shadow: 0 4px 12px rgba(0,0,0,.08); gap: 16px;
    }
    .nav-links.open { display: flex; }
    .nav-toggle { display: flex; }
    .nav > .btn-sm { display: none; }

    .footer-inner { flex-direction: column; text-align: center; }
    .pricing-grid { max-width: 100%; }
}

@media (max-width: 480px) {
    .hero { padding: 110px 0 56px; }
    .hero h1 { font-size: 1.7rem; }
    .btn-lg { padding: 12px 24px; font-size: .95rem; }
    .cta-actions { flex-direction: column; align-items: center; }
}