:root{
    --blue:#66b7dc;
    --blue-deep:#2f7fa7;
    --yellow:#fff2b8;
    --orange:#f6a45e;
    --orange-soft:#ffe0be;
    --cream:#fffaf0;
    --white:#ffffff;
    --ink:#263746;
    --muted:#667987;
    --line:#e3eef5;
    --shadow:0 18px 45px rgba(48,104,130,.13);
    --radius:28px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
    margin:0;
    font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",Arial,sans-serif;
    background:linear-gradient(180deg,#f5fbff 0%,#fffaf0 45%,#ffffff 100%);
    color:var(--ink);
    line-height:1.75;
}
img{max-width:100%;height:auto;display:block}
a{color:inherit;text-decoration:none}
.site-header{
    position:sticky;
    top:0;
    z-index:20;
    display:flex;
    align-items:center;
    justify-content:space-between;
    gap:24px;
    padding:16px clamp(18px,4vw,64px);
    background:rgba(255,255,255,.86);
    backdrop-filter:blur(16px);
    border-bottom:1px solid rgba(102,183,220,.15);
}
.brand{
    display:inline-flex;
    align-items:center;
    gap:10px;
    font-weight:800;
    font-size:1.24rem;
    color:var(--blue-deep);
}
.brand-mark{width:42px;height:42px}
.site-nav{
    display:flex;
    align-items:center;
    gap:6px;
}
.site-nav a{
    padding:10px 14px;
    border-radius:999px;
    color:#426071;
    font-weight:650;
}
.site-nav a:hover,.site-nav a.active{
    background:var(--yellow);
    color:#1f6f99;
}
.nav-toggle{
    display:none;
    width:44px;
    height:44px;
    border:0;
    background:var(--yellow);
    border-radius:16px;
}
.nav-toggle span{
    display:block;
    width:22px;
    height:2px;
    background:var(--blue-deep);
    margin:5px auto;
}
main{overflow:hidden}
.hero,.page-hero{
    width:min(1180px,calc(100% - 36px));
    margin:38px auto 0;
    display:grid;
    grid-template-columns:1.05fr .95fr;
    gap:42px;
    align-items:center;
    padding:clamp(28px,5vw,62px);
    border-radius:42px;
    background:
      radial-gradient(circle at 92% 8%,rgba(255,242,184,.95),transparent 28%),
      linear-gradient(135deg,#ffffff 0%,#effaff 52%,#fff7d8 100%);
    box-shadow:var(--shadow);
}
.hero h1,.page-hero h1{
    margin:0 0 18px;
    font-size:clamp(2.25rem,5vw,4.7rem);
    line-height:1.08;
    letter-spacing:-.04em;
}
.page-hero h1{font-size:clamp(2rem,4vw,3.6rem)}
.hero p,.page-hero p{font-size:1.08rem;color:var(--muted);margin:0 0 18px}
.eyebrow{
    display:inline-flex;
    width:max-content;
    max-width:100%;
    align-items:center;
    gap:8px;
    padding:6px 13px;
    border-radius:999px;
    background:#e7f7ff;
    color:var(--blue-deep)!important;
    font-weight:800;
    font-size:.9rem!important;
    margin:0 0 14px!important;
}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin-top:26px}
.btn{
    display:inline-flex;
    align-items:center;
    justify-content:center;
    border:0;
    border-radius:999px;
    min-height:48px;
    padding:12px 22px;
    font-weight:800;
    cursor:pointer;
    transition:transform .2s ease,box-shadow .2s ease,background .2s ease;
}
.btn:hover{transform:translateY(-2px)}
.btn.primary{background:var(--blue-deep);color:#fff;box-shadow:0 12px 26px rgba(47,127,167,.22)}
.btn.soft{background:var(--yellow);color:#6d5522}
.text-link{
    display:inline-flex;
    margin-top:18px;
    font-weight:800;
    color:var(--blue-deep);
}
.text-link::after{content:"→";margin-left:8px}
.section{
    width:min(1120px,calc(100% - 36px));
    margin:78px auto;
}
.section-head{
    max-width:740px;
    margin-bottom:26px;
}
.section h2{
    margin:0 0 14px;
    font-size:clamp(1.7rem,3.2vw,2.7rem);
    line-height:1.15;
    letter-spacing:-.03em;
}
.section-head p:not(.eyebrow),.section p{color:var(--muted)}
.age-grid,.card-grid,.principle-grid,.question-grid,.testimonial-grid{
    display:grid;
    gap:18px;
}
.age-grid{grid-template-columns:repeat(4,1fr)}
.age-card,.content-card,.sample-card,.principle-grid article,.question-grid article,.testimonial-grid article,.topic-board article,.list-board article,.value-stack article,.contact-aside,.contact-form,.faq details{
    background:rgba(255,255,255,.92);
    border:1px solid var(--line);
    border-radius:var(--radius);
    padding:24px;
    box-shadow:0 12px 30px rgba(53,105,127,.08);
}
.age-card span,.sample-card span,.tag,.principle-grid span,.list-board span,.question-grid span,.info-row span{
    display:inline-flex;
    border-radius:999px;
    padding:5px 10px;
    background:var(--orange-soft);
    color:#8b551e;
    font-weight:800;
    font-size:.86rem;
}
.age-card h3,.content-card h3,.sample-card h3,.topic-board h3,.list-board h3,.principle-grid h3,.video-card h3{
    margin:12px 0 8px;
    font-size:1.25rem;
}
.card-grid.three{grid-template-columns:repeat(3,1fr)}
.card-grid.four{grid-template-columns:repeat(4,1fr)}
.content-card img{border-radius:22px;background:#f2fbff;margin-bottom:16px}
.split{
    display:grid;
    grid-template-columns:1fr .9fr;
    align-items:center;
    gap:42px;
}
.split.reverse{grid-template-columns:.9fr 1fr}
.split>img{
    border-radius:34px;
    background:#fff;
    box-shadow:var(--shadow);
}
.check-list{padding:0;margin:18px 0 0;list-style:none}
.check-list li{
    position:relative;
    padding-left:30px;
    margin:10px 0;
    color:#526a78;
}
.check-list li::before{
    content:"";
    position:absolute;
    left:0;top:.48em;
    width:16px;height:16px;
    border-radius:50%;
    background:var(--blue);
    box-shadow:inset 0 0 0 5px #dff4ff;
}
.soft-panel{
    padding:38px;
    border-radius:36px;
    background:linear-gradient(135deg,#eefaff,#fff7d2);
    border:1px solid rgba(102,183,220,.2);
}
.guide-row{
    display:grid;
    grid-template-columns:repeat(4,1fr);
    gap:16px;
}
.guide-row.tall{grid-template-columns:repeat(3,1fr)}
.guide-step{
    border-radius:26px;
    background:#fff;
    border:1px solid var(--line);
    padding:22px;
    display:flex;
    flex-direction:column;
    gap:12px;
}
.guide-step b{font-size:1.35rem;color:var(--blue-deep)}
.guide-step span{color:#536a78;font-weight:650}
.mini-cards{
    display:flex;
    flex-wrap:wrap;
    gap:10px;
    margin-top:20px;
}
.mini-cards span{
    background:#fff;
    border:1px solid var(--line);
    padding:10px 14px;
    border-radius:999px;
    font-weight:800;
    color:#426071;
}
.mini-cards.wide span{padding-inline:18px}
.topic-board,.list-board,.video-grid{
    display:grid;
    grid-template-columns:repeat(3,1fr);
    gap:18px;
}
.testimonial-zone{
    padding:36px;
    border-radius:36px;
    background:#fff9df;
}
.testimonial-grid{grid-template-columns:repeat(2,1fr)}
.testimonial-grid img{width:78px;margin-bottom:12px}
.faq details{margin-bottom:14px}
.faq summary{
    cursor:pointer;
    font-weight:850;
    font-size:1.1rem;
}
.contact-strip{
    display:flex;
    align-items:center;
    justify-content:space-between;
    gap:24px;
    padding:34px;
    border-radius:34px;
    background:linear-gradient(135deg,#eaf8ff,#fff2b8);
    border:1px solid rgba(102,183,220,.24);
}
.value-stack{display:grid;gap:14px}
.value-stack article{display:flex;gap:18px;align-items:center}
.value-stack b{
    width:62px;height:62px;
    display:grid;place-items:center;
    border-radius:20px;
    background:var(--yellow);
    color:#89631c;
}
.timeline{
    display:grid;
    gap:18px;
}
.timeline article{
    display:grid;
    grid-template-columns:110px 1fr 2fr;
    gap:18px;
    align-items:start;
    background:#fff;
    border:1px solid var(--line);
    border-radius:26px;
    padding:22px;
}
.timeline b{
    display:inline-flex;
    align-items:center;
    justify-content:center;
    border-radius:18px;
    background:#e7f7ff;
    color:var(--blue-deep);
    padding:10px;
}
.timeline h3,.timeline p{margin:0}
.video-card{
    background:#fff;
    border:1px solid var(--line);
    border-radius:30px;
    overflow:hidden;
    box-shadow:0 12px 30px rgba(53,105,127,.08);
}
.video-card h3,.video-card p,.video-card .info-row{margin-left:22px;margin-right:22px}
.video-cover{position:relative;background:#eefaff}
.video-cover img{width:100%}
.play-badge{
    position:absolute;
    left:18px;
    bottom:18px;
    border-radius:999px;
    background:rgba(255,255,255,.92);
    color:var(--blue-deep);
    padding:8px 13px;
    font-weight:900;
}
.info-row{
    display:flex;
    gap:8px;
    flex-wrap:wrap;
    margin-bottom:22px;
}
.contact-layout{
    display:grid;
    grid-template-columns:1.1fr .9fr;
    gap:24px;
    align-items:start;
}
.contact-form label{
    display:grid;
    gap:8px;
    font-weight:800;
    color:#426071;
    margin-bottom:16px;
}
.contact-form input,.contact-form select,.contact-form textarea{
    width:100%;
    border:1px solid var(--line);
    border-radius:18px;
    padding:13px 15px;
    font:inherit;
    background:#fbfeff;
    color:var(--ink);
}
.form-note{font-size:.92rem;margin-bottom:0}
.domain-card{
    display:inline-grid;
    gap:4px;
    margin-top:12px;
    background:#fff;
    border:1px solid var(--line);
    border-radius:22px;
    padding:14px 18px;
    box-shadow:0 10px 24px rgba(47,127,167,.1);
}
.domain-card span{color:var(--muted);font-size:.9rem}
.domain-card strong{color:var(--blue-deep);font-size:1.05rem}
.site-footer{
    margin-top:90px;
    padding:38px clamp(18px,4vw,64px);
    background:#253f4d;
    color:#eaf8ff;
}
.footer-grid{
    width:min(1120px,100%);
    margin:auto;
    display:grid;
    grid-template-columns:1.3fr 1fr 1.2fr;
    gap:24px;
}
.site-footer p{color:#cfe1e9;margin:.45rem 0 0}
.site-footer strong{color:#fff;font-size:1.05rem}
@media (max-width:980px){
    .site-nav{
        position:absolute;
        left:18px;right:18px;top:76px;
        display:none;
        flex-direction:column;
        align-items:stretch;
        padding:12px;
        border-radius:24px;
        background:#fff;
        box-shadow:var(--shadow);
    }
    .site-nav.open{display:flex}
    .nav-toggle{display:block}
    .hero,.page-hero,.split,.split.reverse,.contact-layout{
        grid-template-columns:1fr;
    }
    .age-grid,.card-grid.three,.card-grid.four,.topic-board,.list-board,.video-grid,.footer-grid{
        grid-template-columns:1fr 1fr;
    }
    .guide-row,.guide-row.tall{grid-template-columns:1fr}
    .timeline article{grid-template-columns:1fr}
}
@media (max-width:620px){
    .site-header{padding:12px 16px}
    .hero,.page-hero{width:calc(100% - 24px);padding:24px;border-radius:30px;margin-top:20px}
    .section{width:calc(100% - 24px);margin:54px auto}
    .age-grid,.card-grid.three,.card-grid.four,.topic-board,.list-board,.video-grid,.testimonial-grid,.footer-grid{
        grid-template-columns:1fr;
    }
    .contact-strip{align-items:flex-start;flex-direction:column}
    .soft-panel,.testimonial-zone{padding:24px}
    .hero-actions .btn{width:100%}
}