:root{
    --bg:#f6f7f9; --card:#ffffff; --text:#0b1220; --muted:#6b7280; --line:#e5e7eb;
    --brand:#0ea5e9; --brand-2:#22c55e; --radius:16px;
}
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji"; background:var(--bg); color:var(--text); overflow-x:hidden;}
.wrap{max-width:1120px;margin-inline:auto;padding:16px 12px}
header{display:flex;align-items:center;justify-content:space-between;padding:8px 0}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;letter-spacing:.2px}
.brand-badge{inline-size:28px;block-size:28px;border-radius:8px;background:linear-gradient(135deg,var(--brand),#7c3aed);}
nav a{color:var(--muted);text-decoration:none;margin-left:18px;font-size:14px}
nav a:hover{color:var(--text)}
.hero{padding:28px 0 8px}
.hero h1{margin:6px 0;font-size:clamp(24px, 4vw, 40px);line-height:1.15}
.hero p{margin:8px 0 0;color:var(--muted)}

.grid{display:grid;gap:14px;margin-top:18px;grid-template-columns:repeat(1,minmax(0,1fr))}
@media (min-width:640px){.grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (min-width:960px){.grid{grid-template-columns:repeat(4,minmax(0,1fr))}}

.card{background:var(--card); border:1px solid var(--line); border-radius:var(--radius); padding:14px; display:flex; flex-direction:column; min-height:auto; width:100%; transition:transform .18s ease, box-shadow .18s ease}
/* .card:hover{transform:translateY(-2px); box-shadow:0 6px 22px rgba(0,0,0,.06)} */
.head{display:flex;align-items:center;gap:12px;width:100%}
.logo{inline-size:100px;block-size:100px;border-radius:12px;background:#f1f5f9;display:grid;place-items:center;overflow:hidden;border:1px solid var(--line)}
.logo img{inline-size:100%;block-size:100%;object-fit:contain;max-width:100%;height:auto;display:block}
.title{font-size:23px;font-weight:700}
.sub{font-size:16px;color:var(--muted)}
.desc{margin:10px 0 14px;color:#374151;font-size:14px}

.actions{margin-top:auto;display:flex;gap:8px;flex-wrap:wrap}
.btn{appearance:none;border:1px solid var(--line);background:#fff;color:#111827;border-radius:999px;padding:8px 12px;font-weight:600;font-size:14px;cursor:pointer}
.btn:hover{border-color:#cbd5e1}
.btn.primary{background:var(--text); color:#fff; border-color:var(--text)}
.btn.primary:hover{opacity:.92}

footer{color:var(--muted);font-size:13px;padding:18px 0;margin-top:18px}

/* 轻微的首屏动画，纯 CSS，无 JS 依赖 */
.fade{opacity:0;transform:translateY(8px);animation:fadeIn .45s ease forwards}
.card:nth-child(1){animation-delay:.02s}
.card:nth-child(2){animation-delay:.06s}
.card:nth-child(3){animation-delay:.1s}
.card:nth-child(4){animation-delay:.14s}
.card:nth-child(5){animation-delay:.18s}
.card:nth-child(6){animation-delay:.22s}
.card:nth-child(7){animation-delay:.26s}
.card:nth-child(8){animation-delay:.3s}
@keyframes fadeIn{to{opacity:1;transform:none}}

/* 强制小屏单列，避免生成空列 */
/*@media (max-width: 639.98px){*/
/*  .grid{grid-template-columns:1fr !important}*/
/*  .actions{display:grid;grid-template-columns:1fr 1fr;gap:8px}*/
/*  .btn{width:100%;text-align:center}*/
/*}*/
@media (max-width: 639.98px){
    /* 移动端：网格改为双列 */
    .grid{
        grid-template-columns: repeat(2, minmax(0, 1fr)) !important;
        gap: 12px;
    }

    /* 为了双列更协调，logo 和字级稍收一点，避免拥挤 */
    .logo{
        inline-size: 72px;
        block-size: 72px;
        flex-basis: 72px;
    }
    .title{ font-size: 18px; }
    .sub{ font-size: 13px; }
    .desc{ font-size: 13px; }

    /* 按钮两列排布保持不变（可选：让它仍旧两列） */
    .actions{
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 8px;
    }
    .btn{ font-size: 13px; width: 100%; text-align: center; padding:8px 10px; }
}
/* Highlights & FAQ */
.section-title{display:flex;align-items:center;gap:10px;margin:22px 0 8px}
.section-title .bar{inline-size:6px;block-size:18px;border-radius:6px;background:linear-gradient(135deg,var(--brand),var(--brand-2));}
.feature-grid{display:grid;gap:14px;margin-top:12px}
@media (min-width:640px){.feature-grid{grid-template-columns:repeat(2,1fr)}}
@media (min-width:960px){.feature-grid{grid-template-columns:repeat(4,1fr)}}
.feature{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:14px}
.feature .icon{inline-size:36px;block-size:36px;border-radius:10px;display:grid;place-items:center;background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff;font-weight:700}
.feature h3{margin:8px 0 6px;font-size:16px}
.feature p{margin:0;color:#374151;font-size:14px}
.faq{margin-top:12px}
.faq details{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:14px}
.faq details+details{margin-top:10px}
.faq summary{cursor:pointer;font-weight:700}