/*
Theme Name: LT Union Blog Child
Template: twentytwentyfive
Version: 1.0
Description: Child theme for blog.ltunion.com — header/footer matching ltunion.com official site.
*/

/* ===== LT Union Packaging design system (from ltunion.com css/site.css) ===== */
:root{
  --ink:#16232e; --navy:#12314b; --brand:#0e4a86; --brand-d:#0a3a69;
  --accent:#e0682a; --accent-d:#c5561d;
  --kraft:#f6efe3; --paper:#ffffff; --line:#e3e8ee; --muted:#5a6b7a;
  --ok:#1f8a4c; --warn:#b7791f;
  --radius:12px; --shadow:0 10px 30px rgba(18,49,75,.10);
  --container:1200px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"PingFang SC","Microsoft YaHei",sans-serif;color:var(--ink);line-height:1.65;background:var(--paper);font-size:16px}
img{max-width:100%;height:auto;display:block}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{line-height:1.25;font-weight:800;color:var(--navy);letter-spacing:-.01em}
h1{font-size:clamp(1.9rem,4.2vw,3rem)}
h2{font-size:clamp(1.45rem,3vw,2.2rem)}
h3{font-size:1.2rem}
.container{max-width:var(--container);margin:0 auto;padding:0 20px}
.muted{color:var(--muted)}
.small{font-size:.9rem}
.text-center{text-align:center}

/* 按钮 */
.btn{display:inline-block;padding:14px 28px;border-radius:10px;font-weight:800;font-size:1rem;border:2px solid transparent;cursor:pointer;transition:transform .15s ease,box-shadow .15s ease,background .15s ease;text-align:center}
.btn:hover{transform:translateY(-1px);text-decoration:none}
.btn-primary{background:var(--accent);color:#fff;box-shadow:0 8px 20px rgba(224,104,42,.28)}
.btn-primary:hover{background:var(--accent-d)}
.btn-secondary{background:var(--brand);color:#fff}
.btn-secondary:hover{background:var(--brand-d)}
.btn-outline{background:transparent;color:var(--brand);border-color:var(--brand)}
.btn-outline:hover{background:var(--brand);color:#fff}
.btn-lg{padding:17px 36px;font-size:1.05rem}
.btn-block{display:block;width:100%}
.btn-row{display:flex;gap:14px;flex-wrap:wrap;align-items:center}

/* 头部导航 */
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.96);backdrop-filter:blur(6px);border-bottom:1px solid var(--line)}
.nav-wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:84px}
.brand{font-weight:900;font-size:1.15rem;color:var(--navy);letter-spacing:.02em;display:inline-flex;align-items:center;gap:10px;line-height:1.15}
.brand img{display:block;width:72px;height:auto;flex:0 0 auto}
.brand small{display:block;font-size:.68rem;font-weight:700;color:var(--muted);letter-spacing:.12em;text-transform:uppercase}
.nav-links{display:flex;align-items:center;gap:22px;font-weight:600;font-size:.95rem}
.nav-links a{color:var(--ink)}
.nav-links a:hover{color:var(--brand)}
.nav-cta{margin-left:6px}
.nav-toggle{display:none;background:none;border:0;font-size:1.5rem;color:var(--navy);cursor:pointer;padding:6px}
@media(max-width:980px){
  .nav-toggle{display:block}
  .nav-links{position:absolute;top:84px;left:0;right:0;background:#fff;flex-direction:column;align-items:flex-start;gap:4px;padding:12px 20px 20px;border-bottom:1px solid var(--line);display:none;box-shadow:var(--shadow)}
  .nav-links.open{display:flex}
  .nav-links a{padding:8px 0;width:100%}
  .nav-cta{margin:10px 0 0;width:100%}
}

/* 页脚 */
.site-footer{background:var(--navy);color:#c3d7ec;padding:56px 0 30px;margin-top:0}
.site-footer h4{color:#fff;font-size:.95rem;margin-bottom:14px;letter-spacing:.04em}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.4fr;gap:36px;margin-bottom:40px}
@media(max-width:900px){.footer-grid{grid-template-columns:1fr 1fr}}
@media(max-width:560px){.footer-grid{grid-template-columns:1fr}}
.site-footer ul{list-style:none}
.site-footer ul li{margin:7px 0}
.site-footer ul a{color:#c3d7ec;font-size:.92rem}
.site-footer ul a:hover{color:#fff}
.entity-block{background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.14);border-radius:10px;padding:14px 16px;margin-top:10px;font-size:.8rem;line-height:1.5}
.entity-block b{color:#fff;display:block;margin-bottom:2px;font-size:.82rem}
.footer-bottom{border-top:1px solid rgba(255,255,255,.12);padding-top:22px;font-size:.8rem;color:#8fb0d2;display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap}
.footer-bottom a{color:#9fc4e8}
.footer-bottom a:hover{color:#fff}
.skip-link{position:absolute;left:-9999px;top:0;background:#fff;padding:10px 16px;z-index:99}
.skip-link:focus{left:8px;top:8px}

/* 正文排版与官网一致 */
main#main{padding:40px 0 56px}
.entry-content h1,.entry-content h2,.entry-content h3,.entry-content h4{color:var(--navy)}