/*
Theme Name: Litbuy Spreadsheet
Theme URI: https://sheetcn.com/
Author: Litbuy
Author URI: https://sheetcn.com/
Description: SEO-optimized WordPress theme for the Litbuy Spreadsheet brand. Features a category dropdown, product category buttons, and CTA buttons that drive traffic to sheetcn.com.
Version: 1.0.0
Requires at least: 5.5
Requires PHP: 7.2
License: GNU General Public License v2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html
Text Domain: litbuy-spreadsheet
Tags: seo, blog, one-column, two-columns, custom-menu, featured-images, threaded-comments
*/

/* ---------- Reset & Base ---------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:'Inter','Helvetica Neue',Arial,'PingFang SC','Microsoft YaHei',sans-serif;
  font-size:16px;line-height:1.65;color:#1f2328;background:#ffffff;
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
}
img{max-width:100%;height:auto;display:block}
a{color:#0a66c2;text-decoration:none;transition:color .2s ease}
a:hover{color:#004182;text-decoration:underline}
h1,h2,h3,h4,h5,h6{font-family:'Inter','Helvetica Neue',sans-serif;line-height:1.25;color:#0d1117;margin:0 0 .75em;font-weight:700}
h1{font-size:2.25rem}
h2{font-size:1.75rem;margin-top:1.5em}
h3{font-size:1.35rem;margin-top:1.2em}
p{margin:0 0 1em}
ul,ol{margin:0 0 1em 1.5em}
li{margin-bottom:.4em}
blockquote{border-left:4px solid #0a66c2;background:#f6f8fa;padding:1em 1.25em;margin:1.25em 0;font-style:italic;color:#444}
code{background:#f1f3f5;padding:2px 6px;border-radius:4px;font-size:.92em}

/* ---------- Layout ---------- */
.container{max-width:1180px;margin:0 auto;padding:0 20px}
.site-wrapper{min-height:100vh;display:flex;flex-direction:column}
main{flex:1}

/* ---------- Header ---------- */
.site-header{
  background:#ffffff;border-bottom:1px solid #e5e7eb;
  position:sticky;top:0;z-index:1000;
  box-shadow:0 1px 3px rgba(0,0,0,.03);
}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:16px 0;gap:24px;flex-wrap:wrap}
.site-branding a{display:flex;align-items:center;gap:10px;color:#0d1117;text-decoration:none}
.site-branding a:hover{text-decoration:none}
.site-logo{width:38px;height:38px;background:linear-gradient(135deg,#ff5f1f 0%,#ff2e63 100%);border-radius:8px;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:800;font-size:1.1rem}
.site-title{font-size:1.3rem;font-weight:800;letter-spacing:-.01em}
.site-tagline{font-size:.78rem;color:#656d76;font-weight:500;margin-top:-2px}

/* Nav */
.main-nav{display:flex;align-items:center;gap:8px}
.main-nav ul{list-style:none;margin:0;padding:0;display:flex;gap:4px;align-items:center}
.main-nav li{margin:0}
.main-nav a{
  display:inline-block;padding:9px 14px;color:#24292f;font-weight:500;font-size:.95rem;border-radius:6px;
}
.main-nav a:hover{background:#f3f4f6;color:#0a66c2;text-decoration:none}

/* Dropdown */
.has-dropdown{position:relative}
.dropdown-toggle{
  background:#0d1117;color:#fff !important;padding:9px 16px;border-radius:6px;cursor:pointer;
  display:inline-flex;align-items:center;gap:6px;border:none;font-weight:600;font-size:.95rem;
}
.dropdown-toggle:hover{background:#24292f !important;color:#fff !important}
.dropdown-toggle::after{content:'▾';font-size:.75rem;transition:transform .2s}
.has-dropdown:hover .dropdown-toggle::after,
.has-dropdown.open .dropdown-toggle::after{transform:rotate(180deg)}
.dropdown-menu{
  position:absolute;top:calc(100% + 8px);right:0;min-width:240px;
  background:#fff;border:1px solid #e5e7eb;border-radius:10px;
  box-shadow:0 10px 30px rgba(0,0,0,.12);
  padding:8px;opacity:0;visibility:hidden;transform:translateY(-6px);transition:all .18s ease;
  z-index:1100;
}
.has-dropdown:hover .dropdown-menu,
.has-dropdown.open .dropdown-menu,
.has-dropdown:focus-within .dropdown-menu{opacity:1;visibility:visible;transform:translateY(0)}
.dropdown-menu li{display:block}
.dropdown-menu a{
  display:block;padding:10px 14px;color:#24292f;font-weight:500;font-size:.95rem;border-radius:6px;
}
.dropdown-menu a:hover{background:#fff4ec;color:#ff5f1f;text-decoration:none}

/* ---------- Hero ---------- */
.hero{
  background:linear-gradient(135deg,#0d1117 0%,#1a1f29 50%,#2d1b3d 100%);
  color:#fff;padding:80px 0 70px;position:relative;overflow:hidden;
}
.hero::before{
  content:'';position:absolute;top:-50%;right:-10%;width:600px;height:600px;
  background:radial-gradient(circle,rgba(255,95,31,.25) 0%,transparent 70%);
  border-radius:50%;
}
.hero-inner{position:relative;z-index:2;max-width:820px}
.hero-badge{display:inline-block;background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.2);color:#ffb088;padding:6px 14px;border-radius:999px;font-size:.85rem;font-weight:600;margin-bottom:20px;letter-spacing:.02em}
.hero h1{font-size:3rem;color:#fff;line-height:1.15;margin-bottom:20px;letter-spacing:-.015em}
.hero h1 span{background:linear-gradient(135deg,#ff5f1f,#ff2e63);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.hero-sub{font-size:1.15rem;color:#c9d1d9;margin-bottom:32px;max-width:680px;line-height:1.6}
.hero-ctas{display:flex;gap:14px;flex-wrap:wrap}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:14px 28px;border-radius:10px;font-weight:700;font-size:1rem;
  text-decoration:none;transition:all .2s ease;border:2px solid transparent;cursor:pointer;
  line-height:1;letter-spacing:.01em;
}
.btn-primary{background:linear-gradient(135deg,#ff5f1f,#ff2e63);color:#fff;box-shadow:0 4px 14px rgba(255,95,31,.4)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(255,95,31,.55);color:#fff;text-decoration:none}
.btn-secondary{background:#fff;color:#0d1117;border-color:#fff}
.btn-secondary:hover{background:transparent;color:#fff;text-decoration:none}
.btn-outline{background:transparent;color:#0d1117;border-color:#0d1117}
.btn-outline:hover{background:#0d1117;color:#fff;text-decoration:none}
.btn-sm{padding:10px 18px;font-size:.9rem}

/* ---------- Section ---------- */
.section{padding:70px 0}
.section-alt{background:#f8f9fb}
.section-header{text-align:center;max-width:720px;margin:0 auto 48px}
.section-header .eyebrow{color:#ff5f1f;font-weight:700;font-size:.9rem;text-transform:uppercase;letter-spacing:.08em;margin-bottom:10px;display:inline-block}
.section-header h2{font-size:2.25rem;margin-bottom:12px}
.section-header p{color:#656d76;font-size:1.08rem}

/* ---------- Category Grid ---------- */
.category-grid{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
  gap:16px;
}
.category-card{
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  background:#fff;border:1px solid #e5e7eb;border-radius:14px;padding:28px 20px;text-align:center;
  color:#0d1117;font-weight:600;transition:all .25s ease;text-decoration:none;
  min-height:140px;
}
.category-card:hover{
  transform:translateY(-4px);border-color:#ff5f1f;color:#ff5f1f;
  box-shadow:0 12px 24px rgba(255,95,31,.15);text-decoration:none;
}
.category-icon{
  width:52px;height:52px;border-radius:12px;
  background:linear-gradient(135deg,#fff4ec,#ffe5d4);
  display:flex;align-items:center;justify-content:center;font-size:1.6rem;margin-bottom:12px;
  transition:all .25s ease;
}
.category-card:hover .category-icon{background:linear-gradient(135deg,#ff5f1f,#ff2e63);color:#fff}
.category-name{font-size:1.05rem;font-weight:700;margin-bottom:4px}
.category-meta{font-size:.82rem;color:#656d76;font-weight:500}
.category-card:hover .category-meta{color:#ff5f1f}

/* ---------- Article Cards ---------- */
.article-grid{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));
  gap:24px;
}
.article-card{
  background:#fff;border:1px solid #e5e7eb;border-radius:14px;overflow:hidden;
  transition:all .25s ease;display:flex;flex-direction:column;
}
.article-card:hover{transform:translateY(-4px);box-shadow:0 14px 32px rgba(0,0,0,.08);border-color:#d0d7de}
.article-card-thumb{
  height:160px;background:linear-gradient(135deg,#0d1117,#2d1b3d);
  display:flex;align-items:center;justify-content:center;color:#ff5f1f;font-size:2.5rem;font-weight:800;
  position:relative;overflow:hidden;
}
.article-card-thumb::after{
  content:'';position:absolute;top:0;left:0;right:0;bottom:0;
  background:radial-gradient(circle at 70% 30%,rgba(255,95,31,.3),transparent 60%);
}
.article-card-body{padding:22px;flex:1;display:flex;flex-direction:column}
.article-card .tag{display:inline-block;background:#fff4ec;color:#ff5f1f;padding:3px 10px;border-radius:999px;font-size:.75rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em;margin-bottom:10px;align-self:flex-start}
.article-card h3{font-size:1.2rem;margin-bottom:10px;line-height:1.3}
.article-card h3 a{color:#0d1117}
.article-card h3 a:hover{color:#ff5f1f;text-decoration:none}
.article-card p{color:#656d76;font-size:.95rem;margin-bottom:16px;flex:1}
.article-card .read-more{color:#ff5f1f;font-weight:700;font-size:.92rem;display:inline-flex;align-items:center;gap:4px}
.article-card .read-more:hover{text-decoration:none;gap:8px}

/* ---------- Content / Article ---------- */
.content-section{padding:70px 0;background:#fff}
.content-wrap{max-width:820px;margin:0 auto}
.content-wrap h1{font-size:2.4rem;margin-bottom:16px;letter-spacing:-.015em}
.content-wrap h2{font-size:1.7rem;margin-top:1.8em;padding-top:.2em;border-top:1px solid #f1f3f5;padding-top:1em}
.content-wrap h2:first-of-type{border-top:none;padding-top:0}
.content-wrap h3{font-size:1.25rem;margin-top:1.5em;color:#24292f}
.content-wrap p{color:#24292f;font-size:1.05rem;line-height:1.75}
.content-wrap ul,.content-wrap ol{margin-left:1.5em;color:#24292f}
.content-wrap li{line-height:1.75;margin-bottom:.6em}
.content-wrap strong{color:#0d1117;font-weight:700}
.content-wrap a{color:#ff5f1f;font-weight:600;border-bottom:1px dashed #ff5f1f}
.content-wrap a:hover{color:#c73410;text-decoration:none;border-bottom-style:solid}
.article-meta{color:#656d76;font-size:.92rem;margin-bottom:28px;display:flex;gap:14px;flex-wrap:wrap;align-items:center}
.article-meta .cat{background:#0d1117;color:#fff;padding:4px 12px;border-radius:999px;font-size:.78rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em}

/* Breadcrumb */
.breadcrumb{font-size:.9rem;color:#656d76;margin-bottom:18px}
.breadcrumb a{color:#656d76}
.breadcrumb a:hover{color:#ff5f1f}
.breadcrumb .sep{margin:0 8px;color:#d0d7de}

/* Internal link callout */
.home-link-callout{
  background:linear-gradient(135deg,#fff4ec,#ffe5d4);border:1px solid #ffd4b8;
  border-radius:12px;padding:20px 24px;margin:30px 0;
}
.home-link-callout p{margin-bottom:8px;font-weight:600;color:#0d1117}
.home-link-callout a{color:#ff5f1f;font-weight:700}

/* ---------- CTA Band ---------- */
.cta-band{
  background:linear-gradient(135deg,#ff5f1f,#ff2e63);color:#fff;padding:60px 0;text-align:center;
}
.cta-band h2{color:#fff;font-size:2.1rem;margin-bottom:14px}
.cta-band p{color:rgba(255,255,255,.95);font-size:1.1rem;margin-bottom:28px;max-width:620px;margin-left:auto;margin-right:auto}
.cta-band .btn-secondary{color:#ff5f1f}
.cta-band .btn-secondary:hover{background:#0d1117;border-color:#0d1117;color:#fff}

/* ---------- Footer ---------- */
.site-footer{background:#0d1117;color:#c9d1d9;padding:50px 0 24px}
.footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr;gap:40px;margin-bottom:36px}
.footer-col h4{color:#fff;font-size:1rem;margin-bottom:16px;text-transform:uppercase;letter-spacing:.05em}
.footer-col ul{list-style:none;margin:0;padding:0}
.footer-col li{margin-bottom:8px}
.footer-col a{color:#c9d1d9;font-size:.95rem}
.footer-col a:hover{color:#ff5f1f;text-decoration:none}
.footer-col p{font-size:.95rem;line-height:1.65;color:#9ba3af}
.footer-bottom{border-top:1px solid #30363d;padding-top:20px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;font-size:.88rem;color:#656d76}
.footer-bottom a{color:#9ba3af}

/* ---------- 404 ---------- */
.error-404{text-align:center;padding:100px 0}
.error-404 h1{font-size:6rem;background:linear-gradient(135deg,#ff5f1f,#ff2e63);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;margin-bottom:0}
.error-404 h2{font-size:1.8rem;margin-bottom:14px}
.error-404 p{color:#656d76;margin-bottom:28px}

/* ---------- Responsive ---------- */
@media (max-width:860px){
  .hero h1{font-size:2.2rem}
  .hero{padding:60px 0 54px}
  .section{padding:50px 0}
  .section-header h2{font-size:1.75rem}
  .footer-grid{grid-template-columns:1fr;gap:28px}
  .header-inner{gap:12px}
  .main-nav ul{flex-wrap:wrap;justify-content:flex-end}
  .content-wrap h1{font-size:1.9rem}
  .content-wrap h2{font-size:1.4rem}
  .cta-band h2{font-size:1.6rem}
}
@media (max-width:520px){
  .hero h1{font-size:1.8rem}
  .hero-sub{font-size:1rem}
  .btn{padding:12px 20px;font-size:.95rem}
  .site-title{font-size:1.1rem}
  .site-tagline{display:none}
  .dropdown-menu{right:auto;left:0}
}