:root {
  --bg-primary:    #0D1117;
  --bg-secondary:  #161B22;
  --bg-card:       #1C2333;
  --bg-code:       #0D1F2D;
  --ps-blue:       #012456;
  --ps-cyan:       #00B4FF;
  --ps-cyan-dark:  #0090CC;
  --text-primary:  #E6EDF3;
  --text-muted:    #8B949E;
  --text-link:     #58A6FF;
  --border:        #30363D;
  --tag-beginner:  #1F6325;
  --tag-inter:     #7D4E00;
  --tag-advanced:  #6E2020;
  --radius:        8px;
  --radius-lg:     12px;
  --font-mono:     'Cascadia Code', 'Fira Code', 'Consolas', monospace;
  --font-body:     'Segoe UI', system-ui, -apple-system, sans-serif;
  --transition:    0.2s ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
}
a { color: var(--text-link); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--ps-cyan); }
.container { max-width: 1100px; margin: 0 auto; padding: 0 1.5rem; }

/* HEADER */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(13, 17, 23, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { display: flex; align-items: center; gap: 0.4rem; font-family: var(--font-mono); font-size: 1.2rem; color: var(--text-primary); }
.logo-ps { background: var(--ps-blue); color: var(--ps-cyan); padding: 2px 8px; border-radius: 4px; font-weight: 700; font-size: 1rem; border: 1px solid var(--ps-cyan); }
.logo-domain { font-weight: 600; }
.main-nav { display: flex; gap: 2rem; }
.main-nav a { color: var(--text-muted); font-size: 0.95rem; transition: color var(--transition); }
.main-nav a:hover { color: var(--ps-cyan); }
.nav-toggle { display: none; background: none; border: 1px solid var(--border); color: var(--text-primary); padding: 6px 10px; border-radius: var(--radius); cursor: pointer; font-size: 1.1rem; }

/* HERO */
.hero { background: linear-gradient(135deg, var(--ps-blue) 0%, #0A0F1A 60%); padding: 6rem 0 5rem; border-bottom: 1px solid var(--border); }
.hero-prompt { font-family: var(--font-mono); font-size: 1.1rem; color: var(--text-muted); margin-bottom: 1.5rem; min-height: 1.8rem; }
.ps-prompt { color: var(--ps-cyan); font-weight: 600; }
.hero-cmd { color: #C9D1D9; margin-left: 0.5rem; }
.cursor { animation: blink 1s step-end infinite; color: var(--ps-cyan); }
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:0} }
.hero-title { font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 800; line-height: 1.2; margin-bottom: 1rem; background: linear-gradient(90deg, #fff 0%, var(--ps-cyan) 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero-sub { font-size: 1.15rem; color: var(--text-muted); max-width: 600px; margin-bottom: 2rem; }
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }

/* BUTTONS */
.btn { display: inline-block; padding: 0.7rem 1.6rem; border-radius: var(--radius); font-size: 0.95rem; font-weight: 600; cursor: pointer; transition: all var(--transition); border: 2px solid transparent; }
.btn-primary { background: var(--ps-cyan); color: var(--bg-primary); border-color: var(--ps-cyan); }
.btn-primary:hover { background: var(--ps-cyan-dark); border-color: var(--ps-cyan-dark); color: #fff; }
.btn-secondary { background: transparent; color: var(--ps-cyan); border-color: var(--ps-cyan); }
.btn-secondary:hover { background: var(--ps-cyan); color: var(--bg-primary); }

/* CODE PREVIEW */
.code-preview { padding: 4rem 1.5rem; }
.code-preview h2, .articles-section h2, .search-section h2, .about h2 { font-size: 1.6rem; font-weight: 700; margin-bottom: 1.5rem; }
.code-tabs { display: flex; gap: 0.5rem; margin-bottom: 0; border-bottom: 1px solid var(--border); }
.tab-btn { background: none; border: none; color: var(--text-muted); padding: 0.6rem 1.2rem; cursor: pointer; font-size: 0.9rem; border-bottom: 2px solid transparent; margin-bottom: -1px; transition: all var(--transition); font-family: var(--font-body); }
.tab-btn.active, .tab-btn:hover { color: var(--ps-cyan); border-bottom-color: var(--ps-cyan); }
.tab-content { display: none; background: var(--bg-code); border: 1px solid var(--border); border-top: none; border-radius: 0 0 var(--radius) var(--radius); }
.tab-content.active { display: block; }
.tab-content pre { margin: 0; overflow-x: auto; }
.tab-content code { font-family: var(--font-mono); font-size: 0.92rem; line-height: 1.6; }

/* ARTICLES GRID */
.articles-section { padding: 4rem 1.5rem; }
.articles-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 1.5rem; }
.card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 1.5rem; transition: border-color var(--transition), transform var(--transition); }
.card:hover { border-color: var(--ps-cyan); transform: translateY(-3px); }
.card-tag { display: inline-block; font-size: 0.75rem; font-weight: 600; padding: 2px 10px; border-radius: 20px; margin-bottom: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; }
.card:nth-child(1) .card-tag { background: var(--tag-beginner); color: #7EE787; }
.card:nth-child(2) .card-tag { background: var(--tag-inter); color: #FFA657; }
.card:nth-child(3) .card-tag { background: var(--tag-advanced); color: #FF7B72; }
.card h3 { font-size: 1.05rem; margin-bottom: 0.5rem; }
.card p { font-size: 0.9rem; color: var(--text-muted); margin-bottom: 0.75rem; }
.card-date { font-size: 0.8rem; color: var(--text-muted); font-family: var(--font-mono); }

/* SEARCH */
.search-section { padding: 4rem 1.5rem; background: var(--bg-secondary); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.search-box { display: flex; gap: 0.5rem; max-width: 600px; }
.search-box input { flex: 1; background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 0.75rem 1rem; color: var(--text-primary); font-size: 1rem; transition: border-color var(--transition); font-family: var(--font-body); }
.search-box input:focus { outline: none; border-color: var(--ps-cyan); }
.search-box button { background: var(--ps-cyan); border: none; color: var(--bg-primary); padding: 0.75rem 1.1rem; border-radius: var(--radius); cursor: pointer; font-size: 1.1rem; transition: background var(--transition); }
.search-box button:hover { background: var(--ps-cyan-dark); }
.search-results { list-style: none; margin-top: 1.5rem; max-width: 600px; display: flex; flex-direction: column; gap: 0.75rem; }
.search-results li { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 0.8rem 1rem; }
.search-results a { font-weight: 600; display: block; }
.search-results small { color: var(--text-muted); font-size: 0.85rem; }

/* ABOUT */
.about { padding: 4rem 1.5rem; }

/* ARTICLE PAGE */
.article-content { max-width: 780px; margin: 0 auto; padding: 3rem 1.5rem; }
.article-content h1 { font-size: clamp(1.6rem, 4vw, 2.4rem); margin-bottom: 0.5rem; }
.article-meta { color: var(--text-muted); font-size: 0.9rem; margin-bottom: 2rem; font-family: var(--font-mono); }
.article-content h2 { font-size: 1.4rem; margin: 2.5rem 0 1rem; color: var(--ps-cyan); }
.article-content h3 { font-size: 1.15rem; margin: 2rem 0 0.75rem; }
.article-content p { margin-bottom: 1.2rem; }
.article-content pre { background: var(--bg-code); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.2rem; overflow-x: auto; margin: 1.5rem 0; }
.article-content code { font-family: var(--font-mono); font-size: 0.9rem; }
.article-content p code, .article-content li code { background: var(--bg-code); padding: 2px 6px; border-radius: 4px; color: var(--ps-cyan); font-size: 0.9em; }
.article-content ul, .article-content ol { padding-left: 1.5rem; margin-bottom: 1.2rem; }
.article-content li { margin-bottom: 0.4rem; }

/* BREADCRUMB */
.breadcrumb { font-size: 0.88rem; color: var(--text-muted); padding: 1rem 1.5rem; border-bottom: 1px solid var(--border); }
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--ps-cyan); }

/* ARTICLES LIST PAGE */
.articles-list { max-width: 860px; margin: 0 auto; padding: 3rem 1.5rem; }
.articles-list h1 { font-size: 2rem; margin-bottom: 2rem; }
.article-item { border-bottom: 1px solid var(--border); padding: 1.5rem 0; }
.article-item h2 { font-size: 1.2rem; margin-bottom: 0.4rem; }
.article-item p { color: var(--text-muted); font-size: 0.93rem; }

/* FOOTER */
.site-footer { border-top: 1px solid var(--border); padding: 2rem 0; background: var(--bg-secondary); }
.footer-inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.5rem; color: var(--text-muted); font-size: 0.88rem; }

/* RESPONSIVE */
@media (max-width: 768px) {
  .main-nav { display: none; flex-direction: column; gap: 0; }
  .main-nav.open { display: flex; position: absolute; top: 64px; left: 0; right: 0; background: var(--bg-secondary); border-bottom: 1px solid var(--border); padding: 1rem; gap: 1rem; }
  .nav-toggle { display: block; }
  .hero { padding: 4rem 0 3rem; }
  .hero-actions { flex-direction: column; align-items: flex-start; }
  .articles-grid { grid-template-columns: 1fr; }
  .code-tabs { flex-wrap: wrap; }
  .footer-inner { flex-direction: column; align-items: center; text-align: center; }
}

/* HIGHLIGHT.JS OVERRIDE */
.hljs { background: var(--bg-code) !important; padding: 1.2rem !important; border-radius: var(--radius); }