*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #f5f5f4; --white: #ffffff; --border: #e2e2e0; --border2: #d0d0ce;
  --text: #1a1a1a; --sub: #6b6b6b; --muted: #9a9a9a;
  --accent: #1a6b3a; --accent-lt: #e8f5ee;
  --danger: #c0392b; --warn: #b7660a;
  --sans: 'Geist', sans-serif; --mono: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --radius: 8px; --shadow: 0 1px 3px rgba(0,0,0,0.08);
}
body { background: var(--bg); color: var(--text); font-family: var(--sans); font-size: 16px; line-height: 1.7; }
.topnav { background: var(--white); border-bottom: 1px solid var(--border); height: 56px; display: flex; align-items: center; padding: 0 24px; gap: 12px; position: sticky; top: 0; z-index: 100; }
.logo { font-size: 18px; font-weight: 700; color: var(--text); text-decoration: none; letter-spacing: -0.02em; display: flex; align-items: center; gap: 8px; }
.logo-icon { width: 28px; height: 28px; background: var(--text); border-radius: 6px; display: flex; align-items: center; justify-content: center; color: white; font-size: 13px; font-weight: 700; }
.nav-links { display: flex; gap: 4px; margin-left: 8px; }
.nav-link { font-size: 13px; font-weight: 500; color: var(--sub); text-decoration: none; padding: 6px 12px; border-radius: 6px; transition: background 0.15s, color 0.15s; }
.nav-link:hover { background: var(--bg); color: var(--text); }
.nav-link.active { background: var(--bg); color: var(--text); font-weight: 600; }
.nav-tag { font-size: 12px; color: var(--muted); margin-left: auto; }
.nav-tag a { color: var(--muted); text-decoration: none; font-weight: 600; }
.page-wrap { max-width: 1100px; margin: 0 auto; padding: 40px 24px 80px; display: grid; grid-template-columns: 1fr 300px; gap: 40px; align-items: start; }
@media (max-width: 800px) { .page-wrap { grid-template-columns: 1fr; } .sidebar { display: none; } }
article { background: var(--white); border: 1px solid var(--border); border-radius: 12px; overflow: hidden; box-shadow: var(--shadow); }
.article-hero { background: linear-gradient(135deg, #1a1a1a 0%, #2d4a35 100%); padding: 48px 40px; color: white; }
.article-cat { font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.12em; color: #6ee7a0; margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.article-cat::before { content: ''; display: inline-block; width: 20px; height: 1px; background: #6ee7a0; }
.article-hero h1 { font-size: clamp(22px, 4vw, 34px); font-weight: 700; letter-spacing: -0.02em; line-height: 1.25; margin-bottom: 16px; }
.article-meta { font-size: 13px; color: rgba(255,255,255,0.55); display: flex; gap: 14px; flex-wrap: wrap; }
.article-body { padding: 40px; }
.breadcrumb { font-size: 12px; color: var(--muted); margin-bottom: 24px; display: flex; gap: 6px; align-items: center; flex-wrap: wrap; }
.breadcrumb a { color: var(--muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb span { color: var(--border2); }
.article-body h2 { font-size: 22px; font-weight: 700; letter-spacing: -0.02em; margin: 36px 0 14px; padding-top: 8px; color: var(--text); }
.article-body h3 { font-size: 17px; font-weight: 600; margin: 24px 0 10px; color: var(--text); }
.article-body .article-cta h3 { color: white !important; margin: 0 0 8px; }
.article-body .article-cta p { color: rgba(255,255,255,0.75) !important; }
.article-body p { color: var(--sub); margin-bottom: 16px; line-height: 1.75; }
.article-body ul, .article-body ol { color: var(--sub); padding-left: 22px; margin-bottom: 16px; }
.article-body li { margin-bottom: 8px; line-height: 1.65; }
.article-body strong { color: var(--text); font-weight: 600; }
.article-body a { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }
.step-box { background: var(--bg); border: 1px solid var(--border); border-left: 4px solid var(--accent); border-radius: 0 var(--radius) var(--radius) 0; padding: 20px 22px; margin: 24px 0; }
.step-num { font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: var(--accent); margin-bottom: 6px; }
.step-box h3 { font-size: 16px; font-weight: 700; color: var(--text); margin: 0 0 8px; }
.step-box p { color: var(--sub); font-size: 14px; margin: 0; }
.warn-box { background: #fef8f0; border: 1px solid #f5dbb8; border-radius: var(--radius); padding: 16px 20px; margin: 20px 0; display: flex; gap: 12px; }
.warn-box .wi { font-size: 20px; flex-shrink: 0; margin-top: 1px; }
.warn-box p { color: var(--warn); font-size: 14px; margin: 0; }
.tip-box { background: var(--accent-lt); border: 1px solid #b8dfc9; border-radius: var(--radius); padding: 16px 20px; margin: 20px 0; display: flex; gap: 12px; }
.tip-box .wi { font-size: 20px; flex-shrink: 0; margin-top: 1px; }
.tip-box p { color: #1a5c30; font-size: 14px; margin: 0; line-height: 1.6; }
.danger-box { background: #fdf2f1; border: 1px solid #f5c6c3; border-radius: var(--radius); padding: 16px 20px; margin: 20px 0; display: flex; gap: 12px; }
.danger-box .wi { font-size: 20px; flex-shrink: 0; }
.danger-box p { color: var(--danger); font-size: 14px; margin: 0; }
.checklist { list-style: none; padding: 0; margin: 16px 0; }
.checklist li { display: flex; gap: 10px; align-items: flex-start; padding: 8px 0; border-bottom: 1px solid var(--border); font-size: 14px; color: var(--sub); }
.checklist li:last-child { border-bottom: none; }
.checklist li::before { content: '☐'; font-size: 16px; color: var(--border2); flex-shrink: 0; margin-top: 1px; }
.num-list { list-style: none; padding: 0; margin: 16px 0; counter-reset: numlist; }
.num-list li { display: flex; gap: 14px; align-items: flex-start; padding: 12px 0; border-bottom: 1px solid var(--border); font-size: 14px; color: var(--sub); counter-increment: numlist; }
.num-list li:last-child { border-bottom: none; }
.num-list li::before { content: counter(numlist); font-family: var(--sans); font-size: 12px; font-weight: 700; color: var(--accent); background: var(--accent-lt); border: 1px solid #b8dfc9; width: 26px; height: 26px; border-radius: 50%; display: flex; align-items: center; justify-content: center; flex-shrink: 0; margin-top: 1px; }
.article-cta { background: var(--text); color: white; border-radius: 10px; padding: 28px; text-align: center; margin: 36px 0; }
.article-cta h3 { font-size: 18px; font-weight: 700; margin-bottom: 8px; color: white !important; }
.article-cta p { font-size: 13px; opacity: 0.75; margin-bottom: 18px; color: rgba(255,255,255,0.75) !important; }
.btn-cta { display: inline-block; background: var(--accent); color: white !important; font-weight: 600; font-size: 14px; padding: 11px 26px; border-radius: var(--radius); text-decoration: none !important; }
.author-box { background: var(--bg); border: 1px solid var(--border); border-radius: 10px; padding: 20px 24px; margin-top: 36px; display: flex; gap: 16px; align-items: center; }
.author-avatar { width: 48px; height: 48px; background: var(--text); border-radius: 50%; display: flex; align-items: center; justify-content: center; color: white; font-weight: 700; font-size: 16px; flex-shrink: 0; }
.author-info h4 { font-size: 14px; font-weight: 600; margin-bottom: 3px; }
.author-info p { font-size: 13px; color: var(--sub); margin: 0; }
.sidebar { position: sticky; top: 76px; display: flex; flex-direction: column; gap: 16px; }
.sidebar-card { background: var(--white); border: 1px solid var(--border); border-radius: 10px; padding: 20px; box-shadow: var(--shadow); }
.sidebar-card h4 { font-size: 13px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin-bottom: 14px; padding-bottom: 10px; border-bottom: 1px solid var(--border); }
.toc { list-style: none; padding: 0; }
.toc li { margin-bottom: 8px; }
.toc a { font-size: 13px; color: var(--sub); text-decoration: none; display: flex; gap: 8px; align-items: flex-start; line-height: 1.4; transition: color 0.15s; }
.toc a:hover { color: var(--accent); }
.toc-num { font-family: var(--sans); font-size: 11px; color: var(--muted); flex-shrink: 0; margin-top: 1px; }
.related-post { display: flex; gap: 12px; align-items: flex-start; text-decoration: none; color: inherit; padding: 10px 0; border-bottom: 1px solid var(--border); transition: background 0.1s; }
.related-post:last-child { border-bottom: none; padding-bottom: 0; }
.related-icon { font-size: 22px; flex-shrink: 0; }
.related-post h5 { font-size: 13px; font-weight: 600; color: var(--text); line-height: 1.4; margin-bottom: 3px; }
.related-post span { font-size: 11px; color: var(--muted); }
.all-posts-sidebar { list-style: none; padding: 0; }
.all-posts-sidebar li { border-bottom: 1px solid var(--border); }
.all-posts-sidebar li:last-child { border-bottom: none; }
.all-posts-sidebar a { display: flex; gap: 8px; align-items: flex-start; padding: 9px 0; text-decoration: none; color: var(--sub); font-size: 13px; line-height: 1.4; transition: color 0.15s; }
.all-posts-sidebar a:hover { color: var(--accent); }
.all-posts-sidebar .ai { flex-shrink: 0; font-size: 16px; }
footer { border-top: 1px solid var(--border); background: var(--white); padding: 20px 24px; text-align: center; font-size: 12px; color: var(--muted); line-height: 1.8; }
footer a { color: var(--muted); text-decoration: none; }
footer a:hover { color: var(--text); }

/* ── Mobile hamburger nav ── */
.hamburger{display:none;flex-direction:column;justify-content:center;gap:5px;width:38px;height:38px;background:none;border:none;cursor:pointer;padding:6px;margin-left:auto;border-radius:6px;flex-shrink:0;}
.hamburger:hover{background:var(--bg);}
.hamburger span{display:block;width:20px;height:2px;background:var(--text);border-radius:2px;transition:all 0.25s;}
.hamburger.open span:nth-child(1){transform:translateY(7px) rotate(45deg);}
.hamburger.open span:nth-child(2){opacity:0;transform:scaleX(0);}
.hamburger.open span:nth-child(3){transform:translateY(-7px) rotate(-45deg);}
.mob-menu{display:none;position:fixed;top:56px;left:0;right:0;background:#fff;border-bottom:1px solid #e2e2e0;box-shadow:0 8px 24px rgba(0,0,0,0.12);z-index:9999;}
.mob-menu.show{display:block;}
.mob-menu a{display:flex;align-items:center;gap:12px;padding:14px 20px;font-size:15px;font-weight:500;color:#1a1a1a;text-decoration:none;border-bottom:1px solid #f0f0f0;}
.mob-menu a:hover{background:#f5f5f4;}
.mob-menu a.cur{color:#1a6b3a;font-weight:600;}
.mob-menu .mfi{font-size:17px;width:24px;text-align:center;}
.mob-footer{padding:12px 20px;font-size:12px;color:#9a9a9a;background:#fafafa;border-top:1px solid #e2e2e0;}
.mob-overlay{display:none;position:fixed;inset:0;top:56px;background:rgba(0,0,0,0.25);z-index:9998;}
.mob-overlay.show{display:block;}
@media(max-width:700px){
  .nav-links{display:none!important;}
  .nav-tag{display:none!important;}
  .hamburger{display:flex!important;}
  .topnav{height:52px!important;padding:0 14px!important;}
  .mob-menu{top:52px;}
  .mob-overlay{top:52px;}
}