/* ── Dark (default) ── */
:root,[data-theme="dark"]{--bg:#070a10;--s1:rgba(12,16,26,0.92);--s2:rgba(18,23,36,0.75);--border:rgba(255,255,255,0.07);--border2:rgba(255,255,255,0.13);--text:#d8e2f0;--muted:#62708a;--accent:#6aaeff;--green:#3fffc4;--amber:#ffb84d;--red:#ff4466;--purple:#b06aff;--header-bg:rgba(7,10,16,.92);--toggle-bg:rgba(255,255,255,0.08);--toggle-hover:rgba(255,255,255,0.14)}

/* ── Light ── */
[data-theme="light"]{--bg:#f4f4fb;--s1:rgba(255,255,255,0.95);--s2:rgba(236,236,250,0.8);--border:rgba(0,0,0,0.08);--border2:rgba(0,0,0,0.15);--text:#1a1a2e;--muted:#6b6b90;--accent:#4070e0;--green:#0a7a50;--amber:#a06000;--red:#c01030;--purple:#6030b0;--header-bg:rgba(244,244,251,.92);--toggle-bg:rgba(0,0,0,0.06);--toggle-hover:rgba(0,0,0,0.10)}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{min-height:100vh;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;font-size:15px;line-height:1.75;overflow-x:hidden;transition:background .25s,color .25s}
body::before{content:'';position:fixed;inset:0;z-index:0;pointer-events:none}
[data-theme="dark"] body::before{background:radial-gradient(ellipse 80% 50% at 15% 110%,rgba(30,70,180,.1),transparent 60%),radial-gradient(ellipse 55% 35% at 85% -5%,rgba(90,40,190,.07),transparent 55%)}
[data-theme="light"] body::before{background:radial-gradient(ellipse 80% 50% at 15% 110%,rgba(100,130,255,.06),transparent 60%),radial-gradient(ellipse 55% 35% at 85% -5%,rgba(150,100,255,.04),transparent 55%)}
header{position:sticky;top:0;z-index:20;display:flex;align-items:center;justify-content:space-between;padding:0 24px;height:52px;border-bottom:1px solid var(--border);background:var(--header-bg);backdrop-filter:blur(16px);transition:background .25s,border-color .25s}
.logo{display:flex;align-items:center;gap:9px;font-size:15px;font-weight:700;text-decoration:none;color:var(--text);letter-spacing:-.01em}
.logo-mark{width:26px;height:26px;border-radius:7px;background:linear-gradient(135deg,#6aaeff,#b06aff);display:flex;align-items:center;justify-content:center;font-size:13px}
.header-right{display:flex;align-items:center;gap:10px}
.back-btn{padding:5px 13px;border:1px solid var(--border2);border-radius:6px;background:transparent;color:var(--muted);font-family:inherit;font-size:12px;text-decoration:none;transition:color .15s}
.back-btn:hover{color:var(--text)}

/* ── Theme toggle ── */
.theme-toggle{width:30px;height:30px;border-radius:7px;border:1px solid var(--border2);background:var(--toggle-bg);cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:14px;transition:background .2s;flex-shrink:0}
.theme-toggle:hover{background:var(--toggle-hover)}
.theme-toggle .icon-dark{display:block}
.theme-toggle .icon-light{display:none}
[data-theme="light"] .theme-toggle .icon-dark{display:none}
[data-theme="light"] .theme-toggle .icon-light{display:block}

/* ── Article layout ── */
.article-wrap{position:relative;z-index:1;max-width:760px;margin:0 auto;padding:52px 24px 96px}
.breadcrumb{font-size:12px;color:var(--muted);margin-bottom:32px}
.breadcrumb a{color:var(--muted);text-decoration:none}
.breadcrumb a:hover{color:var(--accent)}
.breadcrumb span{margin:0 6px}
.article-meta{display:flex;align-items:center;gap:14px;margin-bottom:20px;flex-wrap:wrap}
.meta-tag{display:inline-block;padding:3px 10px;border-radius:5px;font-size:11px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;background:rgba(106,174,255,.1);border:1px solid rgba(106,174,255,.2);color:var(--accent)}
.meta-date{font-size:12px;color:var(--muted)}
.meta-read{font-size:12px;color:var(--muted)}
h1.article-title{font-size:36px;font-weight:900;letter-spacing:-.03em;line-height:1.15;margin-bottom:16px}
.article-lead{font-size:17px;color:var(--muted);line-height:1.8;margin-bottom:40px;padding-bottom:32px;border-bottom:1px solid var(--border)}
.article-body h2{font-size:20px;font-weight:800;letter-spacing:-.02em;color:var(--text);margin:40px 0 14px}
.article-body h3{font-size:15px;font-weight:700;color:var(--text);margin:28px 0 10px}
.article-body p{color:var(--muted);margin-bottom:18px;line-height:1.85}
.article-body ul,.article-body ol{color:var(--muted);padding-left:22px;margin-bottom:18px}
.article-body li{margin-bottom:8px;line-height:1.75}
.article-body strong{color:var(--text);font-weight:600}
.article-body a{color:var(--accent);text-decoration:none}
.article-body a:hover{text-decoration:underline}
.article-body table{width:100%;border-collapse:collapse;margin:24px 0;font-size:13px}
.article-body th{text-align:left;padding:10px 14px;border-bottom:1px solid var(--border2);font-size:11px;font-weight:700;letter-spacing:.07em;text-transform:uppercase;color:var(--muted)}
.article-body td{padding:10px 14px;border-bottom:1px solid var(--border);color:var(--muted)}
.article-body td:first-child{color:var(--text);font-weight:500}
.article-body tr:last-child td{border-bottom:none}
.highlight-box{background:var(--s1);border:1px solid rgba(106,174,255,.2);border-left:3px solid var(--accent);border-radius:10px;padding:18px 20px;margin:24px 0}
.highlight-box p{margin:0;color:var(--text)}

/* ── CTA ── */
.article-cta{background:var(--s1);border:1px solid var(--border);border-radius:16px;padding:36px 32px;text-align:center;margin:48px 0 0}
.article-cta h3{font-size:20px;font-weight:800;margin-bottom:10px}
.article-cta p{color:var(--muted);font-size:14px;margin-bottom:24px}
.cta-btn{display:inline-flex;align-items:center;gap:8px;padding:13px 32px;border-radius:10px;background:rgba(106,174,255,.13);border:1px solid rgba(106,174,255,.38);color:var(--accent);font-family:inherit;font-size:14px;font-weight:700;text-decoration:none;transition:all .15s}
.cta-btn:hover{background:rgba(106,174,255,.22);transform:translateY(-1px)}

/* ── Related articles ── */
.related{margin-top:56px;padding-top:32px;border-top:1px solid var(--border)}
.related h3{font-size:12px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:16px}
.related-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}
@media(max-width:520px){.related-grid{grid-template-columns:1fr}}
.related-card{background:var(--s1);border:1px solid var(--border);border-radius:12px;padding:16px 18px;text-decoration:none;transition:border-color .15s;display:block}
.related-card:hover{border-color:var(--border2)}
.related-card .rc-tag{font-size:10px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--accent);margin-bottom:7px}
.related-card .rc-title{font-size:13px;font-weight:600;color:var(--text);line-height:1.4}

/* ── Footer ── */
footer{position:relative;z-index:1;text-align:center;padding:20px;font-size:11px;color:var(--muted);border-top:1px solid var(--border)}
footer a{color:var(--muted);text-decoration:none;margin:0 8px}
footer a:hover{color:var(--accent)}

/* ── Blog index ── */
.blog-hero{position:relative;z-index:1;padding:64px 24px 48px;border-bottom:1px solid var(--border);text-align:center}
.blog-hero h1{font-size:40px;font-weight:900;letter-spacing:-.03em;margin-bottom:12px}
.blog-hero p{color:var(--muted);font-size:15px;max-width:480px;margin:0 auto}
.blog-grid-wrap{position:relative;z-index:1;max-width:940px;margin:0 auto;padding:48px 24px 96px}
.blog-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
@media(max-width:720px){.blog-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:480px){.blog-grid{grid-template-columns:1fr}}
.blog-card{background:var(--s1);border:1px solid var(--border);border-radius:14px;padding:22px;text-decoration:none;display:flex;flex-direction:column;gap:10px;transition:border-color .2s}
.blog-card:hover{border-color:var(--border2)}
.bc-tag{font-size:10px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--accent)}
.bc-title{font-size:15px;font-weight:700;color:var(--text);line-height:1.4}
.bc-desc{font-size:12px;color:var(--muted);line-height:1.7;flex:1}
.bc-meta{font-size:11px;color:var(--muted)}

@media(max-width:480px){
  .article-wrap{padding:36px 16px 72px}
  h1.article-title{font-size:26px}
  .article-lead{font-size:15px}
  .article-cta{padding:24px 20px}
  header{padding:0 14px}
}