/* ============================================
   TRẦN CÔNG THẮNG — BLOG v7.0
   Clean · Accessible · Refined
============================================ */

@font-face{font-family:'SVN-Gilroy';src:url('fonts/SVN-Gilroy_Regular.otf') format('opentype');font-weight:400;font-display:swap}
@font-face{font-family:'SVN-Gilroy';src:url('fonts/SVN-Gilroy_Medium.otf') format('opentype');font-weight:500;font-display:swap}
@font-face{font-family:'SVN-Gilroy';src:url('fonts/SVN-Gilroy_SemiBold.otf') format('opentype');font-weight:600;font-display:swap}
@font-face{font-family:'SVN-Gilroy';src:url('fonts/SVN-Gilroy_Bold.otf') format('opentype');font-weight:700;font-display:swap}

:root{
  --bg:#fafafa;--bg-card:#fff;--bg-code:#1e2030;--bg-subtle:#f3f3f3;--bg-hover:#ebebeb;
  --border:#e5e5e5;--border-hover:#d0d0d0;
  --ink:#1a1a1a;--body:#525252;--muted:#737373;--faint:#a3a3a3;
  --c-seo:#0d9668;--c-seo-bg:rgba(13,150,104,.06);--c-biz:#c2810e;--c-biz-bg:rgba(194,129,14,.06);--c-dev:#2563eb;--c-dev-bg:rgba(37,99,235,.06);--c-ai:#7c3aed;--c-ai-bg:rgba(124,58,237,.06);--c-life:#dc2646;--c-life-bg:rgba(220,38,70,.06);
  --nav-h:56px;--max-w:1080px;--content-w:680px;--r:10px;--r-lg:14px;
  --spring:cubic-bezier(.22,1,.36,1);--ease:cubic-bezier(.16,1,.3,1);--t:.25s;
  --font:'SVN-Gilroy',-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;
  --serif:Georgia,'Times New Roman',serif;
  --mono:'JetBrains Mono','SF Mono',Consolas,monospace;
}
[data-theme="dark"]{
  --bg:#111113;--bg-card:#191a1e;--bg-code:#1c1e2a;--bg-subtle:#232429;--bg-hover:#2c2d33;
  --border:#333339;--border-hover:#4a4a52;
  --ink:#dcdce0;--body:#9c9ca8;--muted:#7b7b8a;--faint:#5c5c6a;
  --c-seo:#5eead4;--c-biz:#fbbf24;--c-dev:#7dbbfe;--c-ai:#a598fd;--c-life:#f9a8d4;
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:var(--font);background:var(--bg);color:var(--body);line-height:1.6;-webkit-font-smoothing:antialiased;overflow-x:hidden;transition:background .3s ease,color .3s ease}
a{text-decoration:none;color:inherit}
button{font-family:inherit;cursor:pointer;border:none;background:none}
img{max-width:100%;display:block}
::selection{background:var(--ink);color:var(--bg)}

/* ══ FOCUS — accessibility ══ */
:focus-visible{outline:2px solid var(--c-dev);outline-offset:2px;border-radius:4px}
:focus:not(:focus-visible){outline:none}

/* ══ SCROLL REVEAL ══ */
.rv{opacity:0;transform:translateY(16px);transition:opacity .5s var(--spring),transform .5s var(--spring)}
.rv.vis{opacity:1;transform:translateY(0)}
.rv-scale{opacity:0;transform:scale(.96);transition:opacity .5s var(--spring),transform .5s var(--spring)}
.rv-scale.vis{opacity:1;transform:scale(1)}
.rv-left{opacity:0;transform:translateX(-20px);transition:opacity .5s var(--spring),transform .5s var(--spring)}
.rv-left.vis{opacity:1;transform:translateX(0)}
.rv-right{opacity:0;transform:translateX(20px);transition:opacity .5s var(--spring),transform .5s var(--spring)}
.rv-right.vis{opacity:1;transform:translateX(0)}
.rv-blur{opacity:0;filter:blur(4px);transform:translateY(10px);transition:opacity .5s var(--spring),filter .5s var(--spring),transform .5s var(--spring)}
.rv-blur.vis{opacity:1;filter:blur(0);transform:translateY(0)}

/* ══ NAV ══ */
.nav{position:sticky;top:0;z-index:200;background:rgba(250,250,250,.88);backdrop-filter:blur(16px) saturate(1.4);border-bottom:1px solid var(--border);transition:all .4s var(--ease)}
[data-theme="dark"] .nav{background:rgba(17,17,19,.9)}
.nav.scrolled{box-shadow:0 1px 20px rgba(0,0,0,.06);border-color:transparent}
[data-theme="dark"] .nav.scrolled{box-shadow:0 1px 20px rgba(0,0,0,.5)}
.nav-inner{max-width:var(--max-w);margin:0 auto;padding:0 24px;height:var(--nav-h);display:flex;align-items:center;gap:28px}
.logo{font-weight:700;font-size:.9rem;color:var(--ink);display:flex;align-items:center;gap:7px;letter-spacing:-.02em;transition:all .4s var(--spring);flex-shrink:0}
.logo:hover{opacity:.6;transform:scale(.97)}
.logo-mark{width:24px;height:24px;background:var(--ink);border-radius:6px;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.65rem;color:var(--bg);transition:all .4s var(--spring)}
.logo:hover .logo-mark{transform:rotate(-12deg) scale(1.05)}
.nav-links{display:flex;gap:1px;margin-left:auto}
.nav-links a{font-size:.8rem;font-weight:500;color:var(--muted);padding:6px 12px;border-radius:6px;transition:all .15s ease;position:relative}
.nav-links a:hover{color:var(--ink);background:var(--bg-hover)}
.nav-links a.active{color:var(--ink);font-weight:600}
.nav-links a.active::after{content:'';position:absolute;bottom:1px;left:50%;transform:translateX(-50%);width:4px;height:4px;background:var(--ink);border-radius:50%}
.nav-actions{display:flex;align-items:center;gap:2px}
.nav-icon-btn{width:32px;height:32px;display:flex;align-items:center;justify-content:center;border-radius:8px;color:var(--muted);transition:all .15s ease;background:transparent;border:none}
.nav-icon-btn:hover{color:var(--ink);background:var(--bg-hover)}
.nav-icon-btn svg{width:15px;height:15px}
.nav-login{display:inline-flex;align-items:center;padding:5px 14px;background:var(--ink);color:var(--bg);border-radius:100px;font-size:.72rem;font-weight:600;font-family:var(--font);transition:opacity .15s ease;text-decoration:none;margin-left:4px}
.nav-login:hover{opacity:.8}
[data-theme="dark"] .nav-login{background:#fff;color:#111}
.hamburger{display:none;flex-direction:column;gap:4px;width:32px;height:32px;align-items:center;justify-content:center}
.hamburger span{width:16px;height:1.5px;background:var(--ink);border-radius:1px;transition:all .35s var(--spring)}
.hamburger.open span:nth-child(1){transform:translateY(5.5px) rotate(45deg)}
.hamburger.open span:nth-child(2){opacity:0;transform:scaleX(0)}
.hamburger.open span:nth-child(3){transform:translateY(-5.5px) rotate(-45deg)}
.mobile-overlay{position:fixed;inset:0;background:rgba(0,0,0,.3);backdrop-filter:blur(4px);z-index:150;opacity:0;visibility:hidden;transition:all .4s var(--ease)}
.mobile-overlay.show{opacity:1;visibility:visible}

@media(max-width:768px){
  .nav-inner{padding:0 16px;gap:12px}
  .nav-links{position:fixed;top:var(--nav-h);right:0;width:280px;height:calc(100dvh - var(--nav-h));background:var(--bg-card);border-left:1px solid var(--border);flex-direction:column;gap:2px;padding:16px;margin:0;transform:translateX(100%);transition:transform .4s var(--ease);z-index:160;box-shadow:-8px 0 24px rgba(0,0,0,.06)}
  .nav-links.open{transform:translateX(0)}
  .nav-links a{padding:14px 16px;font-size:.9rem;border-radius:8px}
  .nav-links a.active::after{display:none}
  .hamburger{display:flex}
  .nav-login span{display:none}
  .nav-login{padding:5px 8px;margin-left:0}
  .nav-login::before{content:'';width:15px;height:15px;background:currentColor;-webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2'%3E%3Cpath d='M20 21v-2a4 4 0 0 0-4-4H8a4 4 0 0 0-4 4v2'/%3E%3Ccircle cx='12' cy='7' r='4'/%3E%3C/svg%3E") center/contain no-repeat;mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2'%3E%3Cpath d='M20 21v-2a4 4 0 0 0-4-4H8a4 4 0 0 0-4 4v2'/%3E%3Ccircle cx='12' cy='7' r='4'/%3E%3C/svg%3E") center/contain no-repeat}
}
@media(max-width:480px){
  .nav-inner{padding:0 16px}
  .logo span:not(.logo-mark){display:none}
}

/* ══ PROGRESS BAR ══ */
.progress-bar{position:fixed;top:0;left:0;height:2px;background:var(--ink);width:0;z-index:1000;transition:width .15s linear}

/* ══ BACK TO TOP ══ */
.back-top{position:fixed;bottom:20px;right:20px;width:40px;height:40px;background:var(--ink);color:var(--bg);border:none;border-radius:50%;display:flex;align-items:center;justify-content:center;opacity:0;visibility:hidden;transform:translateY(16px) scale(.8);transition:all .4s var(--spring);z-index:100;box-shadow:0 4px 16px rgba(0,0,0,.15)}
.back-top.visible{opacity:1;visibility:visible;transform:translateY(0) scale(1)}
.back-top:hover{transform:translateY(-3px) scale(1.05);box-shadow:0 8px 28px rgba(0,0,0,.2)}
@media(max-width:480px){.back-top{width:36px;height:36px;bottom:16px;right:16px}}

/* ══ POST CARD ══ */
.post-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--r);overflow:hidden;transition-property:opacity,transform,border-color,box-shadow;transition-duration:.5s,.5s,.2s,.2s;transition-timing-function:var(--spring);display:flex;flex-direction:column;position:relative}
.post-card:hover{border-color:var(--border-hover);transform:translateY(-2px);box-shadow:0 4px 16px rgba(0,0,0,.06)}
.post-card:active{transform:translateY(0) scale(.99);transition-duration:.1s}
[data-theme="dark"] .post-card:hover{box-shadow:none;border-color:var(--border-hover)}

.post-thumb{aspect-ratio:3/2;background:var(--bg-subtle);position:relative;overflow:hidden}
.post-thumb img{width:100%;height:100%;object-fit:cover;transition:transform .5s var(--spring)}
.post-card:hover .post-thumb img{transform:scale(1.03)}

.post-body{padding:18px 20px 20px;flex:1;display:flex;flex-direction:column}
.post-cat{display:inline-flex;align-items:center;gap:5px;font-size:.65rem;font-weight:600;letter-spacing:.05em;text-transform:uppercase;margin-bottom:8px}
.cat-dot{width:6px;height:6px;border-radius:50%}
.cat-seo{color:var(--c-seo)}.cat-seo .cat-dot{background:var(--c-seo)}
.cat-biz{color:var(--c-biz)}.cat-biz .cat-dot{background:var(--c-biz)}
.cat-dev{color:var(--c-dev)}.cat-dev .cat-dot{background:var(--c-dev)}
.cat-ai{color:var(--c-ai)}.cat-ai .cat-dot{background:var(--c-ai)}
.cat-life{color:var(--c-life)}.cat-life .cat-dot{background:var(--c-life)}

.series-tag{display:inline-flex;padding:2px 7px;background:var(--bg-subtle);border:1px solid var(--border);border-radius:4px;font-size:.58rem;font-weight:600;color:var(--muted);margin-left:6px;text-transform:none;letter-spacing:0}

.post-card h2{font-size:1.05rem;font-weight:600;color:var(--ink);line-height:1.3;margin-bottom:6px;letter-spacing:-.02em}

.post-excerpt{font-size:.82rem;color:var(--muted);line-height:1.6;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;margin-bottom:14px;flex:1}
.post-meta{display:flex;align-items:center;gap:8px;font-size:.72rem;color:var(--faint);font-weight:400}
.post-meta-dot{width:2px;height:2px;background:var(--faint);border-radius:50%}

@media(max-width:480px){
  .post-body{padding:14px 16px 16px}
  .post-card h2{font-size:.95rem}
  .post-excerpt{font-size:.78rem}
}

/* ══ FILTER TABS ══ */
.filter-row{display:flex;gap:6px;overflow-x:auto;scrollbar-width:none;padding-bottom:4px;-webkit-overflow-scrolling:touch}
.filter-row::-webkit-scrollbar{display:none}
.filter-btn{display:flex;align-items:center;gap:5px;padding:8px 14px;background:transparent;border:1px solid var(--border);border-radius:100px;font-size:.72rem;font-weight:500;color:var(--muted);white-space:nowrap;transition:all .15s ease}
.filter-btn:hover{border-color:var(--border-hover);color:var(--ink)}
.filter-btn:active{transform:scale(.96);transition-duration:.1s}
.filter-btn.active{color:var(--bg);border-color:transparent;box-shadow:0 2px 8px rgba(0,0,0,.08)}
.filter-btn[data-cat="all"].active{background:var(--ink);color:var(--bg)}
.filter-btn[data-cat="seo"].active{background:var(--c-seo);color:#fff}
.filter-btn[data-cat="biz"].active{background:var(--c-biz);color:#fff}
.filter-btn[data-cat="dev"].active{background:var(--c-dev);color:#fff}
.filter-btn[data-cat="ai"].active{background:var(--c-ai);color:#fff}
.filter-btn[data-cat="life"].active{background:var(--c-life);color:#fff}
[data-theme="dark"] .filter-btn[data-cat="seo"].active,[data-theme="dark"] .filter-btn[data-cat="biz"].active{color:#000}
.filter-dot{width:6px;height:6px;border-radius:50%}
.filter-btn.active .filter-dot{opacity:.5!important}

@media(max-width:480px){
  .filter-btn{padding:8px 12px;font-size:.68rem}
}

/* ══ SEARCH ══ */
.search-ov{position:fixed;inset:0;background:rgba(10,10,10,.35);backdrop-filter:blur(8px);z-index:300;display:none;align-items:flex-start;justify-content:center;padding-top:12vh}
.search-ov.on{display:flex}
.search-box{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--r-lg);width:520px;max-width:94vw;overflow:hidden;box-shadow:0 24px 72px rgba(0,0,0,.15);animation:searchIn .3s var(--spring)}
@keyframes searchIn{from{opacity:0;transform:scale(.96) translateY(-8px)}to{opacity:1;transform:scale(1) translateY(0)}}
[data-theme="dark"] .search-box{box-shadow:0 24px 72px rgba(0,0,0,.6)}
.search-input-row{display:flex;align-items:center;gap:8px;padding:14px 16px;border-bottom:1px solid var(--border)}
.search-input{flex:1;border:none;background:none;font-family:var(--font);font-size:.92rem;font-weight:400;color:var(--ink);outline:none}
.search-input::placeholder{color:var(--faint);font-weight:400}
.search-clear{width:22px;height:22px;border-radius:50%;background:var(--bg-subtle);border:none;display:none;align-items:center;justify-content:center;color:var(--muted);font-size:.65rem;transition:all .15s ease}
.search-clear.show{display:flex}
.search-clear:hover{background:var(--bg-hover);color:var(--ink)}
.search-cats{display:flex;gap:4px;padding:10px 16px;border-bottom:1px solid var(--border);overflow-x:auto}
.s-cat-btn{display:flex;align-items:center;gap:4px;padding:8px 12px;border-radius:100px;font-size:.7rem;font-weight:500;border:1px solid var(--border);background:transparent;color:var(--muted);white-space:nowrap;transition:all .15s ease}
.s-cat-btn:hover{border-color:var(--border-hover);color:var(--ink)}
.s-cat-btn.active{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.s-cat-dot{width:5px;height:5px;border-radius:50%}
.s-cat-btn.active .s-cat-dot{background:rgba(255,255,255,.35)!important}
.search-results{max-height:320px;overflow-y:auto}
.s-item{display:flex;align-items:flex-start;gap:10px;padding:10px 16px;cursor:pointer;transition:all .15s ease}
.s-item:hover,.s-item.focused{background:var(--bg-hover)}
.s-item-icon{width:32px;height:32px;border-radius:8px;background:var(--bg-subtle);display:flex;align-items:center;justify-content:center;font-size:.85rem;flex-shrink:0}
.s-item-body{flex:1}
.s-title{font-size:.82rem;font-weight:600;color:var(--ink);margin-bottom:2px;letter-spacing:-.01em}
.s-title mark{background:none;font-weight:700;color:var(--c-dev)}
.s-meta{font-size:.68rem;color:var(--muted);display:flex;gap:6px}
.search-empty{padding:32px 16px;text-align:center;color:var(--muted);font-size:.82rem;display:none}
.search-empty.show{display:block}
.search-hint{padding:10px 16px;border-top:1px solid var(--border);display:flex;gap:14px;font-size:.65rem;color:var(--faint)}
.search-hint kbd{background:var(--bg-subtle);border:1px solid var(--border);padding:1px 5px;border-radius:4px;font-family:var(--mono);font-size:.6rem}

@media(max-width:480px){
  .search-ov{padding-top:8vh}
  .search-box{border-radius:0;max-width:100vw;width:100%;margin:0}
  .search-input{font-size:1rem}
}

/* ══ FOOTER ══ */
.site-footer{border-top:1px solid var(--border);margin-top:80px}
.footer-inner{max-width:var(--max-w);margin:0 auto;padding:40px 24px;display:grid;grid-template-columns:2fr 1fr 1fr;gap:32px}
.footer-brand .logo{margin-bottom:10px}
.footer-brand p{font-size:.78rem;color:var(--muted);line-height:1.6;max-width:240px}
.f-col h4{font-size:.62rem;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--faint);margin-bottom:10px}
.f-col a{display:block;font-size:.78rem;color:var(--muted);padding:3px 0;transition:color .15s ease}
.f-col a:hover{color:var(--ink)}
.footer-bottom{max-width:var(--max-w);margin:0 auto;padding:14px 24px;border-top:1px solid var(--border);display:flex;justify-content:space-between;font-size:.72rem;color:var(--faint)}
/* Newsletter */
.newsletter{margin-top:16px}
.newsletter-form{display:flex;gap:6px}
.newsletter-input{flex:1;padding:8px 12px;border:1px solid var(--border);border-radius:8px;background:var(--bg);color:var(--ink);font-family:var(--font);font-size:.78rem;outline:none;transition:border-color .15s ease}
.newsletter-input:focus{border-color:var(--c-dev)}
.newsletter-input::placeholder{color:var(--faint)}
.newsletter-btn{padding:8px 14px;background:var(--ink);color:var(--bg);border:none;border-radius:8px;font-size:.72rem;font-weight:600;font-family:var(--font);cursor:pointer;transition:opacity .15s ease;white-space:nowrap}
.newsletter-btn:hover{opacity:.8}

@media(max-width:768px){.footer-inner{grid-template-columns:1fr 1fr;gap:24px;padding:32px 20px}}
@media(max-width:560px){
  .footer-inner{grid-template-columns:1fr;gap:20px;padding:32px 16px}
  .footer-bottom{flex-direction:column;gap:6px;text-align:center;padding:12px 16px}
}

.section-label{font-size:.65rem;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--faint)}

@keyframes fadeUp{from{opacity:0;transform:translateY(16px)}to{opacity:1;transform:translateY(0)}}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.3}}

/* ══ PAGE TRANSITION ══ */
body{animation:pageIn .4s var(--ease) both}
@keyframes pageIn{from{opacity:0}to{opacity:1}}

/* ══ PRINT ══ */
@media print{
  .nav,.back-top,.search-ov,.mobile-overlay,.progress-bar,.site-footer{display:none!important}
  body{background:#fff;color:#000;font-size:12pt}
  .post-card{break-inside:avoid;box-shadow:none;border:1px solid #ccc}
}

/* ══ REDUCED MOTION ══ */
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
  .rv,.rv-scale,.rv-left,.rv-right,.rv-blur{opacity:1;transform:none;filter:none}
}