:root{--bg:#f5f8fc;--paper:#fff;--ink:#172334;--muted:#5d6b7a;--line:#dbe5ef;--brand:#0d5fae;--brand2:#1678d2;--accent:#11a36a;--soft:#eaf4ff;--shadow:0 10px 28px rgba(25,55,85,.09);--radius:22px;--content:1180px;--fs:17px}
*{box-sizing:border-box}
html{scroll-behavior:smooth;max-width:100%;overflow-x:hidden}
body{margin:0;max-width:100%;overflow-x:hidden;background:linear-gradient(160deg,#f5f9ff 0%,#eef8ff 34%,#f7f4ff 68%,#f3fbf7 100%);background-attachment:scroll;color:var(--ink);font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Arial,sans-serif;font-size:var(--fs);line-height:1.65;text-rendering:optimizeLegibility}
body.dark{--bg:#101722;background:linear-gradient(160deg,#101722 0%,#132231 50%,#171d2b 100%);--paper:#172230;--ink:#f4f7fb;--muted:#c2ccd7;--line:#314254;--brand:#76b9ff;--brand2:#98cbff;--accent:#72d4a7;--soft:#1d3044;--shadow:none;color-scheme:dark}
img,svg{display:block;max-width:100%}a{color:inherit;text-decoration:none}button,input,select{font:inherit}button{cursor:pointer}.skip-link{position:absolute;left:12px;top:-60px;z-index:10000;background:#000;color:#fff;padding:10px 14px;border-radius:10px}.skip-link:focus{top:12px}
.site-header{position:relative;z-index:100;background:var(--paper);border-bottom:1px solid var(--line)}.header-inner{width:min(100% - 28px,var(--content));min-height:78px;margin:auto;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{display:flex;align-items:center;min-width:0}.brand img{width:250px;height:auto}.header-actions{display:flex;align-items:center;gap:8px}.icon-button,.menu-button{min-height:42px;border:1px solid var(--line);background:var(--paper);color:var(--ink);border-radius:12px;padding:8px 11px;font-weight:800}.menu-button{display:none;align-items:center;gap:7px}.main-nav{border-top:1px solid var(--line);background:var(--paper)}.nav-inner{width:min(100% - 28px,var(--content));margin:auto;display:flex;justify-content:center;align-items:center;gap:4px;flex-wrap:wrap;padding:7px 0}.main-nav a{font-size:.87rem;font-weight:750;padding:8px 10px;border-radius:9px;white-space:nowrap}.main-nav a:hover,.main-nav a:focus-visible,.main-nav a[aria-current="page"]{background:var(--soft);color:var(--brand)}
main{width:min(100% - 28px,var(--content));margin:auto}.hero{padding:56px 0 34px;display:grid;grid-template-columns:minmax(0,1.25fr) minmax(280px,.75fr);gap:28px;align-items:center}.badge,.eyebrow,.article-tag{display:inline-flex;width:max-content;max-width:100%;font-size:.76rem;letter-spacing:.08em;text-transform:uppercase;font-weight:900;color:var(--brand);background:var(--soft);padding:7px 10px;border-radius:999px}.hero h1{font-size:clamp(2.15rem,5vw,4.7rem);line-height:1.02;letter-spacing:-.045em;margin:15px 0 18px;max-width:900px}.hero p{font-size:clamp(1rem,1.6vw,1.18rem);color:var(--muted);max-width:760px;margin:0}.button-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:25px}.button{display:inline-flex;align-items:center;justify-content:center;min-height:46px;border-radius:13px;padding:11px 17px;font-weight:850;border:1px solid transparent}.button.primary{background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff}.button.secondary{background:var(--paper);color:var(--ink);border-color:var(--line)}.button.light{background:#fff;color:#133353}.hero-panel{background:linear-gradient(145deg,#0c5baa,#13a26b);padding:15px;border-radius:26px;box-shadow:var(--shadow);display:grid;grid-template-columns:1fr 1fr;gap:10px}.hero-panel a{background:rgba(255,255,255,.95);color:#15263a;border-radius:16px;padding:18px;min-height:116px;display:flex;flex-direction:column;justify-content:center}.hero-panel strong{font-size:1.03rem}.hero-panel span{font-size:.85rem;color:#5a6978;margin-top:4px}
.home-section{margin-top:34px;content-visibility:auto;contain-intrinsic-size:1px 650px}.feature-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.feature-card,.article-card,.link-card,.spotlight-card,.translate-section,.latest,.about{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}.feature-card{padding:23px}.feature-card h2{font-size:1.15rem;margin:10px 0 8px}.feature-card p{color:var(--muted);margin:0 0 13px}.feature-card a,.text-link,.article-card a{color:var(--brand);font-weight:850}.feature-number,.feature-icon{display:inline-grid;place-items:center;min-width:44px;height:44px;padding:0 10px;border-radius:13px;background:var(--soft);color:var(--brand);font-weight:950}.latest,.about,.translate-section{padding:28px;display:flex;align-items:center;justify-content:space-between;gap:24px}.latest h2,.about h2,.translate-section h2{margin:8px 0 7px;font-size:clamp(1.45rem,3vw,2.2rem);line-height:1.15}.latest p,.about p,.translate-section p{margin:0;color:var(--muted);max-width:820px}.section-heading{text-align:center;margin-bottom:18px}.section-heading .eyebrow{margin:auto}.section-heading h2{font-size:clamp(1.5rem,3vw,2.3rem);margin:10px 0}.topics{overflow:hidden}.topic-window{overflow:hidden;background:var(--paper);border:1px solid var(--line);border-radius:18px;padding:14px 0}.topic-track{display:flex;gap:11px;width:max-content;animation:topicMove 38s linear infinite;will-change:transform}.topic-track span{white-space:nowrap;border:1px solid var(--line);background:var(--soft);color:var(--ink);font-weight:800;border-radius:999px;padding:8px 13px}@keyframes topicMove{to{transform:translateX(-50%)}}.business-callout{background:linear-gradient(135deg,#0b5da9,#0b8c68);color:#fff;padding:29px;border-radius:var(--radius);display:flex;align-items:center;justify-content:space-between;gap:24px}.business-callout .eyebrow{background:rgba(255,255,255,.14);color:#fff}.business-callout h2{margin:9px 0 5px;font-size:clamp(1.5rem,3vw,2.25rem)}.business-callout p{margin:0;max-width:760px;color:#eef7ff}.translate-box{min-width:300px;display:flex;align-items:stretch;flex-direction:column;gap:9px}.translate-label{font-size:.86rem;font-weight:900;color:var(--ink)}.select-wrap{position:relative;width:100%}.select-wrap:after{content:"⌄";position:absolute;right:14px;top:50%;transform:translateY(-54%);pointer-events:none;font-size:1.1rem;color:var(--brand)}.language-select{display:block;width:100%;min-height:48px;appearance:none;-webkit-appearance:none;border:1px solid var(--line);border-radius:13px;padding:10px 42px 10px 13px;background:var(--paper);color:var(--ink);font-weight:800;box-shadow:0 5px 16px rgba(30,70,110,.06)}.language-select:focus{border-color:var(--brand)}.small-note{font-size:.78rem;color:var(--muted)}.google-translate-engine{position:absolute!important;width:1px!important;height:1px!important;overflow:hidden!important;clip:rect(0 0 0 0)!important;clip-path:inset(50%)!important;white-space:nowrap!important}.goog-te-banner-frame,.goog-te-balloon-frame,#goog-gt-tt{display:none!important}body{top:0!important}.card-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.link-card{padding:20px;transition:transform .18s ease,border-color .18s ease}.link-card:hover{transform:translateY(-3px);border-color:var(--brand)}.link-card strong,.link-card span{display:block}.link-card span{color:var(--muted);font-size:.91rem;margin-top:5px}.spotlight-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.spotlight-card{padding:27px;min-height:240px}.spotlight-card h2{font-size:clamp(1.4rem,2.5vw,2rem);line-height:1.15;margin:11px 0 8px}.spotlight-card p{color:var(--muted)}.course-card{background:linear-gradient(145deg,var(--paper),#edf6ff)}.book-card{background:linear-gradient(145deg,var(--paper),#fff6df)}.tech-card{background:linear-gradient(145deg,var(--paper),#effaf5)}.feedback-card{background:linear-gradient(145deg,var(--paper),#f8efff)}body.dark .course-card,body.dark .book-card,body.dark .tech-card,body.dark .feedback-card{background:var(--paper)}.article-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.article-card{padding:23px}.article-card h3{font-size:1.15rem;line-height:1.3;margin:11px 0 7px}.article-card p{color:var(--muted)}
.site-footer{margin-top:50px;background:#0d1a29;color:#e9f0f7}.footer-grid{width:min(100% - 28px,var(--content));margin:auto;display:grid;grid-template-columns:1.7fr repeat(3,1fr);gap:28px;padding:38px 0 28px}.footer-grid h2{font-size:1rem;margin:0 0 11px}.footer-grid a{display:block;color:#dbe7f2;margin:7px 0}.footer-about p{color:#aebdca;max-width:470px}.footer-brand{font-size:1.35rem!important;font-weight:950;color:#fff!important}.socials{display:flex;flex-wrap:wrap;gap:8px;margin-top:15px}.socials a{width:38px;height:38px;border-radius:10px;background:#172a3e;display:grid;place-items:center;margin:0}.socials svg{width:19px;height:19px;fill:#fff}.copyright{text-align:center;border-top:1px solid #27384a;padding:15px 14px 20px;color:#aebdca;font-size:.84rem}.go-top{position:fixed;right:18px;bottom:18px;width:46px;height:46px;border:0;border-radius:50%;background:var(--brand);color:#fff;font-size:1.35rem;font-weight:900;box-shadow:var(--shadow);opacity:0;visibility:hidden;transform:translateY(10px);transition:.2s;z-index:90}.go-top.show{opacity:1;visibility:visible;transform:none}
:focus-visible{outline:3px solid #ffbf47;outline-offset:3px}
html[dir="rtl"] body{text-align:right}html[dir="rtl"] .header-inner,html[dir="rtl"] .latest,html[dir="rtl"] .about,html[dir="rtl"] .translate-section,html[dir="rtl"] .business-callout{direction:rtl}html[dir="rtl"] .topic-track{animation-direction:reverse}
@media(max-width:900px){.menu-button{display:flex}.main-nav{display:none;border-top:1px solid var(--line)}.main-nav.open{display:block}.nav-inner{padding:12px 14px;display:grid;grid-template-columns:1fr 1fr;align-items:stretch}.main-nav a{white-space:normal;background:var(--bg);padding:12px}.hero{grid-template-columns:1fr;padding-top:34px}.feature-grid{grid-template-columns:1fr 1fr}.card-grid{grid-template-columns:1fr 1fr}.footer-grid{grid-template-columns:1.5fr 1fr 1fr}.footer-grid>div:last-child{grid-column:2/4}.header-actions .icon-button{display:none}}
@media(max-width:600px){:root{--fs:16px;--shadow:0 4px 14px rgba(25,55,85,.06)}.header-inner{width:min(100% - 18px,var(--content));min-height:68px}.brand img{width:195px}.menu-label{display:none}.main-nav .nav-inner{width:100%;grid-template-columns:1fr;padding:10px}.hero{padding-top:28px}.hero h1{font-size:clamp(2.05rem,11.2vw,3.4rem)}.hero-panel{grid-template-columns:1fr 1fr;padding:10px}.hero-panel a{min-height:95px;padding:13px}.feature-grid,.card-grid,.spotlight-grid,.article-grid{grid-template-columns:1fr}.latest,.about,.translate-section,.business-callout{align-items:flex-start;flex-direction:column;padding:22px}.translate-box{min-width:0;width:100%}.home-section{contain-intrinsic-size:1px 850px}.topic-track{animation:none;will-change:auto}.link-card:hover{transform:none}.hero-panel,.feature-card,.article-card,.link-card,.spotlight-card,.translate-section,.latest,.about{box-shadow:none}.footer-grid{grid-template-columns:repeat(3,1fr);gap:14px}.footer-about{grid-column:1/-1}.footer-grid>div:last-child{grid-column:auto}.footer-grid h2{font-size:.94rem}.footer-grid a{font-size:.84rem;overflow-wrap:anywhere}.socials a{width:36px;height:36px}.go-top{right:12px;bottom:12px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.topic-track{animation:none}.link-card,.go-top{transition:none}}
@media print{.site-header,.button-row,.translate-section,.business-callout,.socials,.go-top{display:none!important}body{background:#fff;color:#000}.home-section{content-visibility:visible}.feature-card,.article-card,.link-card,.spotlight-card,.latest,.about{box-shadow:none;border:1px solid #aaa}}


/* Fast attention-first hero: CSS only, no image/video/JS dependency */
.hero{position:relative;isolation:isolate;overflow:hidden}
.hero::before{content:"";position:absolute;z-index:-2;inset:0;background:linear-gradient(135deg,rgba(30,106,220,.10),rgba(118,69,211,.08) 45%,rgba(28,173,150,.09))}
.hero::after{content:"";position:absolute;z-index:-1;width:280px;height:280px;border-radius:50%;right:4%;top:8%;background:radial-gradient(circle,rgba(29,111,222,.16),rgba(29,111,222,0) 68%);pointer-events:none}
.hero-copy{max-width:760px}
.hero-kicker{display:inline-flex;align-items:center;gap:9px;padding:8px 12px;border:1px solid var(--line);border-radius:999px;background:rgba(255,255,255,.76);font-size:.82rem;font-weight:800;letter-spacing:.02em;box-shadow:0 4px 14px rgba(20,60,100,.05)}
.hero-kicker-dot{width:9px;height:9px;border-radius:50%;background:linear-gradient(135deg,#1877d2,#6b4fd3);box-shadow:0 0 0 5px rgba(24,119,210,.08)}
.hero h1{max-width:760px;line-height:1.02;letter-spacing:-.045em;margin:.5em 0 .3em}
.hero h1 span{background:linear-gradient(90deg,#126bc5,#7654d8,#168e7a);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero-lead{max-width:680px;font-size:clamp(1.02rem,2.1vw,1.2rem);line-height:1.7;color:var(--muted);margin:0 0 16px}
.hero-benefits{display:flex;flex-wrap:wrap;gap:8px 10px;margin:0 0 20px}
.hero-benefits span{display:inline-flex;align-items:center;min-height:34px;padding:7px 11px;border-radius:999px;background:rgba(255,255,255,.72);border:1px solid var(--line);font-size:.84rem;font-weight:800}
.hero-buttons{margin-top:4px}
.hero-primary{box-shadow:0 10px 24px rgba(13,95,174,.18)}
.hero-primary span{font-size:1.08em}
.hero-note{font-size:.82rem;color:var(--muted);margin:10px 0 0}
.hero-panel-fast{position:relative}
.hero-panel-fast a{position:relative;overflow:hidden;background:rgba(255,255,255,.78);backdrop-filter:none}
.hero-panel-fast a::after{content:"";position:absolute;left:0;right:0;bottom:0;height:3px;background:linear-gradient(90deg,#1877d2,#6f54d8,#16927b);opacity:.65}
.panel-mark{display:inline-grid;place-items:center;width:34px;height:34px;border-radius:10px;background:linear-gradient(135deg,rgba(24,119,210,.12),rgba(111,84,216,.12));font-size:.74rem;font-weight:950;color:var(--brand);margin-bottom:7px}
body.dark .hero-kicker,body.dark .hero-benefits span,body.dark .hero-panel-fast a{background:rgba(24,35,48,.92)}
@media(max-width:600px){
  .hero{min-height:auto;padding-top:22px;padding-bottom:26px}
  .hero::after{width:180px;height:180px;right:-50px;top:10px}
  .hero-kicker{font-size:.73rem;padding:7px 10px}
  .hero h1{font-size:clamp(2.2rem,12vw,3.6rem);margin-top:16px}
  .hero-lead{font-size:1rem;line-height:1.58;margin-bottom:14px}
  .hero-benefits{gap:7px;margin-bottom:16px}
  .hero-benefits span{font-size:.76rem;min-height:31px;padding:6px 9px}
  .hero-buttons{display:grid;grid-template-columns:1fr;gap:9px}
  .hero-buttons .button{width:100%;min-height:48px}
  .hero-note{margin-top:8px}
  .hero-panel-fast{margin-top:18px;grid-template-columns:1fr 1fr}
  .hero-panel-fast a{min-height:104px}
}


/* Hero quick links + lightweight hover polish */
.hero-explore{min-width:0}
.hero-mini-card{isolation:isolate}
.hero-mini-card b{position:absolute;right:12px;top:10px;font-size:.82rem;color:var(--muted);opacity:.55;transition:transform .18s ease,opacity .18s ease}
.hero-topic-links{display:flex;flex-wrap:wrap;gap:8px;margin-top:10px}
.hero-topic-links a{display:inline-flex;align-items:center;min-height:36px;padding:7px 10px;border:1px solid var(--line);border-radius:999px;background:rgba(255,255,255,.76);color:var(--ink);font-size:.78rem;font-weight:850;text-decoration:none;transition:transform .18s ease,border-color .18s ease,box-shadow .18s ease}
.translate-attribution{margin:10px 0 0;font-size:.77rem;line-height:1.5;color:var(--muted)}
.translate-attribution a{font-weight:800;color:var(--brand)}
.translate-disclaimer{margin-top:8px;border-top:1px solid var(--line);padding-top:8px;font-size:.76rem;color:var(--muted)}
.translate-disclaimer summary{cursor:pointer;font-weight:850;color:var(--ink)}
.translate-disclaimer p{margin:7px 0 0}
body.dark .hero-topic-links a{background:rgba(24,35,48,.92)}
@media(hover:hover) and (pointer:fine){
  .hero-mini-card:hover{transform:translateY(-4px);border-color:rgba(24,119,210,.38);box-shadow:0 14px 28px rgba(26,72,119,.12)}
  .hero-mini-card:hover b{transform:translate(2px,-2px);opacity:1}
  .hero-topic-links a:hover{transform:translateY(-2px);border-color:rgba(24,119,210,.45);box-shadow:0 8px 18px rgba(24,79,130,.09)}
}
@media(max-width:600px){
  .hero-topic-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:7px}
  .hero-topic-links a{justify-content:center;min-width:0;font-size:.73rem;padding:6px 7px}
  .translate-attribution,.translate-disclaimer{font-size:.72rem}
}


/* Compact category panel: short, fast and mobile-friendly */
.explore-shell{position:relative;overflow:hidden;border:1px solid rgba(105,134,170,.18);border-radius:22px;padding:14px;background:linear-gradient(145deg,rgba(255,255,255,.94),rgba(239,247,255,.88));box-shadow:0 12px 30px rgba(36,76,120,.07)}
.explore-shell::before{content:"";position:absolute;width:130px;height:130px;border-radius:50%;right:-60px;top:-70px;background:radial-gradient(circle,rgba(60,142,232,.12),rgba(60,142,232,0) 70%);pointer-events:none}
.explore-heading{position:relative;margin-bottom:9px}.explore-kicker{display:block;color:var(--brand);font-size:.68rem;font-weight:900;letter-spacing:.07em;text-transform:uppercase;margin-bottom:2px}.explore-heading strong{display:block;font-size:.94rem;line-height:1.22}
.category-tiles{position:relative;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:7px}.category-tile{display:grid;grid-template-columns:34px minmax(0,1fr) 22px;align-items:center;gap:8px;min-height:52px;padding:7px 8px;border:1px solid rgba(111,139,170,.18);border-radius:13px;background:rgba(255,255,255,.86);box-shadow:0 3px 10px rgba(38,73,112,.035);transform:translateZ(0);transition:transform .16s ease,border-color .16s ease,box-shadow .16s ease,background-color .16s ease}
.category-icon{width:34px;height:34px;display:grid;place-items:center;border-radius:10px;background:linear-gradient(145deg,#edf6ff,#f7fbff);font-size:.94rem;font-weight:950;color:var(--brand)}
.category-copy{min-width:0}.category-copy strong,.category-copy small{display:block}.category-copy strong{font-size:.80rem;line-height:1.15}.category-copy small{color:var(--muted);font-size:.66rem;line-height:1.15;margin-top:2px}.category-arrow{display:grid;place-items:center;width:22px;height:22px;border-radius:50%;background:var(--soft);color:var(--brand);font-size:.78rem;font-weight:950;transition:transform .16s ease}
.games-tile .category-icon{background:linear-gradient(145deg,#eef8ff,#f3f0ff)}.crypto-tile .category-icon{background:linear-gradient(145deg,#fff8e6,#fffdf6)}.marketing-tile .category-icon{background:linear-gradient(145deg,#effbf5,#f8fffb)}.math-tile .category-icon{background:linear-gradient(145deg,#f2f5ff,#fafbff)}.language-tile .category-icon{background:linear-gradient(145deg,#fff1f7,#fff9fc)}
body.dark .explore-shell{background:linear-gradient(145deg,rgba(23,34,48,.97),rgba(24,45,62,.94));border-color:#304359;box-shadow:none}body.dark .category-tile{background:rgba(26,39,54,.92);border-color:#33495f}body.dark .category-icon{background:#21374b}
@media(hover:hover) and (pointer:fine){.category-tile:hover{transform:translateY(-3px) scale(1.008);border-color:rgba(22,120,210,.38);box-shadow:0 12px 26px rgba(31,77,123,.10);background:#fff}.category-tile:hover .category-arrow{transform:translateX(3px)}body.dark .category-tile:hover{background:#1d3042}}
@media(max-width:600px){.explore-shell{padding:10px;border-radius:17px;box-shadow:none}.category-tiles{grid-template-columns:repeat(2,minmax(0,1fr));gap:6px}.category-tile{min-height:44px;padding:6px 7px;grid-template-columns:30px minmax(0,1fr);gap:7px;box-shadow:none;transition:none}.category-icon{width:30px;height:30px;border-radius:9px;font-size:.82rem}.category-copy strong{font-size:.74rem;line-height:1.1}.category-copy small,.category-arrow{display:none}.explore-heading{margin-bottom:7px}.explore-kicker{font-size:.62rem}.explore-heading strong{font-size:.84rem}}
@media(prefers-reduced-motion:reduce){.category-tile,.category-arrow{transition:none!important}}

.ai-tile .category-icon{background:linear-gradient(145deg,#eef7ff,#f5f1ff)}.web-tile .category-icon{background:linear-gradient(145deg,#eefcf8,#f7fffc)}.programming-tile .category-icon{background:linear-gradient(145deg,#f5f2ff,#fbfaff)}.security-tile .category-icon{background:linear-gradient(145deg,#fff4ef,#fffaf7)}.data-tile .category-icon{background:linear-gradient(145deg,#eef8ff,#f7fbff)}