/* USA AI Tools design system: modern, fast, accessible. No external fonts or libraries. */
:root{--bg:#f6f7fb;--surface:#fff;--surface2:#f1f3f9;--text:#0f172a;--muted:#64748b;--line:#e5e8f0;--brand:#6366f1;--brand2:#8b5cf6;--accent:#ec4899;--ok:#059669;--bad:#dc2626;--shadow:0 1px 2px rgba(15,23,42,.05),0 8px 24px -12px rgba(15,23,42,.12);--shadow-lg:0 2px 4px rgba(15,23,42,.06),0 24px 48px -16px rgba(79,70,229,.25);--r:16px;--font:ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,Inter,"Helvetica Neue",Arial,sans-serif}
:root[data-theme=dark]{--bg:#0b1020;--surface:#131a2e;--surface2:#1a2340;--text:#e8ecf8;--muted:#98a2c3;--line:#242e4d;--shadow:0 1px 2px rgba(0,0,0,.3),0 8px 24px -12px rgba(0,0,0,.5);--shadow-lg:0 2px 4px rgba(0,0,0,.3),0 24px 48px -16px rgba(99,102,241,.35)}
@media(prefers-color-scheme:dark){:root:not([data-theme=light]){--bg:#0b1020;--surface:#131a2e;--surface2:#1a2340;--text:#e8ecf8;--muted:#98a2c3;--line:#242e4d;--shadow:0 1px 2px rgba(0,0,0,.3),0 8px 24px -12px rgba(0,0,0,.5);--shadow-lg:0 2px 4px rgba(0,0,0,.3),0 24px 48px -16px rgba(99,102,241,.35)}}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;font-family:var(--font);background:var(--bg);color:var(--text);line-height:1.6;-webkit-font-smoothing:antialiased;font-size:16px}
img{max-width:100%;height:auto}a{color:var(--brand);text-decoration:none}a:hover{text-decoration:underline}
.wrap{max-width:1180px;margin:0 auto;padding:0 20px}.narrow{max-width:780px}
h1,h2,h3,h4{line-height:1.2;letter-spacing:-.02em;margin:0 0 .5em}h1{font-size:clamp(2rem,4.4vw,3.3rem)}h2{font-size:clamp(1.4rem,2.6vw,1.9rem)}h3{font-size:1.15rem}
.muted{color:var(--muted)}.small{font-size:.85rem}.center{text-align:center}
.skip{position:absolute;left:-999px}.skip:focus{left:12px;top:12px;background:var(--surface);padding:8px 12px;border-radius:8px;z-index:100}
/* header */
.hdr{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--bg) 82%,transparent);backdrop-filter:saturate(1.6) blur(14px);border-bottom:1px solid var(--line)}
.hdr .wrap{display:flex;align-items:center;gap:20px;height:64px}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.2rem;color:var(--text);letter-spacing:-.03em}.logo:hover{text-decoration:none}
.logo i{width:32px;height:32px;border-radius:10px;background:linear-gradient(135deg,var(--brand),var(--accent));display:grid;place-items:center;color:#fff;font-style:normal;font-size:16px;box-shadow:0 6px 16px -4px rgba(99,102,241,.6)}
.nav{display:flex;gap:4px;margin-left:12px}.nav a{color:var(--text);padding:8px 14px;border-radius:10px;font-weight:600;font-size:.95rem}.nav a:hover{background:var(--surface2);text-decoration:none}
.sp{flex:1}.ibtn{border:1px solid var(--line);background:var(--surface);color:var(--text);width:40px;height:40px;border-radius:12px;cursor:pointer;font-size:17px;display:grid;place-items:center}.ibtn:hover{background:var(--surface2)}
#menu{display:none}
@media(max-width:780px){#menu{display:grid}.nav{display:none;position:absolute;left:0;right:0;top:64px;background:var(--surface);flex-direction:column;padding:12px 20px;border-bottom:1px solid var(--line);margin:0}.nav-open .nav{display:flex}}
/* hero */
.hero{position:relative;overflow:hidden;padding:72px 0 56px;text-align:center}
.hero:before{content:"";position:absolute;inset:-20% -10% auto -10%;height:520px;background:radial-gradient(60% 60% at 25% 20%,rgba(99,102,241,.28),transparent 70%),radial-gradient(50% 55% at 80% 10%,rgba(236,72,153,.22),transparent 70%);z-index:-1;filter:blur(10px)}
.pill{display:inline-flex;gap:8px;align-items:center;padding:6px 14px;border:1px solid var(--line);background:var(--surface);border-radius:99px;font-size:.85rem;font-weight:600;box-shadow:var(--shadow)}
.pill b{color:var(--ok)}
.grad{background:linear-gradient(120deg,var(--brand),var(--accent));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p.lead{font-size:1.2rem;color:var(--muted);max-width:640px;margin:0 auto 28px}
.search{position:relative;max-width:640px;margin:0 auto}.search input{width:100%;padding:18px 20px 18px 54px;font-size:1.05rem;border-radius:18px;border:1px solid var(--line);background:var(--surface);color:var(--text);box-shadow:var(--shadow-lg);outline:none;font-family:inherit}
.search input:focus{border-color:var(--brand);box-shadow:0 0 0 4px rgba(99,102,241,.18),var(--shadow-lg)}.search svg{position:absolute;left:20px;top:50%;transform:translateY(-50%);color:var(--muted)}
.search kbd{position:absolute;right:16px;top:50%;transform:translateY(-50%);font:600 .75rem var(--font);border:1px solid var(--line);border-radius:6px;padding:2px 8px;color:var(--muted);background:var(--surface2)}
.chips{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin-top:18px}.chip{display:inline-block;padding:5px 12px;border-radius:99px;background:var(--surface2);font-size:.85rem;font-weight:600;color:var(--text)}
.chips a.chip:hover{background:var(--brand);color:#fff;text-decoration:none}.chip.good{background:rgba(5,150,105,.14);color:var(--ok)}.chip.bad{background:rgba(220,38,38,.12);color:var(--bad)}
.trust{display:flex;flex-wrap:wrap;gap:24px 40px;justify-content:center;margin-top:36px;color:var(--muted);font-size:.95rem}.trust b{color:var(--text);font-size:1.4rem;display:block;letter-spacing:-.02em}
/* sections */
.sec{padding:48px 0}.sec-h{display:flex;align-items:end;justify-content:space-between;gap:16px;margin-bottom:22px;flex-wrap:wrap}.sec-h h2{margin:0}
/* cards */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px}
.card{--c:var(--brand);display:flex;flex-direction:column;gap:10px;padding:20px;background:var(--surface);border:1px solid var(--line);border-radius:var(--r);color:var(--text);transition:transform .18s,box-shadow .18s,border-color .18s;position:relative;box-shadow:var(--shadow)}
.card:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg);border-color:color-mix(in srgb,var(--c) 45%,var(--line));text-decoration:none}
.card[hidden]{display:none}
.ic{width:44px;height:44px;border-radius:13px;display:grid;place-items:center;font-size:21px;background:color-mix(in srgb,var(--c) 14%,transparent)}
.card h3{margin:0;font-size:1.05rem}.card p{margin:0;color:var(--muted);font-size:.92rem}
.tag{position:absolute;top:16px;right:16px;font-size:.68rem;font-weight:800;letter-spacing:.06em;padding:3px 8px;border-radius:99px;background:color-mix(in srgb,var(--c) 14%,transparent);color:var(--c)}
.cat-card{flex-direction:row;align-items:center;gap:14px}.cat-card .meta{min-width:0}.cat-card .meta span{font-size:.85rem;color:var(--muted)}
.filters{display:flex;gap:8px;overflow-x:auto;padding:4px 2px 12px;scrollbar-width:thin}.filters button{flex:none;border:1px solid var(--line);background:var(--surface);color:var(--text);padding:8px 14px;border-radius:99px;font:600 .88rem var(--font);cursor:pointer}
.filters button.on,.filters button:hover{background:var(--brand);border-color:var(--brand);color:#fff}
.tools-top{display:grid;gap:14px;margin-bottom:18px}
#empty{padding:40px;text-align:center;color:var(--muted)}
/* features / blog */
.feat{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:16px}.feat>div{padding:22px;background:var(--surface);border:1px solid var(--line);border-radius:var(--r)}.feat h3{margin-bottom:6px}.feat p{margin:0;color:var(--muted);font-size:.95rem}
.post-card{padding:0;overflow:hidden}.post-card .cover{height:120px;background:linear-gradient(135deg,var(--c),color-mix(in srgb,var(--c) 40%,#ec4899));display:grid;place-items:center;font-size:42px}.post-card .b{padding:18px 20px 20px;display:flex;flex-direction:column;gap:8px}
/* buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:1px solid var(--line);background:var(--surface);color:var(--text);padding:10px 18px;border-radius:12px;font:600 .95rem var(--font);cursor:pointer;transition:all .15s}
.btn:hover{background:var(--surface2);text-decoration:none}.btn.primary{background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff;border-color:transparent;box-shadow:0 8px 20px -8px rgba(99,102,241,.7)}.btn.primary:hover{filter:brightness(1.08);transform:translateY(-1px)}
.btn.lg{padding:14px 28px;font-size:1.05rem;border-radius:14px}.btn.sm{padding:6px 12px;font-size:.85rem;border-radius:9px}.btn.ok{background:var(--ok);color:#fff;border-color:var(--ok)}.btn:disabled{opacity:.65;cursor:wait}
.actions{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-top:16px}
/* tool page */
.crumbs{font-size:.88rem;color:var(--muted);padding:22px 0 8px}.crumbs a{color:var(--muted)}
.t-head{display:flex;gap:16px;align-items:flex-start;margin:6px 0 24px}.t-head .ic{width:56px;height:56px;font-size:27px;flex:none}.t-head h1{font-size:clamp(1.6rem,3.2vw,2.3rem);margin:0 0 4px}.t-head p{margin:0;color:var(--muted);font-size:1.05rem}
.t-layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:24px;align-items:start}@media(max-width:960px){.t-layout{grid-template-columns:1fr}}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:20px;padding:24px;box-shadow:var(--shadow)}
.field{margin-bottom:16px}.field label,.check{display:block;font-weight:600;font-size:.9rem;margin-bottom:6px}.check{display:flex;align-items:center;gap:10px;font-weight:500;margin:6px 0}
input[type=text],input[type=number],input[type=date],input[type=time],input[type=datetime-local],select,textarea,input:not([type]){width:100%;padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:var(--bg);color:var(--text);font:inherit;outline:none;transition:border-color .15s,box-shadow .15s}
input:focus,select:focus,textarea:focus{border-color:var(--brand);box-shadow:0 0 0 4px rgba(99,102,241,.15)}textarea{resize:vertical;min-height:90px}input[type=color]{width:100%;height:46px;border:1px solid var(--line);border-radius:12px;background:var(--bg);padding:4px;cursor:pointer}input[type=file]{width:100%;padding:12px;border:2px dashed var(--line);border-radius:12px;background:var(--bg);color:var(--text)}input[type=checkbox]{width:18px;height:18px;accent-color:var(--brand)}
#tool-out{margin-top:20px;padding:20px;border-radius:16px;background:var(--surface2);border:1px solid var(--line)}#tool-out.err{background:rgba(220,38,38,.08);border-color:rgba(220,38,38,.3);color:var(--bad)}
pre.out{white-space:pre-wrap;word-break:break-word;font:.95rem/1.6 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;margin:0;background:var(--bg);padding:16px;border-radius:12px;border:1px solid var(--line);max-height:480px;overflow:auto}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;margin-bottom:12px}.stat{background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:14px 16px}.stat span{display:block;font-size:.8rem;color:var(--muted);font-weight:600}.stat b{font-size:1.25rem;letter-spacing:-.01em;word-break:break-word}
.note{font-size:.88rem;color:var(--muted);margin:10px 0 0}
.tw{overflow-x:auto;margin:12px 0}table{width:100%;border-collapse:collapse;font-size:.92rem;background:var(--bg);border-radius:12px;overflow:hidden}th,td{padding:10px 12px;text-align:left;border-bottom:1px solid var(--line)}th{background:var(--surface);font-size:.8rem;text-transform:uppercase;letter-spacing:.04em;color:var(--muted)}table.mono td:last-child{font-family:ui-monospace,monospace;word-break:break-all;font-size:.8rem}
.ai-out{font-size:1.02rem}.ai-out p{margin:.4em 0}.ai-out ul,.ai-out ol{padding-left:22px}.ai-out h4{margin:1em 0 .3em}.ai-out code{background:var(--bg);padding:2px 6px;border-radius:6px}
.skel{height:14px;border-radius:8px;margin:12px 0;background:linear-gradient(90deg,var(--line),var(--surface),var(--line));background-size:200% 100%;animation:sh 1.2s infinite}.skel.s2{width:80%}.skel.s3{width:55%}@keyframes sh{to{background-position:-200% 0}}
.spin{width:16px;height:16px;border:2px solid rgba(255,255,255,.4);border-top-color:#fff;border-radius:50%;animation:rot .7s linear infinite;display:inline-block}@keyframes rot{to{transform:rotate(360deg)}}
.big{font-size:clamp(1.5rem,4vw,2.3rem);font-weight:800;letter-spacing:-.02em;margin:10px 0}.clock{font-size:clamp(3rem,10vw,5rem);font-weight:800;font-variant-numeric:tabular-nums;letter-spacing:-.04em;margin:16px 0}
.tabs{display:inline-flex;background:var(--surface2);padding:4px;border-radius:12px;gap:4px;flex-wrap:wrap;justify-content:center}.tabs button{border:0;background:transparent;color:var(--text);padding:8px 14px;border-radius:9px;font:600 .9rem var(--font);cursor:pointer}.tabs button.on{background:var(--surface);box-shadow:var(--shadow)}
.sw{display:flex;flex-wrap:wrap;gap:10px}.swatch{flex:1 1 90px;height:90px;border:0;border-radius:14px;font:700 .85rem ui-monospace,monospace;cursor:pointer;box-shadow:var(--shadow)}.prev{height:130px;border-radius:16px;border:1px solid var(--line);margin:10px 0}
.emoji-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(48px,1fr));gap:6px}.emo{font-size:26px;border:1px solid var(--line);background:var(--surface);border-radius:12px;padding:8px;cursor:pointer}.emo:hover{background:var(--surface2);transform:scale(1.1)}.emo.ok{background:var(--ok)}h3.mini{font-size:.85rem;text-transform:uppercase;letter-spacing:.06em;color:var(--muted);margin:16px 0 8px}
.row{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:10px 0;border-bottom:1px solid var(--line)}.row small{color:var(--muted)}.row .big{font-size:1.3rem;margin:2px 0;word-break:break-all}
.diff ins{background:rgba(5,150,105,.2);text-decoration:none;border-radius:3px}.diff del{background:rgba(220,38,38,.2);border-radius:3px}.diff{white-space:pre-wrap;background:var(--bg);padding:14px;border-radius:12px;border:1px solid var(--line)}mark{background:#fde68a;color:#111;border-radius:3px}
.og{border:1px solid var(--line);border-radius:14px;overflow:hidden;max-width:500px;background:var(--bg)}.og-img{aspect-ratio:1.91/1;background:var(--surface2);display:grid;place-items:center;color:var(--muted);font-size:.85rem}.og-img img{width:100%;height:100%;object-fit:cover}.og-b{padding:12px 14px;display:flex;flex-direction:column;gap:2px}.og-b small{color:var(--muted)}.og-b span{color:var(--muted);font-size:.9rem}
.serp{background:var(--bg);padding:14px 16px;border-radius:12px;border:1px solid var(--line)}.serp small{color:#188038;display:block}.serp b{color:#1a0dab;font-weight:500;font-size:1.15rem;display:block}.serp span{color:var(--muted);font-size:.9rem}
:root[data-theme=dark] .serp b{color:#8ab4f8}
.inv{background:#fff;color:#111;padding:28px;border-radius:12px;border:1px solid var(--line)}.inv h2{letter-spacing:.1em}.inv .cols{display:flex;gap:28px;flex-wrap:wrap;margin:12px 0}.inv .cols p{margin:2px 0;font-size:.9rem}.inv table{background:transparent}.inv th,.inv td{border-color:#e5e7eb;color:#111;background:transparent}.inv .r{text-align:right}.inv .tot{text-align:right;margin-top:14px}.inv .tot b{margin-left:14px}.inv .gt{font-size:1.2rem;margin-top:6px}
.wheel{max-width:100%;height:auto}
/* sidebar & content */
.aside{display:grid;gap:16px;position:sticky;top:84px}.aside .box{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:18px}.aside h3{font-size:.9rem;text-transform:uppercase;letter-spacing:.05em;color:var(--muted)}.aside ul{list-style:none;padding:0;margin:0;display:grid;gap:8px}.aside li a{color:var(--text);font-weight:600;font-size:.93rem}
.prose{font-size:1.05rem}.prose h2{margin-top:1.6em}.prose h3{margin-top:1.3em}.prose p,.prose li{color:color-mix(in srgb,var(--text) 88%,var(--muted))}.prose ol,.prose ul{padding-left:22px}.prose li{margin:.3em 0}
details{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px 18px;margin:10px 0}summary{cursor:pointer;font-weight:700}details p{margin:.6em 0 0}
.below{margin-top:36px}
.ad{margin:28px 0;min-height:90px;text-align:center}.ad small{display:block;color:var(--muted);font-size:.7rem;letter-spacing:.1em;text-transform:uppercase}
.post-meta{color:var(--muted);font-size:.92rem;margin-bottom:24px}
/* forms/pages */
.page{padding:36px 0 64px}.page h1{margin-bottom:.3em}.hp{position:absolute;left:-9999px}.flash{padding:14px 18px;border-radius:12px;margin:16px 0;background:rgba(5,150,105,.12);color:var(--ok);font-weight:600}.flash.e{background:rgba(220,38,38,.1);color:var(--bad)}
/* footer */
.ftr{border-top:1px solid var(--line);margin-top:48px;padding:48px 0 28px;background:var(--surface)}.fcols{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:32px}@media(max-width:820px){.fcols{grid-template-columns:1fr 1fr}}
.ftr h4{font-size:.8rem;text-transform:uppercase;letter-spacing:.06em;color:var(--muted)}.ftr ul{list-style:none;padding:0;margin:0;display:grid;gap:8px}.ftr li a{color:var(--text);font-size:.93rem}.fbot{margin-top:32px;padding-top:20px;border-top:1px solid var(--line);color:var(--muted);font-size:.85rem}
#cookie{position:fixed;left:16px;right:16px;bottom:16px;max-width:560px;margin:auto;background:var(--surface);border:1px solid var(--line);box-shadow:var(--shadow-lg);border-radius:16px;padding:16px 18px;display:flex;gap:14px;align-items:center;z-index:90;font-size:.9rem}#cookie[hidden]{display:none}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}
@media print{.hdr,.ftr,.aside,#cookie,.ad{display:none}}

.logo img{display:block;border-radius:10px;box-shadow:0 6px 16px -4px rgba(79,70,229,.5)}