:root {
  --yellow:#f4b400; --yellow-2:#ffc928; --blue:#1f74c9; --ink:#11161e; --dark:#0d1117;
  --soft:#f4f5f7; --muted:#68707c; --line:#e2e5e9; --white:#fff;
  --radius:18px; --shadow:0 22px 60px rgba(13,17,23,.10); --wrap:1180px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;max-width:100%;overflow-x:hidden}
body{margin:0;max-width:100%;overflow-x:hidden;color:var(--ink);font-family:Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;line-height:1.55;background:#fff}
img{max-width:100%;height:auto}
.wrap{width:min(calc(100% - 44px),var(--wrap));margin:0 auto}
.header{height:76px;position:sticky;top:0;z-index:50;background:rgba(255,255,255,.95);backdrop-filter:blur(14px);border-bottom:1px solid rgba(226,229,233,.9)}.nav{height:100%;display:flex;align-items:center;justify-content:space-between;gap:28px}.brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none;font-size:20px;font-weight:950;letter-spacing:-.03em}.brand img{width:42px;height:42px;object-fit:contain}.navlinks{display:flex;align-items:center;gap:23px}.navlinks a{color:#303640;text-decoration:none;font-size:13px;font-weight:780;transition:color .2s}.navlinks a:hover{color:#000}.navlinks .client{color:#626a75}.pill{display:inline-flex;align-items:center;justify-content:center;min-height:45px;padding:0 20px;border-radius:999px;background:var(--yellow);color:#181818!important;text-decoration:none;font-size:13px;font-weight:950;transition:transform .2s,background .2s}.pill:hover{background:var(--yellow-2);transform:translateY(-1px)}.nav-cta{min-height:39px;padding:0 17px}.menu{display:none;border:0;background:transparent;font-size:26px;line-height:1;width:42px;height:42px;align-items:center;justify-content:center;cursor:pointer}
.hero{min-height:720px;position:relative;display:flex;align-items:center;color:#fff;overflow:hidden;background:#151a20}.hero::before{content:"";position:absolute;inset:0;background:linear-gradient(90deg,rgba(7,10,15,.96) 0%,rgba(7,10,15,.79) 39%,rgba(7,10,15,.32) 70%,rgba(7,10,15,.14) 100%),url('../fotosWeb/img5.JPEG') center 50%/cover no-repeat;transform:scale(1.01)}.hero::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,transparent 55%,rgba(0,0,0,.24))}.hero-content{position:relative;z-index:2;padding:105px 0 128px}.eyebrow{display:flex;align-items:center;gap:10px;color:var(--yellow-2);font-size:11px;font-weight:950;letter-spacing:.15em;text-transform:uppercase}.eyebrow::before{content:"";width:30px;height:2px;background:currentColor}.dark-eyebrow{color:#9a7100}.hero h1{max-width:840px;margin:16px 0 24px;font-size:clamp(50px,6.5vw,83px);line-height:.98;letter-spacing:-.052em;font-weight:920}.hero p{max-width:760px;margin:0;color:#e3e6ea;font-size:20px;line-height:1.55}.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:31px}.ghost{display:inline-flex;align-items:center;justify-content:center;padding:12px 19px;border:1px solid rgba(255,255,255,.52);border-radius:999px;text-decoration:none;font-size:13px;font-weight:900;color:#fff;transition:.2s}.ghost:hover{background:rgba(255,255,255,.1);border-color:#fff}.scroll-cue{position:absolute;z-index:3;bottom:84px;right:max(24px,calc((100vw - var(--wrap))/2));width:42px;height:42px;border:1px solid rgba(255,255,255,.35);border-radius:50%;display:grid;place-items:center}.scroll-cue span{width:8px;height:8px;border-right:2px solid #fff;border-bottom:2px solid #fff;transform:rotate(45deg) translate(-2px,-2px)}
.value-strip{position:relative;z-index:4;margin-top:-54px}.stats-grid{display:grid;grid-template-columns:repeat(3,1fr);background:#fff;border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow)}.stat{padding:27px 30px;border-right:1px solid var(--line)}.stat:last-child{border-right:0}.stat strong{display:block;font-size:18px;line-height:1.2}.stat span{display:block;margin-top:7px;color:var(--muted);font-size:14px}
.section{padding:105px 0}.section-title{display:grid;grid-template-columns:.94fr 1.06fr;gap:72px;align-items:end;margin-bottom:45px}.section-title h2{max-width:690px;margin:8px 0 0;font-size:clamp(37px,4.3vw,58px);line-height:1.03;letter-spacing:-.043em}.section-title p{max-width:650px;margin:0;color:var(--muted);font-size:18px}.services{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.service{display:flex;flex-direction:column;min-height:315px;padding:30px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);transition:.22s}.service:hover{transform:translateY(-4px);box-shadow:var(--shadow);border-color:#d6d9de}.service-top{display:flex;justify-content:space-between;align-items:center}.num{color:#9c7200;font-size:12px;font-weight:950}.service-mark{display:inline-flex;min-width:44px;height:28px;padding:0 9px;align-items:center;justify-content:center;background:#f8f3e2;border-radius:999px;color:#755600;font-size:10px;font-weight:950;letter-spacing:.08em}.service h3{margin:43px 0 11px;font-size:23px;line-height:1.12}.service p{margin:0;color:var(--muted)}.service-tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:auto;padding-top:22px}.service-tags span{padding:5px 8px;background:#f5f6f7;border-radius:7px;color:#626a74;font-size:10px;font-weight:850;text-transform:uppercase;letter-spacing:.05em}
.engineering-section{background:var(--dark);color:#fff;overflow:hidden}.engineering-heading p{color:#c9cfd7}.engineering-showcase{display:grid;grid-template-columns:1.15fr .85fr;gap:16px}.engineering-main,.engineering-side figure{position:relative;margin:0;background:#fff;border-radius:20px;overflow:hidden}.engineering-main{height:630px}.engineering-main img,.engineering-side img{width:100%;height:100%;display:block;object-fit:contain;background:#edf0f2;padding:18px}.engineering-side{display:grid;grid-template-rows:1fr 1fr;gap:16px}.engineering-side figure{min-height:0}.engineering-main figcaption,.engineering-side figcaption{position:absolute;left:14px;right:14px;bottom:14px;display:flex;gap:12px;align-items:flex-start;padding:15px 17px;background:rgba(13,17,23,.93);backdrop-filter:blur(8px);border-radius:12px;color:#fff}.engineering-main figcaption>span,.engineering-side figcaption>span{color:var(--yellow-2);font-size:11px;font-weight:950}.engineering-main figcaption div,.engineering-side figcaption div{display:flex;flex-direction:column}.engineering-main figcaption strong,.engineering-side figcaption strong{font-size:15px}.engineering-main figcaption small,.engineering-side figcaption small{margin-top:2px;color:#c8ced5;font-size:12px}.engineering-code-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:16px}.tech-card{display:grid;grid-template-columns:.8fr 1.2fr;min-height:305px;background:#171d25;border:1px solid #29313c;border-radius:20px;overflow:hidden}.tech-copy{padding:30px;display:flex;flex-direction:column;justify-content:center}.tech-index{color:var(--yellow-2);font-size:11px;font-weight:950}.tech-copy h3{margin:10px 0 9px;font-size:23px;line-height:1.1}.tech-copy p{margin:0;color:#bfc6cf;font-size:14px}.tech-card img{width:100%;height:100%;object-fit:cover;object-position:left top;background:#fff}.technology-row{display:flex;flex-wrap:wrap;justify-content:center;gap:8px;margin-top:26px}.technology-row span{padding:8px 12px;border:1px solid #343c47;border-radius:999px;color:#d6dbe1;font-size:11px;font-weight:850;letter-spacing:.04em}
.dark-section{background:#f2f3f5}.process-intro{display:grid;grid-template-columns:1fr 1fr;gap:70px;align-items:end;margin-bottom:40px}.process-intro .eyebrow{color:#9a7100}.process-intro h2{margin:8px 0 0;font-size:clamp(38px,4.5vw,58px);line-height:1.03;letter-spacing:-.043em}.process-intro p{margin:0;color:var(--muted);font-size:18px}.process-visual{display:grid;grid-template-columns:1fr 42px 1fr 42px 1fr;align-items:center}.process-step{background:#fff;border-radius:18px;overflow:hidden;border:1px solid var(--line)}.process-image{height:300px;background:#eef0f2}.process-image img{width:100%;height:100%;object-fit:cover}.process-step:first-child .process-image img{object-fit:contain;padding:13px}.process-copy{display:grid;grid-template-columns:32px 1fr;column-gap:7px;padding:18px 20px 20px}.process-copy span{grid-row:1/3;color:#9c7200;font-size:11px;font-weight:950}.process-copy strong{font-size:16px}.process-copy p{margin:2px 0 0;color:var(--muted);font-size:12px}.process-arrow{text-align:center;font-size:28px;color:#aeb4bc}
.projects-heading{margin-bottom:32px}.projects{display:grid;grid-template-columns:repeat(12,1fr);grid-auto-rows:255px;gap:14px}.project{position:relative;margin:0;background:#ddd;border-radius:16px;overflow:hidden}.project img{width:100%;height:100%;display:block;object-fit:cover;transition:transform .4s}.project:hover img{transform:scale(1.035)}.project::after{content:"";position:absolute;inset:38% 0 0;background:linear-gradient(transparent,rgba(0,0,0,.8))}.project figcaption{position:absolute;z-index:2;left:18px;right:18px;bottom:16px;display:flex;flex-direction:column;color:#fff;line-height:1.25}.project figcaption strong{font-size:16px}.project figcaption span{margin-top:3px;color:#e2e5e9;font-size:12px}.p1{grid-column:span 7;grid-row:span 2}.p2,.p3{grid-column:span 5}.p4,.p5,.p6{grid-column:span 4}.p7{grid-column:span 8}.p8{grid-column:span 4}
.company-section{background:var(--soft)}.brands{display:grid;grid-template-columns:1fr 1fr;gap:20px}.brandcard{position:relative;padding:38px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden}.brandcard::before{content:"";position:absolute;top:0;left:0;right:0;height:5px}.brandcard.ay::before{background:var(--yellow)}.brandcard.ne::before{background:var(--blue)}.brand-label{color:var(--muted);font-size:11px;font-weight:900;letter-spacing:.1em;text-transform:uppercase}.brandcard h3{margin:9px 0 10px;font-size:31px}.brandcard p{margin:0 0 24px;color:var(--muted)}.brandcard ul{display:grid;gap:9px;margin:0 0 28px;padding:0;list-style:none}.brandcard li{position:relative;padding-left:20px;font-size:14px;font-weight:750}.brandcard li::before{content:"";position:absolute;left:0;top:.62em;width:7px;height:7px;border-radius:50%;background:var(--yellow)}.brandcard.ne li::before{background:var(--blue)}.brand-address{padding-top:21px;border-top:1px solid var(--line);font-size:14px;font-weight:850}
.cta-band{padding:54px 0;background:var(--dark);color:#fff}.cta-grid{display:flex;align-items:center;justify-content:space-between;gap:40px}.cta-grid h2{margin:9px 0 0;font-size:clamp(31px,4vw,50px);line-height:1;letter-spacing:-.039em}.light-pill{flex:0 0 auto}.contact-grid{display:grid;grid-template-columns:.85fr 1.15fr;gap:60px;align-items:start}.contact-info h2{margin:8px 0 20px;font-size:clamp(38px,4vw,52px);line-height:1.04;letter-spacing:-.035em}.contact-info>p{max-width:500px;color:var(--muted);font-size:18px}.contact-cards{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:32px}.contact-card{display:block;min-height:100px;padding:18px;background:#fff;border:1px solid var(--line);border-radius:14px;text-decoration:none}.contact-card span{display:block;margin-bottom:6px;color:var(--muted);font-size:11px;font-weight:850;letter-spacing:.08em;text-transform:uppercase}.contact-card strong{display:block;color:var(--ink);font-size:14px;line-height:1.35;overflow-wrap:anywhere}a.contact-card:hover{border-color:#cfd3da;box-shadow:0 10px 30px rgba(13,17,23,.06)}.contact-form{display:grid;gap:16px;padding:32px;background:var(--soft);border-radius:22px}.form-row{display:grid;grid-template-columns:1fr 1fr;gap:14px}label{display:block;margin-bottom:6px;font-size:13px;font-weight:800}input,textarea{width:100%;padding:13px 14px;background:#fff;border:1px solid #dfe2e7;border-radius:12px;color:var(--ink);font:inherit;outline:none;transition:.2s}input:focus,textarea:focus{border-color:#c99700;box-shadow:0 0 0 3px rgba(244,180,0,.14)}textarea{min-height:165px;resize:vertical}.submit{padding:14px 18px;border:0;border-radius:12px;background:var(--yellow);color:#161616;font-size:16px;font-weight:950;cursor:pointer;transition:.2s}.submit:hover{background:var(--yellow-2);transform:translateY(-1px)}.form-note{color:#757c86;line-height:1.4}.hp{position:absolute!important;left:-10000px!important;width:1px!important;height:1px!important;opacity:0!important}.map{width:100%;height:420px;border:0;display:block}.footer{padding:46px 0;background:#0a0d12;color:#c9ced6}.footer-grid{display:grid;grid-template-columns:1.25fr 1fr auto;gap:34px;align-items:center}.footer-brand{display:flex;align-items:center;gap:12px}.footer-brand img{width:42px;height:42px;border-radius:9px}.footer-brand b{display:block;color:#fff}.footer-brand small{display:block;margin-top:2px}.footer-links{display:flex;flex-wrap:wrap;gap:18px}.footer-links a{color:#dce0e6;text-decoration:none;font-size:13px;font-weight:700}.footer-links a:hover{color:#fff}
@media(max-width:980px){.navlinks{display:none;position:absolute;top:75px;left:0;right:0;flex-direction:column;align-items:stretch;padding:18px 20px 24px;background:#fff;border-bottom:1px solid var(--line);box-shadow:0 16px 35px rgba(0,0,0,.08)}.navlinks.open{display:flex}.navlinks a{text-align:center}.menu{display:flex}.hero{min-height:650px}.value-strip{margin-top:0}.stats-grid,.services,.brands,.contact-grid{grid-template-columns:1fr}.stat{border-right:0;border-bottom:1px solid var(--line)}.stat:last-child{border-bottom:0}.section-title,.process-intro{grid-template-columns:1fr;gap:18px}.engineering-showcase{grid-template-columns:1fr}.engineering-main{height:530px}.engineering-side{grid-template-columns:1fr 1fr;grid-template-rows:none}.engineering-side figure{height:320px}.engineering-code-grid{grid-template-columns:1fr}.process-visual{grid-template-columns:1fr}.process-arrow{transform:rotate(90deg);padding:4px}.projects{grid-template-columns:1fr 1fr;grid-auto-rows:300px}.project{grid-column:auto!important;grid-row:auto!important}.p1{grid-column:span 2!important}.footer-grid{grid-template-columns:1fr;align-items:start}}
@media(max-width:640px){.wrap{width:min(calc(100% - 28px),var(--wrap))}.nav{height:68px}.header{height:68px}.navlinks{top:67px}.brand img{width:36px;height:36px}.hero{min-height:calc(100svh - 68px)}.hero-content{padding:78px 0 92px}.hero h1{font-size:clamp(36px,11vw,44px)}.hero p{font-size:18px}.scroll-cue{display:none}.section{padding:74px 0}.section-title h2{font-size:37px}.service{min-height:auto;padding:26px}.service h3{margin-top:33px}.engineering-main{height:470px}.engineering-side{grid-template-columns:1fr}.engineering-side figure{height:300px}.engineering-main figcaption,.engineering-side figcaption{left:9px;right:9px;bottom:9px}.tech-card{grid-template-columns:1fr}.tech-card img{height:250px}.process-image{height:275px}.projects{grid-template-columns:1fr;grid-auto-rows:280px}.p1{grid-column:auto!important}.brandcard{padding:30px 26px}.cta-grid{flex-direction:column;align-items:flex-start}.contact-cards,.form-row{grid-template-columns:1fr}.contact-form{padding:24px}.map{height:340px}.footer-links{gap:13px 17px}}

/* Projecte real: recorregut visual esquema -> 3D -> fabricació -> programació */
.project-path{
  position:relative;
  display:grid;
  grid-template-columns:minmax(0,1.35fr) 72px minmax(0,.95fr);
  grid-template-areas:
    "step1 arrowTop step2"
    ". . arrowDown"
    "step4 arrowBottom step3";
  gap:18px 0;
  align-items:center;
  margin-top:38px;
  padding:10px 0 4px;
}
.path-card{
  position:relative;
  overflow:hidden;
  background:#151b23;
  border:1px solid #29313c;
  border-radius:22px;
  box-shadow:0 18px 45px rgba(0,0,0,.16);
}
.path-card-1{grid-area:step1}
.path-card-2{grid-area:step2}
.path-card-3{grid-area:step3}
.path-card-4{grid-area:step4}

.path-media{
  position:relative;
  overflow:hidden;
  background:#eef1f4;
}
.path-media img{
  width:100%;
  height:100%;
  display:block;
}
.path-media-schematic{
  aspect-ratio:16/8.4;
}
.path-media-schematic img{
  object-fit:contain;
  padding:12px;
  background:#fff;
}
.path-media-3d{
  aspect-ratio:4/5;
  max-height:430px;
}
.path-media-3d img{
  object-fit:contain;
  padding:10px;
  background:#edf0f2;
}
.path-media-photo{
  aspect-ratio:4/5;
  max-height:455px;
}
.path-media-photo img{
  object-fit:cover;
  object-position:center center;
}
.path-media-code{
  aspect-ratio:16/9;
}
.path-media-code img{
  object-fit:cover;
  object-position:left top;
}

.path-copy{
  display:grid;
  grid-template-columns:42px 1fr;
  gap:11px;
  align-items:start;
  padding:18px 20px 20px;
}
.path-number{
  display:grid;
  place-items:center;
  width:34px;
  height:34px;
  border-radius:50%;
  background:var(--yellow);
  color:#111;
  font-size:11px;
  font-weight:950;
}
.path-copy strong{
  display:block;
  margin-top:1px;
  color:#fff;
  font-size:18px;
  line-height:1.15;
}
.path-copy small{
  display:block;
  margin-top:5px;
  color:#bfc6cf;
  font-size:12px;
  line-height:1.45;
}

.path-arrow{
  position:relative;
  display:grid;
  place-items:center;
  color:var(--yellow-2);
  font-size:34px;
  font-weight:900;
  line-height:1;
  z-index:2;
}
.path-arrow::before{
  content:"";
  position:absolute;
  z-index:-1;
  background:linear-gradient(90deg,transparent,rgba(255,201,40,.72),transparent);
}
.path-arrow-top{grid-area:arrowTop}
.path-arrow-top::before,
.path-arrow-bottom::before{
  width:64px;
  height:2px;
}
.path-arrow-down{
  grid-area:arrowDown;
  height:54px;
}
.path-arrow-down::before{
  width:2px;
  height:50px;
  background:linear-gradient(180deg,transparent,rgba(255,201,40,.72),transparent);
}
.path-arrow-bottom{grid-area:arrowBottom}

@media(max-width:980px){
  .project-path{
    grid-template-columns:minmax(0,1fr) 58px minmax(0,1fr);
  }
  .path-media-3d,
  .path-media-photo{
    max-height:390px;
  }
}
@media(max-width:820px){
  .project-path{
    grid-template-columns:1fr;
    grid-template-areas:
      "step1"
      "arrowTop"
      "step2"
      "arrowDown"
      "step3"
      "arrowBottom"
      "step4";
    gap:10px;
  }
  .path-arrow{
    height:34px;
    transform:none;
  }
  .path-arrow-top span{font-size:0}
  .path-arrow-top span::after{content:"↓";font-size:30px}
  .path-arrow-bottom span{font-size:0}
  .path-arrow-bottom span::after{content:"↓";font-size:30px}
  .path-arrow-top::before,
  .path-arrow-bottom::before,
  .path-arrow-down::before{
    width:2px;
    height:32px;
    background:linear-gradient(180deg,transparent,rgba(255,201,40,.72),transparent);
  }
  .path-media-schematic,
  .path-media-code{
    aspect-ratio:16/10;
  }
  .path-media-3d,
  .path-media-photo{
    aspect-ratio:4/4.6;
    max-height:none;
  }
}


@media(max-width:420px){
  .wrap{width:min(calc(100% - 24px),var(--wrap))}
  .hero-content{padding:66px 0 78px}
  .hero p{font-size:17px}
  .actions{gap:9px;margin-top:26px}
  .actions .pill,.actions .ghost{width:100%}
  .section{padding:64px 0}
  .section-title h2,.process-intro h2,.contact-info h2{font-size:34px}
  .service{padding:23px}
  .brandcard{padding:26px 22px}
  .contact-form{padding:20px}
  .path-copy{grid-template-columns:38px 1fr;padding:16px}
  .path-copy strong{font-size:17px}
  .footer{padding:38px 0}
}

.contact-status {
    display: none;
    margin-top: 12px;
    padding: 12px 14px;
    border-radius: 12px;
    font-size: 14px;
    line-height: 1.45;
}

.contact-status.ok {
    display: block;
    background: #ecfdf3;
    border: 1px solid #16a34a;
    color: #166534;
    font-weight: 600;
}

.contact-status.error {
    display: block;
    background: #fff1f2;
    border: 1px solid #dc2626;
    color: #991b1b;
    font-weight: 600;
}

.contact-form .submit:disabled {
    opacity: 0.65;
    cursor: wait;
}

body.login-open {
    overflow: hidden;
}

.login-modal {
    position: fixed;
    inset: 0;
    z-index: 9999;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.login-modal.open {
    display: flex;
}

.login-modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(5, 10, 18, 0.72);
    backdrop-filter: blur(5px);
}

.login-modal-dialog {
    position: relative;
    z-index: 1;
    width: min(100%, 460px);
    background: #ffffff;
    color: #111827;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.35);
}

.login-modal-dialog h2 {
    margin: 6px 0 8px;
}

.login-modal-dialog > p {
    margin: 0 0 24px;
    color: #64748b;
}

.login-modal-close {
    position: absolute;
    top: 14px;
    right: 16px;
    width: 36px;
    height: 36px;
    border: 0;
    border-radius: 50%;
    background: #f1f5f9;
    color: #111827;
    font-size: 24px;
    line-height: 1;
    cursor: pointer;
}

.login-field {
    margin-bottom: 16px;
}

.login-field label {
    display: block;
    margin-bottom: 7px;
    font-size: 14px;
    font-weight: 600;
}

.login-field input {
    width: 100%;
    box-sizing: border-box;
    padding: 12px 14px;
    border: 1px solid #cbd5e1;
    border-radius: 10px;
    background: #fff;
    color: #111827;
    font: inherit;
}

.login-field input:focus {
    outline: none;
    border-color: #f5b400;
    box-shadow: 0 0 0 3px rgba(245, 180, 0, 0.15);
}

.login-status {
    display: none;
    margin-bottom: 14px;
    padding: 10px 12px;
    border-radius: 10px;
    font-size: 14px;
}

.login-status.error {
    display: block;
    background: #fff1f2;
    border: 1px solid #dc2626;
    color: #991b1b;
    font-weight: 600;
}

.login-modal .submit {
    width: 100%;
}

.login-modal .submit:disabled {
    opacity: 0.65;
    cursor: wait;
}

.login-forgot {
    display: block;
    margin-top: 16px;
    text-align: center;
    color: #475569;
    font-size: 14px;
}

.login-forgot:hover {
    color: #111827;
}

@media (max-width: 600px) {

    .login-modal {
        padding: 14px;
    }

    .login-modal-dialog {
        padding: 24px 20px;
        border-radius: 16px;
    }
}

.back-to-top {
    position: fixed;
    right: 24px;
    bottom: 24px;
    z-index: 900;

    width: 48px;
    height: 48px;

    display: flex;
    align-items: center;
    justify-content: center;

    border: 0;
    border-radius: 50%;

    background: #f5b400;
    color: #0d1117;

    font-size: 24px;
    font-weight: 700;
    line-height: 1;

    cursor: pointer;

    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.22);

    opacity: 0;
    visibility: hidden;
    transform: translateY(12px);

    transition:
        opacity 0.25s ease,
        transform 0.25s ease,
        visibility 0.25s ease,
        background 0.2s ease;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: #ffc21c;
    transform: translateY(-3px);
}

.back-to-top:active {
    transform: translateY(0);
}

@media (max-width: 600px) {
    .back-to-top {
        right: 16px;
        bottom: 16px;
        width: 44px;
        height: 44px;
        font-size: 21px;
    }
}