/* =========================================================
   Kit C — Domótica Educacional  |  LED Portugal
   ========================================================= */
:root {
  --bg:#0f1117;--surface:#161b24;--surface2:#1c2333;--border:#252e40;
  --text:#e2e8f4;--muted:#64748b;--dim:#334155;
  --teal:#0dd6b8;--blue:#3b9eff;--purple:#a78bfa;--green:#22d472;
  --yellow:#fbbf24;--orange:#fb923c;--red:#f87171;--pink:#f472b6;
  --mono:'Fira Mono','Consolas','Courier New',monospace;
  --sans:'Segoe UI',system-ui,-apple-system,sans-serif;
  --r:10px;--r-sm:6px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:var(--sans);background:var(--bg);color:var(--text);line-height:1.7}
a{color:var(--teal);text-decoration:none}
a:hover{text-decoration:underline}
code,pre{font-family:var(--mono);font-size:.88rem}

/* NAV */
nav{position:sticky;top:0;z-index:100;background:rgba(15,17,23,.95);
  backdrop-filter:blur(12px);border-bottom:1px solid var(--border);
  padding:0 clamp(1rem,4vw,3rem);display:flex;align-items:center;gap:.25rem;
  height:56px;overflow-x:auto}
nav a{font-size:.8rem;font-weight:500;color:var(--muted);white-space:nowrap;
  padding:.35rem .7rem;border-radius:var(--r-sm);transition:color .2s,background .2s}
nav a:hover{color:var(--text);background:var(--surface2);text-decoration:none}
nav a.active{color:var(--teal)}
nav .logo{font-weight:700;font-size:.9rem;color:var(--teal);margin-right:.5rem;white-space:nowrap}
nav .sep{color:var(--dim);user-select:none;padding:0 .1rem}

/* BREADCRUMB */
.breadcrumb{font-size:.78rem;color:var(--muted);padding:.75rem clamp(1rem,4vw,3rem);
  border-bottom:1px solid var(--border);display:flex;align-items:center;gap:.4rem;flex-wrap:wrap}
.breadcrumb a{color:var(--muted)}.breadcrumb a:hover{color:var(--teal)}

/* PAGE */
.page{max-width:1000px;margin:0 auto;padding:2.5rem clamp(1rem,4vw,2.5rem) 5rem}
.page-wide{max-width:1200px;margin:0 auto;padding:2.5rem clamp(1rem,4vw,2.5rem) 5rem}

/* HERO */
.hero{background:linear-gradient(135deg,rgba(13,214,184,.06) 0%,rgba(59,158,255,.05) 50%,rgba(167,139,250,.06) 100%);
  border-bottom:1px solid var(--border);padding:clamp(3rem,6vw,5rem) clamp(1rem,4vw,3rem);
  text-align:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;inset:0;
  background-image:linear-gradient(rgba(13,214,184,.04) 1px,transparent 1px),
  linear-gradient(90deg,rgba(13,214,184,.04) 1px,transparent 1px);
  background-size:40px 40px;pointer-events:none}
.hero-tag{display:inline-block;font-size:.72rem;font-weight:600;letter-spacing:.1em;
  text-transform:uppercase;color:var(--teal);background:rgba(13,214,184,.1);
  border:1px solid rgba(13,214,184,.25);padding:.3rem .9rem;border-radius:99px;margin-bottom:1.2rem}
.hero h1{font-size:clamp(1.8rem,4vw,3rem);font-weight:800;line-height:1.15;margin-bottom:.8rem}
.hero p{color:var(--muted);font-size:clamp(.9rem,1.5vw,1.05rem);max-width:600px;margin:0 auto 2rem}
.hero-btns{display:flex;flex-wrap:wrap;gap:.75rem;justify-content:center}

/* BUTTONS */
.btn{display:inline-flex;align-items:center;gap:.4rem;padding:.6rem 1.3rem;
  border-radius:var(--r-sm);font-size:.85rem;font-weight:600;cursor:pointer;
  transition:all .2s;border:1px solid transparent;text-decoration:none!important}
.btn-primary{background:var(--teal);color:#0a1014;border-color:var(--teal)}
.btn-primary:hover{background:#0fc4aa}
.btn-outline{background:transparent;color:var(--text);border-color:var(--border)}
.btn-outline:hover{background:var(--surface2);border-color:var(--teal);color:var(--teal)}

/* HEADINGS */
.section-title{font-size:clamp(1.2rem,2.5vw,1.6rem);font-weight:700;margin-bottom:.5rem;
  display:flex;align-items:center;gap:.5rem}
.section-sub{color:var(--muted);font-size:.9rem;margin-bottom:1.8rem}
.section-sep{border:none;border-top:1px solid var(--border);margin:3rem 0}
h2{font-size:clamp(1.4rem,3vw,2rem);font-weight:800;margin:2.5rem 0 .5rem}
h3{font-size:1.1rem;font-weight:700;margin:1.8rem 0 .5rem}

/* CARDS */
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:1rem}
.cards.cols2{grid-template-columns:repeat(auto-fill,minmax(320px,1fr))}
.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--r);
  padding:1.4rem;transition:transform .2s,border-color .2s;
  display:flex;flex-direction:column;gap:.5rem;text-decoration:none;color:var(--text)}
.card:hover{transform:translateY(-3px);border-color:var(--teal);text-decoration:none}
.card-icon{font-size:1.6rem}
.card h3{font-size:1rem;font-weight:700;margin:0}
.card p{font-size:.84rem;color:var(--muted);flex:1}
.card .card-meta{display:flex;flex-wrap:wrap;gap:.35rem;margin-top:.5rem;
  padding-top:.7rem;border-top:1px solid var(--border)}

/* BADGES */
.badge{font-size:.68rem;font-weight:600;letter-spacing:.04em;text-transform:uppercase;
  padding:.15rem .55rem;border-radius:3px;border:1px solid}
.badge-teal{color:var(--teal);border-color:rgba(13,214,184,.3);background:rgba(13,214,184,.08)}
.badge-blue{color:var(--blue);border-color:rgba(59,158,255,.3);background:rgba(59,158,255,.08)}
.badge-green{color:var(--green);border-color:rgba(34,212,114,.3);background:rgba(34,212,114,.08)}
.badge-yellow{color:var(--yellow);border-color:rgba(251,191,36,.3);background:rgba(251,191,36,.08)}
.badge-orange{color:var(--orange);border-color:rgba(251,146,60,.3);background:rgba(251,146,60,.08)}
.badge-red{color:var(--red);border-color:rgba(248,113,113,.3);background:rgba(248,113,113,.08)}
.badge-purple{color:var(--purple);border-color:rgba(167,139,250,.3);background:rgba(167,139,250,.08)}
.level-init{color:var(--green);font-size:.75rem;font-weight:600}
.level-inter{color:var(--yellow);font-size:.75rem;font-weight:600}
.level-adv{color:var(--red);font-size:.75rem;font-weight:600}

/* TABLE */
.tbl-wrap{overflow-x:auto;margin:1rem 0}
table{width:100%;border-collapse:collapse;font-size:.88rem}
th{font-size:.72rem;font-weight:700;letter-spacing:.07em;text-transform:uppercase;
  color:var(--muted);padding:.75rem 1rem;text-align:left;
  border-bottom:1px solid var(--border);background:var(--surface)}
td{padding:.7rem 1rem;border-bottom:1px solid var(--border);color:var(--text);vertical-align:top}
tr:last-child td{border-bottom:none}
tr:hover td{background:rgba(255,255,255,.015)}
td code{background:var(--surface2);padding:.1rem .35rem;border-radius:3px;font-size:.82rem}

/* CODE BLOCK */
.code-block{background:#0a0d12;border:1px solid var(--border);border-radius:var(--r);
  overflow:hidden;margin:1rem 0}
.code-header{display:flex;align-items:center;justify-content:space-between;
  padding:.5rem 1rem;background:var(--surface);border-bottom:1px solid var(--border);
  font-size:.72rem;color:var(--muted);font-family:var(--mono)}
.dot-row{display:flex;gap:.35rem}
.dot-row span{width:10px;height:10px;border-radius:50%}
.dot-row span:nth-child(1){background:#f87171}
.dot-row span:nth-child(2){background:#fbbf24}
.dot-row span:nth-child(3){background:#22d472}
.code-block pre{padding:1.2rem 1.4rem;overflow-x:auto;line-height:1.65;font-size:.83rem}
.code-block pre code{color:var(--text)}
.c-kw{color:#c084fc}.c-fn{color:#60a5fa}.c-str{color:#86efac}
.c-num{color:#fb923c}.c-cm{color:#475569;font-style:italic}
.c-pp{color:#f472b6}.c-tp{color:#34d399}

/* CALLOUT */
.callout{display:flex;gap:.9rem;align-items:flex-start;padding:1rem 1.2rem;
  border-radius:var(--r);margin:1rem 0;font-size:.9rem}
.callout-icon{font-size:1.2rem;flex-shrink:0;margin-top:.05em}
.callout h4{font-weight:700;font-size:.88rem;margin-bottom:.2rem}
.callout p{color:var(--muted);font-size:.86rem;margin:0}
.callout.tip{background:rgba(13,214,184,.07);border:1px solid rgba(13,214,184,.2)}
.callout.warn{background:rgba(251,191,36,.07);border:1px solid rgba(251,191,36,.2)}
.callout.warn .callout-icon{color:var(--yellow)}
.callout.info{background:rgba(59,158,255,.07);border:1px solid rgba(59,158,255,.2)}
.callout.info .callout-icon{color:var(--blue)}
.callout.danger{background:rgba(248,113,113,.07);border:1px solid rgba(248,113,113,.2)}
.callout.danger .callout-icon{color:var(--red)}

/* STEPS */
.steps{display:flex;flex-direction:column;gap:0}
.step{display:grid;grid-template-columns:52px 1fr;gap:0;position:relative}
.step:not(:last-child) .step-line{position:absolute;left:25px;top:52px;bottom:0;
  width:2px;background:var(--border);z-index:0}
.step-num-w{display:flex;flex-direction:column;align-items:center;padding-top:4px;z-index:1}
.step-n{width:44px;height:44px;border-radius:50%;display:grid;place-items:center;
  font-size:.85rem;font-weight:800;border:2px solid var(--teal);
  background:rgba(13,214,184,.1);color:var(--teal);flex-shrink:0}
.step-body{padding:0 0 2.5rem 1.3rem}
.step-body h4{font-size:1rem;font-weight:700;margin-bottom:.4rem}
.step-body p{font-size:.9rem;color:var(--muted);margin-bottom:.5rem}

/* PIN COLOURS */
.pin-sig{color:var(--yellow);font-weight:700}
.pin-vcc{color:var(--red);font-weight:700}
.pin-gnd{color:var(--muted);font-weight:700}
.pin-dig{color:var(--blue);font-weight:700}
.pin-ana{color:var(--green);font-weight:700}

/* TOC */
.toc{background:var(--surface);border:1px solid var(--border);border-radius:var(--r);
  padding:1.2rem 1.5rem;margin-bottom:2rem}
.toc h4{font-size:.82rem;font-weight:700;letter-spacing:.07em;text-transform:uppercase;
  color:var(--muted);margin-bottom:.8rem}
.toc ul{list-style:none;display:flex;flex-direction:column;gap:.35rem}
.toc li a{font-size:.88rem;color:var(--muted)}
.toc li a:hover{color:var(--teal)}
.toc li{border-left:2px solid var(--border);padding-left:.75rem;transition:border-color .2s}
.toc li:hover{border-color:var(--teal)}

/* FOOTER */
footer{border-top:1px solid var(--border);padding:2rem clamp(1rem,4vw,3rem);
  text-align:center;color:var(--muted);font-size:.8rem}
footer a{color:var(--teal)}

/* BACK TOP / PROGRESS */
#bt{position:fixed;bottom:1.5rem;right:1.5rem;width:38px;height:38px;
  border-radius:var(--r-sm);background:var(--surface2);border:1px solid var(--border);
  display:grid;place-items:center;color:var(--muted);cursor:pointer;
  opacity:0;pointer-events:none;transition:opacity .3s;font-size:.9rem;z-index:200}
#bt.show{opacity:1;pointer-events:all}
#bt:hover{border-color:var(--teal);color:var(--teal)}
#prog{position:fixed;top:0;left:0;height:2px;z-index:999;
  background:linear-gradient(90deg,var(--teal),var(--blue));width:0;transition:width .1s}

/* PAGE NAV */
.page-nav{display:flex;gap:1rem;flex-wrap:wrap;margin-top:3rem;
  padding-top:2rem;border-top:1px solid var(--border)}
.page-nav a{flex:1;min-width:180px;background:var(--surface);border:1px solid var(--border);
  border-radius:var(--r);padding:1rem 1.2rem;display:flex;flex-direction:column;gap:.2rem;
  transition:border-color .2s}
.page-nav a:hover{border-color:var(--teal);text-decoration:none}
.pn-dir{font-size:.7rem;color:var(--muted);text-transform:uppercase;letter-spacing:.08em}
.pn-title{font-size:.95rem;font-weight:700;color:var(--text)}
.pn-next{text-align:right}

@media(max-width:640px){
  .hero h1{font-size:1.8rem}
  .step{grid-template-columns:40px 1fr}
  .step-n{width:36px;height:36px;font-size:.75rem}
  .step-line{left:19px!important}
}