/* =========================================================
   Roof Pitch Calculator — global stylesheet
   Aesthetic: architect's blueprint / technical drawing
   ========================================================= */

:root{
  --paper:#f4f1ea;
  --paper-2:#ece7db;
  --ink:#1b2a3a;
  --ink-soft:#42526a;
  --line:#c9c2b0;
  --line-soft:#ddd6c5;
  --rust:#d8651e;
  --rust-dark:#b14f12;
  --blue:#2c5f7c;
  --blue-soft:#dbe6ec;
  --white:#fffefb;
  --shadow:rgba(27,42,58,.14);
  --radius:14px;
  --maxw:1140px;
  --font-display:"Bricolage Grotesque","Spline Sans",sans-serif;
  --font-body:"Spline Sans","Segoe UI",sans-serif;
  --font-mono:"Spline Sans Mono","Courier New",monospace;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--font-body);
  background-color:var(--paper);
  background-image:
    linear-gradient(rgba(44,95,124,.05) 1px,transparent 1px),
    linear-gradient(90deg,rgba(44,95,124,.05) 1px,transparent 1px);
  background-size:26px 26px;
  color:var(--ink);
  line-height:1.65;
  font-size:17px;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block}
a{color:var(--rust-dark);text-decoration:none}
a:hover{text-decoration:underline}

.wrap{max-width:var(--maxw);margin:0 auto;padding:0 22px}

/* ---------- Header ---------- */
.site-header{
  background:var(--ink);
  color:var(--paper);
  border-bottom:3px solid var(--rust);
  position:sticky;top:0;z-index:50;
}
.site-header .wrap{display:flex;align-items:center;gap:18px;padding-top:14px;padding-bottom:14px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:11px;font-family:var(--font-display);
  font-weight:800;font-size:1.22rem;color:var(--paper);letter-spacing:-.02em}
.brand:hover{text-decoration:none}
.brand .mark{
  width:34px;height:34px;flex:none;border-radius:8px;background:var(--rust);
  display:grid;place-items:center;
}
.brand .mark svg{width:22px;height:22px}
.brand small{display:block;font-family:var(--font-mono);font-weight:400;
  font-size:.62rem;letter-spacing:.14em;text-transform:uppercase;color:#8fa6b5}

.main-nav{margin-left:auto;display:flex;gap:6px;flex-wrap:wrap}
.main-nav a{
  color:#cdd6dd;font-size:.94rem;font-weight:500;padding:7px 12px;
  border-radius:7px;transition:.15s;
}
.main-nav a:hover{background:rgba(255,255,255,.09);color:#fff;text-decoration:none}
.main-nav a.active{background:var(--rust);color:#fff}

.lang-switch{display:flex;align-items:center;gap:4px;
  border-left:1px solid #3a4c60;padding-left:12px;margin-left:4px}
.lang-switch a{
  font-family:var(--font-mono);font-size:.74rem;font-weight:500;
  color:#8fa6b5;padding:5px 8px;border-radius:6px;letter-spacing:.05em;
}
.lang-switch a:hover{background:rgba(255,255,255,.1);color:#fff;text-decoration:none}
.lang-switch a.active{color:var(--rust);font-weight:700}

.nav-toggle{display:none;background:none;border:1px solid #3a4c60;color:var(--paper);
  border-radius:7px;padding:7px 10px;font-size:1rem;cursor:pointer}

/* ---------- Hero ---------- */
.hero{padding:54px 0 30px;border-bottom:1px dashed var(--line)}
.hero .eyebrow{
  font-family:var(--font-mono);font-size:.78rem;letter-spacing:.16em;
  text-transform:uppercase;color:var(--rust-dark);font-weight:600;margin-bottom:12px}
h1{
  font-family:var(--font-display);font-weight:800;letter-spacing:-.025em;
  font-size:clamp(2rem,4.6vw,3.2rem);line-height:1.08;color:var(--ink);
}
.hero p.lead{font-size:1.12rem;color:var(--ink-soft);margin-top:16px;max-width:660px}

/* ---------- Calculator ---------- */
.calc{
  background:var(--white);border:1px solid var(--line);
  border-radius:var(--radius);box-shadow:0 18px 40px -24px var(--shadow);
  overflow:hidden;margin:30px 0 14px;
}
.calc-head{
  background:var(--ink);color:var(--paper);padding:16px 24px;
  display:flex;align-items:center;gap:10px;flex-wrap:wrap;
}
.calc-head h2{font-family:var(--font-display);font-size:1.15rem;font-weight:700;color:#fff;border:0;padding:0;margin:0}
.calc-head .tag{
  margin-left:auto;font-family:var(--font-mono);font-size:.7rem;
  background:var(--rust);color:#fff;padding:4px 9px;border-radius:5px;letter-spacing:.08em}
.calc-body{display:grid;grid-template-columns:1fr 1fr;gap:0}
.calc-inputs{padding:26px 24px;border-right:1px solid var(--line-soft)}
.calc-results{padding:26px 24px;background:var(--paper-2)}

.field{margin-bottom:20px}
.field label{display:block;font-weight:600;font-size:.92rem;margin-bottom:7px}
.field .hint{font-size:.78rem;color:var(--ink-soft);font-weight:400}
.input-row{display:flex;gap:8px}
.input-row input{
  flex:1;font-family:var(--font-mono);font-size:1.1rem;
  padding:11px 13px;border:1.5px solid var(--line);border-radius:9px;
  background:var(--white);color:var(--ink);width:100%;
}
.input-row input:focus{outline:none;border-color:var(--rust);box-shadow:0 0 0 3px rgba(216,101,30,.14)}
.input-row select{
  font-family:var(--font-mono);font-size:.95rem;padding:11px 10px;
  border:1.5px solid var(--line);border-radius:9px;background:var(--white);color:var(--ink);
}
.unit-toggle{display:flex;gap:6px;margin-bottom:20px}
.unit-toggle button{
  flex:1;font-family:var(--font-mono);font-size:.82rem;padding:8px;cursor:pointer;
  border:1.5px solid var(--line);border-radius:8px;background:var(--white);color:var(--ink-soft);
  transition:.15s;
}
.unit-toggle button.on{background:var(--blue);color:#fff;border-color:var(--blue)}

.result-card{
  background:var(--white);border:1px solid var(--line-soft);border-radius:10px;
  padding:14px 16px;margin-bottom:12px;display:flex;align-items:baseline;justify-content:space-between;gap:10px;
}
.result-card .rl{font-size:.86rem;font-weight:600;color:var(--ink-soft)}
.result-card .rv{font-family:var(--font-mono);font-weight:700;font-size:1.5rem;color:var(--ink)}
.result-card.primary{background:var(--ink);border-color:var(--ink)}
.result-card.primary .rl{color:#9fb3c0}
.result-card.primary .rv{color:var(--rust);font-size:1.85rem}
.result-note{font-size:.8rem;color:var(--ink-soft);margin-top:6px}

.calc-visual{padding:14px 24px 22px;background:var(--paper-2);border-top:1px dashed var(--line)}
.calc-visual svg{width:100%;height:auto;max-height:320px;margin-top:6px;
  touch-action:none;-webkit-user-select:none;user-select:none}

/* interactive diagram header row */
.visual-head{display:flex;align-items:center;justify-content:space-between;
  gap:12px;flex-wrap:wrap;margin-bottom:2px}
.visual-head .vh-title{font-family:var(--font-display);font-weight:700;
  font-size:1rem;color:var(--ink);display:flex;align-items:center;gap:8px}
.visual-head .vh-title .pulse{display:inline-block;width:8px;height:8px;
  border-radius:50%;background:var(--rust);
  box-shadow:0 0 0 0 rgba(216,101,30,.5);animation:vh-pulse 2s infinite}
@keyframes vh-pulse{
  0%{box-shadow:0 0 0 0 rgba(216,101,30,.45)}
  70%{box-shadow:0 0 0 9px rgba(216,101,30,0)}
  100%{box-shadow:0 0 0 0 rgba(216,101,30,0)}}
#calc-reset{font-family:var(--font-mono);font-size:.74rem;font-weight:600;
  letter-spacing:.04em;text-transform:uppercase;cursor:pointer;
  padding:6px 12px;border:1.5px solid var(--line);border-radius:7px;
  background:var(--white);color:var(--ink-soft);transition:.15s}
#calc-reset:hover{border-color:var(--blue);color:var(--blue)}

/* draggable SVG handles */
.roof-handle{cursor:grab;transition:r .12s ease,fill .12s ease}
.roof-handle:active,svg.dragging .roof-handle{cursor:grabbing}
.roof-handle.apex{fill:var(--rust)}
.roof-handle.axis{fill:var(--blue)}
.roof-handle:hover{r:13}
.roof-handle:focus{outline:none}
.roof-handle:focus-visible{outline:none}
.handle-ring{fill:none;stroke-width:2;opacity:.24;
  transition:opacity .14s ease,r .14s ease;pointer-events:none}
.handle-ring.apex{stroke:var(--rust)}
.handle-ring.axis{stroke:var(--blue)}
.handle-ring.active{opacity:.85}
svg.dragging .handle-ring{opacity:.55}
svg.dragging .handle-ring.active{opacity:.9}
#roof-line{cursor:grab}
svg.dragging #roof-line{cursor:grabbing}
.drag-hint{font-size:.82rem;color:var(--ink-soft);margin-top:8px;
  display:flex;align-items:center;gap:7px}
.drag-hint svg{width:15px;height:15px;flex:none}

/* ---------- Generic content ---------- */
main section{padding:34px 0}
h2{
  font-family:var(--font-display);font-weight:700;letter-spacing:-.02em;
  font-size:clamp(1.5rem,2.8vw,2rem);color:var(--ink);
  padding-bottom:8px;border-bottom:2px solid var(--rust);display:inline-block;margin-bottom:18px;
}
h3{font-family:var(--font-display);font-weight:700;font-size:1.22rem;color:var(--ink);
  margin:22px 0 8px}
h4{font-family:var(--font-body);font-weight:700;font-size:1.03rem;color:var(--blue);margin:16px 0 6px}
p{margin-bottom:14px}
section ul,section ol{margin:0 0 16px 22px}
section li{margin-bottom:7px}
strong{color:var(--ink)}
.formula{
  font-family:var(--font-mono);background:var(--ink);color:var(--paper);
  padding:13px 16px;border-radius:9px;font-size:.96rem;margin:14px 0;overflow-x:auto;
}
.formula .v{color:var(--rust)}

.callout{
  background:var(--blue-soft);border-left:4px solid var(--blue);
  padding:14px 18px;border-radius:0 10px 10px 0;margin:16px 0;font-size:.96rem;
}
.steps{counter-reset:step;list-style:none;margin-left:0!important}
.steps li{position:relative;padding-left:46px;margin-bottom:14px}
.steps li::before{
  counter-increment:step;content:counter(step);
  position:absolute;left:0;top:-2px;width:32px;height:32px;border-radius:8px;
  background:var(--rust);color:#fff;font-family:var(--font-mono);font-weight:700;
  display:grid;place-items:center;
}

/* ---------- Tables ---------- */
.table-wrap{overflow-x:auto;margin:16px 0;border:1px solid var(--line);border-radius:10px}
table{width:100%;border-collapse:collapse;background:var(--white);font-size:.95rem}
th,td{padding:10px 14px;text-align:left;border-bottom:1px solid var(--line-soft)}
th{background:var(--ink);color:var(--paper);font-family:var(--font-display);
  font-weight:600;font-size:.86rem;letter-spacing:.02em}
tr:last-child td{border-bottom:0}
tbody tr:nth-child(even){background:var(--paper)}
td.num{font-family:var(--font-mono);color:var(--blue)}

/* ---------- Cards grid ---------- */
.grid{display:grid;gap:18px;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));margin:18px 0}
.card{
  background:var(--white);border:1px solid var(--line);border-radius:11px;padding:18px 20px;
  transition:.15s;
}
.card:hover{transform:translateY(-3px);box-shadow:0 14px 30px -20px var(--shadow)}
.card h3{margin-top:0;font-size:1.08rem}
.card p{font-size:.92rem;color:var(--ink-soft);margin-bottom:0}

/* ---------- FAQ ---------- */
.faq details{
  background:var(--white);border:1px solid var(--line);border-radius:10px;
  padding:0 18px;margin-bottom:10px;
}
.faq summary{
  font-family:var(--font-display);font-weight:700;font-size:1.04rem;
  padding:14px 0;cursor:pointer;list-style:none;display:flex;justify-content:space-between;gap:12px;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--rust);font-size:1.4rem;line-height:1}
.faq details[open] summary::after{content:"\2013"}
.faq details[open] summary{border-bottom:1px dashed var(--line)}
.faq details p{padding:12px 0 16px;margin:0;font-size:.96rem;color:var(--ink-soft)}

/* ---------- Buttons ---------- */
.btn{
  display:inline-block;font-family:var(--font-display);font-weight:700;
  background:var(--rust);color:#fff;padding:11px 22px;border-radius:9px;
  border:0;cursor:pointer;font-size:.98rem;transition:.15s;
}
.btn:hover{background:var(--rust-dark);text-decoration:none}
.btn.ghost{background:transparent;color:var(--ink);border:1.5px solid var(--ink)}
.btn.ghost:hover{background:var(--ink);color:#fff}

/* ---------- Breadcrumb ---------- */
.crumb{font-family:var(--font-mono);font-size:.78rem;color:var(--ink-soft);
  padding:14px 0 0}
.crumb a{color:var(--blue)}

/* ---------- Forms ---------- */
.form-grid{display:grid;gap:16px;max-width:560px}
.form-grid label{font-weight:600;font-size:.92rem;display:block;margin-bottom:6px}
.form-grid input,.form-grid textarea,.form-grid select{
  width:100%;font-family:var(--font-body);font-size:1rem;padding:11px 13px;
  border:1.5px solid var(--line);border-radius:9px;background:var(--white);color:var(--ink);
}
.form-grid textarea{min-height:130px;resize:vertical}
.form-grid input:focus,.form-grid textarea:focus{outline:none;border-color:var(--rust)}

/* ---------- 404 ---------- */
.err{text-align:center;padding:70px 0}
.err .code{font-family:var(--font-display);font-weight:800;font-size:clamp(5rem,18vw,10rem);
  color:var(--rust);line-height:1;letter-spacing:-.04em}
.err h1{margin:8px 0 14px}

/* ---------- Footer ---------- */
.site-footer{
  background:var(--ink);color:#aebcc7;margin-top:40px;
  border-top:3px solid var(--rust);
}
.site-footer .wrap{padding:40px 22px 22px}
.foot-grid{display:grid;gap:28px;grid-template-columns:1.6fr 1fr 1fr 1fr}
.foot-grid h4{color:#fff;font-family:var(--font-display);font-size:.92rem;
  letter-spacing:.04em;margin-bottom:12px;text-transform:uppercase}
.foot-grid ul{list-style:none;margin:0}
.foot-grid li{margin-bottom:7px}
.foot-grid a{color:#aebcc7;font-size:.9rem}
.foot-grid a:hover{color:var(--rust)}
.foot-about p{font-size:.9rem;color:#92a2af;margin-top:8px}
.foot-lang{display:flex;gap:8px;margin-top:10px}
.foot-lang a{font-family:var(--font-mono);font-size:.74rem;border:1px solid #3a4c60;
  padding:4px 9px;border-radius:6px}
.foot-bottom{
  border-top:1px solid #2c3a4b;margin-top:30px;padding-top:18px;
  display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap;
  font-size:.82rem;color:#7e8f9d;
}
.foot-bottom .mono{font-family:var(--font-mono)}

/* ---------- Responsive ---------- */
@media(max-width:860px){
  .calc-body{grid-template-columns:1fr}
  .calc-inputs{border-right:0;border-bottom:1px solid var(--line-soft)}
  .foot-grid{grid-template-columns:1fr 1fr}
}
@media(max-width:680px){
  body{font-size:16px}
  .nav-toggle{display:block;margin-left:auto}
  .main-nav{
    display:none;width:100%;flex-direction:column;gap:2px;
    padding-top:8px;order:3;
  }
  .main-nav.open{display:flex}
  .main-nav a{padding:10px 12px}
  .lang-switch{border-left:0;padding-left:0;margin-left:0;
    border-top:1px solid #3a4c60;padding-top:8px;width:100%}
  .foot-grid{grid-template-columns:1fr}
  .foot-bottom{flex-direction:column}
  h2{display:block}
}