/* K-app — design system del sito di presentazione.
   Stessa palette del prodotto: inchiostro scuro, smeraldo operativo,
   ambra per gli accenti di fiducia. Tipografia system, niente font
   esterni: il sito non chiama reti di terze parti, come il prodotto. */
:root {
  --bg: #0d1117; --panel: #161b22; --panel2: #1c2330;
  --fg: #e6edf3; --dim: #8b949e; --line: #2b353c;
  --acc: #34d399; --acc-dim: #1f7a5c; --amber: #e3b341;
  --bad: #f85149;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; background: var(--bg); color: var(--fg);
  font: 16px/1.6 ui-sans-serif, system-ui, "Segoe UI", sans-serif;
}
a { color: var(--acc); text-decoration: none; }
a:hover { text-decoration: underline; }
code, .mono { font: 0.9em ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* nav */
nav {
  border-bottom: 1px solid var(--line);
  background: rgba(13,17,23,.85); backdrop-filter: blur(8px);
  position: sticky; top: 0; z-index: 10;
}
nav .wrap { display: flex; align-items: center; gap: 24px; height: 60px; }
nav img { width: 30px; height: 30px; border-radius: 7px; }
nav .brand { display: flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: .04em; }
nav .brand small { color: var(--dim); font-weight: 400; }
nav .links { margin-left: auto; display: flex; gap: 20px; font-size: 14px; }
nav .links a { color: var(--fg); }
nav .cta-mini {
  background: var(--acc); color: #052e1f !important; padding: 7px 14px;
  border-radius: 8px; font-weight: 700;
}
nav .cta-mini:hover { filter: brightness(1.1); text-decoration: none; }

/* hero */
.hero { padding: 96px 0 72px; text-align: center; }
.hero h1 {
  font-size: clamp(32px, 5vw, 52px); line-height: 1.12; margin: 0 0 20px;
  letter-spacing: -0.02em;
}
.hero h1 .accent { color: var(--acc); }
.hero p.sub {
  font-size: 19px; color: var(--dim); max-width: 720px; margin: 0 auto 36px;
}
.cta-row { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 14px 26px; border-radius: 10px;
  font-weight: 700; font-size: 15px; border: 1px solid var(--line);
  color: var(--fg); background: var(--panel); cursor: pointer;
}
.btn.primary { background: var(--acc); border-color: var(--acc); color: #052e1f; }
.btn.primary:hover { filter: brightness(1.12); text-decoration: none; }
.btn:hover { border-color: var(--acc-dim); text-decoration: none; }
.hero .hint { margin-top: 18px; font-size: 13px; color: var(--dim); }

/* pillars */
.pillars { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; padding: 24px 0 64px; }
.pillar {
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px;
  padding: 26px;
}
.pillar h3 { margin: 0 0 10px; font-size: 17px; }
.pillar h3 .ic { color: var(--acc); margin-right: 8px; }
.pillar p { color: var(--dim); font-size: 14px; margin: 0; }

/* sections */
section.block { padding: 56px 0; border-top: 1px solid var(--line); }
section.block h2 { font-size: 30px; margin: 0 0 8px; letter-spacing: -0.01em; }
section.block .lede { color: var(--dim); max-width: 680px; margin-bottom: 32px; }

/* arch diagram */
.arch {
  background: #0a0d12; border: 1px solid var(--line); border-radius: 14px;
  padding: 28px; font-size: 13px; overflow-x: auto;
}
.arch pre { margin: 0; color: var(--dim); line-height: 1.7; }
.arch .k { color: var(--acc); }
.arch .w { color: var(--amber); }

/* metric strip */
.metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.metric {
  background: var(--panel); border: 1px solid var(--line); border-radius: 12px;
  padding: 18px; text-align: center;
}
.metric .v { font-size: 26px; font-weight: 800; color: var(--acc); }
.metric .l { font-size: 12px; color: var(--dim); margin-top: 4px; }

/* pricing */
.tiers { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.tier {
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px;
  padding: 28px; display: flex; flex-direction: column;
}
.tier.featured { border-color: var(--acc); background: var(--panel2); }
.tier .name { font-size: 14px; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; color: var(--dim); }
.tier.featured .name { color: var(--acc); }
.tier .price { font-size: 34px; font-weight: 800; margin: 12px 0 4px; }
.tier .price small { font-size: 14px; font-weight: 400; color: var(--dim); }
.tier ul { list-style: none; padding: 0; margin: 18px 0 24px; flex: 1; }
.tier li { padding: 7px 0 7px 24px; position: relative; font-size: 14px; color: var(--fg); border-bottom: 1px dashed var(--line); }
.tier li::before { content: "✓"; color: var(--acc); position: absolute; left: 0; font-weight: 700; }
.tier li.no { color: var(--dim); }
.tier li.no::before { content: "—"; color: var(--dim); }
.note-box {
  margin-top: 28px; background: var(--panel); border-left: 3px solid var(--amber);
  border-radius: 0 10px 10px 0; padding: 16px 20px; font-size: 14px; color: var(--dim);
}
.note-box b { color: var(--amber); }

/* tables */
table.spec { width: 100%; border-collapse: collapse; font-size: 14px; }
table.spec th, table.spec td { text-align: left; padding: 12px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
table.spec th { color: var(--dim); font-weight: 600; font-size: 12px; text-transform: uppercase; letter-spacing: .06em; }
table.spec td:first-child { color: var(--dim); }

/* forms */
form.panel {
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px;
  padding: 28px; display: grid; gap: 14px; max-width: 560px;
}
form.panel label { display: grid; gap: 6px; font-size: 13px; color: var(--dim); }
form.panel input, form.panel select, form.panel textarea {
  background: var(--bg); border: 1px solid var(--line); color: var(--fg);
  border-radius: 8px; padding: 11px 12px; font: inherit; font-size: 14px;
}
form.panel input:focus, form.panel select:focus { outline: 1px solid var(--acc-dim); border-color: var(--acc-dim); }
form.panel .btn { justify-self: start; }
.form-state { font-size: 14px; min-height: 20px; }
.form-state.ok { color: var(--acc); }
.form-state.err { color: var(--bad); }

/* download cards */
.dl-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.dl-card {
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px;
  padding: 24px; text-align: center;
}
.dl-card .os { font-size: 20px; font-weight: 700; margin-bottom: 6px; }
.dl-card .fmt { color: var(--dim); font-size: 12px; margin-bottom: 16px; }
.req { background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 24px; }
.req h3 { margin-top: 0; font-size: 15px; }
.req table.spec td:first-child { width: 40%; }

footer {
  border-top: 1px solid var(--line); padding: 40px 0; margin-top: 40px;
  color: var(--dim); font-size: 13px;
}
footer .wrap { display: flex; gap: 24px; flex-wrap: wrap; }
footer .grow { flex: 1; }

@media (max-width: 860px) {
  .pillars, .tiers, .dl-grid, .metrics { grid-template-columns: 1fr; }
  nav .links { gap: 12px; font-size: 13px; }
}