/* =========================================================
   Sri Tech Resources — stylesheet
   Dark technical theme, text-only. Monospace labels, spec-sheet
   solutions table, subtle CSS grid background.
   ========================================================= */

:root {
  --bg: #0a1017;
  --bg-2: #0f1822;
  --panel: #121d29;
  --line: #213141;
  --cyan: #2fb9d8;
  --cyan-dark: #1b93ae;
  --text: #d5dde5;
  --muted: #8d9cac;
  --white: #f3f7fa;
  --radius: 3px;
  --maxw: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "IBM Plex Sans", system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--white);
  margin: 0 0 0.5em;
}
p { margin: 0 0 1rem; }
a { color: var(--cyan); text-decoration: none; }
a:hover { text-decoration: underline; }

a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.muted { color: var(--muted); }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

.mono-label {
  font-family: "IBM Plex Mono", ui-monospace, Menlo, monospace;
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyan);
  margin: 0 0 1rem;
}
.mono-label::before { content: "// "; color: var(--cyan-dark); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 0.85rem 1.6rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.92rem;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--cyan); color: #04141b; }
.btn-primary:hover { background: var(--white); color: #04141b; }
.btn-outline { background: transparent; color: var(--white); border-color: #3a5166; }
.btn-outline:hover { border-color: var(--cyan); color: var(--cyan); }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(10, 16, 23, 0.94);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 70px; }
.brand { font-weight: 600; font-size: 1.15rem; color: var(--white); letter-spacing: 0.01em; }
.brand:hover { text-decoration: none; color: var(--white); }
.nav ul { list-style: none; display: flex; gap: 2rem; margin: 0; padding: 0; align-items: center; }
.nav a { font-size: 0.92rem; font-weight: 500; color: var(--text); }
.nav a:hover { color: var(--cyan); text-decoration: none; }
.nav .nav-cta { padding: 0.5rem 1.2rem; border: 1px solid var(--cyan); border-radius: var(--radius); color: var(--cyan); }
.nav .nav-cta:hover { background: var(--cyan); color: #04141b; }
.nav-toggle { display: none; }

/* ---------- Hero ---------- */
.hero {
  padding: 96px 0 88px;
  border-bottom: 1px solid var(--line);
  background-color: var(--bg);
  background-image:
    linear-gradient(rgba(47, 185, 216, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(47, 185, 216, 0.06) 1px, transparent 1px);
  background-size: 44px 44px;
}
.hero-grid { display: grid; grid-template-columns: 1.3fr 0.8fr; gap: 64px; align-items: center; }
.hero h1 { font-size: clamp(2.1rem, 4.2vw, 3.3rem); max-width: 18ch; }
.lead { font-size: 1.1rem; color: var(--muted); max-width: 56ch; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 1.8rem; }

.spec { background: var(--panel); border: 1px solid var(--line); border-top: 2px solid var(--cyan); padding: 1.5rem 1.6rem; }
.spec-title { font-family: "IBM Plex Mono", monospace; font-size: 0.75rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); margin: 0 0 0.8rem; }
.spec dl { margin: 0; }
.spec dl > div { display: flex; gap: 1rem; padding: 0.95rem 0; border-top: 1px solid var(--line); }
.spec dt { font-family: "IBM Plex Mono", monospace; color: var(--cyan); font-size: 0.9rem; }
.spec dd { margin: 0; color: var(--white); }

/* ---------- Sections ---------- */
.section { padding: 88px 0; }
.section-panel { background: var(--bg-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section h2 { font-size: clamp(1.7rem, 3vw, 2.3rem); }

.about { display: grid; grid-template-columns: 0.95fr 1.05fr; gap: 72px; align-items: start; }
.prose p { color: var(--muted); font-size: 1.05rem; }

/* ---------- Solutions table ---------- */
.solutions { width: 100%; border-collapse: collapse; margin-top: 2rem; border: 1px solid var(--line); background: var(--panel); }
.solutions thead th {
  text-align: left;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 0.9rem 1.4rem;
  border-bottom: 1px solid var(--line);
  background: #0e1721;
}
.solutions tbody th, .solutions tbody td { text-align: left; vertical-align: top; padding: 1.6rem 1.4rem; border-bottom: 1px solid var(--line); }
.solutions tbody tr:last-child th, .solutions tbody tr:last-child td { border-bottom: 0; }
.solutions tbody th { width: 24%; font-size: 1.15rem; font-weight: 600; color: var(--white); }
.row-id { display: block; font-family: "IBM Plex Mono", monospace; font-size: 0.8rem; font-weight: 500; color: var(--cyan); margin-bottom: 0.3rem; }
.solutions tbody td:nth-child(2) { width: 36%; color: var(--muted); }
.solutions ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.5rem; }
.solutions li { position: relative; padding-left: 1.2rem; font-size: 0.95rem; }
.solutions li::before { content: ""; position: absolute; left: 0; top: 0.7em; width: 8px; height: 2px; background: var(--cyan); }

/* ---------- Delivery ---------- */
.delivery { display: grid; grid-template-columns: 0.8fr 1.2fr; gap: 72px; align-items: start; }
.checklist { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--line); }
.checklist li { display: grid; grid-template-columns: 56px 1fr; gap: 18px; padding: 1.4rem 0; border-bottom: 1px solid var(--line); }
.step-id { font-family: "IBM Plex Mono", monospace; color: var(--cyan); font-size: 1rem; padding-top: 0.15rem; }
.checklist h3 { font-size: 1.2rem; margin-bottom: 0.15em; }
.checklist p { margin: 0; color: var(--muted); }

/* ---------- Contact ---------- */
.contact { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: start; }
.contact-list { margin: 1.8rem 0 0; border-top: 1px solid var(--line); }
.contact-list > div { padding: 1rem 0; border-bottom: 1px solid var(--line); }
.contact-list dt { font-family: "IBM Plex Mono", monospace; font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--cyan); margin-bottom: 0.3rem; }
.contact-list dd { margin: 0; color: var(--white); }

.contact-form { background: var(--panel); border: 1px solid var(--line); padding: 2rem; }
.field { margin-bottom: 1.2rem; }
.field label { display: block; font-size: 0.82rem; font-weight: 500; margin-bottom: 0.35rem; color: var(--text); }
.field input, .field textarea {
  width: 100%; padding: 0.75rem 0.9rem; border: 1px solid #2d4155; border-radius: var(--radius);
  font: inherit; color: var(--white); background: var(--bg);
}
.field input:focus, .field textarea:focus { border-color: var(--cyan); }
.form-note { font-size: 0.9rem; margin: 0.8rem 0 0; min-height: 1.2em; }
.form-note.ok { color: #7fe0a6; }
.form-note.err { color: #ff9d96; }

/* ---------- Footer ---------- */
.site-footer { background: #070b10; color: var(--muted); padding: 26px 0; font-size: 0.88rem; border-top: 1px solid var(--line); }
.footer-inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.8rem; }
.footer-inner strong { color: var(--white); font-weight: 600; }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero { padding: 64px 0 56px; }
  .section { padding: 64px 0; }
  .hero-grid, .about, .delivery, .contact { grid-template-columns: 1fr; gap: 36px; }

  /* Table becomes stacked blocks */
  .solutions, .solutions tbody, .solutions tr, .solutions th, .solutions td { display: block; width: 100% !important; }
  .solutions thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
  .solutions tbody tr { border-bottom: 1px solid var(--line); padding: 0.6rem 0; }
  .solutions tbody tr:last-child { border-bottom: 0; }
  .solutions tbody th, .solutions tbody td { border-bottom: 0 !important; padding: 0.6rem 1.2rem; }
}

@media (max-width: 760px) {
  .nav-toggle { display: flex; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
  .nav-toggle span { width: 24px; height: 2px; background: var(--white); }
  .nav {
    position: absolute; top: 70px; left: 0; right: 0;
    background: var(--bg-2); border-bottom: 1px solid var(--line);
    max-height: 0; overflow: hidden; transition: max-height 0.3s ease;
  }
  .nav.open { max-height: 420px; }
  .nav ul { flex-direction: column; align-items: stretch; gap: 0; padding: 0.4rem 24px 1.2rem; }
  .nav li { border-bottom: 1px solid var(--line); }
  .nav li:last-child { border-bottom: 0; padding-top: 0.8rem; }
  .nav a { display: block; padding: 0.85rem 0; }
  .nav .nav-cta { text-align: center; padding: 0.75rem 1rem; }
  .contact-form { padding: 1.4rem; }
}

@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; transition: none !important; }
}