/* ==========================================================================
   RT Technologies — site styles
   Palette: charcoal + RT blue, white ground
   ========================================================================== */

:root {
  --blue: #1b6db8;
  --blue-dark: #0b4f8f;
  --blue-light: #e8f1fa;
  --charcoal: #1e1e1e;
  --charcoal-2: #2e2e2e;
  --gray-700: #4a4a4a;
  --gray-500: #6b6b6b;
  --gray-300: #d9dde2;
  --gray-100: #f4f6f8;
  --white: #ffffff;
  --radius: 12px;
  --shadow: 0 8px 30px rgba(20, 40, 70, 0.08);
  --shadow-lg: 0 18px 50px rgba(20, 40, 70, 0.14);
  --max: 1140px;
  --font: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--charcoal);
  background: var(--white);
}
img { max-width: 100%; display: block; }
a { color: var(--blue); text-decoration: none; }
a:hover { color: var(--blue-dark); }
h1, h2, h3 { line-height: 1.15; margin: 0 0 0.5em; font-weight: 800; letter-spacing: -0.01em; }
h1 { font-size: clamp(2.1rem, 4.5vw, 3.4rem); }
h2 { font-size: clamp(1.7rem, 3.2vw, 2.4rem); }
h3 { font-size: 1.2rem; font-weight: 700; }
p { margin: 0 0 1em; }
.hidden { display: none !important; }

.container { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 20px; }
.section { padding: clamp(64px, 9vw, 110px) 0; }
.section-alt { background: var(--gray-100); }
.section-dark { background: linear-gradient(135deg, var(--charcoal) 0%, var(--charcoal-2) 100%); color: #e9ecef; }
.section-head { max-width: 640px; margin-bottom: 48px; }
.section-sub { color: var(--gray-500); font-size: 1.05rem; }

.eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 12px;
}
.eyebrow-light { color: #7fb3e6; }
.accent { color: var(--blue); }

/* Buttons ------------------------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 14px 26px; border-radius: 8px; font-weight: 600; font-size: 0.98rem;
  border: 2px solid transparent; cursor: pointer; transition: all .18s ease;
  font-family: inherit; line-height: 1.2;
}
.btn-primary { background: linear-gradient(90deg, var(--blue), var(--blue-dark)); color: #fff; box-shadow: 0 6px 18px rgba(27,109,184,.28); }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 10px 24px rgba(27,109,184,.36); color: #fff; }
.btn-ghost { background: transparent; color: var(--charcoal); border-color: var(--gray-300); }
.btn-ghost:hover { border-color: var(--charcoal); color: var(--charcoal); }
.btn-sm { padding: 10px 18px; font-size: 0.9rem; }
.btn-block { width: 100%; }
.btn[disabled] { opacity: .7; cursor: default; transform: none; }

/* Header -------------------------------------------------------------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--gray-300);
}
.nav-wrap { display: flex; align-items: center; justify-content: space-between; height: 72px; }
.brand { display: flex; align-items: center; gap: 12px; color: var(--charcoal); font-weight: 800; font-size: 1.15rem; letter-spacing: -0.01em; }
.brand-mark { height: 30px; width: auto; }
.brand-text span { font-weight: 500; color: var(--gray-700); }
.nav { display: flex; align-items: center; gap: 28px; }
.nav a { color: var(--charcoal-2); font-weight: 500; font-size: 0.95rem; }
.nav a:not(.btn):hover { color: var(--blue); }
.nav-toggle { display: none; background: none; border: 0; padding: 8px; cursor: pointer; }
.nav-toggle span { display: block; width: 24px; height: 2px; background: var(--charcoal); margin: 5px 0; transition: transform .2s, opacity .2s; }

/* Hero ---------------------------------------------------------------- */
.hero {
  padding: clamp(56px, 8vw, 100px) 0;
  background:
    radial-gradient(900px 400px at 85% 0%, rgba(27,109,184,.12), transparent 60%),
    linear-gradient(180deg, #fff 0%, var(--gray-100) 100%);
}
.hero-grid { display: grid; grid-template-columns: 1.15fr 1fr; gap: 56px; align-items: center; }
.lead { font-size: 1.15rem; color: var(--gray-700); max-width: 560px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin: 28px 0 32px; }
.hero-points { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 10px 26px; color: var(--gray-700); font-size: 0.95rem; }
.hero-points li::before { content: ''; display: inline-block; width: 8px; height: 8px; border-radius: 50%; background: var(--blue); margin-right: 9px; vertical-align: middle; }
.hero-visual { display: flex; justify-content: center; }
.hero-logo {
  width: 100%; max-width: 460px;
  padding: 36px 40px;
  background: #fff; border-radius: 20px;
  box-shadow: var(--shadow-lg);
}

/* Cards --------------------------------------------------------------- */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.card {
  background: #fff; border: 1px solid var(--gray-300); border-radius: var(--radius);
  padding: 30px 28px; transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: transparent; }
.card-icon {
  width: 48px; height: 48px; border-radius: 10px;
  background: var(--blue-light); color: var(--blue);
  display: grid; place-items: center; margin-bottom: 18px;
}
.card-icon svg { width: 24px; height: 24px; }
.card p { color: var(--gray-500); margin: 0; font-size: 0.97rem; }

/* Projects ------------------------------------------------------------ */
.projects { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.project {
  display: flex; flex-direction: column; background: #fff; border-radius: var(--radius);
  overflow: hidden; color: inherit; box-shadow: var(--shadow); transition: transform .18s ease, box-shadow .18s ease;
}
.project:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); color: inherit; }
.project-preview {
  height: 170px; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--tint) 0%, color-mix(in srgb, var(--tint) 55%, #1e1e1e) 100%);
  position: relative;
}
.project-preview::after {
  content: ''; position: absolute; inset: 0;
  background: repeating-linear-gradient(135deg, rgba(255,255,255,.05) 0 2px, transparent 2px 14px);
}
.project-initial { font-size: 4.2rem; font-weight: 800; color: rgba(255,255,255,.92); letter-spacing: -0.03em; position: relative; z-index: 1; }
.project-body { padding: 26px 26px 28px; display: flex; flex-direction: column; gap: 6px; flex: 1; }
.project-body h3 { margin: 0; }
.project-type { color: var(--blue); font-size: 0.82rem; font-weight: 600; text-transform: uppercase; letter-spacing: .08em; margin: 0 0 6px; }
.project-body p { color: var(--gray-500); font-size: 0.96rem; margin: 0; }
.project-link { margin-top: auto; padding-top: 16px; font-weight: 600; color: var(--charcoal); font-size: 0.93rem; }
.project:hover .project-link { color: var(--blue); }

/* Process ------------------------------------------------------------- */
.steps { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 28px; counter-reset: step; }
.steps li { position: relative; padding-top: 18px; border-top: 3px solid var(--blue-light); }
.steps li::before { content: ''; position: absolute; top: -3px; left: 0; width: 48px; height: 3px; background: var(--blue); }
.step-num { display: block; font-size: 0.8rem; font-weight: 700; letter-spacing: .12em; color: var(--blue); margin-bottom: 10px; }
.steps p { color: var(--gray-500); margin: 0; font-size: 0.96rem; }

/* About --------------------------------------------------------------- */
.about-grid { display: grid; grid-template-columns: 1fr 1.2fr; gap: 56px; align-items: start; }
.about-grid h2 { color: #fff; }
.about-copy p { color: #c9ced4; font-size: 1.05rem; }
.about-stats { list-style: none; padding: 0; margin: 32px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.about-stats li { border-left: 3px solid var(--blue); padding-left: 14px; }
.about-stats strong { display: block; color: #fff; font-size: 1.15rem; margin-bottom: 4px; }
.about-stats span { display: block; color: #a9b0b8; font-size: 0.88rem; line-height: 1.4; }

/* Contact ------------------------------------------------------------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1.35fr; gap: 56px; align-items: start; }
.contact-intro p { color: var(--gray-700); }
.contact-details { list-style: none; padding: 0; margin: 32px 0 0; display: grid; gap: 18px; }
.contact-label { display: block; font-size: 0.75rem; font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--gray-500); margin-bottom: 2px; }
.contact-form {
  background: #fff; border: 1px solid var(--gray-300); border-radius: 16px;
  padding: 34px; box-shadow: var(--shadow);
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.field { display: flex; flex-direction: column; gap: 6px; margin-bottom: 18px; }
.field label { font-weight: 600; font-size: 0.9rem; }
.optional { font-weight: 400; color: var(--gray-500); }
.field input, .field select, .field textarea {
  font-family: inherit; font-size: 1rem; color: var(--charcoal);
  padding: 12px 14px; border: 1.5px solid var(--gray-300); border-radius: 8px; background: #fff;
  transition: border-color .15s, box-shadow .15s; width: 100%;
}
.field textarea { resize: vertical; min-height: 140px; }
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(27,109,184,.18);
}
.field input.invalid, .field textarea.invalid { border-color: #d64545; }
.form-status { margin: 14px 0 0; font-size: 0.95rem; min-height: 1.4em; }
.form-status.success { color: #1d7f4a; font-weight: 600; }
.form-status.error { color: #c93a3a; font-weight: 600; }

/* Footer -------------------------------------------------------------- */
.site-footer { background: var(--charcoal); color: #b8bec5; padding: 56px 0 26px; font-size: 0.93rem; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; align-items: start; }
.footer-logo { width: 150px; background: #fff; padding: 12px 14px; border-radius: 10px; margin-bottom: 14px; }
.footer-nav { display: grid; gap: 10px; }
.footer-nav a, .footer-contact a { color: #d6dae0; }
.footer-nav a:hover, .footer-contact a:hover { color: #fff; }
.footer-contact { display: grid; gap: 8px; }
.footer-bottom { border-top: 1px solid #333; margin-top: 40px; padding-top: 20px; font-size: 0.85rem; color: #8a9199; }

/* Responsive ---------------------------------------------------------- */
@media (max-width: 960px) {
  .cards, .projects { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .hero-grid, .about-grid, .contact-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero-visual { order: -1; }
  .hero-logo { max-width: 340px; padding: 28px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  .nav-toggle { display: block; }
  .nav {
    position: absolute; top: 72px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--gray-300);
    flex-direction: column; align-items: stretch; gap: 0; padding: 8px 20px 16px;
    display: none;
  }
  .nav.open { display: flex; }
  .nav a { padding: 12px 0; border-bottom: 1px solid var(--gray-100); }
  .nav a.btn { margin-top: 12px; border: 0; }
  .nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  .cards, .projects, .steps, .about-stats, .form-row, .footer-grid { grid-template-columns: 1fr; }
  .contact-form { padding: 24px 20px; }
  .brand-text { font-size: 1rem; }
}