/* ISKT — iskt.co.th */
:root {
  --ink: #0C1A28;
  --navy: #0B1D2E;
  --navy-panel: #0F2538;
  --navy-deep: #07131F;
  --navy-line: #2B4258;
  --navy-line-soft: #1E3549;
  --paper: #F3F5F1;
  --white: #FFFFFF;
  --line: #D9DED6;
  --line-strong: #B9C2B6;
  --field-line: #8A968F;
  --muted: #43515E;
  --muted-dark: #A9B8C6;
  --soft-dark: #C5D1DC;
  --pale-dark: #E3EAF0;
  --accent: #8CC63F;
  --accent-text: #3F6B12;
  --link: #0E6E9E;
  --link-hover: #0A4F73;
  --font-body: 'IBM Plex Sans Thai', 'Leelawadee UI', Tahoma, sans-serif;
  --font-display: 'Bai Jamjuree', 'Leelawadee UI', sans-serif;
  --font-mono: 'IBM Plex Mono', Consolas, monospace;
  --gutter: clamp(20px, 5vw, 80px);
  --section-y: clamp(64px, 8vw, 112px);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, p, ul, ol, dl, dd { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img { max-width: 100%; display: block; }
a { color: var(--link); }
a:hover { color: var(--link-hover); }
:focus-visible { outline: 3px solid #25B7E9; outline-offset: 3px; }

.skip-link {
  position: absolute; left: 16px; top: -60px; z-index: 100;
  background: var(--ink); color: var(--white); padding: 10px 16px; border-radius: 4px;
}
.skip-link:focus { top: 12px; color: var(--white); }

.container { max-width: 1200px; margin: 0 auto; }
.section { padding: var(--section-y) var(--gutter); }
.section--white { background: var(--white); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section--dark { background: var(--navy); color: var(--white); }
.stack { display: flex; flex-direction: column; gap: 48px; }

.eyebrow { font-family: var(--font-mono); font-size: 14px; letter-spacing: 0.08em; color: var(--accent-text); }
.section--dark .eyebrow, .hero .eyebrow { color: var(--accent); }
.section-head { display: flex; flex-direction: column; gap: 14px; max-width: 720px; }
.section-head p { color: var(--muted); }
h2 { font-family: var(--font-display); font-weight: 700; font-size: clamp(28px, 3.4vw, 42px); line-height: 1.3; }
h3 { font-family: var(--font-display); font-weight: 600; font-size: 20px; line-height: 1.3; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 48px; padding: 11px 24px; border: 0; border-radius: 4px;
  font: inherit; font-weight: 600; text-decoration: none; cursor: pointer;
  transition: background-color .15s ease, transform .15s ease;
}
.btn--ink { background: var(--ink); color: var(--white); }
.btn--ink:hover { background: #1B3147; color: var(--white); }
.btn--accent { background: var(--accent); color: var(--ink); padding: 14px 28px; }
.btn--accent:hover { background: #A2D75B; color: var(--ink); }
.text-link { font-weight: 500; padding: 10px 0; }
.text-link--light, .text-link--light:hover { color: var(--white); }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: var(--white); border-bottom: 1px solid var(--line);
  padding: 12px var(--gutter);
}
.site-header__inner { display: flex; align-items: center; justify-content: space-between; gap: 16px 32px; }
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; color: var(--ink); }
.brand:hover { color: var(--ink); }
.brand__mark { width: 46px; height: 46px; flex: none; }
.brand__text { display: flex; flex-direction: column; gap: 3px; }
.brand__name { font-family: var(--font-display); font-weight: 700; font-size: 21px; letter-spacing: 0.05em; line-height: 1; }
.brand__sub { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em; line-height: 1; color: var(--accent-text); }
.nav { display: flex; align-items: center; gap: 4px 28px; }
.nav a:not(.btn) { color: var(--ink); text-decoration: none; font-weight: 500; font-size: 16px; padding: 10px 0; }
.nav a:not(.btn):hover { color: var(--link); }
.nav .btn { font-size: 16px; }
.nav-toggle {
  display: none; width: 48px; height: 48px; padding: 0;
  background: transparent; border: 1px solid var(--line-strong); border-radius: 4px;
  color: var(--ink); cursor: pointer; align-items: center; justify-content: center;
}

/* Hero */
.hero {
  background-color: var(--navy); color: var(--white);
  padding: clamp(56px, 8vw, 112px) var(--gutter);
  background-image:
    linear-gradient(rgba(255,255,255,0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.035) 1px, transparent 1px);
  background-size: 48px 48px;
}
.hero__inner { display: flex; flex-wrap: wrap; align-items: flex-start; gap: 56px 72px; }
.hero__copy { flex: 1 1 500px; min-width: 0; display: flex; flex-direction: column; gap: 28px; }
.hero h1 {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(34px, 5vw, 62px); line-height: 1.22; text-wrap: balance;
}
.hero__lead { font-size: clamp(17px, 1.5vw, 20px); color: var(--soft-dark); max-width: 560px; }
.hero__actions { display: flex; flex-wrap: wrap; align-items: center; gap: 16px 28px; }

.flow { flex: 1 1 420px; min-width: 0; border: 1px solid var(--navy-line); background: var(--navy-panel); border-radius: 6px; }
.flow__head {
  display: flex; justify-content: space-between; gap: 16px; padding: 16px 24px;
  border-bottom: 1px solid var(--navy-line);
  font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.06em; color: var(--muted-dark);
}
.flow__list li { display: flex; align-items: baseline; gap: 18px; padding: 16px 24px; border-bottom: 1px solid var(--navy-line-soft); }
.flow__list li:last-child { border-bottom: 0; }
.flow__no { font-family: var(--font-mono); font-size: 14px; color: var(--accent); }
.flow__step { flex: 1 1 auto; font-weight: 500; }
.flow__sys { font-family: var(--font-mono); font-size: 14px; color: var(--soft-dark); text-align: right; }

/* Systems */
.systems { border-top: 2px solid var(--ink); }
.system { display: flex; flex-wrap: wrap; gap: 12px 40px; padding: 32px 0; border-bottom: 1px solid var(--line); }
.system__no { flex: 0 0 72px; font-family: var(--font-mono); font-size: 15px; color: var(--accent-text); padding-top: 6px; }
.system__name { flex: 1 1 280px; min-width: 0; display: flex; flex-direction: column; gap: 6px; }
.system__name h3 { font-size: 26px; }
.system__name span { color: var(--muted); font-size: 16px; }
.system__body { flex: 2 1 420px; min-width: 0; display: flex; flex-direction: column; gap: 16px; }

.tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tags li { font-family: var(--font-mono); font-size: 13px; border: 1px solid var(--line-strong); border-radius: 3px; padding: 5px 10px; color: #26323E; }
.tags--dark li { border-color: #3B556C; color: var(--pale-dark); }

/* Integration */
.split { display: flex; flex-wrap: wrap; gap: 48px 72px; }
.split__intro { flex: 1 1 360px; min-width: 0; display: flex; flex-direction: column; gap: 14px; }
.split__intro p { color: var(--muted); }
.ruled-grid { flex: 1.4 1 480px; min-width: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(min(220px, 100%), 1fr)); gap: 32px 40px; }
.ruled { display: flex; flex-direction: column; gap: 8px; border-top: 2px solid var(--ink); padding-top: 16px; }
.ruled p { color: var(--muted); font-size: 16px; }
.ruled__no { font-family: var(--font-mono); font-size: 14px; color: var(--accent-text); display: flex; flex-wrap: wrap; align-items: center; gap: 6px 12px; }
.ruled .tags { margin-top: auto; padding-top: 8px; }

/* Business systems */
.case-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(250px, 100%), 1fr)); gap: 40px 32px; }
.section--white .ai-side { background: var(--paper); }

/* AI */
.ai-grid { display: flex; flex-wrap: wrap; gap: 24px; }
.ai-main {
  flex: 2 1 520px; min-width: 0; background: var(--navy); color: var(--white);
  border-radius: 6px; padding: clamp(28px, 4vw, 48px);
  display: flex; flex-direction: column; align-items: flex-start; gap: 20px;
}
.ai-main h3 { font-weight: 700; font-size: clamp(26px, 3vw, 34px); }
.ai-main p { color: var(--soft-dark); max-width: 560px; }
.ai-side {
  flex: 1 1 300px; min-width: 0; background: var(--white); border: 1px solid var(--line);
  border-radius: 6px; padding: clamp(28px, 4vw, 40px);
  display: flex; flex-direction: column; align-items: flex-start; gap: 16px;
}
.ai-side h3 { font-size: 24px; }
.ai-side p { color: var(--muted); font-size: 16px; }
.badge { font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.06em; border-radius: 3px; padding: 4px 10px; }
.badge--accent { background: var(--accent); color: var(--ink); }
.badge--outline { border: 1px solid var(--line-strong); color: #26323E; }

/* Process */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(200px, 100%), 1fr)); gap: 32px 28px; }

/* Contact */
.contact__info { flex: 1 1 380px; min-width: 0; display: flex; flex-direction: column; gap: 24px; }
.contact__info > p { color: var(--soft-dark); max-width: 460px; }
.contact__list { display: flex; flex-direction: column; gap: 18px; }
.contact__list dt { font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.06em; color: var(--muted-dark); }
.contact__list dd { font-size: 20px; font-weight: 500; }
.contact__list dd.address { font-size: 17px; font-weight: 400; color: var(--pale-dark); }
.contact__list a, .contact__list a:hover { color: var(--white); }

.form {
  flex: 1 1 420px; min-width: 0; background: var(--white); color: var(--ink);
  border-radius: 6px; padding: clamp(24px, 4vw, 40px);
  display: flex; flex-direction: column; gap: 18px;
}
.form__row { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(200px, 100%), 1fr)); gap: 18px; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field label { font-size: 15px; font-weight: 500; }
.field .req { color: #B3261E; }
.field input, .field textarea {
  width: 100%; border: 1px solid var(--field-line); border-radius: 4px;
  padding: 0 14px; font: inherit; font-size: 16px; color: var(--ink); background: var(--white);
}
.field input { height: 48px; }
.field textarea { padding: 12px 14px; resize: vertical; min-height: 120px; }
.field input:focus, .field textarea:focus { outline: 3px solid #25B7E9; outline-offset: 1px; border-color: var(--ink); }
.field [aria-invalid="true"] { border-color: #B3261E; }
.field__error { font-size: 14px; color: #B3261E; min-height: 0; }
.form .btn { align-self: flex-start; min-height: 50px; padding: 0 28px; font-size: 17px; }
.form__note { font-size: 14px; color: var(--muted); }
.form__status { font-size: 15px; color: var(--accent-text); font-weight: 500; }

/* Footer */
.site-footer { background: var(--navy-deep); color: var(--muted-dark); padding: 32px var(--gutter); font-size: 15px; }
.site-footer__inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px 32px; }
.site-footer .mono { font-family: var(--font-mono); font-size: 14px; }

/* Mobile */
@media (max-width: 900px) {
  .nav-toggle { display: inline-flex; }
  .nav {
    display: none; position: absolute; left: 0; right: 0; top: 100%;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--white); border-bottom: 1px solid var(--line);
    padding: 8px var(--gutter) 20px;
  }
  .nav.is-open { display: flex; }
  .nav a:not(.btn) { padding: 14px 0; border-bottom: 1px solid var(--line); }
  .nav .btn { margin-top: 16px; }
  .system__no { flex-basis: 100%; padding-top: 0; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn { transition: none; }
}