/* ==========================================================================
   Coesolution — design tokens
   Style: Minimalism / Swiss grid · Palette: professional navy + technical blue
   Type: IBM Plex Sans Thai (UI) + IBM Plex Mono (technical metadata)
   ========================================================================== */

:root {
  /* color */
  --c-primary: #0f172a;
  --c-primary-hover: #1e293b;
  --c-on-primary: #ffffff;
  --c-accent: #0369a1;
  --c-accent-hover: #075985;
  --c-on-accent: #ffffff;
  --c-bg: #f8fafc;
  --c-fg: #020617;
  --c-card: #ffffff;
  --c-muted: #e8ecf1;
  --c-muted-fg: #475569;
  --c-border: #e2e8f0;
  --c-border-strong: #cbd5e1;
  --c-ring: #0369a1;

  /* type */
  --font-sans: "IBM Plex Sans Thai", "Noto Sans Thai", system-ui, -apple-system, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", monospace;

  /* space (density 5 — standard) */
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-6: 24px;
  --sp-8: 32px;
  --sp-12: 48px;
  --sp-16: 64px;

  /* geometry — sharp corners read as technical, not playful */
  --radius: 4px;
  --radius-lg: 6px;
  --wrap: 1100px;
  --wrap-narrow: 760px;

  --shadow-sm: 0 1px 2px rgba(2, 6, 23, 0.06);
  --shadow-md: 0 4px 12px rgba(2, 6, 23, 0.08);
  --transition: 200ms ease;
}

@media (prefers-color-scheme: dark) {
  :root {
    --c-primary: #e2e8f0;
    --c-primary-hover: #f1f5f9;
    --c-on-primary: #0f172a;
    --c-accent: #38bdf8;
    --c-accent-hover: #7dd3fc;
    --c-on-accent: #0f172a;
    --c-bg: #0b1220;
    --c-fg: #e6edf6;
    --c-card: #111a2b;
    --c-muted: #1b2740;
    --c-muted-fg: #a3b2c7;
    --c-border: #23304a;
    --c-border-strong: #334155;
    --c-ring: #38bdf8;
    --shadow-sm: none;
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  }
}

/* ==========================================================================
   base
   ========================================================================== */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--c-bg);
  color: var(--c-fg);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3 {
  line-height: 1.35;
  letter-spacing: -0.01em;
  margin: 0 0 var(--sp-3);
  text-wrap: balance;
}

h1 {
  font-size: clamp(1.75rem, 1.3rem + 2vw, 2.6rem);
  font-weight: 600;
}

h2 {
  font-size: clamp(1.25rem, 1.1rem + 0.7vw, 1.6rem);
  font-weight: 600;
}

h3 {
  font-size: 1.05rem;
  font-weight: 600;
}

p {
  margin: 0 0 var(--sp-4);
}

a {
  color: var(--c-accent);
  text-underline-offset: 3px;
}

a:hover {
  color: var(--c-accent-hover);
}

:focus-visible {
  outline: 2px solid var(--c-ring);
  outline-offset: 2px;
  border-radius: 2px;
}

.wrap {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--sp-4);
}

.wrap-narrow {
  max-width: var(--wrap-narrow);
  margin-inline: auto;
  padding-inline: var(--sp-4);
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.02em;
}

.muted {
  color: var(--c-muted-fg);
}

/* Thai has no spaces between words: keep proper names from breaking mid-name */
.nw {
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--c-accent);
  color: var(--c-on-accent);
  padding: var(--sp-2) var(--sp-4);
  z-index: 100;
}

.skip-link:focus {
  left: var(--sp-4);
  top: var(--sp-2);
}

/* ==========================================================================
   header
   ========================================================================== */

.site-header {
  background: #0f172a;
  border-bottom: 3px solid var(--c-accent);
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  min-height: 64px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-3);
  color: #ffffff;
  text-decoration: none;
  font-weight: 600;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
}

.brand:hover {
  color: #ffffff;
}

.brand svg {
  flex: none;
  color: #38bdf8;
}

.brand small {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 400;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #94a3b8;
  line-height: 1.2;
}

.site-header nav a {
  color: #cbd5e1;
  text-decoration: none;
  font-size: 0.95rem;
  padding: var(--sp-2) var(--sp-1);
  transition: color var(--transition);
}

.site-header nav a:hover {
  color: #ffffff;
}

/* ==========================================================================
   hero — subtle blueprint grid, no images needed
   ========================================================================== */

.hero {
  background-color: #0f172a;
  background-image:
    linear-gradient(rgba(56, 189, 248, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(56, 189, 248, 0.07) 1px, transparent 1px);
  background-size: 32px 32px;
  color: #f1f5f9;
  padding: var(--sp-16) 0 var(--sp-12);
}

.hero h1 {
  color: #ffffff;
  max-width: 20ch;
}

.hero p.lead {
  color: #cbd5e1;
  font-size: 1.05rem;
  max-width: 60ch;
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: #7dd3fc;
  border: 1px solid rgba(125, 211, 252, 0.35);
  border-radius: 2px;
  padding: 2px var(--sp-2);
  margin-bottom: var(--sp-4);
}

.trust-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2) var(--sp-6);
  margin-top: var(--sp-6);
  padding: 0;
  list-style: none;
}

.trust-row li {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  color: #cbd5e1;
  font-size: 0.92rem;
}

.trust-row svg {
  flex: none;
  color: #4ade80;
}

/* ==========================================================================
   stats strip
   ========================================================================== */

.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  background: var(--c-card);
  box-shadow: var(--shadow-sm);
  margin-top: calc(var(--sp-8) * -1);
  position: relative;
  overflow: hidden;
}

.stats div {
  padding: var(--sp-4);
  text-align: center;
  border-right: 1px solid var(--c-border);
}

.stats div:last-child {
  border-right: 0;
}

.stats b {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--c-fg);
  line-height: 1.3;
}

.stats span {
  font-size: 0.85rem;
  color: var(--c-muted-fg);
}

/* ==========================================================================
   sections & cards
   ========================================================================== */

main {
  display: block;
  padding-bottom: var(--sp-16);
}

section {
  padding-top: var(--sp-12);
}

.section-head {
  border-top: 2px solid var(--c-fg);
  padding-top: var(--sp-3);
  margin-bottom: var(--sp-6);
}

.section-label {
  display: block;
  font-size: 0.82rem;
  color: var(--c-muted-fg);
  margin-bottom: var(--sp-1);
}

.section-label .mono {
  color: var(--c-accent);
}

.spec-table caption {
  text-align: left;
  font-size: 0.82rem;
  color: var(--c-muted-fg);
  padding-bottom: var(--sp-2);
}

.card {
  display: block;
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  padding: var(--sp-6);
  box-shadow: var(--shadow-sm);
  text-decoration: none;
  color: inherit;
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

a.card:hover {
  border-color: var(--c-accent);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

a.card:hover .card-title {
  color: var(--c-accent);
}

.card-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--c-fg);
  margin: var(--sp-1) 0 var(--sp-2);
  transition: color var(--transition);
}

.card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
  margin-bottom: var(--sp-3);
}

.tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--c-muted-fg);
  background: var(--c-muted);
  border-radius: 2px;
  padding: 2px var(--sp-2);
}

.card p {
  margin: 0;
  color: var(--c-muted-fg);
  font-size: 0.95rem;
}

.card-cta {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  margin-top: var(--sp-4);
  color: var(--c-accent);
  font-weight: 500;
  font-size: 0.95rem;
}

/* feature grid */
.features {
  display: grid;
  gap: var(--sp-4);
  grid-template-columns: 1fr;
}

.feature {
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  padding: var(--sp-6);
}

.feature svg {
  color: var(--c-accent);
  margin-bottom: var(--sp-3);
}

.feature h3 {
  margin-bottom: var(--sp-2);
}

.feature p {
  margin: 0;
  color: var(--c-muted-fg);
  font-size: 0.95rem;
}

/* ==========================================================================
   detail page
   ========================================================================== */

.breadcrumb {
  font-size: 0.88rem;
  color: var(--c-muted-fg);
  padding-top: var(--sp-6);
}

.breadcrumb a {
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.page-head {
  padding: var(--sp-4) 0 var(--sp-8);
  border-bottom: 1px solid var(--c-border);
  margin-bottom: var(--sp-8);
}

.spec-table {
  width: 100%;
  border-collapse: collapse;
  border: 1px solid var(--c-border);
  background: var(--c-card);
  margin-bottom: var(--sp-6);
  font-size: 0.95rem;
}

.spec-table th,
.spec-table td {
  text-align: left;
  padding: var(--sp-3) var(--sp-4);
  border-bottom: 1px solid var(--c-border);
  vertical-align: top;
}

.spec-table tr:last-child th,
.spec-table tr:last-child td {
  border-bottom: 0;
}

.spec-table th {
  width: 34%;
  font-weight: 500;
  color: var(--c-muted-fg);
  background: var(--c-bg);
  white-space: nowrap;
}

/* Thai has no monospace companion in IBM Plex — keep mono for latin/numeric only,
   otherwise Thai falls back to a system mono face and looks stretched */
.spec-table td {
  font-variant-numeric: tabular-nums;
}

.table-scroll {
  overflow-x: auto;
}

.file-list {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--sp-6);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  background: var(--c-card);
}

.file-list li {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-3) var(--sp-4);
  border-bottom: 1px solid var(--c-border);
}

.file-list li:last-child {
  border-bottom: 0;
}

.file-list svg {
  flex: none;
  color: var(--c-muted-fg);
}

.file-list .name {
  font-weight: 500;
}

.file-list .size {
  margin-left: auto;
  font-size: 0.82rem;
  color: var(--c-muted-fg);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

/* latin branch codes read well in mono and reinforce the technical tone */
.file-list .size.code {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.03em;
}

/* download block */
.download-box {
  border: 1px solid var(--c-border-strong);
  border-left: 4px solid var(--c-accent);
  border-radius: var(--radius);
  background: var(--c-card);
  padding: var(--sp-6);
  margin: var(--sp-8) 0;
}

.download-box h2 {
  margin-bottom: var(--sp-2);
}

.download-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  min-height: 48px;
  padding: var(--sp-3) var(--sp-8);
  background: var(--c-accent);
  color: var(--c-on-accent);
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
}

.download-btn:hover {
  background: var(--c-accent-hover);
  color: var(--c-on-accent);
  transform: translateY(-1px);
}

.download-btn.secondary {
  background: transparent;
  color: var(--c-accent);
  border: 1px solid var(--c-border-strong);
}

.download-btn.secondary:hover {
  background: var(--c-muted);
  color: var(--c-accent);
}

.download-note {
  margin: var(--sp-3) 0 0;
  font-size: 0.85rem;
  color: var(--c-muted-fg);
}

/* ==========================================================================
   ads — clearly labelled, never adjacent to the download button
   ========================================================================== */

.ad-slot {
  margin: var(--sp-12) 0;
  padding: var(--sp-4);
  border: 1px dashed var(--c-border-strong);
  border-radius: var(--radius);
  text-align: center;
  color: var(--c-muted-fg);
  background: var(--c-card);
}

.ad-slot::before {
  content: "โฆษณา";
  display: block;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-muted-fg);
  margin-bottom: var(--sp-2);
}

/* ==========================================================================
   footer
   ========================================================================== */

.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: var(--sp-8) 0;
  font-size: 0.9rem;
}

.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-4);
  justify-content: space-between;
  align-items: center;
}

.site-footer a {
  color: #cbd5e1;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2) var(--sp-6);
}

.footer-nav a {
  text-decoration: none;
}

.footer-nav a:hover {
  color: #ffffff;
  text-decoration: underline;
}

/* ==========================================================================
   contact & legal pages
   ========================================================================== */

.contact-list {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--sp-8);
  display: grid;
  gap: var(--sp-3);
}

.contact-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-4);
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  padding: var(--sp-4);
}

.contact-list svg {
  flex: none;
  color: var(--c-accent);
  margin-top: 3px;
}

.contact-list .label {
  display: block;
  font-size: 0.8rem;
  color: var(--c-muted-fg);
  line-height: 1.5;
}

.contact-list .value {
  font-weight: 500;
  font-size: 1.02rem;
}

.contact-list a.value {
  text-decoration: none;
}

.contact-list a.value:hover {
  text-decoration: underline;
}

.updated {
  font-size: 0.85rem;
  color: var(--c-muted-fg);
  border-left: 3px solid var(--c-border-strong);
  padding-left: var(--sp-3);
  margin-bottom: var(--sp-8);
}

.legal h2 {
  margin-top: var(--sp-8);
}

.legal ul {
  padding-left: 1.25rem;
  margin: 0 0 var(--sp-4);
}

.legal li {
  margin-bottom: var(--sp-2);
}

/* ==========================================================================
   responsive
   ========================================================================== */

@media (min-width: 768px) {
  .features {
    grid-template-columns: repeat(3, 1fr);
  }

  .hero {
    padding: calc(var(--sp-16) * 1.4) 0 var(--sp-16);
  }
}

@media (max-width: 520px) {
  .stats {
    grid-template-columns: 1fr;
  }

  .stats div {
    border-right: 0;
    border-bottom: 1px solid var(--c-border);
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    text-align: left;
  }

  .stats div:last-child {
    border-bottom: 0;
  }

  .stats b {
    font-size: 1.2rem;
  }

  .file-list li {
    flex-wrap: wrap;
  }

  .download-btn {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }

  a.card:hover,
  .download-btn:hover {
    transform: none;
  }
}