/* ==========================================================================
   CODING HUB — STYLE SYSTEM
   Design concept: "Blueprint" — เส้นบางแบบเอกสารทางวิศวกรรม, จัดชิดซ้าย,
   สีหลัก Ink Navy + Brass/Amber (สื่อถึงความน่าเชื่อถือ) + Teal (เทคโนโลยี/ข้อมูล)
   Mobile First: เขียน Base = Mobile ก่อน แล้วขยายด้วย min-width
   ========================================================================== */

/* ---------- 1. DESIGN TOKENS ---------- */
:root {
  /* Color */
  --color-ink:        #12182B; /* พื้นเข้มหลัก / ข้อความบนพื้นสว่าง */
  --color-ink-soft:   #1D2540; /* พื้นเข้มรอง (การ์ด/แถบบนพื้นเข้ม) */
  --color-surface:    #F3F4F1; /* พื้นสว่างหลัก */
  --color-surface-alt:#E9EAE4; /* พื้นสว่างรอง สำหรับสลับ section */
  --color-white:      #FFFFFF;
  --color-brass:      #C08A3D; /* Accent หลัก */
  --color-brass-dark: #9C6E2C;
  --color-teal:       #2C6E71; /* Accent รอง */
  --color-teal-dark:  #1F4F52;
  --color-text:       #1A1F2E;
  --color-text-muted: #545B6B;
  --color-text-inverse: #EDEEEA;
  --color-border:     #D8D6CC;
  --color-border-dark:rgba(237,238,234,0.18);
  --color-success:    #2C6E71;

  /* Type */
  --font-heading: 'Sarabun', 'IBM Plex Sans Thai', sans-serif;
  --font-body: 'IBM Plex Sans Thai', 'Sarabun', sans-serif;

  --fs-h1: 2rem;
  --fs-h2: 1.6rem;
  --fs-h3: 1.15rem;
  --fs-body: 1rem;
  --fs-small: 0.875rem;

  /* Layout */
  --container-max: 1180px;
  --container-pad: 1.25rem;
  --radius-sm: 4px;
  --radius-md: 8px;
  --header-h: 64px;

  /* Motion */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- 2. RESET / BASE ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.65;
  color: var(--color-text);
  background: var(--color-surface);
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.3;
  margin: 0 0 0.6em;
  color: var(--color-ink);
}
h1 { font-size: var(--fs-h1); font-weight: 800; letter-spacing: -0.01em; }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }

p { margin: 0 0 1em; max-width: 68ch; }
p:last-child { margin-bottom: 0; }

a { color: inherit; text-decoration: none; }
ul, ol { margin: 0; padding: 0; list-style: none; }

img { max-width: 100%; height: auto; display: block; }

/* Focus visibility — accessibility */
a:focus-visible,
button:focus-visible,
summary:focus-visible,
input:focus-visible,
textarea:focus-visible {
  outline: 3px solid var(--color-brass);
  outline-offset: 2px;
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.container {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}

section { padding: 3rem 0; }
.section-lead {
  color: var(--color-text-muted);
  font-size: 1.05rem;
  margin-top: -0.4em;
  margin-bottom: 2rem;
  max-width: 60ch;
}

/* ---------- 3. BUTTONS (CTA) ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1rem;
  border: 2px solid transparent;
  cursor: pointer;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.btn-primary {
  background: var(--color-brass);
  color: var(--color-ink);
}
.btn-primary:hover { background: var(--color-brass-dark); }

.btn-outline {
  background: transparent;
  border-color: var(--color-ink);
  color: var(--color-ink);
}
.btn-outline:hover { background: var(--color-ink); color: var(--color-white); }

.btn-outline-light {
  background: transparent;
  border-color: var(--color-text-inverse);
  color: var(--color-text-inverse);
}
.btn-outline-light:hover { background: var(--color-text-inverse); color: var(--color-ink); }

/* ---------- 4. HEADER / NAV ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-h);
  gap: 1rem;
}
.logo img { height: 32px; width: auto; }

.main-nav {
  display: none; /* ซ่อนบนมือถือ เปิดผ่าน nav-toggle */
  position: absolute;
  top: var(--header-h);
  left: 0; right: 0;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}
.main-nav.is-open { display: block; }
.main-nav ul { display: flex; flex-direction: column; }
.main-nav a {
  display: block;
  padding: 0.9rem var(--container-pad);
  border-top: 1px solid var(--color-border);
  font-weight: 500;
}
.main-nav a[aria-current="page"] { color: var(--color-brass-dark); font-weight: 700; }

.header-cta { display: none; } /* โชว์ปุ่มบน tablet ขึ้นไป ปุ่มหลักบนมือถือคือ sticky bar */

.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px; height: 44px;
  background: none;
  border: none;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 24px; height: 2px;
  background: var(--color-ink);
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}
.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); }

/* ---------- 5. HERO ---------- */
.hero { padding-top: 2.5rem; padding-bottom: 2.5rem; }
.hero-grid { display: grid; gap: 2rem; }
.hero-content h1 { max-width: 20ch; }
.hero-lead { color: var(--color-text-muted); font-size: 1.05rem; max-width: 52ch; }
.hero-actions { display: flex; flex-direction: column; gap: 0.75rem; margin-top: 1.5rem; }
.hero-media img {
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

/* ---------- 6. TRUST ---------- */
.trust { background: var(--color-ink); color: var(--color-text-inverse); }
.trust-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem 1rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--color-border-dark);
  margin-bottom: 1.5rem;
}
.trust-item { display: flex; flex-direction: column; gap: 0.25rem; }
.trust-value {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--color-brass);
}
.trust-label { font-size: var(--fs-small); color: var(--color-text-inverse); opacity: 0.85; }

.trust-partners-label { font-size: var(--fs-small); text-transform: none; opacity: 0.8; margin-bottom: 1rem; }
.partner-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.partner-badges li {
  padding: 0.5rem 1rem;
  border: 1px solid var(--color-border-dark);
  border-radius: 999px;
  font-size: var(--fs-small);
  font-weight: 700;
  color: var(--color-text-inverse);
  opacity: 0.9;
}
.partner-badges-light li { border-color: var(--color-border); color: var(--color-ink); }

/* ---------- 7. PROBLEM ---------- */
.problem-grid { display: grid; gap: 1.5rem; }
.problem-list li {
  position: relative;
  padding: 0.85rem 0 0.85rem 1.5rem;
  border-top: 1px solid var(--color-border);
}
.problem-list li:last-child { border-bottom: 1px solid var(--color-border); }
.problem-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 1.15rem;
  width: 8px; height: 8px;
  background: var(--color-teal);
}

/* ---------- 8. SERVICES ---------- */
.services-grid { display: grid; gap: 1.5rem; margin-bottom: 2.5rem; }
.service-card {
  padding: 1.75rem;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-brass);
}
.service-icon { margin-bottom: 1rem; }
.service-points { margin: 1rem 0; }
.service-points li {
  position: relative;
  padding-left: 1.1rem;
  margin-bottom: 0.4rem;
  font-size: var(--fs-small);
  color: var(--color-text-muted);
}
.service-points li::before { content: "—"; position: absolute; left: 0; }
.service-link {
  display: inline-block;
  margin-top: 0.5rem;
  font-weight: 700;
  color: var(--color-teal-dark);
  border-bottom: 1px solid currentColor;
}

.specialty-band {
  display: grid;
  gap: 1px;
  background: var(--color-border);
  border: 1px solid var(--color-border);
}
.specialty-item { background: var(--color-surface-alt); padding: 1.5rem; }
.specialty-item h4 { font-size: 1rem; margin-bottom: 0.4rem; }
.specialty-item p { font-size: var(--fs-small); color: var(--color-text-muted); margin: 0; }

/* ---------- 9. WHY CHOOSE US ---------- */
.why-us { background: var(--color-surface-alt); }
.why-us-grid { display: grid; gap: 2rem; }
.why-us-list { display: grid; gap: 1.5rem; }
.why-us-list li { padding-top: 1rem; border-top: 2px solid var(--color-ink); }
.why-us-list p { color: var(--color-text-muted); }

/* ---------- 10. PORTFOLIO ---------- */
.portfolio-grid { display: grid; gap: 1.5rem; }
.portfolio-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  overflow: hidden;
}
.portfolio-card img { aspect-ratio: 400 / 260; object-fit: cover; }
.portfolio-body { padding: 1.25rem; }
.portfolio-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-teal-dark);
  margin-bottom: 0.5rem;
}
.portfolio-cta { margin-top: 2rem; text-align: left; }

/* ---------- 11. PROCESS ---------- */
.process-list { display: grid; gap: 0; }
.process-list li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.25rem 1rem;
  padding: 1.25rem 0;
  border-top: 1px solid var(--color-border);
}
.process-list li:last-child { border-bottom: 1px solid var(--color-border); }
.process-num {
  grid-row: span 2;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.5rem;
  color: var(--color-brass);
  align-self: start;
}
.process-list h3 { margin: 0; align-self: end; }
.process-list p { margin: 0; color: var(--color-text-muted); font-size: var(--fs-small); }

/* ---------- 12. PRICING ---------- */
.pricing { background: var(--color-ink); color: var(--color-text-inverse); }
.pricing-inner { max-width: 60ch; }
.pricing h2 { color: var(--color-white); }
.pricing p { color: var(--color-text-inverse); opacity: 0.85; }
.pricing .btn { margin-top: 1rem; }

/* ---------- 13. TESTIMONIALS ---------- */
.testimonial-grid { display: grid; gap: 1.25rem; }
.testimonial-card {
  margin: 0;
  padding: 1.5rem;
  background: var(--color-white);
  border: 1px dashed var(--color-border);
}
.testimonial-placeholder p { color: var(--color-text-muted); font-style: italic; }
.testimonial-card footer { margin-top: 0.75rem; font-size: var(--fs-small); font-weight: 700; }

/* ---------- 14. FAQ ---------- */
.faq-list { display: grid; gap: 0; }
.faq-item {
  border-top: 1px solid var(--color-border);
  padding: 1rem 0;
}
.faq-item:last-child { border-bottom: 1px solid var(--color-border); }
.faq-item summary {
  cursor: pointer;
  font-weight: 700;
  font-family: var(--font-heading);
  list-style: none;
  position: relative;
  padding-right: 2rem;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 0; top: 0;
  font-size: 1.25rem;
  color: var(--color-brass-dark);
}
.faq-item[open] summary::after { content: "–"; }
.faq-item p { margin-top: 0.75rem; color: var(--color-text-muted); }

/* ---------- 15. FINAL CTA ---------- */
.final-cta { background: var(--color-teal-dark); color: var(--color-text-inverse); }
.final-cta-inner { max-width: 56ch; }
.final-cta h2 { color: var(--color-white); }
.final-cta p { color: var(--color-text-inverse); opacity: 0.9; }
.final-cta-actions { display: flex; flex-direction: column; gap: 0.75rem; margin-top: 1.5rem; }

/* ---------- 16. FOOTER ---------- */
.site-footer { background: var(--color-ink); color: var(--color-text-inverse); padding-top: 3rem; }
.footer-grid { display: grid; gap: 2rem; padding-bottom: 2rem; }
.footer-brand img { margin-bottom: 1rem; }
.footer-brand p { color: var(--color-text-inverse); opacity: 0.75; font-size: var(--fs-small); }
.footer-col h3 { color: var(--color-white); font-size: 1rem; margin-bottom: 0.9rem; }
.footer-col address, .footer-col p { font-style: normal; font-size: var(--fs-small); opacity: 0.85; line-height: 1.9; }
.footer-col ul li { margin-bottom: 0.5rem; font-size: var(--fs-small); opacity: 0.85; }
.footer-col a:hover { color: var(--color-brass); }

.footer-bottom { border-top: 1px solid var(--color-border-dark); padding: 1.25rem 0; }
.footer-bottom-inner {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  font-size: var(--fs-small);
  opacity: 0.7;
}
.footer-bottom-inner ul { display: flex; gap: 1.25rem; }

/* ---------- 17. MOBILE STICKY CTA BAR ---------- */
.mobile-sticky-bar {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  z-index: 60;
  display: grid;
  grid-template-columns: 1fr 1fr;
  background: var(--color-ink);
  border-top: 1px solid var(--color-border-dark);
  padding-bottom: env(safe-area-inset-bottom, 0);
}
.mobile-sticky-bar a {
  padding: 0.9rem 0.5rem;
  text-align: center;
  color: var(--color-text-inverse);
  font-weight: 700;
  font-size: var(--fs-small);
}
.mobile-sticky-bar a:first-child { background: var(--color-brass); color: var(--color-ink); }
.mobile-sticky-bar a:last-child { background: var(--color-teal); }

/* เผื่อพื้นที่ด้านล่างสุดของหน้า ไม่ให้ Sticky Bar บังเนื้อหา/Footer บนมือถือ */
body { padding-bottom: 56px; }

.site-header.is-scrolled { box-shadow: 0 1px 0 var(--color-border); }

/* ---------- 18. FORM (Contact Page) ---------- */
.contact-form { display: grid; gap: 1.25rem; max-width: 640px; }
.form-field { display: grid; gap: 0.4rem; }
.form-field label { font-weight: 700; font-size: var(--fs-small); }
.form-field input,
.form-field textarea,
.form-field select {
  font-family: var(--font-body);
  font-size: 1rem;
  padding: 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-white);
  color: var(--color-text);
  min-height: 48px;
}
.form-field textarea { min-height: 140px; resize: vertical; }
.form-field input:focus,
.form-field textarea:focus,
.form-field select:focus {
  border-color: var(--color-teal);
}
.form-field input[aria-invalid="true"],
.form-field textarea[aria-invalid="true"] {
  border-color: #B5432E;
}
.field-error {
  font-size: var(--fs-small);
  color: #B5432E;
  min-height: 1.2em;
}
.form-feedback {
  padding: 0.9rem 1rem;
  border-radius: var(--radius-sm);
  font-size: var(--fs-small);
  font-weight: 700;
  display: none;
}
.form-feedback:not(:empty) { display: block; }
.form-feedback-success { background: #E4EFE9; color: var(--color-teal-dark); }
.form-feedback-error { background: #F7E6E2; color: #B5432E; }

/* ---------- 19. PAGE HEADER (หน้าใน เช่น About, Services, Contact) ---------- */
.page-header { background: var(--color-ink); color: var(--color-text-inverse); padding: 2.5rem 0; }
.page-header h1 { color: var(--color-white); max-width: 24ch; margin-bottom: 0.5rem; }
.page-header p { color: var(--color-text-inverse); opacity: 0.85; max-width: 60ch; margin: 0; }
.breadcrumb { font-size: var(--fs-small); opacity: 0.7; margin-bottom: 1rem; }
.breadcrumb a { text-decoration: underline; }

/* ---------- 20. GENERIC CONTENT PAGE (Privacy / Terms) ---------- */
.content-page { padding: 2.5rem 0 3.5rem; }
.content-page .container { max-width: 800px; }
.content-page h2 { margin-top: 2rem; }
.content-page ul { list-style: disc; padding-left: 1.4rem; margin-bottom: 1em; }
.content-page ul li { margin-bottom: 0.5em; }
.content-page .updated-note { color: var(--color-text-muted); font-size: var(--fs-small); margin-bottom: 2rem; }

/* ---------- 21. TEAM / VALUES (About Page) ---------- */
.values-grid { display: grid; gap: 1.5rem; }
.value-card { padding: 1.5rem; background: var(--color-white); border: 1px solid var(--color-border); border-top: 3px solid var(--color-teal); }
.stats-band { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; margin: 2rem 0; }
.stats-band .trust-item { color: var(--color-ink); }
.stats-band .trust-value { color: var(--color-teal-dark); }
.stats-band .trust-label { color: var(--color-text-muted); opacity: 1; }

@media (min-width: 768px) {
  .values-grid { grid-template-columns: repeat(3, 1fr); }
  .stats-band { grid-template-columns: repeat(4, 1fr); }
}
@media (min-width: 768px) {
  :root { --fs-h1: 2.75rem; --fs-h2: 2rem; --fs-h3: 1.25rem; }

  .main-nav {
    display: block;
    position: static;
    border-bottom: none;
    background: none;
  }
  .main-nav ul { flex-direction: row; gap: 0.5rem; }
  .main-nav a { border-top: none; padding: 0.5rem 0.85rem; }
  .header-cta { display: inline-flex; }
  .nav-toggle { display: none; }

  .hero-grid { grid-template-columns: 1.1fr 1fr; align-items: center; }
  .hero-actions { flex-direction: row; }

  .trust-grid { grid-template-columns: repeat(4, 1fr); }

  .problem-grid { grid-template-columns: 1fr 1fr; align-items: start; }

  .services-grid { grid-template-columns: repeat(3, 1fr); }
  .specialty-band { grid-template-columns: repeat(3, 1fr); }

  .why-us-grid { grid-template-columns: 1fr 1.2fr; }
  .why-us-list { grid-template-columns: 1fr 1fr; }

  .portfolio-grid { grid-template-columns: repeat(2, 1fr); }

  .process-list { grid-template-columns: 1fr 1fr; }
  .process-list li { grid-template-columns: 60px 1fr; }

  .testimonial-grid { grid-template-columns: repeat(3, 1fr); }

  .final-cta-actions { flex-direction: row; }

  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; }
  .footer-bottom-inner { flex-direction: row; justify-content: space-between; }

  /* หน้าจอกว้างพอสำหรับ Header CTA แล้ว ไม่จำเป็นต้องมี Sticky Bar ล่างสุด */
  .mobile-sticky-bar { display: none; }
  body { padding-bottom: 0; }
}

/* ==========================================================================
   RESPONSIVE — DESKTOP (>= 1025px)
   ========================================================================== */
@media (min-width: 1025px) {
  .portfolio-grid { grid-template-columns: repeat(3, 1fr); }
  .process-list { grid-template-columns: repeat(4, 1fr); }
  .process-list li { border-top: none; padding: 0 1.25rem 0 0; border-left: 1px solid var(--color-border); }
  .process-list li:first-child { border-left: none; }
  .process-list li:last-child { border-bottom: none; }
}