/* ==========================================================================
   รับซื้อแอร์เก่ามือสอง.com — Design tokens
   ธีม: "ช่างแอร์มืออาชีพ" กราไฟต์เข้ม + ฟ้าเย็น (น้ำยาแอร์) + ทองแดง (สายทองแดงในแอร์)
   ========================================================================== */

:root {
  --graphite-900: #12161c;
  --graphite-800: #1b222b;
  --graphite-700: #262f3a;
  --steel-600: #3a5a73;
  --cyan-400: #5fe0da;
  --cyan-300: #9df0ec;
  --copper-500: #c97a3d;
  --copper-400: #e2a472;
  --copper-600: #a75f2b;
  --paper-100: #f1f4f6;
  --paper-50: #fafbfc;
  --ink-900: #161c22;
  --ink-600: #4b5763;

  --font-display: "Kanit", "Noto Sans Thai", sans-serif;
  --font-body: "Noto Sans Thai", "Kanit", sans-serif;

  --radius-md: 10px;
  --radius-lg: 18px;
  --shadow-soft: 0 20px 45px -20px rgba(18, 22, 28, 0.45);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--paper-100);
  color: var(--ink-900);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  margin: 0 0 0.5em;
  line-height: 1.25;
  font-weight: 600;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font-family: inherit; cursor: pointer; }

.container {
  width: 100%;
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 20px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  color: var(--copper-500);
  font-weight: 600;
  margin-bottom: 14px;
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  background: var(--copper-500);
  display: inline-block;
}

/* ---------- Buttons / CTA ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 26px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 1rem;
  border: 2px solid transparent;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}
.btn:active { transform: translateY(1px); }

.btn-copper {
  background: linear-gradient(135deg, var(--copper-400), var(--copper-600));
  color: #17120c;
  box-shadow: 0 12px 30px -12px rgba(201, 122, 61, 0.65);
}
.btn-copper:hover { box-shadow: 0 16px 34px -10px rgba(201, 122, 61, 0.8); }

.btn-outline {
  background: transparent;
  border-color: rgba(255,255,255,0.35);
  color: #fff;
}
.btn-outline:hover { border-color: var(--cyan-400); color: var(--cyan-400); }

.btn-outline-dark {
  background: transparent;
  border-color: var(--graphite-800);
  color: var(--graphite-800);
}
.btn-outline-dark:hover { border-color: var(--copper-500); color: var(--copper-500); }

.btn-block { width: 100%; }
.btn-lg { padding: 16px 32px; font-size: 1.05rem; }

.cta-row { display: flex; flex-wrap: wrap; gap: 14px; }

/* ---------- Top bar ---------- */
.topbar {
  background: var(--graphite-900);
  color: #fff;
  font-size: 0.85rem;
}
.topbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 8px;
  padding-bottom: 8px;
  gap: 12px;
  flex-wrap: wrap;
}
.topbar a { color: var(--cyan-300); }
.topbar .topbar-links { display: flex; gap: 18px; flex-wrap: wrap; }

/* ---------- Nav ---------- */
.navbar {
  background: var(--graphite-900);
  border-bottom: 1px solid rgba(255,255,255,0.08);
  position: sticky;
  top: 0;
  z-index: 40;
}
.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  padding-bottom: 14px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
}
.brand .brand-mark {
  width: 38px; height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--cyan-400), var(--steel-600));
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}
.nav-links {
  display: flex;
  gap: 26px;
  color: #cfd8df;
  font-size: 0.95rem;
}
.nav-links a:hover { color: var(--cyan-400); }
.nav-cta { display: flex; gap: 10px; }

.nav-toggle { display: none; }

/* ---------- Hero ---------- */
.hero {
  background: radial-gradient(circle at 85% 0%, rgba(95,224,218,0.14), transparent 45%), var(--graphite-900);
  color: #fff;
  padding: 72px 0 90px;
  position: relative;
  overflow: hidden;
}
.hero .container {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}
.hero h1 {
  font-size: clamp(2.1rem, 4vw, 3.1rem);
  color: #fff;
}
.hero h1 span { color: var(--copper-400); }
.hero p.lead {
  color: #c7d2da;
  font-size: 1.1rem;
  max-width: 46ch;
  margin-bottom: 28px;
}
.hero-stats {
  display: flex;
  gap: 28px;
  margin-top: 40px;
  flex-wrap: wrap;
}
.hero-stats .stat b {
  font-family: var(--font-display);
  font-size: 1.6rem;
  color: var(--cyan-300);
  display: block;
}
.hero-stats .stat span { font-size: 0.85rem; color: #9fb0bb; }

/* ---- Gauge (signature element) ---- */
.gauge-wrap {
  display: flex;
  justify-content: center;
  position: relative;
}
.gauge-card {
  background: var(--graphite-800);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-lg);
  padding: 28px 26px 22px;
  box-shadow: var(--shadow-soft);
  width: 100%;
  max-width: 380px;
  text-align: center;
}
.gauge-card .gauge-caption {
  font-family: var(--font-display);
  color: var(--cyan-300);
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  margin-bottom: 6px;
}
.gauge-needle {
  transform-origin: 150px 150px;
  animation: needle-sweep 1.6s cubic-bezier(.2,.9,.25,1) forwards;
}
@keyframes needle-sweep {
  0%   { transform: rotate(-90deg); }
  100% { transform: rotate(52deg); }
}
@media (prefers-reduced-motion: reduce) {
  .gauge-needle { animation: none; transform: rotate(52deg); }
}
.gauge-readout {
  margin-top: 10px;
  font-family: var(--font-display);
  font-size: 1.4rem;
  color: var(--copper-400);
}
.gauge-readout small { display: block; font-size: 0.75rem; color: #9fb0bb; font-family: var(--font-body); font-weight: 400; }

/* ---------- Section shell ---------- */
.section { padding: 84px 0; }
.section-alt { background: #fff; }
.section-dark { background: var(--graphite-900); color: #fff; }
.section-head { max-width: 640px; margin-bottom: 48px; }
.section-head p { color: var(--ink-600); font-size: 1.05rem; }
.section-dark .section-head p { color: #b7c2cb; }

/* ---------- Service cards ---------- */
.grid { display: grid; gap: 24px; }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: #fff;
  border: 1px solid #e4e9ec;
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-soft); }
.card .icon {
  width: 48px; height: 48px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--cyan-400), var(--steel-600));
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 16px;
}
.card h3 { font-size: 1.15rem; }
.card p { color: var(--ink-600); font-size: 0.95rem; margin: 0; }

/* ---------- Why us ---------- */
.why-list { display: flex; flex-direction: column; gap: 22px; }
.why-item { display: flex; gap: 16px; }
.why-item .num {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--copper-500);
  font-size: 1.4rem;
  min-width: 44px;
}
.why-item h4 { margin-bottom: 4px; }
.why-item p { margin: 0; color: var(--ink-600); }

/* ---------- Steps ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  counter-reset: step;
}
.step {
  background: var(--graphite-800);
  border-radius: var(--radius-lg);
  padding: 26px 22px;
  position: relative;
  border: 1px solid rgba(255,255,255,0.06);
}
.step .step-index {
  font-family: var(--font-display);
  color: var(--cyan-400);
  font-size: 2rem;
  font-weight: 700;
  opacity: 0.9;
}
.step h4 { color: #fff; margin-top: 10px; }
.step p { color: #aab6c0; margin: 0; font-size: 0.92rem; }

/* ---------- Areas ---------- */
.area-tags { display: flex; flex-wrap: wrap; gap: 10px; }
.area-tags span {
  background: var(--paper-50);
  border: 1px solid #dfe6ea;
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 0.9rem;
  color: var(--ink-600);
}

/* ---------- Testimonials ---------- */
.testimonial {
  background: var(--paper-50);
  border: 1px solid #e4e9ec;
  border-radius: var(--radius-lg);
  padding: 26px 24px;
}
.testimonial p.quote { font-style: normal; color: var(--ink-900); }
.testimonial .who { display: flex; align-items: center; gap: 10px; margin-top: 16px; }
.testimonial .avatar {
  width: 40px; height: 40px; border-radius: 50%;
  background: linear-gradient(135deg, var(--copper-400), var(--steel-600));
}
.testimonial .who b { display: block; font-size: 0.92rem; }
.testimonial .who span { font-size: 0.8rem; color: var(--ink-600); }
.stars { color: var(--copper-500); letter-spacing: 2px; margin-bottom: 10px; }

/* ---------- Form ---------- */
.form-wrap {
  background: #fff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  padding: 36px;
  border: 1px solid #e4e9ec;
}
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-field { display: flex; flex-direction: column; gap: 6px; margin-bottom: 16px; }
.form-field.full { grid-column: 1 / -1; }
.form-field label { font-size: 0.88rem; font-weight: 600; color: var(--ink-900); }
.form-field input,
.form-field select,
.form-field textarea {
  border: 1px solid #d7dde1;
  border-radius: var(--radius-md);
  padding: 12px 14px;
  font-size: 0.98rem;
  font-family: inherit;
  background: var(--paper-50);
}
.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
  outline: 2px solid var(--cyan-400);
  outline-offset: 1px;
  background: #fff;
}
.form-note { font-size: 0.82rem; color: var(--ink-600); margin-top: 10px; }
.form-error {
  background: #fdecec;
  border: 1px solid #f3b8b8;
  color: #a13030;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  margin-bottom: 18px;
  font-size: 0.9rem;
}

/* ---------- FAQ ---------- */
.faq-item {
  border-bottom: 1px solid #e4e9ec;
  padding: 20px 0;
}
.faq-item summary {
  font-family: var(--font-display);
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; font-size: 1.3rem; color: var(--copper-500); }
.faq-item[open] summary::after { content: "–"; }
.faq-item p { color: var(--ink-600); margin: 12px 0 0; }

/* ---------- Sticky mobile CTA ---------- */
.sticky-cta {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  background: var(--graphite-900);
  padding: 12px 16px;
  display: none;
  gap: 10px;
  z-index: 50;
  box-shadow: 0 -10px 30px rgba(0,0,0,0.25);
}

/* ---------- Footer ---------- */
footer {
  background: var(--graphite-900);
  color: #aab6c0;
  padding: 56px 0 26px;
}
footer h4 { color: #fff; font-size: 1rem; }
footer .grid-4 { gap: 32px; }
footer a:hover { color: var(--cyan-400); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  margin-top: 40px;
  padding-top: 20px;
  font-size: 0.82rem;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- Gallery / Portfolio (ผลงานลูกค้า) ---------- */
.job-card {
  background: #fff;
  border: 1px solid #e4e9ec;
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 32px;
}
.job-media {
  display: grid;
  grid-template-columns: 1fr 1fr;
}
.job-media figure { margin: 0; position: relative; }
.job-media figcaption {
  position: absolute;
  top: 10px; left: 10px;
  background: rgba(18,22,28,0.72);
  color: #fff;
  font-family: var(--font-display);
  font-size: 0.75rem;
  padding: 4px 10px;
  border-radius: 999px;
  letter-spacing: 0.04em;
}
.job-media img { width: 100%; height: 240px; object-fit: cover; }

.img-placeholder {
  width: 100%;
  height: 240px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: repeating-linear-gradient(135deg, #eef2f4, #eef2f4 10px, #e6ebee 10px, #e6ebee 20px);
  border: 2px dashed #c7d0d5;
  color: var(--ink-600);
  text-align: center;
  padding: 12px;
}
.img-placeholder span { font-size: 0.78rem; max-width: 22ch; }
.img-placeholder code {
  font-size: 0.7rem;
  background: #fff;
  padding: 2px 6px;
  border-radius: 6px;
  border: 1px solid #d7dde1;
}

.job-body { padding: 24px 26px 28px; }
.job-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 12px;
}
.job-meta span {
  font-size: 0.78rem;
  background: var(--paper-50);
  border: 1px solid #dfe6ea;
  padding: 4px 12px;
  border-radius: 999px;
  color: var(--ink-600);
}
.job-body h3 { margin-bottom: 6px; }
.job-body p.summary { color: var(--ink-600); margin: 0 0 18px; }

.job-review {
  border-top: 1px solid #eef1f3;
  padding-top: 18px;
  display: flex;
  gap: 14px;
  align-items: flex-start;
}
.avatar-initial {
  width: 44px; height: 44px;
  border-radius: 50%;
  flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, var(--copper-400), var(--steel-600));
  color: #fff;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
}
.job-review .quote { margin: 0 0 6px; color: var(--ink-900); }
.job-review .who { font-size: 0.85rem; color: var(--ink-600); }

.gallery-note {
  background: #fff8ec;
  border: 1px solid #f0dfb8;
  color: #7a5c1e;
  padding: 16px 20px;
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  margin-bottom: 40px;
}

@media (max-width: 640px) {
  .job-media { grid-template-columns: 1fr; }
  .job-media img, .img-placeholder { height: 200px; }
}

.text-center { text-align: center; }
.mx-auto { margin-left: auto; margin-right: auto; }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero .container { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .nav-links, .nav-cta { display: none; }
}

@media (max-width: 640px) {
  .section { padding: 56px 0; }
  .grid-4, .grid-3, .grid-2, .steps { grid-template-columns: 1fr; }
  .form-grid { grid-template-columns: 1fr; }
  .sticky-cta { display: flex; }
  body { padding-bottom: 70px; }
  .hero-stats { gap: 18px; }
}