/* ===== ĐIỆN LẠNH ĐỨC MẠNH - Stylesheet ===== */
:root {
  --primary: #0b6cd1;
  --primary-dark: #084f9c;
  --primary-light: #e8f2fd;
  --accent: #ff6b1a;
  --accent-dark: #e05a0f;
  --text: #1c2733;
  --text-light: #5a6b7a;
  --bg: #ffffff;
  --bg-alt: #f4f8fc;
  --border: #e1e8ef;
  --zalo: #0068ff;
  --messenger-a: #00c6ff;
  --messenger-b: #0068ff;
  --radius: 12px;
  --shadow: 0 4px 20px rgba(11, 108, 209, 0.08);
  --shadow-lg: 0 10px 30px rgba(11, 108, 209, 0.15);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Segoe UI', 'Roboto', Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

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

/* ===== Top bar ===== */
.topbar {
  background: var(--primary-dark);
  color: #fff;
  font-size: 13px;
}
.topbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 8px;
  padding-bottom: 8px;
  flex-wrap: wrap;
  gap: 6px;
}
.topbar a { color: #fff; }
.topbar .topbar-contacts { display: flex; gap: 18px; flex-wrap: wrap; }
.topbar .topbar-contacts span { opacity: .95; }

/* ===== Header ===== */
.site-header {
  background: #fff;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  padding-bottom: 14px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 20px;
  color: var(--primary-dark);
  letter-spacing: .3px;
}
.logo .logo-badge {
  width: 44px; height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 20px; flex-shrink: 0;
  overflow: hidden;
}
.logo .logo-badge img {
  width: 100%; height: 100%;
  object-fit: cover;
}
.footer-logo img {
  width: 40px; height: 40px;
  border-radius: 50%;
  object-fit: cover;
}
.logo small {
  display: block;
  font-weight: 500;
  font-size: 11px;
  color: var(--text-light);
  letter-spacing: .5px;
}

.main-nav { display: flex; gap: 28px; align-items: center; }
.main-nav a {
  font-weight: 600;
  font-size: 15px;
  color: var(--text);
  padding: 6px 0;
  border-bottom: 2px solid transparent;
  transition: .2s;
}
.main-nav a:hover, .main-nav a.active { color: var(--primary); border-color: var(--primary); }

.header-cta {
  display: flex;
  align-items: center;
  gap: 10px;
}
.btn-call-header {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--accent);
  color: #fff;
  padding: 10px 16px;
  border-radius: 30px;
  font-weight: 700;
  font-size: 14px;
  white-space: nowrap;
  transition: .2s;
}
.btn-call-header:hover { background: var(--accent-dark); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.nav-toggle span { width: 24px; height: 3px; background: var(--primary-dark); border-radius: 2px; }

/* ===== Hero ===== */
.hero {
  background: linear-gradient(120deg, var(--primary-dark), var(--primary) 70%);
  color: #fff;
  padding: 56px 0;
}
.hero .container {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 40px;
  align-items: center;
}
.hero h1 { font-size: 34px; line-height: 1.25; margin-bottom: 16px; }
.hero h1 span { color: #ffd39c; }
.hero p { font-size: 16px; opacity: .95; margin-bottom: 26px; max-width: 520px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 24px;
  border-radius: 30px;
  font-weight: 700;
  font-size: 15px;
  transition: .2s;
  border: 2px solid transparent;
  cursor: pointer;
}
.btn-accent { background: var(--accent); color: #fff; }
.btn-accent:hover { background: var(--accent-dark); transform: translateY(-2px); }
.btn-outline { border-color: #fff; color: #fff; }
.btn-outline:hover { background: rgba(255,255,255,.15); }
.btn-zalo { background: var(--zalo); color: #fff; }
.btn-zalo:hover { background: #0052cc; transform: translateY(-2px); }

.hero-commitments { margin-top: 28px; }
.hero-commitments .commitments-label {
  display: block;
  font-weight: 700;
  font-size: 12.5px;
  letter-spacing: .8px;
  text-transform: uppercase;
  color: #ffd39c;
  margin-bottom: 12px;
}
.hero-commitments ul { display: flex; flex-direction: column; gap: 10px; }
.hero-commitments li {
  position: relative;
  padding-left: 28px;
  font-size: 14px;
  line-height: 1.55;
  color: rgba(255,255,255,.9);
  max-width: 540px;
}
.hero-commitments li::before {
  content: "✓";
  position: absolute;
  left: 0; top: 1px;
  width: 19px; height: 19px;
  background: rgba(255,255,255,.18);
  border: 1px solid rgba(255,255,255,.3);
  border-radius: 5px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  color: #fff;
}
.hero-commitments li strong { color: #fff; }

.hero-visual {
  background: rgba(255,255,255,.1);
  border: 1px solid rgba(255,255,255,.2);
  border-radius: 20px;
  padding: 30px;
}
.hero-visual ul { display: flex; flex-direction: column; gap: 16px; }
.hero-visual li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: rgba(255,255,255,.08);
  padding: 14px 16px;
  border-radius: 12px;
  font-size: 14px;
}
.hero-visual li .ico {
  width: 34px; height: 34px; border-radius: 8px;
  background: var(--accent);
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0; font-size: 16px;
}

/* ===== Section shared ===== */
.section { padding: 64px 0; }
.section-alt { background: var(--bg-alt); }
.section-head {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 40px;
}
.section-head .eyebrow {
  color: var(--accent);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 8px;
  display: block;
}
.section-head h2 { font-size: 28px; color: var(--primary-dark); margin-bottom: 10px; }
.section-head p { color: var(--text-light); font-size: 15px; }

/* ===== Service icons grid (home) ===== */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.service-card {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  min-height: 240px;
  display: flex;
  align-items: flex-end;
  border: 1px solid var(--border);
  transition: .25s;
}
.service-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.service-card .bg {
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform .4s;
}
.service-card:hover .bg { transform: scale(1.07); }
.service-card .overlay {
  position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(8,20,35,0) 28%, rgba(6,18,34,.94) 100%);
}
.service-card .content {
  position: relative;
  z-index: 2;
  padding: 22px 20px 24px;
  color: #fff;
}
.service-card h3 { font-size: 17px; margin-bottom: 6px; color: #fff; }
.service-card p { font-size: 13.5px; color: rgba(255,255,255,.88); margin: 0; }

/* ===== Article / post cards ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}
.post-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: .25s;
}
.post-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.post-thumb {
  height: 150px;
  display: flex; align-items: center; justify-content: center;
  font-size: 72px;
  color: #fff;
  overflow: hidden;
  transition: transform .3s;
}
.post-card:hover .post-thumb { transform: scale(1.05); }
.post-thumb.t-blue { background: linear-gradient(135deg,#3aa0ff,#0b6cd1); }
.post-thumb.t-cyan { background: linear-gradient(135deg,#33d1c9,#0b8fa3); }
.post-thumb.t-purple { background: linear-gradient(135deg,#7b6bff,#4b3ccf); }
.post-thumb.t-orange { background: linear-gradient(135deg,#ffb648,#ff6b1a); }
.post-thumb.t-green { background: linear-gradient(135deg,#3ed17c,#0f9d58); }
.post-thumb.t-red { background: linear-gradient(135deg,#ff7b7b,#e0393e); }
.post-body { padding: 20px 22px 24px; display: flex; flex-direction: column; flex: 1; }
.post-tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .5px;
  text-transform: uppercase;
  color: var(--primary);
  background: var(--primary-light);
  padding: 4px 10px;
  border-radius: 20px;
  margin-bottom: 10px;
  width: fit-content;
}
.post-tag.tag-ad { color: var(--accent-dark); background: #fff1e6; }
.post-body h3 { font-size: 18px; margin-bottom: 10px; line-height: 1.4; }
.post-body p { font-size: 14px; color: var(--text-light); margin-bottom: 16px; flex: 1; }
.post-readmore { font-weight: 700; font-size: 14px; color: var(--primary); display: inline-flex; align-items: center; gap: 6px; }
.post-readmore:hover { color: var(--primary-dark); }

/* ===== CTA band ===== */
.cta-band {
  background: linear-gradient(120deg, var(--accent), var(--accent-dark));
  color: #fff;
  border-radius: 20px;
  padding: 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}
.cta-band h3 { font-size: 22px; margin-bottom: 6px; }
.cta-band p { opacity: .95; font-size: 14px; }
.cta-band .btn-outline { border-color: #fff; }

/* ===== Why us ===== */
.why-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.why-item { text-align: center; padding: 10px; }
.why-item .num { font-size: 30px; font-weight: 800; color: var(--primary); margin-bottom: 6px; }
.why-item p { font-size: 14px; color: var(--text-light); }

/* ===== Article page ===== */
.article-hero {
  background: var(--bg-alt);
  padding: 40px 0 30px;
  border-bottom: 1px solid var(--border);
}
.breadcrumb { font-size: 13px; color: var(--text-light); margin-bottom: 14px; }
.breadcrumb a { color: var(--primary); }
.article-hero h1 { font-size: 30px; color: var(--primary-dark); max-width: 780px; line-height: 1.3; }
.article-meta { margin-top: 14px; font-size: 13px; color: var(--text-light); display: flex; gap: 16px; flex-wrap: wrap; }

.article-body {
  max-width: 780px;
  margin: 0 auto;
  padding: 44px 20px;
}
.article-body h2 { font-size: 22px; color: var(--primary-dark); margin: 32px 0 14px; }
.article-body h3 { font-size: 18px; color: var(--text); margin: 22px 0 10px; }
.article-body p { margin-bottom: 16px; font-size: 15.5px; color: #333; }
.article-body ul, .article-body ol { margin: 0 0 18px 22px; }
.article-body li { margin-bottom: 8px; font-size: 15.5px; }
.article-body .callout {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  padding: 16px 20px;
  border-radius: 8px;
  margin: 22px 0;
  font-size: 14.5px;
}
.article-body .callout.warn { background: #fff4e6; border-color: var(--accent); }
.article-cta {
  margin-top: 36px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  text-align: center;
}
.article-cta h3 { color: var(--primary-dark); margin-bottom: 8px; font-size: 19px; }
.article-cta p { color: var(--text-light); font-size: 14px; margin-bottom: 18px; }
.article-cta .btn-row { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; }
.article-cta .btn-accent, .article-cta .btn-zalo { color: #fff; }
.article-cta .btn-outline-primary {
  border: 2px solid var(--primary); color: var(--primary);
}
.article-cta .btn-outline-primary:hover { background: var(--primary-light); }

.related-posts { margin-top: 50px; }
.related-posts h3 { font-size: 19px; color: var(--primary-dark); margin-bottom: 18px; }

/* ===== Price table ===== */
.price-table { width: 100%; border-collapse: collapse; margin: 22px 0; font-size: 14.5px; }
.price-table th, .price-table td { border: 1px solid var(--border); padding: 10px 14px; text-align: left; }
.price-table th { background: var(--primary-light); color: var(--primary-dark); }
.price-table tr:nth-child(even) td { background: var(--bg-alt); }

/* ===== Footer ===== */
.site-footer {
  background: #0d2436;
  color: #cfe0ee;
  padding: 50px 0 20px;
  margin-top: 40px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 30px;
  padding-bottom: 30px;
  border-bottom: 1px solid rgba(255,255,255,.1);
}
.footer-grid h4 { color: #fff; font-size: 15px; margin-bottom: 16px; }
.footer-grid p, .footer-grid li { font-size: 13.5px; color: #a9bfd1; margin-bottom: 10px; }
.footer-grid a:hover { color: #fff; }
.footer-logo { display: flex; align-items: center; gap: 10px; font-weight: 800; color: #fff; font-size: 18px; margin-bottom: 14px; }
.footer-bottom { text-align: center; padding-top: 18px; font-size: 12.5px; color: #7d93a6; }

/* ===== Floating contact buttons ===== */
.float-contact {
  position: fixed;
  right: 20px;
  bottom: 22px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  z-index: 999;
}
.float-btn {
  width: 58px; height: 58px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 6px 18px rgba(0,0,0,.25);
  color: #fff;
  font-size: 26px;
  position: relative;
  transition: transform .2s;
}
.float-btn:hover { transform: scale(1.1); }
.float-btn.zalo-btn { background: var(--zalo); }
.float-btn.messenger-btn { background: linear-gradient(135deg, var(--messenger-a), var(--messenger-b)); }
.float-btn.phone-btn { background: linear-gradient(135deg, #ff8a3d, var(--accent-dark)); }
.float-btn svg { position: relative; z-index: 1; filter: drop-shadow(0 1px 2px rgba(0,0,0,.18)); }
.float-btn .ping {
  position: absolute; inset: -6px;
  border-radius: 50%;
  border: 2px solid currentColor;
  opacity: 0;
  animation: ping 2.4s ease-out infinite;
  pointer-events: none;
}
.float-btn.phone-btn .ping { animation-delay: .3s; }
.float-btn.zalo-btn .ping { animation-delay: 1.1s; }
.float-btn.messenger-btn .ping { animation-delay: 1.9s; }
@keyframes ping {
  0% { transform: scale(.9); opacity: .55; }
  70% { transform: scale(1.4); opacity: 0; }
  100% { opacity: 0; }
}
.float-btn.zalo-btn svg { animation: icon-bob 2.4s ease-in-out infinite; }
.float-btn.messenger-btn svg { animation: icon-bob 2.4s ease-in-out infinite; animation-delay: .5s; }
.float-btn.phone-btn svg { animation: icon-ring 3.4s ease-in-out infinite; animation-delay: 1s; transform-origin: 50% 15%; }
.float-btn:hover svg { animation-play-state: paused; }
@keyframes icon-bob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-3px); }
}
@keyframes icon-ring {
  0%, 96%, 100% { transform: rotate(0deg); }
  16% { transform: rotate(-18deg); }
  24% { transform: rotate(15deg); }
  32% { transform: rotate(-12deg); }
  40% { transform: rotate(9deg); }
  48% { transform: rotate(-6deg); }
  56% { transform: rotate(3deg); }
}
.float-label {
  position: absolute;
  right: 68px;
  top: 50%;
  transform: translateY(-50%);
  background: #1c2733;
  color: #fff;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 13px;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s;
}
.float-btn:hover .float-label { opacity: 1; }

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .hero .container { grid-template-columns: 1fr; }
  .services-grid, .card-grid { grid-template-columns: repeat(2, 1fr); }
  .why-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  .main-nav { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: #fff;
    flex-direction: column; justify-content: center; align-items: center; gap: 26px;
    transform: translateX(100%); transition: transform .25s; z-index: 200; }
  .main-nav.open { transform: translateX(0); }
  .main-nav a { font-size: 20px; }
  .nav-toggle { display: flex; }
  .header-cta .btn-call-header span.full { display: none; }
  .topbar .topbar-contacts { justify-content: center; width: 100%; }
  .services-grid, .card-grid { grid-template-columns: 1fr; }
  .why-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 26px; }
  .cta-band { flex-direction: column; text-align: center; }
}