/* ROBOTTECH VIỆT NAM — static site design system */
:root {
  --ink: #0b1420;
  --ink-2: #16243a;
  --steel: #5a6b80;
  --line: #dfe5ec;
  --paper: #ffffff;
  --paper-2: #f4f6f9;
  --brand: #0060af;
  --brand-dk: #004a87;
  --brand-lt: #e6f0fa;
  --amber: #f6a609;
  --radius: 14px;
  --shadow: 0 18px 40px -24px rgba(11, 20, 32, 0.45);
  --wrap: 1200px;
  --head: "Barlow Condensed", "Be Vietnam Pro", system-ui, sans-serif;
  --body: "Be Vietnam Pro", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--body);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--brand); text-decoration: none; }
a:hover { color: var(--brand-dk); }
h1, h2, h3, h4 { font-family: var(--head); line-height: 1.12; margin: 0 0 .5em; letter-spacing: .01em; text-transform: uppercase; }
h1 { font-size: clamp(2.1rem, 4.6vw, 3.6rem); }
h2 { font-size: clamp(1.7rem, 3.2vw, 2.5rem); }
h3 { font-size: 1.25rem; }
p { margin: 0 0 1em; }
.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 20px; }
.muted { color: var(--steel); }
.center { text-align: center; margin-top: 32px; }
.eyebrow {
  display: inline-block; font-weight: 700; font-size: .78rem; letter-spacing: .18em;
  text-transform: uppercase; color: var(--brand); margin-bottom: 10px;
}

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 24px; border-radius: 999px; font-weight: 600; font-size: .95rem;
  border: 1.5px solid transparent; cursor: pointer; transition: .2s ease; white-space: nowrap;
}
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dk); color: #fff; transform: translateY(-2px); }
.btn-ghost { border-color: currentColor; color: var(--ink); background: transparent; }
.btn-ghost:hover { background: var(--ink); color: #fff; border-color: var(--ink); }
.btn.full { width: 100%; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 50; background: rgba(255,255,255,.95); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.topbar { background: var(--ink); color: #c6d2e0; font-size: .82rem; }
.topbar a { color: #c6d2e0; }
.topbar a:hover { color: #fff; }
.topbar-in { display: flex; gap: 20px; align-items: center; padding-block: 7px; }
.topbar-social { margin-left: auto; display: flex; gap: 14px; }
.header-in { display: flex; align-items: center; gap: 20px; padding-block: 14px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); }
.brand-mark {
  display: grid; place-items: center; width: 42px; height: 42px; border-radius: 11px;
  background: linear-gradient(135deg, var(--brand), #0a86e0); color: #fff;
  font-family: var(--head); font-weight: 700; font-size: 1.15rem; letter-spacing: .02em;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.05; font-family: var(--head); }
.brand-text b { font-size: 1.28rem; letter-spacing: .04em; }
.brand-text i { font-style: normal; font-size: .74rem; letter-spacing: .3em; color: var(--steel); }
.nav { display: flex; gap: 4px; margin-left: 12px; }
.nav-link {
  padding: 9px 14px; border-radius: 999px; color: var(--ink); font-weight: 600; font-size: .92rem;
}
.nav-link:hover { background: var(--paper-2); }
.nav-link.is-active { background: var(--brand-lt); color: var(--brand-dk); }
.header-tools { margin-left: auto; display: flex; align-items: center; gap: 10px; }
.search { position: relative; display: flex; align-items: center; }
.search input {
  width: 210px; padding: 10px 40px 10px 16px; border: 1.5px solid var(--line); border-radius: 999px;
  font: inherit; font-size: .9rem; background: var(--paper-2); outline: none; transition: .2s;
}
.search input:focus { width: 260px; border-color: var(--brand); background: #fff; }
.search button {
  position: absolute; right: 5px; width: 30px; height: 30px; border: 0; border-radius: 50%;
  background: var(--brand); color: #fff; cursor: pointer; font-size: 1rem; line-height: 1;
}
.suggest {
  position: absolute; top: calc(100% + 8px); right: 0; width: 340px; max-height: 380px; overflow: auto;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 6px;
}
.suggest a { display: block; padding: 9px 12px; border-radius: 9px; color: var(--ink); font-size: .9rem; }
.suggest a:hover, .suggest a.active { background: var(--brand-lt); }
.suggest small { display: block; color: var(--steel); font-size: .76rem; }
.suggest .none { padding: 12px; color: var(--steel); font-size: .9rem; }
.burger { display: none; border: 1.5px solid var(--line); background: #fff; border-radius: 10px; width: 42px; height: 42px; font-size: 1.1rem; cursor: pointer; }

/* Hero */
.hero { background: linear-gradient(160deg, #0b1420 0%, #16243a 55%, #0d3a63 100%); color: #fff; overflow: hidden; }
.hero-in { display: grid; grid-template-columns: 1.05fr .95fr; gap: 40px; align-items: center; padding-block: 70px; }
.hero h1 { color: #fff; }
.hero h1 em { font-style: normal; color: var(--amber); }
.hero p { color: #c3d1e2; max-width: 52ch; font-size: 1.05rem; }
.hero .eyebrow { color: var(--amber); }
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 22px; }
.hero .btn-ghost { color: #fff; }
.hero .btn-ghost:hover { background: #fff; color: var(--ink); border-color: #fff; }
.hero-stats { list-style: none; display: flex; gap: 34px; padding: 30px 0 0; margin: 30px 0 0; border-top: 1px solid rgba(255,255,255,.14); }
.hero-stats b { display: block; font-family: var(--head); font-size: 2rem; color: #fff; }
.hero-stats span { font-size: .82rem; color: #9db0c6; }
.hero-visual { position: relative; }
.hero-visual::after {
  content: ""; position: absolute; inset: 8% -6% 8% 6%; border-radius: 50%;
  background: radial-gradient(circle, rgba(0,134,224,.42), transparent 68%); filter: blur(12px); z-index: 0;
}
.hero-visual img { position: relative; z-index: 1; margin-inline: auto; max-height: 420px; width: auto; object-fit: contain; }

/* Sections */
.section { padding: 76px 0; }
.section-alt { background: var(--paper-2); }
.section-dark { background: var(--ink); color: #dbe4ee; }
.section-dark h2 { color: #fff; }
.section-dark .section-head p { color: #9db0c6; }
.section-head { max-width: 640px; margin-bottom: 40px; }
.section-head p { color: var(--steel); margin: 0; }
.row-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 20px; max-width: none; }

/* Features */
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.feature { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 26px 22px; transition: .25s; }
.feature:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--brand); }
.feature-ico { font-family: var(--head); font-size: 1.6rem; color: var(--brand); display: block; margin-bottom: 8px; }
.feature p { color: var(--steel); font-size: .93rem; margin: 0; }

/* About split */
.about-split { display: grid; grid-template-columns: 1.15fr .85fr; gap: 46px; align-items: center; }
.about-img img { border-radius: var(--radius); box-shadow: var(--shadow); background: #fff; padding: 18px; }

/* Cards */
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; display: flex; flex-direction: column; transition: .25s; }
.card:hover { transform: translateY(-5px); box-shadow: var(--shadow); border-color: var(--brand); }
.card-media { display: block; aspect-ratio: 4 / 3; background: var(--paper-2); overflow: hidden; }
.card-media img { width: 100%; height: 100%; object-fit: contain; padding: 14px; transition: transform .4s; }
.card:hover .card-media img { transform: scale(1.05); }
.card-body { padding: 20px; display: flex; flex-direction: column; gap: 8px; flex: 1; }
.card-title { font-size: 1.05rem; margin: 0; }
.card-title a { color: var(--ink); }
.card-title a:hover { color: var(--brand); }
.card-excerpt { color: var(--steel); font-size: .88rem; margin: 0; flex: 1; }
.card-more { font-weight: 600; font-size: .88rem; }

/* Filter bar */
.filter-bar { display: flex; align-items: center; gap: 16px; margin-bottom: 28px; flex-wrap: wrap; }
.filter-bar input {
  flex: 1; min-width: 240px; padding: 13px 20px; border: 1.5px solid var(--line);
  border-radius: 999px; font: inherit; font-size: .95rem; outline: none;
}
.filter-bar input:focus { border-color: var(--brand); }
.filter-count { color: var(--steel); font-size: .9rem; }
.empty { text-align: center; color: var(--steel); padding: 40px 0; }

/* Page hero */
.page-hero { background: linear-gradient(140deg, var(--ink) 0%, #123457 100%); color: #fff; padding: 62px 0; }
.page-hero h1 { color: #fff; margin-bottom: .2em; }
.page-hero p { color: #b9c9dc; margin: 0; }
.page-hero .eyebrow { color: var(--amber); }

/* Breadcrumb */
.crumb { background: var(--paper-2); border-bottom: 1px solid var(--line); font-size: .86rem; padding: 12px 0; color: var(--steel); }
.crumb a { color: var(--steel); }
.crumb span { color: var(--ink); font-weight: 600; }

/* Detail */
.detail { display: grid; grid-template-columns: .95fr 1.05fr; gap: 44px; align-items: start; }
.detail-media { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.detail-media img { margin-inline: auto; max-height: 420px; object-fit: contain; }
.detail-main h1 { font-size: clamp(1.6rem, 3vw, 2.3rem); }
.spec { width: 100%; border-collapse: collapse; margin: 18px 0 26px; }
.spec th, .spec td { text-align: left; padding: 11px 14px; border-bottom: 1px solid var(--line); font-size: .93rem; }
.spec th { width: 40%; color: var(--steel); font-weight: 600; }
.spec td { font-weight: 600; }
.detail-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.detail-body { margin-top: 46px; }

/* Prose */
.prose { max-width: 76ch; }
.prose h2, .prose h3 { color: var(--ink); margin-top: 1.5em; }
.prose h3 { font-size: 1.05rem; color: var(--brand); }
.prose p { color: #33404f; }
.prose img { border-radius: var(--radius); margin: 18px 0; }
.prose-split { display: grid; grid-template-columns: 1.4fr .6fr; gap: 46px; align-items: start; }
.side-card { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.side-card img { margin-bottom: 16px; border-radius: 10px; background: #fff; }
.side-card h4 { font-size: 1rem; }

/* Video */
.video-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.video-grid.wide { grid-template-columns: repeat(3, 1fr); }
.video-card iframe { width: 100%; aspect-ratio: 16 / 9; border: 0; border-radius: var(--radius); background: #000; }
.video-card p { margin: 12px 0 0; font-size: .92rem; font-weight: 600; }
.section-dark .video-card p { color: #dbe4ee; }

/* CTA */
.cta { background: linear-gradient(120deg, var(--brand-dk), #0a86e0); color: #fff; padding: 54px 0; }
.cta h2 { color: #fff; margin-bottom: .3em; }
.cta p { color: #dbeafd; margin: 0; }
.cta-in { display: flex; align-items: center; justify-content: space-between; gap: 28px; flex-wrap: wrap; }
.cta-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.cta .btn-primary { background: #fff; color: var(--brand-dk); }
.cta .btn-primary:hover { background: var(--ink); color: #fff; }
.cta .btn-ghost { color: #fff; }
.cta .btn-ghost:hover { background: #fff; color: var(--brand-dk); border-color: #fff; }

/* Contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 46px; align-items: start; }
.contact-list { list-style: none; padding: 0; margin: 0 0 24px; }
.contact-list li { display: flex; flex-direction: column; padding: 13px 0; border-bottom: 1px solid var(--line); }
.contact-list span { font-size: .78rem; text-transform: uppercase; letter-spacing: .12em; color: var(--steel); }
.contact-list b { font-size: 1.02rem; }
.contact-social { display: flex; gap: 12px; }
.contact-form { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 30px; }
.contact-form label { display: block; font-size: .86rem; font-weight: 600; margin-bottom: 14px; color: var(--steel); }
.contact-form input, .contact-form textarea {
  width: 100%; margin-top: 6px; padding: 12px 14px; border: 1.5px solid var(--line); border-radius: 10px;
  font: inherit; font-size: .95rem; color: var(--ink); background: #fff; outline: none;
}
.contact-form input:focus, .contact-form textarea:focus { border-color: var(--brand); }
.hint { font-size: .84rem; color: var(--steel); margin: 14px 0 0; text-align: center; }
.map-wrap iframe { width: 100%; height: 380px; border: 0; border-radius: var(--radius); }

/* Search page */
.search-big { display: flex; gap: 12px; margin-bottom: 20px; flex-wrap: wrap; }
.search-big input { flex: 1; min-width: 240px; padding: 15px 22px; border: 1.5px solid var(--line); border-radius: 999px; font: inherit; outline: none; }
.search-big input:focus { border-color: var(--brand); }
.result-meta { color: var(--steel); font-size: .92rem; }
.results { display: flex; flex-direction: column; gap: 14px; margin-top: 14px; }
.result {
  display: grid; grid-template-columns: 96px 1fr; gap: 18px; align-items: center;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; transition: .2s;
}
.result:hover { border-color: var(--brand); box-shadow: var(--shadow); transform: translateY(-2px); }
.result img { width: 96px; height: 78px; object-fit: contain; background: var(--paper-2); border-radius: 10px; }
.result .tag { font-size: .72rem; text-transform: uppercase; letter-spacing: .12em; color: var(--brand); font-weight: 700; }
.result h3 { margin: 4px 0 4px; font-size: 1.05rem; }
.result h3 a { color: var(--ink); }
.result p { margin: 0; color: var(--steel); font-size: .9rem; }
.result mark { background: #fff3cd; color: inherit; padding: 0 2px; border-radius: 3px; }

/* Footer */
.site-footer { background: var(--ink); color: #a9bacd; padding: 56px 0 22px; margin-top: 0; }
.site-footer h4 { color: #fff; font-size: 1rem; }
.site-footer a { color: #a9bacd; }
.site-footer a:hover { color: #fff; }
.foot-grid { display: grid; grid-template-columns: 1.5fr 1fr 1.3fr; gap: 40px; }
.foot-brand { margin-bottom: 14px; }
.foot-brand .brand-text b { color: #fff; }
.foot-list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 9px; font-size: .92rem; }
.copyright { border-top: 1px solid rgba(255,255,255,.1); margin-top: 40px; padding-top: 18px; font-size: .84rem; color: #7d8fa3; }

/* Responsive */
@media (max-width: 1024px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .grid, .video-grid, .video-grid.wide { grid-template-columns: repeat(2, 1fr); }
  .hero-in, .about-split, .detail, .prose-split, .contact-grid { grid-template-columns: 1fr; }
  .foot-grid { grid-template-columns: 1fr 1fr; }
  .nav { position: absolute; top: 100%; left: 0; right: 0; background: #fff; flex-direction: column; padding: 12px; border-bottom: 1px solid var(--line); display: none; }
  .nav.open { display: flex; }
  .burger { display: block; }
  .site-header .wrap.header-in { position: relative; }
}
@media (max-width: 720px) {
  .search input { width: 42px; padding-right: 40px; }
  .search input:focus { width: 200px; }
  .hide-sm { display: none; }
  .grid, .video-grid, .video-grid.wide, .feature-grid, .foot-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 20px; }
  .section { padding: 52px 0; }
  .result { grid-template-columns: 1fr; }
  .result img { width: 100%; height: 150px; }
}