/* argent.vn — trang công ty Argent
   Cùng hệ màu kim loại với verix.vn, trình bày trang trọng, ít chữ. */
:root {
  --white: #ffffff;
  --canvas: #f4f4f6;
  --border: #dcdce1;
  --border-strong: #c8c8cd;
  --ink: #1d1c21;
  --ink-muted: #4b4a4f;
  --ink-subtle: #6a6970;
  --graphite: #2a292e;
  --steel: #9d9ca1;
  --primary: #1d3958;
  --primary-hover: #294a70;
  --accent: #34597d;
  --accent-subtle: #e7edf4;
  --wrap: 1080px;
  --font: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0; font-family: var(--font); font-size: 16px; line-height: 1.7;
  color: var(--ink); background: var(--white); overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: var(--primary); }
a:hover { color: var(--primary-hover); }
h1, h2, h3 { margin: 0; line-height: 1.25; color: var(--graphite); font-weight: 600; letter-spacing: -.01em; }
p { margin: 0; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 12px; z-index: 100; background: var(--white); padding: 8px 12px; }

/* ---------- Logo: chữ A (ảnh) + chữ ARGENT ---------- */
.logo-argent { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; }
.logo-argent img { height: 32px; width: auto; display: block; }
.logo-argent span {
  font-weight: 600; font-size: 20px; letter-spacing: .32em; margin-right: -.32em;
  background: linear-gradient(100deg, #2c2d31 0%, #65666f 40%, #a0a2a8 55%, #46484e 75%, #1a1c20 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-mark { display: block; height: 120px; width: auto; margin: 0 auto 36px; }

/* ---------- Thanh trên: SÁNG ---------- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, .94);
  backdrop-filter: saturate(160%) blur(10px);
  -webkit-backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.topbar .wrap { display: flex; align-items: center; gap: 24px; height: 72px; }
.nav { display: flex; gap: 4px; margin-left: auto; }
.nav a {
  text-decoration: none; color: var(--ink-muted); font-weight: 500; font-size: 15px;
  padding: 8px 14px; border-radius: 8px;
}
.nav a:hover { color: var(--graphite); background: var(--canvas); }

/* ---------- Nút ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  padding: 13px 22px; border-radius: 10px; font-weight: 600; font-size: 15px;
  text-decoration: none; border: 1px solid transparent; white-space: nowrap;
  transition: background-color .15s, border-color .15s;
}
.btn-primary { background: var(--primary); color: var(--white); }
.btn-primary:hover { background: var(--primary-hover); color: var(--white); }
.btn svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

/* ---------- Hero ---------- */
.hero {
  text-align: center; border-bottom: 1px solid var(--border);
  background:
    radial-gradient(900px 420px at 50% -20%, rgba(52, 89, 125, .09), transparent 65%),
    linear-gradient(180deg, #fbfbfc 0%, var(--canvas) 100%);
}
.hero .wrap { padding-top: 128px; padding-bottom: 136px; }
.hero h1 { font-size: clamp(30px, 4.4vw, 50px); max-width: 820px; margin: 0 auto; }
.hero p { margin: 24px auto 0; max-width: 620px; font-size: 18px; color: var(--ink-muted); }

/* ---------- Mục ---------- */
section { scroll-margin-top: 76px; }
.section { padding: 112px 0; }
.section-alt { background: var(--canvas); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.kicker { font-size: 13px; font-weight: 600; letter-spacing: .14em; text-transform: uppercase; color: var(--accent); margin-bottom: 12px; }
.section h2 { font-size: clamp(26px, 3vw, 34px); }

.about { display: grid; grid-template-columns: .8fr 1.2fr; gap: 64px; align-items: start; }
.about-lead { margin-top: 16px; color: var(--ink-muted); font-size: 17px; }
.pillars { display: grid; gap: 0; border-top: 1px solid var(--border); }
.pillar { display: grid; grid-template-columns: 56px 1fr; gap: 16px; padding: 26px 0; border-bottom: 1px solid var(--border); }
.pillar .n { font-size: 14px; font-weight: 600; color: var(--steel); letter-spacing: .08em; padding-top: 2px; }
.pillar h3 { font-size: 18px; margin-bottom: 6px; }
.pillar p { color: var(--ink-muted); font-size: 15px; }

/* Sản phẩm */
.product {
  display: grid; grid-template-columns: auto 1fr auto; gap: 40px; align-items: center;
  margin-top: 40px; padding: 40px 44px; border-radius: 20px;
  background: linear-gradient(135deg, #ffffff 0%, #f6f6f8 55%, #e7edf4 100%);
  border: 1px solid var(--border);
  box-shadow: 0 1px 2px rgba(29, 28, 33, .05), 0 12px 32px rgba(29, 28, 33, .06);
}
.product-mark { display: flex; align-items: center; gap: 14px; }
.product-mark img { width: 88px; height: auto; }
.product-mark span { font-size: 26px; font-weight: 700; letter-spacing: .16em; color: var(--graphite); }
.product p { color: var(--ink-muted); font-size: 16px; max-width: 520px; }
.product p strong { color: var(--graphite); font-weight: 600; }

/* Liên hệ */
.contact { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; }
.contact-list { display: grid; gap: 0; border-top: 1px solid var(--border); }
.contact-item {
  display: grid; grid-template-columns: 120px 1fr; gap: 16px; align-items: baseline;
  padding: 22px 0; border-bottom: 1px solid var(--border); text-decoration: none; color: var(--graphite);
}
.contact-item small { font-size: 13px; letter-spacing: .1em; text-transform: uppercase; color: var(--ink-subtle); }
.contact-item strong { font-size: 18px; font-weight: 600; overflow-wrap: anywhere; }
.contact-item:hover strong { color: var(--primary); }

/* Chân trang */
.footer { border-top: 1px solid var(--border); background: var(--canvas); padding: 36px 0; font-size: 14px; color: var(--ink-subtle); }
.footer .wrap { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px; }
.footer .logo-argent span { font-size: 16px; }
.footer .logo-argent img { height: 24px; }
.footer a { color: var(--ink-muted); }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .about, .contact { grid-template-columns: 1fr; gap: 32px; }
  .product { grid-template-columns: 1fr; gap: 24px; padding: 32px; }
  .product .btn { justify-self: start; }
}
@media (max-width: 600px) {
  .wrap { padding: 0 16px; }
  .topbar .wrap { height: 64px; }
  .nav a { padding: 8px 8px; font-size: 14px; }
  .logo-argent span { font-size: 17px; letter-spacing: .26em; margin-right: -.26em; }
  .logo-argent img { height: 28px; }
  .hero-mark { height: 88px; margin-bottom: 28px; }
  .hero .wrap { padding-top: 80px; padding-bottom: 88px; }
  .hero p { font-size: 16px; }
  .section { padding: 72px 0; }
  .pillar { grid-template-columns: 40px 1fr; gap: 10px; }
  .product { padding: 24px 18px; }
  .product .btn { justify-self: stretch; }
  .product-mark img { width: 64px; }
  .product-mark span { font-size: 22px; }
  .contact-item { grid-template-columns: 1fr; gap: 2px; }
  .footer .wrap { flex-direction: column; align-items: flex-start; }
}
@media (max-width: 400px) {
  .nav a:not(:last-child) { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}