/* ============================================================
   Chemsize — www.chemsize.com
   Fused silica sand, grains & powder for refractory,
   investment casting & technical ceramics
   Style: clean industrial, EU/US buyer friendly, SEO semantic
   ============================================================ */

:root {
  --blue-900: #0f2f55;
  --blue-800: #143c6b;
  --blue-700: #1a4d8f;
  --blue-600: #2e6bb3;
  --blue-100: #e8f0f9;
  --blue-50: #f4f8fc;
  --orange-500: #e87722;
  --orange-600: #d9651a;
  --ink: #1c2733;
  --text: #3d4a58;
  --muted: #66788a;
  --line: #dde5ee;
  --bg: #ffffff;
  --bg-alt: #f5f8fc;
  --green: #1e8e5a;
  --red: #c0392b;
  --radius: 12px;
  --shadow: 0 6px 24px rgba(15, 47, 85, 0.08);
  --font: "Inter", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: var(--blue-700); text-decoration: none; }
a:hover { color: var(--orange-500); }
h1, h2, h3, h4 { color: var(--blue-900); line-height: 1.2; font-weight: 700; }

.container { max-width: 1180px; margin: 0 auto; padding: 0 24px; }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,0.96);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(8px);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand {
  display: flex; align-items: center; gap: 10px;
  font-size: 22px; font-weight: 800; color: var(--blue-900); letter-spacing: -0.3px;
}
.brand .logo-box {
  width: 34px; height: 34px; border-radius: 9px;
  background: linear-gradient(135deg, var(--blue-700), var(--blue-900));
  color: #fff; font-size: 19px; font-weight: 800;
  display: flex; align-items: center; justify-content: center;
}
.nav-links { display: flex; align-items: center; gap: 28px; list-style: none; }
.nav-links a {
  color: var(--ink); font-weight: 600; font-size: 15px;
  padding: 6px 2px; border-bottom: 2px solid transparent;
}
.nav-links a:hover { color: var(--blue-700); border-bottom-color: var(--orange-500); }
.nav-links a.active { color: var(--blue-700); border-bottom-color: var(--blue-700); }
.nav-links .nav-cta {
  background: var(--orange-500); color: #fff; padding: 10px 20px; border-radius: 8px;
  font-weight: 700; border-bottom: none;
}
.nav-links .nav-cta:hover { background: var(--orange-600); color: #fff; }
.nav-toggle {
  display: none; background: none; border: none; cursor: pointer; padding: 8px;
}
.nav-toggle span { display: block; width: 24px; height: 2.5px; background: var(--blue-900); margin: 5px 0; border-radius: 2px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-block; padding: 13px 26px; border-radius: 8px;
  font-weight: 700; font-size: 15px; transition: all 0.18s; border: 2px solid transparent;
}
.btn-primary { background: var(--orange-500); color: #fff; }
.btn-primary:hover { background: var(--orange-600); color: #fff; transform: translateY(-1px); }
.btn-ghost { background: transparent; color: #fff; border-color: rgba(255,255,255,0.7); }
.btn-ghost:hover { background: rgba(255,255,255,0.12); color: #fff; }
.btn-outline { background: transparent; color: var(--blue-700); border-color: var(--blue-700); }
.btn-outline:hover { background: var(--blue-700); color: #fff; }
.btn-whatsapp { background: #25d366; color: #fff; }
.btn-whatsapp:hover { background: #1ebe5d; color: #fff; transform: translateY(-1px); }

/* ---------- Hero ---------- */
.hero {
  background:
    radial-gradient(1100px 500px at 85% -10%, rgba(46,107,179,0.35), transparent 60%),
    linear-gradient(135deg, var(--blue-900) 0%, var(--blue-800) 55%, var(--blue-700) 100%);
  color: #fff; padding: 96px 0 72px;
}
.hero h1 {
  color: #fff; font-size: clamp(30px, 4.6vw, 52px); max-width: 15ch; letter-spacing: -0.5px;
}
.hero .lead {
  color: #dbe7f5; font-size: clamp(16px, 1.6vw, 19px); max-width: 58ch; margin-top: 20px;
}
.hero-btns { display: flex; gap: 14px; margin-top: 34px; flex-wrap: wrap; }
.hero-stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
  margin-top: 56px; padding-top: 32px; border-top: 1px solid rgba(255,255,255,0.18);
}
.hero-stat .num { font-size: clamp(24px, 3vw, 34px); font-weight: 800; color: #fff; }
.hero-stat .lbl { font-size: 13px; color: #b9cce4; margin-top: 4px; }

/* ---------- Sections ---------- */
.section { padding: 84px 0; }
.section.alt { background: var(--bg-alt); }
.section-head { max-width: 720px; margin-bottom: 44px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.eyebrow {
  display: inline-block; font-size: 12px; font-weight: 800; letter-spacing: 1.6px;
  text-transform: uppercase; color: var(--orange-500); margin-bottom: 12px;
}
.section-head h2 { font-size: clamp(26px, 3vw, 38px); letter-spacing: -0.4px; }
.section-head p { color: var(--muted); margin-top: 14px; font-size: 17px; }

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

.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px; box-shadow: var(--shadow); transition: transform 0.2s, box-shadow 0.2s;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 14px 36px rgba(15,47,85,0.12); }
.card h3 { font-size: 19px; margin-bottom: 10px; }
.card p { color: var(--text); font-size: 15px; }
.card ul { margin: 14px 0 0 18px; font-size: 14.5px; color: var(--muted); }
.card li { margin-bottom: 6px; }
.icon-box {
  width: 46px; height: 46px; border-radius: 10px; background: var(--blue-100);
  color: var(--blue-700); display: flex; align-items: center; justify-content: center;
  font-size: 22px; margin-bottom: 16px;
}

/* Problem → Value cards */
.pv-card { border-left: 4px solid var(--orange-500); }
.pv-card .problem { color: var(--red); font-weight: 600; font-size: 14px; }
.pv-card .fix { color: var(--blue-900); font-weight: 700; font-size: 17px; margin: 8px 0 10px; }

/* ---------- Stats band ---------- */
.stat-band {
  background: linear-gradient(90deg, var(--blue-900), var(--blue-700));
  color: #fff; padding: 56px 0;
}
.stat-band .stat { text-align: center; }
.stat-band .num { font-size: clamp(28px, 3.4vw, 42px); font-weight: 800; color: #fff; }
.stat-band .lbl { font-size: 14px; color: #b9cce4; margin-top: 6px; }

/* ---------- Feature rows ---------- */
.feature-row {
  display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center;
}
.feature-text h3 { font-size: 26px; margin-bottom: 16px; }
.feature-text p { margin-bottom: 14px; }
.feature-img img { border-radius: var(--radius); box-shadow: var(--shadow); width: 100%; object-fit: cover; }

/* ---------- Tables ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); }
table.spec {
  width: 100%; border-collapse: collapse; font-size: 14.5px; min-width: 640px;
}
table.spec th {
  background: var(--blue-900); color: #fff; text-align: left; padding: 14px 16px; font-weight: 700;
}
table.spec td { padding: 13px 16px; border-top: 1px solid var(--line); vertical-align: top; }
table.spec tr:nth-child(even) td { background: var(--bg-alt); }
table.spec .hl { color: var(--blue-700); font-weight: 700; }
.badge-win {
  display: inline-block; background: var(--green); color: #fff;
  font-size: 11px; font-weight: 800; padding: 3px 10px; border-radius: 12px; letter-spacing: 0.4px;
}
.badge-base {
  display: inline-block; background: #8a94a6; color: #fff;
  font-size: 11px; font-weight: 800; padding: 3px 10px; border-radius: 12px;
}

/* ---------- Grade cards ---------- */
.grade-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.grade-card {
  border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden;
  background: #fff; box-shadow: var(--shadow);
}
.grade-card .ghead { background: var(--blue-700); color: #fff; padding: 12px 16px; font-weight: 800; display: flex; justify-content: space-between; align-items: center; }
.grade-card .ghead.gb { background: #3a6ea5; }
.grade-card .ghead.gc { background: #6b8cae; }
.grade-card img { height: 200px; width: 100%; object-fit: cover; }
.grade-card .gbody { padding: 18px; font-size: 14px; }
.grade-card .gbody ul { margin-left: 18px; color: var(--text); }
.grade-card .note { font-size: 12.5px; color: var(--muted); margin-top: 12px; font-style: italic; }

/* ---------- Blog / News ---------- */
.post-card { display: block; color: inherit; }
.post-card:hover { color: inherit; }
.post-card .meta { font-size: 12.5px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.6px; margin-bottom: 8px; }
.post-card h3 { font-size: 19px; margin-bottom: 8px; }
.post-card p { font-size: 14.5px; color: var(--text); }
.tag {
  display: inline-block; background: var(--blue-100); color: var(--blue-700);
  font-size: 11.5px; font-weight: 700; padding: 3px 10px; border-radius: 12px; margin-right: 6px;
}

/* ---------- CTA band ---------- */
.cta-band {
  background: linear-gradient(120deg, var(--orange-500), var(--orange-600));
  padding: 60px 0; text-align: center; color: #fff;
}
.cta-band h2 { color: #fff; font-size: clamp(24px, 3vw, 34px); }
.cta-band p { color: rgba(255,255,255,0.92); margin: 12px auto 26px; max-width: 52ch; }
.cta-band .btn { background: #fff; color: var(--orange-600); }
.cta-band .btn:hover { background: var(--blue-900); color: #fff; }

/* ---------- Forms ---------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-grid .full { grid-column: 1 / -1; }
label { display: block; font-weight: 600; font-size: 14px; color: var(--blue-900); margin-bottom: 6px; }
input, select, textarea {
  width: 100%; padding: 12px 14px; border: 1px solid var(--line); border-radius: 8px;
  font-family: inherit; font-size: 15px; background: #fff; color: var(--ink);
}
input:focus, select:focus, textarea:focus { outline: 2px solid var(--blue-600); border-color: transparent; }
.form-note { font-size: 13px; color: var(--muted); margin-top: 12px; }

/* ---------- Footer ---------- */
.site-footer { background: var(--blue-900); color: #b9cce4; padding: 64px 0 28px; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; }
.site-footer h4 { color: #fff; font-size: 15px; margin-bottom: 14px; }
.site-footer a { color: #b9cce4; display: block; margin-bottom: 9px; }
.site-footer a:hover { color: var(--orange-500); }
.footer-brand .brand { color: #fff; margin-bottom: 12px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.12); margin-top: 44px; padding-top: 22px; font-size: 13px; text-align: center; }

/* ---------- Page hero (inner) ---------- */
.page-hero { background: linear-gradient(135deg, var(--blue-900), var(--blue-700)); color: #fff; padding: 64px 0 52px; }
.page-hero h1 { color: #fff; font-size: clamp(28px, 3.6vw, 42px); }
.page-hero p { color: #c9d9ec; margin-top: 14px; max-width: 64ch; font-size: 17px; }
.breadcrumb { font-size: 13px; color: #9db6d6; margin-bottom: 16px; }
.breadcrumb a { color: #c9d9ec; }
.breadcrumb a:hover { color: #fff; }

/* ---------- Callout ---------- */
.callout {
  background: #fff7ed; border-left: 4px solid var(--orange-500); border-radius: 0 10px 10px 0;
  padding: 18px 22px; font-size: 15px; line-height: 1.7; margin: 24px 0;
}
.callout strong { color: var(--blue-900); }
.note { font-size: 13px; color: var(--muted); font-style: italic; margin-top: 10px; }

/* ---------- Responsive ---------- */
@media (max-width: 920px) {
  .grid-3, .grid-4, .grade-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-row { grid-template-columns: 1fr; gap: 28px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .nav-toggle { display: block; }
  .nav-links {
    position: absolute; top: 68px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--line);
    flex-direction: column; align-items: stretch; gap: 0;
    padding: 8px 24px 18px; display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links li a { display: block; padding: 12px 4px; border-bottom: 1px solid var(--line); }
  .nav-links .nav-cta { margin-top: 12px; text-align: center; }
}
@media (max-width: 620px) {
  .grid-2, .grid-3, .grid-4, .grade-grid { grid-template-columns: 1fr; }
  .hero { padding: 64px 0 48px; }
  .section { padding: 60px 0; }
  .form-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
}