/* ==========================================================================
   Kuangcai Stationery — homepage v2
   Visual language referenced from industrial B2B manufacturer sites:
   deep navy #014099, soft blue-grey surfaces, generous whitespace.
   Scoped to the homepage only; other pages keep style.css.
   ========================================================================== */

:root {
  --brand: #014099;
  --brand-2: #01306f;
  --brand-soft: #e8eef7;
  --ink: #212529;
  --ink-2: #494949;
  --ink-3: #78838f;
  --bg-soft: #f2f4f6;
  --bg-alt: #f7f8f9;
  --line: #e6e9ed;
  --radius: 14px;
  --radius-sm: 6px;
  --maxw: 1200px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--ink);
  background: #fff;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { margin: 0; line-height: 1.25; font-weight: 700; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .18s, color .18s, border-color .18s, transform .18s;
  white-space: nowrap;
}
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-2); }
.btn-light { background: #fff; color: var(--brand); }
.btn-light:hover { background: #eef3fb; }
.btn-outline { border-color: rgba(255,255,255,.6); color: #fff; }
.btn-outline:hover { background: rgba(255,255,255,.12); border-color: #fff; }
.btn-outline-dark { border-color: var(--brand); color: var(--brand); }
.btn-outline-dark:hover { background: var(--brand-soft); }

/* ---------- header ---------- */
.hd {
  position: sticky;
  top: 0;
  z-index: 60;
  background: #fff;
  border-bottom: 1px solid var(--line);
}
.hd-in {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
  height: 74px;
  display: flex;
  align-items: center;
  gap: 32px;
}
.brand { display: flex; align-items: baseline; gap: 8px; font-size: 22px; font-weight: 800; letter-spacing: -.02em; color: var(--brand); }
.brand small { font-size: 12px; font-weight: 600; color: var(--ink-3); letter-spacing: .1em; text-transform: uppercase; }
.hd-nav { display: flex; align-items: center; gap: 30px; margin-left: auto; }
.hd-nav a { font-size: 15px; font-weight: 500; color: var(--ink-2); }
.hd-nav a:hover, .hd-nav a.on { color: var(--brand); }
.hd-cta { margin-left: 8px; padding: 11px 22px; font-size: 14px; }
.hd-burger { display: none; margin-left: auto; width: 44px; height: 44px; border: 1px solid var(--line); border-radius: var(--radius-sm); background: #fff; cursor: pointer; }
.hd-burger span, .hd-burger span::before, .hd-burger span::after {
  display: block; width: 18px; height: 2px; background: var(--ink); border-radius: 2px; position: relative; margin: 0 auto;
}
.hd-burger span::before, .hd-burger span::after { content: ""; position: absolute; left: 0; }
.hd-burger span::before { top: -6px; }
.hd-burger span::after { top: 6px; }

@media (max-width: 940px) {
  .hd-nav, .hd-cta { display: none; }
  .hd-burger { display: block; }
  .hd.open .hd-nav {
    display: flex; flex-direction: column; align-items: flex-start; gap: 0;
    position: absolute; left: 0; right: 0; top: 74px; background: #fff;
    border-bottom: 1px solid var(--line); padding: 8px 24px 18px; margin: 0;
  }
  .hd.open .hd-nav a { padding: 13px 0; width: 100%; border-bottom: 1px solid var(--bg-soft); font-size: 16px; }
  .hd.open .hd-cta { display: inline-flex; position: absolute; left: 24px; top: auto; margin: 0; }
}

/* ---------- hero ---------- */
.hero { position: relative; min-height: 620px; display: flex; align-items: center; overflow: hidden; background: #0d2a4d; }
.hero-bg { position: absolute; inset: 0; }
.hero-bg img { width: 100%; height: 100%; object-fit: cover; }
.hero-bg::after {
  content: "";
  position: absolute; inset: 0;
  background: linear-gradient(100deg, rgba(4,26,54,.92) 0%, rgba(4,26,54,.78) 38%, rgba(4,26,54,.34) 68%, rgba(4,26,54,.18) 100%);
}
.hero-in { position: relative; z-index: 2; max-width: var(--maxw); margin: 0 auto; padding: 80px 24px 142px; width: 100%; }
.hero-eyebrow { margin: 0 0 20px; font-size: 12px; font-weight: 700; letter-spacing: .16em; text-transform: uppercase; color: rgba(255,255,255,.72); }
.hero h1 { font-size: 52px; font-weight: 300; color: #fff; letter-spacing: -.02em; margin-bottom: 24px; }
.hero h1 b { font-weight: 800; }
.hero-lead { margin: 0 0 34px; max-width: 600px; font-size: 17px; line-height: 1.7; color: rgba(255,255,255,.85); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; }
.hero-strip {
  position: absolute; left: 0; right: 0; bottom: 0; z-index: 3;
  background: rgba(6,22,43,.42); backdrop-filter: blur(7px);
  border-top: 1px solid rgba(255,255,255,.16);
}
.hero-strip .wrap { display: flex; flex-wrap: wrap; gap: 14px 44px; padding: 18px 24px; }
.hero-strip span { font-size: 14px; color: rgba(255,255,255,.9); display: flex; align-items: center; gap: 9px; }
.hero-strip span::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: #7db2f0; flex: none; }

@media (max-width: 760px) {
  .hero { min-height: 0; }
  .hero h1 { font-size: 33px; }
  .hero-lead { font-size: 15.5px; }
  .hero-in { padding: 54px 24px 176px; }
  .hero-strip .wrap { padding: 14px 24px; gap: 8px 26px; }
  .hero-strip span { font-size: 13px; }
}

/* ---------- section shell ---------- */
.sec { padding: 88px 0; }
.sec-soft { background: var(--bg-soft); }
.sec-alt { background: var(--bg-alt); }
.sec-head { text-align: center; max-width: 760px; margin: 0 auto 56px; }
.sec-head h2 { font-size: 34px; letter-spacing: -.015em; }
.sec-head .rule { width: 44px; height: 3px; background: var(--brand); border-radius: 2px; margin: 18px auto 20px; }
.sec-head p { margin: 0; color: var(--ink-3); font-size: 16px; }
@media (max-width: 760px) {
  .sec { padding: 60px 0; }
  .sec-head h2 { font-size: 26px; }
  .sec-head { margin-bottom: 38px; }
}

/* ---------- category cards ---------- */
.cats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.cat {
  background: #fff; border-radius: var(--radius); overflow: hidden; display: block;
  transition: transform .2s, box-shadow .2s;
}
.cat:hover { transform: translateY(-4px); box-shadow: 0 14px 34px rgba(1,64,153,.13); }
.cat-img { aspect-ratio: 1 / 1; background: var(--bg-soft); overflow: hidden; }
.cat-img img { width: 100%; height: 100%; object-fit: cover; transition: transform .35s; }
.cat:hover .cat-img img { transform: scale(1.05); }
.cat-b { padding: 18px 16px 20px; text-align: center; }
.cat-b h3 { font-size: 16px; font-weight: 600; color: var(--ink); }
.cat-n { display: block; margin-top: 5px; font-size: 13px; color: var(--ink-3); }
.cat-m { display: inline-block; margin-top: 12px; font-size: 13.5px; font-weight: 600; color: var(--brand); }
.cats-foot { text-align: center; margin-top: 44px; }

@media (max-width: 1080px) { .cats { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 760px) { .cats { grid-template-columns: repeat(2, 1fr); gap: 14px; } .cat-b { padding: 13px 10px 16px; } .cat-b h3 { font-size: 14.5px; } }

/* ---------- about ---------- */
.about { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.about-l h2 { font-size: 34px; letter-spacing: -.015em; }
.about-l .rule { width: 44px; height: 3px; background: var(--brand); border-radius: 2px; margin: 18px 0 20px; }
.about-l .sub { font-size: 13px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--brand); margin: 0 0 12px; }
.collage { position: relative; margin-top: 34px; display: grid; grid-template-columns: 1.25fr 1fr; grid-template-rows: repeat(2, 1fr); gap: 12px; height: 340px; }
.collage img { width: 100%; height: 100%; object-fit: cover; border-radius: 12px; }
.collage .tall { grid-row: span 2; }
.about-r {
  position: relative; border-radius: var(--radius); overflow: hidden; min-height: 460px; display: flex;
}
.about-r img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.about-r::after { content: ""; position: absolute; inset: 0; background: linear-gradient(180deg, rgba(1,64,153,.82), rgba(1,29,68,.9)); }
.about-r-in { position: relative; z-index: 2; padding: 52px 46px; display: flex; flex-direction: column; justify-content: center; }
.about-r-in h3 { font-size: 22px; color: #fff; margin-bottom: 18px; }
.about-r-in p { margin: 0 0 16px; color: rgba(255,255,255,.88); font-size: 15px; line-height: 1.78; }
.about-r-in .btn { align-self: flex-start; margin-top: 12px; }

@media (max-width: 940px) {
  .about { grid-template-columns: 1fr; gap: 38px; }
  .about-r { min-height: 0; }
  .about-r-in { padding: 38px 28px; }
  .collage { height: 260px; }
}

/* ---------- stats ---------- */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 30px; text-align: center; }
.stat-c { width: 148px; height: 148px; border-radius: 50%; overflow: hidden; margin: 0 auto 24px; background: var(--bg-soft); border: 6px solid #fff; box-shadow: 0 8px 24px rgba(1,64,153,.1); }
.stat-c img { width: 100%; height: 100%; object-fit: cover; }
.stat-n { font-size: 40px; font-weight: 700; color: var(--brand); line-height: 1; letter-spacing: -.02em; }
.stat-n i { font-style: normal; font-size: 19px; font-weight: 600; margin-left: 3px; }
.stat-l { margin: 12px 0 0; font-size: 14px; color: var(--ink-3); }
@media (max-width: 860px) { .stats { grid-template-columns: repeat(2, 1fr); gap: 34px 20px; } .stat-c { width: 118px; height: 118px; border-width: 4px; } .stat-n { font-size: 32px; } }

/* ---------- advantages checkerboard ---------- */
.adv { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.adv-cell { border-radius: var(--radius); overflow: hidden; min-height: 380px; }
.adv-img img { width: 100%; height: 100%; object-fit: cover; min-height: 380px; }
.adv-blue { background: var(--brand); color: #fff; padding: 56px 52px; display: flex; flex-direction: column; justify-content: center; }
.adv-blue h3 { font-size: 17px; letter-spacing: .12em; text-transform: uppercase; font-weight: 700; margin-bottom: 20px; }
.adv-blue p { margin: 0 0 14px; font-size: 15px; line-height: 1.78; color: rgba(255,255,255,.9); }
.adv-blue p:last-child { margin-bottom: 0; }
@media (max-width: 860px) {
  .adv { grid-template-columns: 1fr; gap: 16px; }
  .adv-cell { min-height: 0; }
  .adv-blue { padding: 38px 28px; }
  .adv-img img { min-height: 240px; }
}

/* ---------- cta ---------- */
.cta { background: var(--brand); color: #fff; padding: 78px 0; text-align: center; }
.cta h2 { font-size: 32px; letter-spacing: -.015em; }
.cta p { margin: 16px auto 32px; max-width: 640px; color: rgba(255,255,255,.85); font-size: 16.5px; }
.cta-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
@media (max-width: 760px) { .cta { padding: 56px 0; } .cta h2 { font-size: 25px; } }

/* ---------- footer ---------- */
.ft { background: #16212e; color: rgba(255,255,255,.72); padding: 64px 0 0; font-size: 14.5px; }
.ft-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.2fr; gap: 40px; }
.ft h4 { font-size: 14px; letter-spacing: .1em; text-transform: uppercase; color: #fff; margin-bottom: 18px; font-weight: 700; }
.ft-brand { font-size: 21px; font-weight: 800; color: #fff; margin-bottom: 14px; letter-spacing: -.02em; }
.ft-brand small { display: block; font-size: 11px; font-weight: 600; letter-spacing: .12em; color: rgba(255,255,255,.5); text-transform: uppercase; margin-top: 4px; }
.ft p { margin: 0 0 12px; line-height: 1.7; }
.ft a { display: block; padding: 6px 0; color: rgba(255,255,255,.72); }
.ft a:hover { color: #fff; }
.ft-bot { margin-top: 52px; border-top: 1px solid rgba(255,255,255,.12); padding: 22px 0; display: flex; justify-content: space-between; gap: 14px; flex-wrap: wrap; font-size: 13.5px; color: rgba(255,255,255,.5); }
@media (max-width: 880px) { .ft-grid { grid-template-columns: 1fr 1fr; gap: 32px; } }
@media (max-width: 560px) { .ft-grid { grid-template-columns: 1fr; } }

/* ---------- misc ---------- */
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 12px; top: 12px; z-index: 99; background: #fff; padding: 10px 16px; border-radius: 6px; }