/* Profpaint / Qiqi Environmental — site stylesheet
   Design tokens + components layered on top of Tailwind CDN utilities. */

:root{
  --navy-950:#061229;
  --navy-900:#0a1f3d;
  --navy-800:#0d2c54;
  --brand-700:#0b3d78;
  --brand-600:#0e4b93;
  --brand-500:#1567c4;
  --brand-400:#2f86e6;
  --brand-100:#e7f0fc;
  --brand-50:#f3f8fe;
  --accent-500:#ff7a29;
  --accent-600:#f0631a;
  --ink-900:#0f172a;
  --ink-700:#334155;
  --ink-500:#64748b;
  --line:#e3e9f2;
  --paper:#f6f9fd;
}

html{scroll-behavior:smooth;}
body{
  font-family:'Inter',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;
  color:var(--ink-900);
  background:#fff;
  -webkit-font-smoothing:antialiased;
}
html[lang="zh-CN"] body, body.zh-active{
  font-family:'Noto Sans SC','Inter',system-ui,sans-serif;
}
.font-display{font-family:'Manrope','Inter',system-ui,sans-serif;}

.zh{font-family:'Noto Sans SC','Inter',system-ui,sans-serif;}

/* ---------- language toggle ---------- */
/* Note: language toggling (main.js) reuses Tailwind's own generated
   `.hidden` utility class — do not redefine `.hidden` here, or it will
   collide with and permanently override Tailwind's responsive
   `hidden sm:flex` / `md:inline-flex` / `lg:flex` patterns site-wide. */

.lang-btn{
  font-size:.72rem;
  font-weight:700;
  letter-spacing:.04em;
  padding:.32rem .62rem;
  border-radius:999px;
  color:#cfe0f7;
  transition:all .2s ease;
}
.lang-btn.active{
  background:#fff;
  color:var(--brand-700);
}

/* ---------- layout helpers ---------- */
.section{padding:5rem 0;}
@media (max-width:768px){ .section{padding:3.25rem 0;} }
.container-px{max-width:1280px;margin:0 auto;padding-left:1.5rem;padding-right:1.5rem;}
@media (min-width:1024px){ .container-px{padding-left:2.5rem;padding-right:2.5rem;} }

.eyebrow{
  display:inline-flex;align-items:center;gap:.5rem;
  font-size:.72rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;
  color:var(--brand-600);
  background:var(--brand-100);
  border:1px solid #d5e6fb;
  padding:.4rem .85rem;border-radius:999px;
}
.eyebrow::before{content:"";width:6px;height:6px;border-radius:50%;background:var(--accent-500);display:inline-block;}

.h-display{
  font-family:'Manrope','Inter',system-ui,sans-serif;
  font-weight:800;
  letter-spacing:normal;
  color:var(--ink-900);
  overflow-wrap:break-word;
}

.text-grad{
  background:linear-gradient(90deg,var(--brand-500),var(--accent-500));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}

/* ---------- header / nav ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(6,18,41,.86);
  backdrop-filter:blur(14px);
  border-bottom:1px solid rgba(255,255,255,.08);
}
.nav-link{
  color:#cfe0f7;font-weight:600;font-size:.92rem;
  padding:.5rem .2rem;position:relative;
}
.nav-link:hover{color:#fff;}
.nav-link.active{color:#fff;}
.nav-link.active::after{
  content:"";position:absolute;left:0;right:0;bottom:-3px;height:2px;
  background:var(--accent-500);border-radius:2px;
}
.btn-primary{
  display:inline-flex;align-items:center;gap:.5rem;
  background:linear-gradient(90deg,var(--accent-500),var(--accent-600));
  color:#fff;font-weight:700;font-size:.92rem;
  padding:.72rem 1.4rem;border-radius:.6rem;
  box-shadow:0 8px 20px -6px rgba(240,99,26,.55);
  transition:transform .18s ease, box-shadow .18s ease;
}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 12px 26px -6px rgba(240,99,26,.65);}
.btn-outline{
  display:inline-flex;align-items:center;gap:.5rem;
  border:1.5px solid rgba(255,255,255,.35);
  color:#fff;font-weight:600;font-size:.92rem;
  padding:.68rem 1.35rem;border-radius:.6rem;
  transition:all .18s ease;
}
.btn-outline:hover{background:rgba(255,255,255,.1);border-color:#fff;}
.btn-outline-dark{
  display:inline-flex;align-items:center;gap:.5rem;
  border:1.5px solid var(--line);
  color:var(--ink-900);font-weight:600;font-size:.92rem;
  padding:.68rem 1.35rem;border-radius:.6rem;
  transition:all .18s ease;
}
.btn-outline-dark:hover{border-color:var(--brand-500);color:var(--brand-600);background:var(--brand-50);}

/* ---------- hero ---------- */
.hero-bg{
  background:
    radial-gradient(1100px 500px at 15% -10%, rgba(47,134,230,.35), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, rgba(255,122,41,.18), transparent 55%),
    linear-gradient(180deg,var(--navy-950), var(--navy-900) 55%, var(--navy-800));
}
.grid-overlay{
  background-image:
    linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px);
  background-size:44px 44px;
  mask-image:linear-gradient(180deg, rgba(0,0,0,.7), transparent 75%);
}

/* ---------- cards ---------- */
.card{
  background:#fff;border:1px solid var(--line);border-radius:1rem;
  transition:transform .22s ease, box-shadow .22s ease, border-color .22s ease;
}
.card:hover{transform:translateY(-4px);box-shadow:0 18px 40px -18px rgba(15,23,42,.22);border-color:#d7e5fa;}

.stat-num{
  font-family:'Manrope','Inter',sans-serif;
  font-weight:800;font-size:2.4rem;line-height:1;
  color:#fff;
}
@media (min-width:768px){ .stat-num{font-size:2.9rem;} }

.chip{
  display:inline-flex;align-items:center;gap:.4rem;
  font-size:.78rem;font-weight:600;color:var(--ink-700);
  background:var(--paper);border:1px solid var(--line);
  padding:.35rem .7rem;border-radius:.5rem;
}

/* product system diagram */
.layer-row{
  display:flex;align-items:center;gap:.75rem;
  padding:.55rem .8rem;border-radius:.6rem;
  background:var(--paper);border:1px solid var(--line);
  font-size:.85rem;font-weight:600;color:var(--ink-700);
}
.layer-dot{
  width:1.6rem;height:1.6rem;border-radius:.4rem;
  display:flex;align-items:center;justify-content:center;
  color:#fff;font-size:.72rem;font-weight:800;flex:none;
  background:linear-gradient(135deg,var(--brand-500),var(--brand-700));
}

/* comparison bars */
.bar-track{height:.55rem;border-radius:999px;background:var(--line);overflow:hidden;}
.bar-fill{height:100%;border-radius:999px;background:linear-gradient(90deg,var(--brand-500),var(--brand-400));}
.bar-fill.accent{background:linear-gradient(90deg,var(--accent-600),var(--accent-500));}

/* case gallery */
.case-card{position:relative;overflow:hidden;border-radius:1rem;background:var(--ink-900);}
.case-card img{transition:transform .5s ease;}
.case-card:hover img{transform:scale(1.06);}
.case-overlay{
  position:absolute;inset:0;
  background:linear-gradient(0deg, rgba(6,14,30,.92) 0%, rgba(6,14,30,.35) 45%, rgba(6,14,30,0) 70%);
}

/* fade-in on scroll */
.reveal{opacity:0;transform:translateY(18px);transition:opacity .6s ease, transform .6s ease;}
.reveal.in{opacity:1;transform:translateY(0);}

/* tabs */
.tab-btn{
  font-weight:700;font-size:.88rem;color:var(--ink-500);
  padding:.7rem 1.1rem;border-radius:.6rem;border:1px solid transparent;
  white-space:nowrap;
}
.tab-btn.active{color:var(--brand-700);background:var(--brand-100);border-color:#d5e6fb;}
.tab-panel{display:none;}
.tab-panel.active{display:block;}

/* table */
.spec-table{width:100%;border-collapse:collapse;font-size:.86rem;}
.spec-table th{
  text-align:left;color:#fff;background:var(--brand-700);
  padding:.65rem .9rem;font-weight:700;font-size:.78rem;letter-spacing:.03em;text-transform:uppercase;
}
.spec-table td{padding:.62rem .9rem;border-bottom:1px solid var(--line);color:var(--ink-700);}
.spec-table tr:nth-child(even) td{background:var(--paper);}
.spec-table td:first-child{font-weight:600;color:var(--ink-900);}

/* footer */
.footer-link{color:#a9c2e6;font-size:.9rem;}
.footer-link:hover{color:#fff;}

/* marquee */
.marquee-track{display:flex;gap:3.2rem;animation:marquee 28s linear infinite;}
@keyframes marquee{ from{transform:translateX(0);} to{transform:translateX(-50%);} }

/* misc */
.divider-grad{height:2px;background:linear-gradient(90deg,var(--brand-500),var(--accent-500));}
.badge-num{
  width:2.6rem;height:2.6rem;border-radius:.75rem;
  background:var(--brand-100);color:var(--brand-700);
  display:flex;align-items:center;justify-content:center;font-weight:800;font-family:'Manrope',sans-serif;
}
::selection{background:var(--brand-500);color:#fff;}

/* image carousel */
.carousel{position:relative;}
.carousel-slide{
  position:absolute;inset:0;width:100%;height:100%;object-fit:cover;
  opacity:0;transform:scale(1.04);
  transition:opacity 1.1s ease, transform 6.5s ease;
  pointer-events:none;
}
.carousel-slide.active{opacity:1;transform:scale(1);z-index:1;pointer-events:auto;}
.carousel-dots{
  position:absolute;bottom:.85rem;left:50%;transform:translateX(-50%);
  display:flex;gap:.4rem;z-index:2;
}
.carousel-dot{
  width:.4rem;height:.4rem;border-radius:999px;background:rgba(255,255,255,.55);
  border:none;padding:0;cursor:pointer;transition:all .25s ease;
}
.carousel-dot.active{background:#fff;width:1.15rem;}

.aspect-4-3{aspect-ratio:4/3;}
.aspect-16-9{aspect-ratio:16/9;}
.aspect-3-4{aspect-ratio:3/4;}