/* ==========================================================================
   HK Turbines — Global Stylesheet
   ========================================================================== */

:root {
  --bg: #0a0e15;
  --bg-alt: #0e141d;
  --surface: #131b26;
  --surface-2: #18222f;
  --line: rgba(255, 255, 255, 0.09);
  --line-strong: rgba(255, 255, 255, 0.16);
  --text: #e9eef6;
  --muted: #97a4b8;
  --accent: #ff7a1a;
  --accent-soft: rgba(255, 122, 26, 0.14);
  --accent-2: #2fd4bd;
  --accent-2-soft: rgba(47, 212, 189, 0.12);
  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 18px 44px rgba(0, 0, 0, 0.42);
  --maxw: 1200px;
  --header-h: 72px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue",
          Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 16px); }

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

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- Typography ---------- */
h1, h2, h3, h4 { line-height: 1.18; font-weight: 700; letter-spacing: -0.02em; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 9px;
  font-size: 0.78rem; font-weight: 700; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 14px;
}
.eyebrow::before {
  content: ""; width: 26px; height: 2px; background: var(--accent); border-radius: 2px;
}

.section-title { font-size: clamp(1.75rem, 3.4vw, 2.6rem); margin-bottom: 14px; }
.section-sub { color: var(--muted); max-width: 640px; font-size: 1.03rem; }
.center { text-align: center; }
.center .section-sub { margin-inline: auto; }

section { padding: clamp(64px, 9vw, 110px) 0; position: relative; }
.section-alt { background: var(--bg-alt); border-block: 1px solid var(--line); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  padding: 13px 26px; border-radius: 999px; font-weight: 650; font-size: 0.95rem;
  border: 1px solid transparent; cursor: pointer; transition: 0.22s ease;
  white-space: nowrap;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent), #ff9d4d);
  color: #1a0d00; box-shadow: 0 8px 24px rgba(255, 122, 26, 0.28);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(255, 122, 26, 0.4); }
.btn-ghost { border-color: var(--line-strong); color: var(--text); background: rgba(255,255,255,0.03); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.btn-lg { padding: 16px 34px; font-size: 1.02rem; }

/* ---------- Header ---------- */
.site-header {
  position: fixed; inset: 0 0 auto 0; height: var(--header-h); z-index: 100;
  background: rgba(10, 14, 21, 0.82);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
  transition: background 0.25s ease;
}
.site-header.scrolled { background: rgba(8, 11, 17, 0.95); }
.nav { height: var(--header-h); display: flex; align-items: center; justify-content: space-between; gap: 20px; }

.brand { display: flex; align-items: center; gap: 11px; font-weight: 800; letter-spacing: -0.01em; }
.brand-mark {
  width: 38px; height: 38px; border-radius: 10px; flex: none;
  background: linear-gradient(135deg, var(--accent), #ffb066);
  display: grid; place-items: center; color: #1a0d00;
}
.brand-mark svg { width: 22px; height: 22px; }
.brand-name { font-size: 1.06rem; line-height: 1.1; }
.brand-name small { display: block; font-size: 0.62rem; font-weight: 600; letter-spacing: 0.2em; color: var(--muted); text-transform: uppercase; }

.nav-links { display: flex; align-items: center; gap: 6px; }
.nav-links a {
  padding: 9px 15px; border-radius: 8px; font-size: 0.94rem; font-weight: 550;
  color: var(--muted); transition: 0.18s;
}
.nav-links a:hover, .nav-links a.active { color: var(--text); background: rgba(255,255,255,0.06); }
.nav-cta { margin-left: 10px; }

.nav-toggle {
  display: none; background: none; border: 1px solid var(--line-strong);
  border-radius: 9px; padding: 9px 11px; color: var(--text); cursor: pointer;
}
.nav-toggle span { display: block; width: 20px; height: 2px; background: currentColor; margin: 4px 0; border-radius: 2px; }

/* ---------- Hero ---------- */
.hero {
  min-height: 100svh; display: flex; align-items: center;
  padding: calc(var(--header-h) + 56px) 0 76px; overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0; z-index: -2;
  background: url("../img/products/HK-family.jpg") center/cover no-repeat;
  filter: saturate(0.85);
}
.hero-bg::after {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(900px 520px at 78% 42%, rgba(255, 122, 26, 0.2), transparent 65%),
    linear-gradient(100deg, rgba(8, 11, 17, 0.97) 8%, rgba(8, 11, 17, 0.82) 46%, rgba(8, 11, 17, 0.55) 100%),
    linear-gradient(to top, var(--bg) 2%, transparent 45%);
}
.hero-inner { display: grid; gap: 40px; }
.hero h1 { font-size: clamp(2.3rem, 5.6vw, 4.1rem); max-width: 15ch; }
.hero h1 em {
  font-style: normal;
  background: linear-gradient(100deg, var(--accent), #ffc08a);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-lede { color: #c3cede; font-size: clamp(1rem, 1.5vw, 1.18rem); max-width: 56ch; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 8px; }

.hero-stats {
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px; background: var(--line); border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden; margin-top: 14px;
  backdrop-filter: blur(6px);
}
.hero-stat { background: rgba(12, 17, 25, 0.72); padding: 20px 18px; }
.hero-stat b { display: block; font-size: clamp(1.3rem, 2.4vw, 1.85rem); color: var(--accent); letter-spacing: -0.02em; }
.hero-stat span { font-size: 0.82rem; color: var(--muted); }

/* ---------- Grid cards ---------- */
.grid { display: grid; gap: 22px; }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 28px; transition: 0.24s ease;
}
.card:hover { border-color: var(--line-strong); transform: translateY(-4px); background: var(--surface-2); }
.card-icon {
  width: 46px; height: 46px; border-radius: 12px; margin-bottom: 18px;
  display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent);
}
.card-icon.teal { background: var(--accent-2-soft); color: var(--accent-2); }
.card-icon svg { width: 23px; height: 23px; }
.card h3 { font-size: 1.14rem; margin-bottom: 9px; }
.card p { color: var(--muted); font-size: 0.94rem; }

/* ---------- Product cards ---------- */
.product-card {
  display: flex; flex-direction: column; overflow: hidden; padding: 0;
}
.product-media {
  position: relative; aspect-ratio: 4 / 3; overflow: hidden;
  background: linear-gradient(160deg, #1a2331, #0d131c);
}
.product-media img {
  width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s ease;
}
.product-card:hover .product-media img { transform: scale(1.055); }
.product-tag {
  position: absolute; top: 13px; left: 13px;
  padding: 5px 12px; border-radius: 999px; font-size: 0.7rem; font-weight: 700;
  letter-spacing: 0.08em; text-transform: uppercase;
  background: rgba(10, 14, 21, 0.82); color: var(--accent);
  border: 1px solid var(--line-strong); backdrop-filter: blur(6px);
}
.product-body { padding: 22px; display: flex; flex-direction: column; gap: 14px; flex: 1; }
.product-body h3 { font-size: 1.28rem; }
.product-body h3 span { color: var(--muted); font-weight: 550; font-size: 0.85rem; margin-left: 6px; }
.spec-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  padding: 6px 12px; border-radius: 7px; font-size: 0.8rem;
  background: rgba(255, 255, 255, 0.045); border: 1px solid var(--line); color: #cdd7e5;
}
.chip b { color: var(--text); font-weight: 650; }
.product-foot { margin-top: auto; display: flex; align-items: center; justify-content: space-between; padding-top: 6px; border-top: 1px solid var(--line); }
.link-arrow { color: var(--accent); font-size: 0.9rem; font-weight: 650; display: inline-flex; align-items: center; gap: 6px; }
.link-arrow:hover { gap: 10px; }

/* ---------- Filter tabs ---------- */
.filters { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin: 30px 0 40px; }
.filter-btn {
  padding: 10px 20px; border-radius: 999px; border: 1px solid var(--line-strong);
  background: transparent; color: var(--muted); font: inherit; font-size: 0.9rem;
  font-weight: 600; cursor: pointer; transition: 0.2s;
}
.filter-btn:hover { color: var(--text); border-color: var(--accent); }
.filter-btn.active { background: var(--accent); border-color: var(--accent); color: #1a0d00; }

/* ---------- Tables ---------- */
.table-wrap {
  overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--surface); -webkit-overflow-scrolling: touch;
}
table.spec { width: 100%; border-collapse: collapse; min-width: 720px; font-size: 0.9rem; }
table.spec th, table.spec td {
  padding: 13px 16px; text-align: left; border-bottom: 1px solid var(--line); white-space: nowrap;
}
table.spec thead th {
  background: var(--surface-2); color: var(--text); font-weight: 700;
  font-size: 0.86rem; letter-spacing: 0.02em; position: sticky; top: 0;
}
table.spec tbody th { font-weight: 600; color: var(--muted); white-space: normal; min-width: 150px; }
table.spec tbody tr:hover { background: rgba(255, 122, 26, 0.05); }
table.spec td { color: #d7dfee; font-variant-numeric: tabular-nums; }
table.spec td:first-child, table.spec thead th:first-child { color: var(--accent); font-weight: 700; }
.table-note { margin-top: 14px; font-size: 0.85rem; color: var(--muted); }

/* ---------- Product detail ---------- */
.detail { border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); overflow: hidden; scroll-margin-top: calc(var(--header-h) + 24px); }
.detail + .detail { margin-top: 28px; }
.detail-head {
  display: flex; align-items: center; gap: 18px; padding: 22px 26px;
  background: linear-gradient(90deg, var(--accent-soft), transparent 60%);
  cursor: pointer; user-select: none;
}
.detail.open .detail-head { border-bottom: 1px solid var(--line); }
.detail-head:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; }
.detail-head h3 { font-size: 1.3rem; }
.detail-head p { color: var(--muted); font-size: 0.88rem; margin-top: 3px; }
.detail-head .chev { margin-left: auto; color: var(--accent); transition: transform 0.25s; flex: none; }
.detail.open .chev { transform: rotate(180deg); }
.detail-body {
  /* 收起状态：整行图片 + 下方参数，通过 max-height 折叠 */
  display: grid; grid-template-columns: 1fr; gap: 0;
  padding: 0 26px; max-height: 0; opacity: 0; overflow: hidden; visibility: hidden;
  transition: max-height .35s ease, opacity .25s ease, padding .35s ease, visibility 0s .35s;
}
.detail.open .detail-body {
  max-height: 3000px; padding: 26px; gap: 26px; opacity: 1; visibility: visible;
  transition: max-height .45s ease, opacity .3s ease, padding .3s ease, visibility 0s;
}
.detail-media { display: flex; justify-content: center; }
.detail-media img { width: 100%; max-width: 760px; height: auto; border-radius: var(--radius-sm); border: 1px solid var(--line); }
.spec-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; background: var(--line); border-radius: var(--radius-sm); overflow: hidden; }
.spec-item { background: var(--surface-2); padding: 13px 16px; display: flex; justify-content: space-between; gap: 12px; }
.spec-item span { color: var(--muted); font-size: 0.87rem; }
.spec-item b { font-weight: 650; font-size: 0.92rem; text-align: right; font-variant-numeric: tabular-nums; }
.spec-item.wide { grid-column: 1 / -1; }
.spec-item.wide b { text-align: left; }

/* ---------- Steps / process ---------- */
.steps { counter-reset: step; display: grid; gap: 20px; }
.step { position: relative; padding: 26px 26px 26px 78px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); }
.step::before {
  counter-increment: step; content: counter(step, decimal-leading-zero);
  position: absolute; left: 26px; top: 26px; font-size: 1.5rem; font-weight: 800; color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.step h3 { font-size: 1.1rem; margin-bottom: 7px; }
.step p { color: var(--muted); font-size: 0.93rem; }

/* ---------- CTA band ---------- */
.cta-band {
  background: linear-gradient(120deg, rgba(255, 122, 26, 0.13), rgba(47, 212, 189, 0.08));
  border: 1px solid var(--line-strong); border-radius: calc(var(--radius) + 6px);
  padding: clamp(36px, 5vw, 62px); text-align: center;
}
.cta-band h2 { font-size: clamp(1.6rem, 3.2vw, 2.3rem); margin-bottom: 12px; }
.cta-band p { color: var(--muted); max-width: 52ch; margin: 0 auto 26px; }

/* ---------- Contact ---------- */
.contact-grid { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 40px; align-items: start; }
.contact-list { display: grid; gap: 14px; }
.contact-item {
  display: flex; gap: 16px; align-items: flex-start; padding: 20px;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  transition: 0.22s;
}
.contact-item:hover { border-color: var(--accent); }
.contact-item .card-icon { margin: 0; width: 42px; height: 42px; flex: none; }
.contact-item b { display: block; font-size: 0.98rem; }
.contact-item span { color: var(--muted); font-size: 0.9rem; word-break: break-word; }

.form-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: clamp(24px, 3.4vw, 38px); }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.field { display: flex; flex-direction: column; gap: 7px; }
.field.full { grid-column: 1 / -1; }
.field label { font-size: 0.86rem; font-weight: 600; color: #cdd7e5; }
.field input, .field select, .field textarea {
  background: var(--bg-alt); border: 1px solid var(--line-strong); color: var(--text);
  padding: 12px 14px; border-radius: var(--radius-sm); font: inherit; font-size: 0.95rem;
  transition: border-color 0.2s;
}
.field input:focus, .field select:focus, .field textarea:focus { outline: none; border-color: var(--accent); }
.field textarea { resize: vertical; min-height: 120px; }
.form-note { font-size: 0.82rem; color: var(--muted); margin-top: 12px; }
.hp { position: absolute; left: -9999px; opacity: 0; }

/* ---------- FAQ ---------- */
.faq { display: grid; gap: 12px; max-width: 820px; margin-inline: auto; }
details.faq-item { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 18px 22px; }
details.faq-item[open] { border-color: var(--accent); }
details.faq-item summary { cursor: pointer; font-weight: 650; list-style: none; display: flex; justify-content: space-between; gap: 14px; }
details.faq-item summary::-webkit-details-marker { display: none; }
details.faq-item summary::after { content: "+"; color: var(--accent); font-size: 1.3rem; line-height: 1; }
details.faq-item[open] summary::after { content: "−"; }
details.faq-item p { margin-top: 12px; color: var(--muted); font-size: 0.94rem; }

/* ---------- Footer ---------- */
.site-footer { background: #070a10; border-top: 1px solid var(--line); padding: 60px 0 28px; margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 36px; }
.footer-grid h4 { font-size: 0.86rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text); margin-bottom: 16px; }
.footer-grid p, .footer-grid li a { color: var(--muted); font-size: 0.92rem; }
.footer-grid li { margin-bottom: 9px; }
.footer-grid li a:hover { color: var(--accent); }
.footer-bottom {
  margin-top: 44px; padding-top: 22px; border-top: 1px solid var(--line);
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  color: var(--muted); font-size: 0.85rem;
}

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity 0.65s ease, transform 0.65s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 760px) {
  .nav-links {
    position: fixed; inset: var(--header-h) 0 auto 0; flex-direction: column;
    align-items: stretch; gap: 2px; padding: 14px 20px 22px;
    background: rgba(8, 11, 17, 0.98); border-bottom: 1px solid var(--line);
    backdrop-filter: blur(16px);
    transform: translateY(-140%); transition: transform 0.3s ease;
  }
  .nav-links.open { transform: none; }
  .nav-links a { padding: 13px 10px; font-size: 1rem; }
  .nav-cta { margin: 10px 0 0; }
  .nav-toggle { display: block; }
  .hero-stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .form-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 26px; }
  .spec-grid { grid-template-columns: 1fr; }
  section { padding: 58px 0; }
}

/* ---------- Language switcher ---------- */
.lang-switch { position: relative; margin-inline-start: auto; }
.lang-btn {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 7px 11px; border-radius: 999px; cursor: pointer;
  background: rgba(255,255,255,0.05); border: 1px solid var(--line);
  color: var(--text); font: inherit; font-size: .86rem; line-height: 1;
}
.lang-btn:hover { background: rgba(255,255,255,0.09); }
.lang-btn svg { width: 15px; height: 15px; color: var(--accent); }
.lang-btn i {
  width: 0; height: 0; border: 4px solid transparent;
  border-top-color: currentColor; margin-top: 3px; opacity: .7;
}
.lang-menu {
  position: absolute; top: calc(100% + 8px); inset-inline-end: 0; z-index: 60;
  min-width: 150px; list-style: none; margin: 0; padding: 6px;
  background: #0d1219; border: 1px solid var(--line); border-radius: var(--radius-sm);
  box-shadow: 0 18px 40px rgba(0,0,0,.5);
  opacity: 0; visibility: hidden; transform: translateY(-6px);
  transition: opacity .2s ease, transform .2s ease, visibility 0s .2s;
}
.lang-switch.open .lang-menu { opacity: 1; visibility: visible; transform: none; transition-delay: 0s; }
.lang-menu li a {
  display: block; padding: 8px 10px; border-radius: 6px;
  font-size: .88rem; color: var(--muted); text-decoration: none; line-height: 1.4;
}
.lang-menu li a:hover { background: rgba(255,255,255,0.07); color: var(--text); }
.lang-menu li a.current { color: var(--accent); }
.lang-footer { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 14px; }
.lang-footer a { font-size: .86rem; color: var(--muted); text-decoration: none; padding: 4px 9px; border: 1px solid var(--line); border-radius: 999px; }
.lang-footer a:hover { color: var(--text); border-color: var(--accent); }
.lang-footer a[aria-current] { color: var(--accent); border-color: var(--accent); }
@media (max-width: 760px) {
  .lang-btn span { display: none; }
  .lang-switch { margin-inline-start: 0; }
  .lang-menu { inset-inline-end: auto; inset-inline-start: 0; }
}

/* ---------- RTL (Persian / Urdu) ---------- */
[dir="rtl"] { text-align: right; }
[dir="rtl"] .brand { flex-direction: row; }
[dir="rtl"] .hero-stats { direction: rtl; }
[dir="rtl"] .chip,
[dir="rtl"] .spec-grid,
[dir="rtl"] .detail-body,
[dir="rtl"] table { direction: rtl; }
[dir="rtl"] table th, [dir="rtl"] table td { text-align: right; }
[dir="rtl"] .cta-band,
[dir="rtl"] .footer-grid { direction: rtl; }
[dir="rtl"] .lang-menu { text-align: right; }
[dir="rtl"] ol, [dir="rtl"] ul { padding-inline-start: 1.4rem; }
[dir="rtl"] .link-arrow,
[dir="rtl"] .btn { display: inline-flex; align-items: center; gap: 8px; }
/* numbers in spec tables stay LTR for readability */
[dir="rtl"] td.n, [dir="rtl"] th.n { direction: ltr; unicode-bidi: isolate; text-align: center; }