/* ============================================================
   HYNN Additive Manufacturing — 恒翼能增材制造官网
   Dark-tech corporate style, bilingual (zh/en)
   ============================================================ */

:root {
  --bg-0: #060b16;
  --bg-1: #0a1220;
  --bg-2: #0f1a2e;
  --bg-3: #16233c;
  --line: rgba(120, 160, 220, 0.14);
  --line-strong: rgba(120, 170, 230, 0.28);
  --txt-0: #f2f6fc;
  --txt-1: #c3cfe0;
  --txt-2: #8b99ad;
  --brand: #00a0e9;
  --brand-deep: #0077c8;
  --accent: #35e0ff;
  --accent-warm: #ff8a3d;
  --grad-brand: linear-gradient(120deg, #00a0e9 0%, #35e0ff 60%, #7cf5d8 100%);
  --radius: 14px;
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.45);
  --nav-h: 72px;
  --font: "Inter", "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg-0);
  color: var(--txt-1);
  line-height: 1.7;
  -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: min(1240px, 92vw); margin: 0 auto; }

/* ---------------- Nav ---------------- */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  height: var(--nav-h);
  display: flex; align-items: center;
  background: rgba(6, 11, 22, 0.55);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: background .3s, border-color .3s;
}
.nav.scrolled { background: rgba(6, 11, 22, 0.92); border-color: var(--line); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.brand img { height: 40px; width: auto; filter: brightness(1.05); }
.brand-sub {
  display: flex; flex-direction: column; line-height: 1.15;
  border-left: 1px solid var(--line-strong); padding-left: 12px;
}
.brand-sub b { color: var(--txt-0); font-size: 15px; letter-spacing: .5px; }
.brand-sub span { color: var(--accent); font-size: 10px; letter-spacing: 1.8px; text-transform: uppercase; }

.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-links a {
  padding: 8px 12px; border-radius: 8px; white-space: nowrap;
  color: var(--txt-1); font-size: 14px; font-weight: 500;
  transition: color .2s, background .2s;
}
.nav-links a:hover { color: var(--txt-0); background: rgba(53, 224, 255, 0.08); }
.nav-links a.active { color: var(--accent); }

.nav-right { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.lang-toggle {
  display: flex; border: 1px solid var(--line-strong); border-radius: 999px; overflow: hidden;
}
.lang-toggle button {
  background: transparent; border: 0; cursor: pointer;
  color: var(--txt-2); font-size: 12.5px; font-weight: 600;
  padding: 6px 14px; font-family: var(--font); letter-spacing: .5px;
  transition: all .2s;
}
.lang-toggle button.on { background: var(--grad-brand); color: #04202e; }
.btn-cta {
  padding: 9px 20px; border-radius: 999px; font-size: 14px; font-weight: 600;
  background: var(--grad-brand); color: #04202e; border: 0; cursor: pointer;
  transition: transform .2s, box-shadow .2s;
}
.btn-cta:hover { transform: translateY(-1px); box-shadow: 0 8px 24px rgba(0, 160, 233, .35); }

.nav-burger { display: none; background: none; border: 0; cursor: pointer; padding: 6px; }
.nav-burger span { display: block; width: 22px; height: 2px; background: var(--txt-0); margin: 5px 0; border-radius: 2px; }

/* ---------------- Hero ---------------- */
.hero {
  position: relative; min-height: 100vh;
  display: flex; align-items: center;
  padding: calc(var(--nav-h) + 60px) 0 90px;
  overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; }
.hero-bg img { width: 100%; height: 100%; object-fit: cover; opacity: .5; }
.hero-bg::after {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(1200px 600px at 75% 20%, rgba(0, 160, 233, .22), transparent 60%),
    linear-gradient(180deg, rgba(6,11,22,.72) 0%, rgba(6,11,22,.55) 45%, var(--bg-0) 100%);
}
.hero-grid { position: relative; z-index: 2; display: grid; grid-template-columns: 1.15fr .85fr; gap: 56px; align-items: center; }
.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 13px; letter-spacing: 3px; color: var(--accent);
  text-transform: uppercase; font-weight: 600; margin-bottom: 22px;
}
.hero-eyebrow::before { content: ""; width: 34px; height: 2px; background: var(--grad-brand); }
.hero h1 {
  color: var(--txt-0); font-size: clamp(34px, 4.6vw, 58px);
  line-height: 1.18; font-weight: 800; letter-spacing: .5px; margin-bottom: 10px;
}
.hero h1 .grad { background: var(--grad-brand); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-en { color: var(--txt-2); font-size: clamp(14px, 1.4vw, 18px); letter-spacing: 2px; text-transform: uppercase; margin-bottom: 26px; font-weight: 500; }
.hero p.lead { font-size: 17px; color: var(--txt-1); max-width: 620px; margin-bottom: 36px; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.btn-ghost {
  padding: 12px 28px; border-radius: 999px; font-size: 15px; font-weight: 600;
  border: 1px solid var(--line-strong); color: var(--txt-0); background: rgba(255,255,255,.03);
  transition: all .25s; cursor: pointer;
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-solid {
  padding: 12px 30px; border-radius: 999px; font-size: 15px; font-weight: 700;
  background: var(--grad-brand); color: #04202e; border: 0; cursor: pointer;
  transition: transform .2s, box-shadow .2s;
}
.btn-solid:hover { transform: translateY(-2px); box-shadow: 0 10px 30px rgba(0,160,233,.4); }

.hero-card {
  background: linear-gradient(160deg, rgba(22,35,60,.85), rgba(10,18,32,.9));
  border: 1px solid var(--line); border-radius: 20px; padding: 30px;
  backdrop-filter: blur(10px); box-shadow: var(--shadow);
}
.hero-card h3 { color: var(--txt-0); font-size: 17px; margin-bottom: 6px; }
.hero-card .sub { color: var(--txt-2); font-size: 12.5px; letter-spacing: 1.5px; text-transform: uppercase; margin-bottom: 20px; }
.hero-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 18px 22px; }
.hero-stats .st b { display: block; font-size: 30px; font-weight: 800; color: var(--accent); line-height: 1.2; }
.hero-stats .st b i { font-style: normal; font-size: 16px; }
.hero-stats .st span { font-size: 12.5px; color: var(--txt-2); }

/* ---------------- Sections ---------------- */
section { padding: 96px 0; position: relative; }
.sec-head { margin-bottom: 54px; }
.sec-eyebrow { color: var(--accent); font-size: 13px; letter-spacing: 3px; text-transform: uppercase; font-weight: 600; }
.sec-head h2 { color: var(--txt-0); font-size: clamp(26px, 3.2vw, 40px); font-weight: 800; margin: 10px 0 6px; }
.sec-head .en { color: var(--txt-2); font-size: 14px; letter-spacing: 2px; text-transform: uppercase; }
.sec-head p.desc { margin-top: 16px; max-width: 780px; color: var(--txt-1); font-size: 15.5px; }
.sec-alt { background: var(--bg-1); }

/* capability duo */
.duo { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.duo-card {
  position: relative; border-radius: 20px; overflow: hidden; min-height: 420px;
  border: 1px solid var(--line); display: flex; flex-direction: column; justify-content: flex-end;
  transition: transform .3s, border-color .3s;
}
.duo-card:hover { transform: translateY(-6px); border-color: var(--line-strong); }
.duo-card img.bg { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; transition: transform .6s; }
.duo-card:hover img.bg { transform: scale(1.05); }
.duo-card .veil { position: absolute; inset: 0; background: linear-gradient(180deg, rgba(6,11,22,.1) 0%, rgba(6,11,22,.55) 45%, rgba(6,11,22,.94) 100%); }
.duo-card .body { position: relative; padding: 34px; }
.duo-card .tag { display: inline-block; font-size: 12px; letter-spacing: 2px; color: #04202e; background: var(--grad-brand); padding: 4px 12px; border-radius: 999px; font-weight: 700; margin-bottom: 14px; }
.duo-card h3 { color: var(--txt-0); font-size: 24px; font-weight: 800; margin-bottom: 4px; }
.duo-card .en { color: var(--accent); font-size: 12.5px; letter-spacing: 2px; text-transform: uppercase; margin-bottom: 12px; }
.duo-card p { color: var(--txt-1); font-size: 14.5px; }
.duo-card ul { margin-top: 16px; display: grid; gap: 8px; }
.duo-card ul li { color: var(--txt-1); font-size: 14px; padding-left: 20px; position: relative; }
.duo-card ul li::before { content: ""; position: absolute; left: 0; top: 9px; width: 8px; height: 8px; border-radius: 2px; background: var(--grad-brand); transform: rotate(45deg); }

/* equipment */
.equip-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.equip-card {
  background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; transition: transform .25s, border-color .25s, box-shadow .25s;
}
.equip-card:hover { transform: translateY(-5px); border-color: rgba(53,224,255,.4); box-shadow: 0 14px 40px rgba(0,0,0,.4); }
.equip-card .ic {
  width: 46px; height: 46px; border-radius: 12px; display: grid; place-items: center;
  background: rgba(0,160,233,.12); border: 1px solid rgba(53,224,255,.25); margin-bottom: 18px;
  color: var(--accent); font-size: 20px; font-weight: 800;
}
.equip-card h4 { color: var(--txt-0); font-size: 17px; margin-bottom: 8px; }
.equip-card p { font-size: 13.8px; color: var(--txt-2); }

.equip-feature { display: grid; grid-template-columns: .9fr 1.1fr; gap: 40px; align-items: center; margin-top: 56px; }
.equip-feature .imgwrap { border-radius: 18px; overflow: hidden; border: 1px solid var(--line); box-shadow: var(--shadow); }
.equip-feature h3 { color: var(--txt-0); font-size: 26px; font-weight: 800; margin-bottom: 6px; }
.equip-feature .en { color: var(--txt-2); font-size: 13px; letter-spacing: 2px; text-transform: uppercase; margin-bottom: 18px; }
.spec-list { display: grid; gap: 12px; margin-top: 8px; }
.spec-list li { display: flex; gap: 12px; align-items: flex-start; font-size: 14.5px; color: var(--txt-1); }
.spec-list li .dot { flex: 0 0 8px; width: 8px; height: 8px; margin-top: 8px; border-radius: 50%; background: var(--grad-brand); }

.airflow { margin-top: 44px; background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 30px; }
.airflow h4 { color: var(--txt-0); font-size: 16px; margin-bottom: 4px; }
.airflow .note { color: var(--txt-2); font-size: 12.5px; margin-bottom: 22px; }
.bar-row { display: grid; grid-template-columns: 150px 1fr 64px; align-items: center; gap: 16px; margin-bottom: 14px; }
.bar-row .name { color: var(--txt-1); font-size: 13.5px; }
.bar-row .track { height: 10px; background: rgba(255,255,255,.06); border-radius: 999px; overflow: hidden; }
.bar-row .fill { height: 100%; border-radius: 999px; background: var(--grad-brand); width: 0; transition: width 1.2s cubic-bezier(.2,.7,.2,1); }
.bar-row.me .fill { background: linear-gradient(90deg, #35e0ff, #7cf5d8); }
.bar-row .val { color: var(--txt-0); font-weight: 700; font-size: 14px; text-align: right; }

/* materials */
.mat-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 44px; align-items: start; }
.mat-img { border-radius: 18px; overflow: hidden; border: 1px solid var(--line); box-shadow: var(--shadow); position: relative; }
.mat-img figcaption { position: absolute; left: 0; right: 0; bottom: 0; padding: 14px 20px; background: linear-gradient(0deg, rgba(6,11,22,.92), transparent); color: var(--txt-2); font-size: 12.5px; }
.mat-table { width: 100%; border-collapse: collapse; margin-top: 6px; font-size: 14px; }
.mat-table th, .mat-table td { padding: 13px 16px; text-align: left; border-bottom: 1px solid var(--line); }
.mat-table th { color: var(--accent); font-size: 12.5px; letter-spacing: 1.5px; text-transform: uppercase; font-weight: 700; }
.mat-table td { color: var(--txt-1); }
.mat-table td b { color: var(--txt-0); font-weight: 700; }
.mat-table tr:hover td { background: rgba(53,224,255,.04); }

.pow-line { margin-top: 48px; }
.pow-line h3 { color: var(--txt-0); font-size: 22px; font-weight: 800; margin-bottom: 6px; }
.pow-line .en { color: var(--txt-2); font-size: 12.5px; letter-spacing: 2px; text-transform: uppercase; margin-bottom: 30px; }
.steps { display: grid; grid-template-columns: repeat(6, 1fr); gap: 14px; }
.step { background: var(--bg-2); border: 1px solid var(--line); border-radius: 12px; padding: 20px 16px; position: relative; transition: border-color .25s, transform .25s; }
.step:hover { border-color: rgba(53,224,255,.4); transform: translateY(-4px); }
.step .no { font-size: 12px; color: var(--accent); font-weight: 800; letter-spacing: 1px; margin-bottom: 8px; }
.step h5 { color: var(--txt-0); font-size: 14.5px; margin-bottom: 6px; }
.step p { color: var(--txt-2); font-size: 12.3px; line-height: 1.6; }

.qc-chips { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.qc-chips span {
  font-size: 12.8px; color: var(--txt-1); padding: 7px 16px; border-radius: 999px;
  border: 1px solid var(--line-strong); background: rgba(53,224,255,.05);
}

/* solutions */
.sol-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.sol-card {
  background: linear-gradient(165deg, var(--bg-2), var(--bg-1));
  border: 1px solid var(--line); border-radius: var(--radius); padding: 26px;
  transition: transform .25s, border-color .25s;
}
.sol-card:hover { transform: translateY(-5px); border-color: rgba(53,224,255,.35); }
.sol-card .no { font-size: 30px; font-weight: 800; background: var(--grad-brand); -webkit-background-clip: text; background-clip: text; color: transparent; opacity: .85; }
.sol-card h4 { color: var(--txt-0); font-size: 16.5px; margin: 10px 0 8px; }
.sol-card p { color: var(--txt-2); font-size: 13.5px; }

/* applications */
.app-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 18px; }
.app-card {
  border-radius: var(--radius); border: 1px solid var(--line); overflow: hidden;
  background: var(--bg-2); transition: transform .25s, border-color .25s; position: relative;
}
.app-card:hover { transform: translateY(-5px); border-color: rgba(53,224,255,.4); }
.app-card .thumb { height: 130px; overflow: hidden; }
.app-card .thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.app-card:hover .thumb img { transform: scale(1.08); }
.app-card .body { padding: 18px; }
.app-card h4 { color: var(--txt-0); font-size: 15.5px; margin-bottom: 6px; }
.app-card p { color: var(--txt-2); font-size: 12.5px; line-height: 1.6; }

/* cases */
.case-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.case-card { background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; transition: transform .25s, border-color .25s, box-shadow .25s; }
.case-card:hover { transform: translateY(-6px); border-color: rgba(53,224,255,.4); box-shadow: 0 16px 44px rgba(0,0,0,.45); }
.case-card .thumb { height: 230px; overflow: hidden; background: #0c1526; display: grid; place-items: center; }
.case-card .thumb img { width: 100%; height: 100%; object-fit: cover; }
.case-card .thumb img.contain { object-fit: contain; padding: 14px; }
.case-card .body { padding: 22px; }
.case-card h4 { color: var(--txt-0); font-size: 16.5px; margin-bottom: 4px; }
.case-card .en { color: var(--txt-2); font-size: 12px; letter-spacing: 1px; text-transform: uppercase; margin-bottom: 12px; }
.case-card p { color: var(--txt-2); font-size: 13.3px; margin-bottom: 14px; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chips span { font-size: 11.8px; padding: 4px 12px; border-radius: 999px; background: rgba(0,160,233,.12); color: var(--accent); border: 1px solid rgba(53,224,255,.22); }

/* about */
.about-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: 48px; align-items: center; }
.about-grid .imgwrap { border-radius: 18px; overflow: hidden; border: 1px solid var(--line); box-shadow: var(--shadow); }
.about-grid h3 { color: var(--txt-0); font-size: 26px; font-weight: 800; margin-bottom: 16px; }
.about-grid p { color: var(--txt-1); font-size: 15px; margin-bottom: 14px; }
.about-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-top: 28px; }
.about-stats .st { background: var(--bg-2); border: 1px solid var(--line); border-radius: 12px; padding: 18px 14px; text-align: center; }
.about-stats .st b { display: block; color: var(--accent); font-size: 24px; font-weight: 800; }
.about-stats .st span { color: var(--txt-2); font-size: 12px; }
.cert-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.cert-row span { font-size: 12.5px; padding: 6px 14px; border-radius: 8px; border: 1px solid var(--line-strong); color: var(--txt-1); }

/* contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 44px; }
.closing-slogan {
  font-size: clamp(22px, 2.4vw, 30px); font-weight: 800; line-height: 1.3;
  margin-bottom: 14px; letter-spacing: .5px;
  background: var(--grad-brand); -webkit-background-clip: text; background-clip: text; color: transparent;
}
.contact-info h3 { color: var(--txt-0); font-size: 24px; font-weight: 800; margin-bottom: 18px; }
.contact-info .row { display: flex; gap: 14px; margin-bottom: 18px; align-items: flex-start; }
.contact-info .row .ic { flex: 0 0 40px; height: 40px; border-radius: 10px; display: grid; place-items: center; background: rgba(0,160,233,.12); border: 1px solid rgba(53,224,255,.25); color: var(--accent); font-size: 16px; }
.contact-info .row b { display: block; color: var(--txt-0); font-size: 14.5px; margin-bottom: 2px; }
.contact-info .row span { color: var(--txt-2); font-size: 13.5px; }
.form-card { background: var(--bg-2); border: 1px solid var(--line); border-radius: 18px; padding: 32px; }
.form-card h3 { color: var(--txt-0); font-size: 19px; margin-bottom: 20px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.form-card label { display: block; color: var(--txt-2); font-size: 12.5px; margin-bottom: 6px; letter-spacing: .5px; }
.form-card input, .form-card textarea, .form-card select {
  width: 100%; background: var(--bg-1); border: 1px solid var(--line); border-radius: 10px;
  color: var(--txt-0); padding: 11px 14px; font-size: 14px; font-family: var(--font);
  margin-bottom: 16px; outline: none; transition: border-color .2s;
}
.form-card input:focus, .form-card textarea:focus, .form-card select:focus { border-color: var(--accent); }
.form-card textarea { resize: vertical; min-height: 100px; }
.form-note { color: var(--txt-2); font-size: 12px; margin-top: 12px; }

/* footer */
footer { background: #04080f; border-top: 1px solid var(--line); padding: 54px 0 30px; }
.foot-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 36px; margin-bottom: 40px; }
.foot-grid h5 { color: var(--txt-0); font-size: 14px; margin-bottom: 16px; letter-spacing: 1px; }
.foot-grid a, .foot-grid p { display: block; color: var(--txt-2); font-size: 13.3px; margin-bottom: 10px; transition: color .2s; }
.foot-grid a:hover { color: var(--accent); }
.foot-brand img { height: 42px; margin-bottom: 16px; }
.foot-bottom { border-top: 1px solid var(--line); padding-top: 22px; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; color: var(--txt-2); font-size: 12.5px; }

/* reveal animation */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }

/* responsive */
@media (max-width: 1500px) {
  .brand-sub { display: none; }
  .nav-links a { padding: 8px 10px; font-size: 13.5px; }
}
@media (max-width: 1080px) {
  .nav-links {
    position: fixed; top: var(--nav-h); right: 0; left: 0;
    background: rgba(6,11,22,.98); flex-direction: column; align-items: stretch;
    padding: 12px 5vw 20px; gap: 2px; display: none; border-bottom: 1px solid var(--line);
    max-height: calc(100vh - var(--nav-h)); overflow-y: auto;
    backdrop-filter: blur(14px);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 13px 10px; font-size: 15px; border-radius: 10px; }
  .nav-burger { display: block; }
  .equip-grid, .sol-grid, .case-grid { grid-template-columns: repeat(2, 1fr); }
  .app-grid { grid-template-columns: repeat(3, 1fr); }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .hero-grid, .mat-wrap, .equip-feature, .about-grid, .contact-grid { grid-template-columns: 1fr; }
  .foot-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 760px) {
  .duo, .equip-grid, .sol-grid, .case-grid { grid-template-columns: 1fr; }
  .app-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .about-stats { grid-template-columns: repeat(2, 1fr); }
  .form-row { grid-template-columns: 1fr; }
  .bar-row { grid-template-columns: 110px 1fr 52px; }
  section { padding: 70px 0; }
  .btn-cta { display: none; }
}