/* ==========================================================================
   Detong Corporate Services — Design System
   Brand: Deep Navy #1E3A8A + Crimson #C0392B
   ========================================================================== */

:root {
  /* Brand */
  --navy: #1E3A8A;
  --navy-deep: #14265E;
  --navy-ink: #0E1B45;
  --navy-soft: #EEF2FB;
  --red: #C0392B;
  --red-soft: #FBEDEB;

  /* Neutrals */
  --ink: #1A2233;
  --muted: #5A6478;
  --muted-light: #8A93A6;
  --line: #E3E7EF;
  --surface: #F6F8FC;
  --white: #FFFFFF;

  /* Type */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-serif: "Songti SC", "Noto Serif SC", Georgia, serif;

  /* Rhythm */
  --container: 1180px;
  --gutter: 24px;
  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(20, 38, 94, 0.06);
  --shadow: 0 8px 30px rgba(20, 38, 94, 0.08);
  --shadow-lg: 0 18px 50px rgba(20, 38, 94, 0.13);

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------------------------- Reset -------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--ink);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
h1, h2, h3, h4 { margin: 0; line-height: 1.28; font-weight: 700; letter-spacing: -0.015em; }
p { margin: 0 0 1.05em; }
p:last-child { margin-bottom: 0; }
a { color: var(--navy); text-decoration: none; transition: color .2s var(--ease); }
a:hover { color: var(--red); }
img, svg { max-width: 100%; display: block; }
ul, ol { margin: 0; padding: 0; }
button { font: inherit; cursor: pointer; border: 0; background: none; }
input, select, textarea { font: inherit; color: inherit; }

/* ------------------------- Bilingual switch ------------------------------ */
/* English is hidden by default (site default = 简体中文) */
html[data-lang="zh"] .i18n-en { display: none !important; }
html[data-lang="en"] .i18n-zh { display: none !important; }

/* ---------------------------- Layout ------------------------------------- */
.container { max-width: var(--container); margin: 0 auto; padding: 0 var(--gutter); }
.section { padding: 92px 0; }
.section--tight { padding: 68px 0; }
.section--surface { background: var(--surface); }
.section--navy { background: var(--navy-deep); color: #E7ECF9; }
.section--navy h2, .section--navy h3 { color: #fff; }
.section-head { max-width: 760px; margin-bottom: 52px; }
.section-head--center { margin-left: auto; margin-right: auto; text-align: center; }
.eyebrow {
  display: inline-block;
  font-size: 12.5px; font-weight: 700; letter-spacing: .16em; text-transform: uppercase;
  color: var(--red); margin-bottom: 14px;
}
.section-head h2 { font-size: clamp(26px, 3vw, 36px); margin-bottom: 16px; }
.section-head p { color: var(--muted); font-size: 16.5px; margin: 0; }
.section--navy .section-head p { color: #ADB9D6; }
.lead { font-size: 18px; color: var(--muted); }

/* ---------------------------- Buttons ------------------------------------ */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  padding: 14px 28px; border-radius: var(--radius-sm);
  font-size: 15.5px; font-weight: 600; letter-spacing: .01em;
  transition: transform .18s var(--ease), box-shadow .22s var(--ease), background .22s var(--ease), color .2s var(--ease);
  white-space: nowrap;
}
.btn svg { width: 16px; height: 16px; }
.btn--primary { background: var(--red); color: #fff; box-shadow: 0 6px 18px rgba(192, 57, 43, .26); }
.btn--primary:hover { background: #A93124; color: #fff; transform: translateY(-2px); box-shadow: 0 12px 26px rgba(192, 57, 43, .32); }
.btn--ghost { background: rgba(255,255,255,.08); color: #fff; border: 1px solid rgba(255,255,255,.42); }
.btn--ghost:hover { background: rgba(255,255,255,.16); color: #fff; transform: translateY(-2px); }
.btn--outline { background: transparent; color: var(--navy); border: 1px solid var(--line); }
.btn--outline:hover { border-color: var(--navy); color: var(--navy); background: var(--navy-soft); }
.btn--block { width: 100%; }

/* ----------------------------- Header ------------------------------------ */
.site-header {
  position: sticky; top: 0; z-index: 60;
  background: rgba(255,255,255,.94);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: box-shadow .25s var(--ease), border-color .25s var(--ease);
}
.site-header.is-scrolled { box-shadow: 0 4px 24px rgba(20,38,94,.07); border-bottom-color: var(--line); }
.site-header__inner { display: flex; align-items: center; gap: 28px; height: 76px; }
.brand { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.brand__logo { width: 42px; height: 42px; flex-shrink: 0; }
.brand__text { display: flex; flex-direction: column; line-height: 1.15; }
.brand__name { font-size: 16px; font-weight: 700; color: var(--navy-ink); letter-spacing: .01em; }
.brand__sub { font-size: 10.5px; letter-spacing: .22em; color: var(--muted-light); text-transform: uppercase; }

.nav { margin-left: auto; display: flex; align-items: center; gap: 4px; }
.nav a {
  position: relative; padding: 9px 15px; border-radius: var(--radius-sm);
  font-size: 15px; font-weight: 500; color: var(--ink);
}
.nav a:hover { color: var(--navy); background: var(--navy-soft); }
.nav a.is-active { color: var(--navy); font-weight: 600; }
.nav a.is-active::after {
  content: ""; position: absolute; left: 15px; right: 15px; bottom: -1px; height: 2px; background: var(--red);
}

.lang-switch {
  display: inline-flex; align-items: center; margin-left: 10px;
  border: 1px solid var(--line); border-radius: 100px; padding: 3px; background: var(--surface);
}
.lang-switch button {
  padding: 5px 14px; border-radius: 100px; font-size: 13px; font-weight: 600; color: var(--muted);
  transition: all .2s var(--ease);
}
.lang-switch button.is-on { background: var(--navy); color: #fff; }
.lang-switch button:not(.is-on):hover { color: var(--navy); }

.nav-toggle { display: none; width: 42px; height: 42px; margin-left: auto; align-items: center; justify-content: center; border-radius: var(--radius-sm); }
.nav-toggle:hover { background: var(--surface); }
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after {
  display: block; width: 20px; height: 2px; background: var(--navy-ink); border-radius: 2px; position: relative; transition: .25s var(--ease);
}
.nav-toggle span::before, .nav-toggle span::after { content: ""; position: absolute; left: 0; }
.nav-toggle span::before { top: -6px; }
.nav-toggle span::after { top: 6px; }

/* ------------------------------ Hero ------------------------------------- */
.hero {
  position: relative; overflow: hidden;
  background:
    radial-gradient(1100px 520px at 82% -10%, rgba(94, 129, 224, .34), transparent 62%),
    linear-gradient(158deg, var(--navy-ink) 0%, var(--navy) 52%, #24449B 100%);
  color: #fff;
}
.hero__skyline {
  position: absolute; left: 0; right: 0; bottom: -1px; width: 100%; height: auto;
  opacity: .2; pointer-events: none;
}
.hero__inner { position: relative; z-index: 2; padding: 118px 0 108px; max-width: 860px; }
.hero__badge {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 7px 16px; border-radius: 100px; margin-bottom: 26px;
  background: rgba(255,255,255,.1); border: 1px solid rgba(255,255,255,.24);
  font-size: 13px; font-weight: 600; letter-spacing: .06em; color: #DCE4F7;
}
.hero__badge::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--red); box-shadow: 0 0 0 3px rgba(192,57,43,.3); }
.hero h1 {
  font-size: clamp(30px, 4.3vw, 50px); font-weight: 700; letter-spacing: -0.02em;
  margin-bottom: 24px; line-height: 1.24;
}
.hero h1 em { font-style: normal; color: #FFD9D3; border-bottom: 3px solid var(--red); padding-bottom: 2px; }
.hero__sub { font-size: 17.5px; line-height: 1.85; color: #C3CFEA; max-width: 720px; margin-bottom: 40px; }
.hero__actions { display: flex; flex-wrap: wrap; gap: 14px; }
.hero__stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px;
  margin-top: 76px; background: rgba(255,255,255,.14);
  border: 1px solid rgba(255,255,255,.14); border-radius: var(--radius);
  overflow: hidden;
}
.hero__stat { background: rgba(11, 22, 56, .34); padding: 22px 20px; }
.hero__stat b { display: block; font-size: 27px; font-weight: 700; color: #fff; letter-spacing: -0.01em; }
.hero__stat span { font-size: 13px; color: #A9B7D8; }

/* -------------------------- Advantage grid ------------------------------- */
.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 28px; transition: transform .25s var(--ease), box-shadow .25s var(--ease), border-color .25s var(--ease);
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #D3DAE9; }
.card__icon {
  width: 46px; height: 46px; border-radius: 12px; margin-bottom: 20px;
  display: flex; align-items: center; justify-content: center;
  background: var(--navy-soft); color: var(--navy);
}
.card__icon svg { width: 23px; height: 23px; }
.card h3 { font-size: 17.5px; margin-bottom: 10px; color: var(--navy-ink); }
.card p { font-size: 15px; color: var(--muted); margin: 0; line-height: 1.82; }

/* Service cards */
.svc-card { position: relative; overflow: hidden; }
.svc-card::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: var(--navy); transform: scaleX(0); transform-origin: left; transition: transform .3s var(--ease);
}
.svc-card:hover::before { transform: scaleX(1); background: var(--red); }
.svc-card__no { font-size: 12.5px; font-weight: 700; letter-spacing: .14em; color: var(--red); margin-bottom: 12px; }
.svc-card h3 { font-size: 17px; margin-bottom: 12px; }
.svc-card ul { margin-top: 16px; }
.svc-card li {
  position: relative; padding-left: 17px; font-size: 14.5px; color: var(--muted); margin-bottom: 7px; line-height: 1.7;
}
.svc-card li::before { content: ""; position: absolute; left: 0; top: 10px; width: 5px; height: 5px; border-radius: 50%; background: var(--red); }

/* --------------------------- Client wall --------------------------------- */
.clients { display: flex; flex-wrap: wrap; gap: 12px; }
.client-chip {
  padding: 13px 22px; border: 1px solid var(--line); border-radius: var(--radius-sm);
  background: #fff; font-size: 14.5px; font-weight: 500; color: #3C4763;
  transition: all .22s var(--ease);
}
.client-chip:hover { border-color: var(--navy); color: var(--navy); box-shadow: var(--shadow-sm); }
.clients__note { margin-top: 22px; font-size: 13.5px; color: var(--muted-light); }

/* ------------------------------ CTA band --------------------------------- */
.cta-band {
  background: linear-gradient(120deg, var(--navy-deep), var(--navy) 70%, #2A4CA8);
  border-radius: var(--radius-lg); padding: 56px 52px; color: #fff;
  display: flex; align-items: center; justify-content: space-between; gap: 40px; flex-wrap: wrap;
  box-shadow: var(--shadow-lg);
}
.cta-band h2 { font-size: clamp(22px, 2.6vw, 30px); margin-bottom: 12px; color: #fff; }
.cta-band p { color: #C3CFEA; margin: 0; max-width: 620px; }

/* ------------------------------ Page hero -------------------------------- */
.page-hero {
  background: linear-gradient(150deg, var(--navy-ink), var(--navy) 68%, #2A4CA8);
  color: #fff; padding: 84px 0 74px; position: relative; overflow: hidden;
}
.page-hero__crumb { font-size: 13px; color: #A9B7D8; margin-bottom: 18px; }
.page-hero__crumb a { color: #C3CFEA; }
.page-hero__crumb a:hover { color: #fff; }
.page-hero h1 { font-size: clamp(28px, 3.4vw, 40px); margin-bottom: 18px; }
.page-hero p { color: #C3CFEA; max-width: 760px; margin: 0; font-size: 16.5px; }

/* ------------------------------- Team ------------------------------------ */
.team-card { display: flex; gap: 22px; align-items: flex-start; }
.avatar {
  width: 62px; height: 62px; flex-shrink: 0; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(140deg, var(--navy), #2F57BD);
  color: #fff; font-size: 19px; font-weight: 700; letter-spacing: .02em;
}
.team-card__name { font-size: 17px; font-weight: 700; color: var(--navy-ink); margin-bottom: 3px; }
.team-card__role { font-size: 13.5px; font-weight: 600; color: var(--red); margin-bottom: 12px; }
.team-card__bio { font-size: 14.5px; color: var(--muted); margin: 0; line-height: 1.8; }

/* ------------------------------ Charts ----------------------------------- */
.chart-wrap { display: grid; grid-template-columns: 260px 1fr; gap: 46px; align-items: center; }
.donut { position: relative; width: 260px; height: 260px; margin: 0 auto; }
.donut svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.donut__ring {
  width: 100%; height: 100%; border-radius: 50%;
  -webkit-mask: radial-gradient(circle at center, transparent 56%, #000 57%);
  mask: radial-gradient(circle at center, transparent 56%, #000 57%);
  box-shadow: inset 0 0 0 1px rgba(20,38,94,.04);
}
.donut__center {
  position: absolute; inset: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: center; text-align: center;
}
.donut__center b { font-size: 30px; color: var(--navy-ink); line-height: 1; }
.donut__center span { font-size: 12.5px; color: var(--muted); margin-top: 6px; }
.legend { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px 26px; }
.legend li { display: flex; align-items: center; gap: 10px; font-size: 14.5px; color: #3C4763; list-style: none; }
.legend i { width: 11px; height: 11px; border-radius: 3px; flex-shrink: 0; }
.legend b { margin-left: auto; font-weight: 700; color: var(--navy-ink); }

/* ------------------------- Service detail list ---------------------------- */
.svc-block { border-top: 1px solid var(--line); padding: 52px 0; }
.svc-block:first-of-type { border-top: 0; padding-top: 0; }
.svc-block__head { display: flex; align-items: baseline; gap: 16px; margin-bottom: 28px; }
.svc-block__no {
  font-size: 13px; font-weight: 700; letter-spacing: .1em; color: var(--red);
  background: var(--red-soft); padding: 5px 12px; border-radius: 100px; flex-shrink: 0;
}
.svc-block h3 { font-size: 22px; color: var(--navy-ink); }
.svc-panel {
  background: #fff; border: 1px solid var(--line); border-left: 3px solid var(--navy);
  border-radius: 0 var(--radius) var(--radius) 0; padding: 26px 28px; margin-bottom: 18px;
  transition: border-color .22s var(--ease), box-shadow .22s var(--ease);
}
.svc-panel:hover { border-left-color: var(--red); box-shadow: var(--shadow-sm); }
.svc-panel h4 { font-size: 16.5px; color: var(--navy-ink); margin-bottom: 8px; }
.svc-panel > p { font-size: 15px; color: var(--muted); margin-bottom: 14px; }
.svc-panel ul { display: grid; gap: 9px; }
.svc-panel li { position: relative; padding-left: 20px; font-size: 14.8px; color: #43506B; line-height: 1.75; }
.svc-panel li::before {
  content: ""; position: absolute; left: 2px; top: 9px; width: 6px; height: 6px;
  border: 1.6px solid var(--red); border-radius: 50%;
}
.tag-list { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 16px; }
.tag {
  font-size: 13px; padding: 6px 13px; border-radius: 100px;
  background: var(--navy-soft); color: var(--navy); font-weight: 500;
}
.tag--custom { background: var(--red-soft); color: var(--red); }

/* ------------------------------ Contact ---------------------------------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1.25fr; gap: 56px; align-items: start; }
.info-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 24px; margin-bottom: 16px;
}
.info-card h3 { font-size: 15px; color: var(--navy-ink); margin-bottom: 10px; display: flex; align-items: center; gap: 9px; }
.info-card h3 svg { width: 17px; height: 17px; color: var(--red); }
.info-card p { font-size: 14.8px; color: var(--muted); margin: 0; line-height: 1.75; }
.info-card a { font-weight: 600; }

.form-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 38px 36px; box-shadow: var(--shadow);
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.field { margin-bottom: 18px; }
.field label { display: block; font-size: 14px; font-weight: 600; color: var(--navy-ink); margin-bottom: 7px; }
.field label .req { color: var(--red); margin-left: 3px; }
.field input, .field select, .field textarea {
  width: 100%; padding: 12px 14px; border: 1px solid var(--line); border-radius: var(--radius-sm);
  background: var(--white); font-size: 15px; transition: border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none; border-color: var(--navy); box-shadow: 0 0 0 3px rgba(30, 58, 138, .1);
}
.field textarea { resize: vertical; min-height: 108px; }
.field.has-error input, .field.has-error select { border-color: var(--red); }
.field__err { display: none; font-size: 13px; color: var(--red); margin-top: 6px; }
.field.has-error .field__err { display: block; }
.form-note { font-size: 13px; color: var(--muted-light); margin-top: 16px; line-height: 1.7; }
.form-success {
  display: none; padding: 16px 18px; border-radius: var(--radius-sm);
  background: var(--navy-soft); border-left: 3px solid var(--navy);
  font-size: 14.5px; color: var(--navy-deep); margin-bottom: 22px;
}
.form-success.is-on { display: block; }

/* ------------------------------ Footer ----------------------------------- */
.site-footer { background: var(--navy-ink); color: #A9B7D8; padding: 68px 0 0; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1.3fr; gap: 40px; padding-bottom: 52px; }
.site-footer .brand__name { color: #fff; }
.site-footer .brand__sub { color: #6C7A9E; }
.footer-about { font-size: 14px; line-height: 1.8; margin-top: 20px; color: #93A1C4; }
.footer-title { font-size: 14px; font-weight: 700; color: #fff; margin-bottom: 18px; letter-spacing: .02em; }
.footer-links li { list-style: none; margin-bottom: 11px; }
.footer-links a { font-size: 14px; color: #A9B7D8; }
.footer-links a:hover { color: #fff; }
.footer-addr { font-size: 14px; line-height: 1.8; margin-bottom: 14px; color: #93A1C4; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1); padding: 24px 0;
  display: flex; align-items: center; justify-content: space-between; gap: 18px; flex-wrap: wrap;
  font-size: 13.5px; color: #7C8AAD;
}
.footer-bottom a { color: #A9B7D8; }
.footer-bottom a:hover { color: #fff; }
.licence-note { font-size: 12.5px; color: #6C7A9E; margin-top: 16px; line-height: 1.7; }

/* ------------------------------ Legal ------------------------------------ */
.legal { max-width: 860px; }
.legal h2 { font-size: 21px; color: var(--navy-ink); margin: 42px 0 14px; }
.legal h2:first-of-type { margin-top: 0; }
.legal p, .legal li { font-size: 15.5px; color: #43506B; line-height: 1.85; }
.legal ul { margin: 0 0 1.05em; padding-left: 22px; }
.legal li { margin-bottom: 8px; }
.legal__meta { font-size: 14px; color: var(--muted-light); margin-bottom: 36px; }

/* --------------------------- Reveal animation ---------------------------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s var(--ease), transform .6s var(--ease); }
.reveal.is-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, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 34px; }
  .contact-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero__stats { grid-template-columns: repeat(2, 1fr); }
  .chart-wrap { grid-template-columns: 1fr; justify-items: center; }
}

@media (max-width: 768px) {
  body { font-size: 16px; }
  .section { padding: 64px 0; }
  .section--tight { padding: 48px 0; }
  .section-head { margin-bottom: 36px; }

  .nav-toggle { display: flex; }
  .nav {
    position: fixed; inset: 76px 0 auto 0; margin-left: 0;
    flex-direction: column; align-items: stretch; gap: 2px;
    background: #fff; border-bottom: 1px solid var(--line);
    padding: 14px 20px 22px; box-shadow: var(--shadow);
    transform: translateY(-12px); opacity: 0; pointer-events: none;
    transition: opacity .22s var(--ease), transform .22s var(--ease);
  }
  .nav.is-open { transform: none; opacity: 1; pointer-events: auto; }
  .nav a { padding: 13px 12px; font-size: 16px; }
  .nav a.is-active::after { display: none; }
  .nav a.is-active { background: var(--navy-soft); }
  .lang-switch { margin: 12px 0 0; align-self: flex-start; }

  .hero__inner { padding: 76px 0 68px; }
  .hero__actions .btn { width: 100%; }
  .hero__stats { margin-top: 52px; }
  .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
  .cta-band { padding: 38px 26px; flex-direction: column; align-items: flex-start; }
  .cta-band .btn { width: 100%; }
  .form-card { padding: 26px 20px; }
  .form-row { grid-template-columns: 1fr; gap: 0; }
  .legend { grid-template-columns: 1fr; }
  .donut { width: 220px; height: 220px; }
  .team-card { flex-direction: column; gap: 14px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 420px) {
  .hero__stat b { font-size: 23px; }
  .client-chip { font-size: 13.5px; padding: 11px 16px; }
}

/* --------------------------- Print --------------------------------------- */
@media print {
  .site-header, .nav-toggle, .lang-switch, .hero__actions, .cta-band .btn { display: none !important; }
  .hero, .page-hero, .site-footer, .section--navy { color: #000 !important; background: #fff !important; }
}