/* HMVIC — Precision Airflow */
@font-face {
  font-family: "Ubuntu";
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url("../fonts/ubuntu-400.woff2") format("woff2");
}
@font-face {
  font-family: "Ubuntu";
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url("../fonts/ubuntu-500.woff2") format("woff2");
}
@font-face {
  font-family: "Ubuntu";
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url("../fonts/ubuntu-700.woff2") format("woff2");
}

:root {
  --blue: #0047bb;
  --blue-deep: #003388;
  --green: #44d62c;
  --green-soft: rgba(68, 214, 44, 0.14);
  --ink: #0a1628;
  --ink-soft: #243247;
  --muted: #5a6b7d;
  --line: #d8e0ea;
  --paper: #f4f7fb;
  --white: #ffffff;
  --hero-a: #071422;
  --hero-b: #0d2748;
  --shadow: 0 18px 50px rgba(10, 22, 40, 0.08);
  --radius: 2px;
  --nav-h: 72px;
  --max: 1120px;
  --font: "Ubuntu", "Noto Sans SC", "Source Han Sans SC", "PingFang SC",
    "Microsoft YaHei", "Segoe UI", sans-serif;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --z-nav: 50;
  --z-overlay: 40;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 12px);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  cursor: pointer;
  border: 0;
  background: none;
  color: inherit;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -48px;
  z-index: 100;
  padding: 10px 14px;
  background: var(--blue);
  color: var(--white);
}
.skip-link:focus {
  top: 12px;
}

.container {
  width: min(100% - 40px, var(--max));
  margin-inline: auto;
}

/* —— Nav —— */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  height: var(--nav-h);
  z-index: var(--z-nav);
  display: flex;
  align-items: center;
  transition: background 0.3s var(--ease), box-shadow 0.3s var(--ease),
    backdrop-filter 0.3s var(--ease);
}

.site-header.is-solid {
  background: rgba(244, 247, 251, 0.92);
  backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 var(--line);
}

.site-header.is-solid .brand-text,
.site-header.is-solid .nav-links a,
.site-header.is-solid .lang-btn,
.site-header.is-solid .menu-toggle {
  color: var(--ink);
}

.nav-inner {
  width: min(100% - 40px, var(--max));
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-height: 44px;
}

.brand-mark {
  width: 36px;
  height: 42px;
  flex-shrink: 0;
  object-fit: contain;
}

.brand-text {
  font-weight: 700;
  letter-spacing: 0.18em;
  font-size: 0.95rem;
  color: var(--white);
  transition: color 0.25s var(--ease);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.88);
  font-size: 0.92rem;
  letter-spacing: 0.02em;
  position: relative;
  padding: 8px 0;
  transition: color 0.2s var(--ease);
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 2px;
  width: 100%;
  height: 2px;
  background: var(--green);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s var(--ease);
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--white);
}

.site-header.is-solid .nav-links a:hover,
.site-header.is-solid .nav-links a:focus-visible {
  color: var(--blue);
}

.nav-links a:hover::after,
.nav-links a:focus-visible::after {
  transform: scaleX(1);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.lang-switch {
  display: inline-flex;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: var(--radius);
  overflow: hidden;
}

.site-header.is-solid .lang-switch {
  border-color: var(--line);
}

.lang-btn {
  min-width: 40px;
  min-height: 36px;
  padding: 0 10px;
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}

.lang-btn.is-active {
  background: var(--green);
  color: var(--ink);
  font-weight: 700;
}

.site-header.is-solid .lang-btn {
  color: var(--muted);
}

.site-header.is-solid .lang-btn.is-active {
  color: var(--ink);
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  place-items: center;
  color: var(--white);
}

.menu-toggle span,
.menu-toggle span::before,
.menu-toggle span::after {
  display: block;
  width: 20px;
  height: 2px;
  background: currentColor;
  position: relative;
  transition: transform 0.25s var(--ease);
}

.menu-toggle span::before,
.menu-toggle span::after {
  content: "";
  position: absolute;
  left: 0;
}

.menu-toggle span::before {
  top: -6px;
}
.menu-toggle span::after {
  top: 6px;
}

.menu-toggle[aria-expanded="true"] span {
  background: transparent;
}
.menu-toggle[aria-expanded="true"] span::before {
  top: 0;
  transform: rotate(45deg);
}
.menu-toggle[aria-expanded="true"] span::after {
  top: 0;
  transform: rotate(-45deg);
}

/* —— Hero —— */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  display: grid;
  align-items: end;
  color: var(--white);
  overflow: hidden;
  background: linear-gradient(155deg, var(--hero-a) 0%, var(--hero-b) 48%, #123a6b 100%);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 50% at 78% 30%, rgba(0, 71, 187, 0.45), transparent 70%),
    radial-gradient(ellipse 50% 40% at 20% 80%, rgba(68, 214, 44, 0.12), transparent 65%);
  pointer-events: none;
}

.hero-flow {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.55;
}

.hero-flow svg {
  width: 100%;
  height: 100%;
}

.hero-inner {
  position: relative;
  z-index: 2;
  width: min(100% - 40px, var(--max));
  margin: 0 auto;
  padding: calc(var(--nav-h) + 48px) 0 72px;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: end;
}

.hero-brand {
  font-size: clamp(2.6rem, 6vw, 4.4rem);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.05;
  margin: 0 0 18px;
}

.hero-brand span {
  display: block;
  font-size: 0.34em;
  font-weight: 500;
  letter-spacing: 0.28em;
  color: rgba(255, 255, 255, 0.55);
  margin-top: 10px;
}

.hero h1 {
  margin: 0 0 18px;
  font-size: clamp(1.35rem, 2.5vw, 1.85rem);
  font-weight: 500;
  line-height: 1.4;
  max-width: 22ch;
  color: rgba(255, 255, 255, 0.95);
}

.hero-lead {
  margin: 0 0 32px;
  max-width: 42ch;
  color: rgba(255, 255, 255, 0.72);
  font-size: 1.02rem;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: var(--radius);
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: transform 0.2s var(--ease), background 0.2s var(--ease),
    color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.btn:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 3px;
}

.btn-primary {
  background: var(--green);
  color: var(--ink);
}

.btn-primary:hover {
  background: #57e63f;
  transform: translateY(-1px);
}

.btn-ghost {
  border: 1px solid rgba(255, 255, 255, 0.35);
  color: var(--white);
}

.btn-ghost:hover {
  border-color: var(--white);
  background: rgba(255, 255, 255, 0.06);
}

.btn-blue {
  background: var(--blue);
  color: var(--white);
}

.btn-blue:hover {
  background: var(--blue-deep);
  transform: translateY(-1px);
}

.hero-visual {
  justify-self: end;
  align-self: center;
  display: grid;
  place-items: center;
  width: min(100%, 340px);
  aspect-ratio: 1;
  position: relative;
}

.hero-visual::before {
  content: "";
  position: absolute;
  inset: 8%;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(68, 214, 44, 0.12), transparent 68%);
}

.hero-logo {
  position: relative;
  width: min(68%, 200px);
  height: auto;
  object-fit: contain;
  filter: drop-shadow(0 16px 40px rgba(0, 0, 0, 0.35));
}

.hero-wave {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  width: 100%;
  height: 72px;
  display: block;
  z-index: 3;
  color: var(--paper);
  pointer-events: none;
}

/* —— Sections —— */
.section {
  padding: 96px 0;
}

.section-head {
  max-width: 640px;
  margin-bottom: 48px;
}

.eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 12px;
}

.section-head h2 {
  margin: 0 0 14px;
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.section-head p,
.lead {
  margin: 0;
  color: var(--muted);
  font-size: 1.05rem;
  max-width: 60ch;
}

/* About */
.about-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 48px;
  align-items: start;
}

.about-body {
  color: var(--ink-soft);
  font-size: 1.05rem;
}

.stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.stat {
  background: var(--white);
  padding: 24px 20px;
  min-height: 110px;
}

.stat-value {
  display: block;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--blue);
  letter-spacing: -0.01em;
  margin-bottom: 6px;
}

.stat-label {
  color: var(--muted);
  font-size: 0.88rem;
}

/* Project */
.section-project {
  background: var(--white);
  position: relative;
}

.section-project::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--blue), var(--green));
}

.project-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: start;
}

.project-subtitle {
  margin: -28px 0 28px;
  color: var(--blue);
  font-weight: 600;
  font-size: 0.98rem;
}

.metrics {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  margin: 28px 0 0;
}

.metric {
  padding: 18px 0;
  border-top: 1px solid var(--line);
}

.metric-value {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.02em;
}

.metric-label {
  color: var(--muted);
  font-size: 0.86rem;
}

.feature-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.feature-list li {
  display: grid;
  grid-template-columns: 18px 1fr;
  gap: 12px;
  align-items: start;
  padding: 16px 18px;
  background: var(--paper);
  border-left: 3px solid var(--green);
  color: var(--ink-soft);
}

.feature-list li::before {
  content: "";
  width: 8px;
  height: 8px;
  margin-top: 7px;
  background: var(--blue);
  border-radius: 50%;
}

/* Value */
.value-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 56px;
}

.value-item {
  padding: 28px 24px 28px 0;
  border-top: 2px solid var(--ink);
}

.value-item h3 {
  margin: 0 0 12px;
  font-size: 1.15rem;
}

.value-item p {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
}

.pledges-title {
  margin: 0 0 20px;
  font-size: 1.1rem;
  letter-spacing: 0.04em;
}

.pledges {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.pledge {
  background: var(--white);
  padding: 24px 20px;
}

.pledge h4 {
  margin: 0 0 8px;
  color: var(--blue);
  font-size: 1rem;
}

.pledge p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

/* Mission band */
.mission {
  position: relative;
  padding: 88px 0;
  color: var(--white);
  background:
    linear-gradient(120deg, rgba(7, 20, 34, 0.92), rgba(0, 71, 187, 0.78)),
    var(--hero-b);
  overflow: hidden;
}

.mission::after {
  content: "";
  position: absolute;
  left: -10%;
  right: -10%;
  bottom: 28%;
  height: 2px;
  background: linear-gradient(
    90deg,
    transparent,
    var(--green) 20%,
    var(--green) 80%,
    transparent
  );
  opacity: 0.7;
  clip-path: polygon(0 100%, 45% 0, 55% 0, 100% 100%, 98% 100%, 55% 20%, 45% 20%, 2% 100%);
}

.mission-inner {
  position: relative;
  z-index: 1;
  max-width: 760px;
}

.mission blockquote {
  margin: 0 0 20px;
  font-size: clamp(1.6rem, 3.2vw, 2.4rem);
  line-height: 1.3;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.mission p {
  margin: 0;
  color: rgba(255, 255, 255, 0.78);
  font-size: 1.05rem;
  max-width: 58ch;
}

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: stretch;
}

.contact-panel {
  background: var(--white);
  border: 1px solid var(--line);
  padding: 36px 32px;
  box-shadow: var(--shadow);
}

.contact-panel h3 {
  margin: 0 0 8px;
  font-size: 1.15rem;
}

.contact-company {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 0.95rem;
}

.contact-row {
  margin: 0 0 18px;
}

.contact-row dt {
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--blue);
  font-weight: 700;
  margin-bottom: 6px;
}

.contact-row dd {
  margin: 0;
  color: var(--ink-soft);
}

.contact-tags {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
}

.contact-cta-box {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 36px 32px;
  background: var(--ink);
  color: var(--white);
  min-height: 280px;
}

.contact-cta-box p {
  margin: 0 0 24px;
  color: rgba(255, 255, 255, 0.72);
}

.contact-cta-box .btn {
  align-self: flex-start;
}

/* Footer */
.site-footer {
  padding: 28px 0 36px;
  border-top: 1px solid var(--line);
  background: var(--paper);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  color: var(--muted);
  font-size: 0.88rem;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 700;
  letter-spacing: 0.12em;
}

.footer-brand img {
  width: 28px;
  height: auto;
}

/* Reveal */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

.hero-copy > * {
  opacity: 0;
  transform: translateY(18px);
  animation: rise 0.8s var(--ease) forwards;
}

.hero-copy > *:nth-child(1) {
  animation-delay: 0.08s;
}
.hero-copy > *:nth-child(2) {
  animation-delay: 0.18s;
}
.hero-copy > *:nth-child(3) {
  animation-delay: 0.28s;
}
.hero-copy > *:nth-child(4) {
  animation-delay: 0.38s;
}
.hero-copy > *:nth-child(5) {
  animation-delay: 0.48s;
}

.hero-visual {
  opacity: 0;
  transform: translateY(18px) scale(0.96);
  animation: rise 0.9s var(--ease) 0.35s forwards;
}

@keyframes rise {
  to {
    opacity: 1;
    transform: none;
  }
}

/* —— Responsive —— */
@media (max-width: 960px) {
  .hero-inner,
  .about-grid,
  .project-layout,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .hero-visual {
    justify-self: start;
    width: min(240px, 60%);
    aspect-ratio: 1;
    order: -1;
  }

  .value-grid {
    grid-template-columns: 1fr;
  }

  .pledges {
    grid-template-columns: 1fr 1fr;
  }

  .hero h1 {
    max-width: none;
  }
}

@media (max-width: 768px) {
  :root {
    --nav-h: 64px;
  }

  .menu-toggle {
    display: grid;
  }

  .nav-links {
    position: fixed;
    inset: var(--nav-h) 0 auto;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 12px 20px 20px;
    background: rgba(244, 247, 251, 0.98);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow);
  }

  .nav-links.is-open {
    display: flex;
  }

  .nav-links a {
    color: var(--ink) !important;
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
    min-height: 44px;
  }

  .nav-links a::after {
    display: none;
  }

  .site-header {
    background: transparent;
  }

  .site-header.menu-open,
  .site-header.is-solid {
    background: rgba(244, 247, 251, 0.96);
    backdrop-filter: blur(12px);
  }

  .site-header.menu-open .brand-text,
  .site-header.menu-open .menu-toggle,
  .site-header.menu-open .lang-btn {
    color: var(--ink);
  }

  .site-header.menu-open .lang-switch {
    border-color: var(--line);
  }

  .section {
    padding: 72px 0;
  }

  .pledges {
    grid-template-columns: 1fr;
  }

  .hero-inner {
    padding-bottom: 56px;
  }
}

@media (max-width: 480px) {
  .container,
  .nav-inner,
  .hero-inner {
    width: min(100% - 28px, var(--max));
  }

  .stats,
  .metrics {
    grid-template-columns: 1fr;
  }

  .contact-panel,
  .contact-cta-box {
    padding: 28px 22px;
  }
}