/* -----------------------------------------------------------------------------
   Hong Kong Spirit Tech Limited — Index
   Tech-forward, modern, detail-rich aesthetic.
   ----------------------------------------------------------------------------- */

:root {
  --bg-deep: #060910;
  --bg-surface: #0a0e17;
  --bg-card: #0f1420;
  --bg-elevated: #141b28;
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-mid: rgba(255, 255, 255, 0.1);
  --text-primary: #f0f4f8;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-cyan: #22d3ee;
  --accent-blue: #0ea5e9;
  --accent-amber: #f59e0b;
  --accent-amber-dim: rgba(245, 158, 11, 0.15);
  --glow-cyan: rgba(34, 211, 238, 0.25);
  --glow-blue: rgba(14, 165, 233, 0.2);
  --font-display: "Syne", system-ui, sans-serif;
  --font-heading: "Outfit", system-ui, sans-serif;
  --font-body: "Inter", system-ui, sans-serif;
  --container-max: 1280px;
  --section-pad-x: clamp(1.5rem, 5vw, 4rem);
  --section-pad-y: clamp(3rem, 8vw, 6rem);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-deep);
  -webkit-font-smoothing: antialiased;
}

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

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

/* -----------------------------------------------------------------------------
   Layout: section inner — horizontal padding, no edge-to-edge content
   ----------------------------------------------------------------------------- */

.section-inner {
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--section-pad-x);
  padding-right: var(--section-pad-x);
  padding-top: var(--section-pad-y);
  padding-bottom: var(--section-pad-y);
}

/* -----------------------------------------------------------------------------
   Header
   ----------------------------------------------------------------------------- */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1rem 0;
  background: rgba(6, 9, 16, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
}

.header-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: var(--section-pad-x);
  padding-right: var(--section-pad-x);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.35rem;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  font-family: var(--font-heading);
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: color 0.2s ease;
}

.nav-link:hover,
.nav-link.is-active {
  color: var(--accent-cyan);
}

.btn-cta-header {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.9rem;
  padding: 0.5rem 1.25rem;
  border-radius: 6px;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  color: var(--bg-deep);
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.btn-cta-header:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

/* -----------------------------------------------------------------------------
   Buttons
   ----------------------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  transition: opacity 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  color: var(--bg-deep);
  border: none;
}

.btn-primary:hover {
  box-shadow: 0 8px 24px var(--glow-cyan);
}

.btn-secondary {
  background: transparent;
  color: var(--accent-cyan);
  border: 1px solid var(--accent-cyan);
}

.btn-secondary:hover {
  background: rgba(34, 211, 238, 0.08);
  box-shadow: 0 0 20px var(--glow-cyan);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1rem;
}

/* -----------------------------------------------------------------------------
   Hero
   ----------------------------------------------------------------------------- */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 50% at 50% 0%, rgba(14, 165, 233, 0.08) 0%, transparent 50%),
              radial-gradient(ellipse 60% 40% at 80% 60%, rgba(34, 211, 238, 0.06) 0%, transparent 50%),
              var(--bg-deep);
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, black 20%, transparent 70%);
}

.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.4;
  pointer-events: none;
}

.hero-glow-1 {
  width: 400px;
  height: 400px;
  background: var(--accent-blue);
  top: -10%;
  left: 10%;
}

.hero-glow-2 {
  width: 300px;
  height: 300px;
  background: var(--accent-cyan);
  top: 40%;
  right: 5%;
}

.hero-glow-3 {
  width: 200px;
  height: 200px;
  background: var(--accent-amber);
  bottom: 10%;
  left: 20%;
  opacity: 0.2;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 8rem var(--section-pad-x) 4rem;
  text-align: center;
}

.hero-tag {
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent-cyan);
  margin-bottom: 1rem;
}

.hero-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin: 0 0 1.25rem;
  max-width: 18ch;
  margin-left: auto;
  margin-right: auto;
}

.hero-title .highlight {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-amber));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 42ch;
  margin: 0 auto 2rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
}

.hero-scroll {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.hero-scroll-label {
  font-family: var(--font-heading);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.hero-scroll-line {
  width: 1px;
  height: 48px;
  background: linear-gradient(to bottom, var(--accent-cyan), transparent);
  border-radius: 2px;
  animation: scroll-pulse 2s ease-in-out infinite;
}

@keyframes scroll-pulse {
  0%, 100% { opacity: 0.5; }
  50% { opacity: 1; }
}

/* -----------------------------------------------------------------------------
   Section pattern: tag, title, description
   ----------------------------------------------------------------------------- */

.section-tag {
  font-family: var(--font-heading);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent-cyan);
  margin-bottom: 0.75rem;
}

.section-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 4vw, 3rem);
  letter-spacing: -0.02em;
  margin: 0 0 1rem;
  color: var(--text-primary);
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 50ch;
  margin: 0 0 2.5rem;
}

/* -----------------------------------------------------------------------------
   Core Business
   ----------------------------------------------------------------------------- */

.core-business {
  background: var(--bg-surface);
}

.business-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.business-card {
  position: relative;
  padding: 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  transition: border-color 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
  overflow: hidden;
}

.business-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-blue));
  opacity: 0;
  transition: opacity 0.25s ease;
}

.business-card:hover {
  border-color: var(--border-mid);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3), 0 0 30px var(--glow-cyan);
  transform: translateY(-4px);
}

.business-card:hover::before {
  opacity: 1;
}

.business-card-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 1.25rem;
  color: var(--accent-cyan);
}

.business-card-icon svg {
  width: 100%;
  height: 100%;
}

.business-card-title {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.2rem;
  margin: 0 0 0.75rem;
  color: var(--text-primary);
}

.business-card-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin: 0 0 1.25rem;
  line-height: 1.55;
}

.business-card-link {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--accent-cyan);
  transition: color 0.2s ease, transform 0.2s ease;
}

.business-card-link:hover {
  color: var(--accent-amber);
  transform: translateX(4px);
}

/* -----------------------------------------------------------------------------
   Advantages
   ----------------------------------------------------------------------------- */

.advantages {
  background: var(--bg-deep);
}

.advantages-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 2rem;
}

.advantage-item {
  padding: 2rem 0;
  border-bottom: 1px solid var(--border-subtle);
  transition: border-color 0.25s ease;
}

.advantage-item:last-child {
  border-bottom: none;
}

.advantage-item:hover {
  border-color: var(--border-mid);
}

.advantage-num {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 2.5rem;
  line-height: 1;
  color: var(--accent-cyan);
  opacity: 0.4;
  margin-bottom: 1rem;
}

.advantage-title {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.15rem;
  margin: 0 0 0.75rem;
  color: var(--text-primary);
}

.advantage-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.6;
}

/* -----------------------------------------------------------------------------
   Cases
   ----------------------------------------------------------------------------- */

.cases {
  background: var(--bg-surface);
}

.cases-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.case-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  overflow: hidden;
  transition: border-color 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
}

.case-card:hover {
  border-color: var(--border-mid);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.35);
  transform: translateY(-4px);
}

.case-card-visual {
  height: 200px;
  background: linear-gradient(135deg, var(--bg-elevated) 0%, var(--bg-card) 100%);
  position: relative;
  overflow: hidden;
}

.case-card-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, transparent 0%, rgba(34, 211, 238, 0.05) 50%, transparent 100%),
    repeating-linear-gradient(
      0deg,
      transparent,
      transparent 2px,
      rgba(255, 255, 255, 0.02) 2px,
      rgba(255, 255, 255, 0.02) 4px
    );
}

.case-card-visual-1 { background: linear-gradient(135deg, #0c1929 0%, #0f1629 50%, #0a0e17 100%); }
.case-card-visual-2 { background: linear-gradient(135deg, #0f1a28 0%, #0a1420 50%, #060910 100%); }
.case-card-visual-3 { background: linear-gradient(135deg, #0a1620 0%, #0c1929 50%, #0a0e17 100%); }

.case-card-content {
  padding: 1.75rem 2rem;
}

.case-card-cat {
  font-family: var(--font-heading);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent-cyan);
  margin-bottom: 0.75rem;
  display: inline-block;
}

.case-card-title {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.2rem;
  margin: 0 0 0.5rem;
  color: var(--text-primary);
}

.case-card-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.55;
}

/* -----------------------------------------------------------------------------
   Partners
   ----------------------------------------------------------------------------- */

.partners {
  background: var(--bg-deep);
}

.partners-strip {
  overflow: hidden;
  padding: 2rem 0;
}

.partners-row {
  display: flex;
  gap: 3rem;
  animation: partners-scroll 25s linear infinite;
  width: max-content;
}

.partner-logo {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--text-muted);
  white-space: nowrap;
  padding: 0.75rem 1.5rem;
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  flex-shrink: 0;
}

@keyframes partners-scroll {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* -----------------------------------------------------------------------------
   News
   ----------------------------------------------------------------------------- */

.news {
  background: var(--bg-surface);
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.news-card {
  padding: 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  transition: border-color 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
}

.news-card:hover {
  border-color: var(--border-mid);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.25);
  transform: translateY(-2px);
}

.news-date {
  font-family: var(--font-heading);
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
  display: block;
}

.news-title {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.1rem;
  margin: 0 0 0.75rem;
  color: var(--text-primary);
  line-height: 1.35;
}

.news-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin: 0 0 1rem;
  line-height: 1.55;
}

.news-link {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--accent-cyan);
  transition: color 0.2s ease, transform 0.2s ease;
}

.news-link:hover {
  color: var(--accent-amber);
  transform: translateX(4px);
}

/* -----------------------------------------------------------------------------
   CTA
   ----------------------------------------------------------------------------- */

.cta {
  position: relative;
  overflow: hidden;
}

.cta-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 60% at 50% 50%, rgba(14, 165, 233, 0.12) 0%, transparent 60%),
              var(--bg-deep);
}

.cta-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 48px 48px;
}

.cta-glow {
  position: absolute;
  bottom: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 500px;
  height: 300px;
  background: var(--accent-blue);
  filter: blur(100px);
  opacity: 0.15;
}

.cta-inner {
  position: relative;
  z-index: 1;
  text-align: center;
}

.cta-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 4vw, 3rem);
  letter-spacing: -0.02em;
  margin: 0 0 1rem;
  color: var(--text-primary);
}

.cta-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 44ch;
  margin: 0 auto 2rem;
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
}

/* -----------------------------------------------------------------------------
   Footer
   ----------------------------------------------------------------------------- */

.site-footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border-subtle);
}

.footer-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 3rem var(--section-pad-x) 2rem;
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-subtle);
}

.footer-logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--text-primary);
}

.footer-nav {
  display: flex;
  gap: 2rem;
}

.footer-nav a {
  font-family: var(--font-heading);
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: color 0.2s ease;
}

.footer-nav a:hover {
  color: var(--accent-cyan);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  justify-content: space-between;
}

.footer-address,
.footer-email,
.footer-copy {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 0;
}

.footer-email a {
  color: var(--accent-cyan);
  transition: color 0.2s ease;
}

.footer-email a:hover {
  color: var(--accent-amber);
}

/* -----------------------------------------------------------------------------
   Responsive
   ----------------------------------------------------------------------------- */

@media (max-width: 768px) {
  .nav {
    display: none;
  }

  .hero-inner {
    padding-top: 6rem;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }

  .cta-actions {
    flex-direction: column;
  }

  .footer-top {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 480px) {
  .business-grid,
  .cases-grid {
    grid-template-columns: 1fr;
  }

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

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