/* ============ Design Tokens ============ */
  :root {
    --color-primary: #4f46e5;
    --color-primary-hover: #4338ca;
    --color-primary-subtle: rgba(79, 70, 229, 0.08);
    --color-accent: #06b6d4;

    --gray-50:  #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-700: #334155;
    --gray-900: #0f172a;

    --surface-base: #ffffff;
    --surface-raised: #f8fafc;
    --surface-dark: #0f172a;

    --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC",
                 "Microsoft YaHei", "Segoe UI", Roboto, "Helvetica Neue",
                 Arial, sans-serif;

    --text-xs:   0.75rem;
    --text-sm:   0.875rem;
    --text-base: 1rem;
    --text-lg:   1.25rem;
    --text-xl:   1.5rem;
    --text-2xl:  2rem;
    --text-3xl:  2.5rem;
    --text-4xl:  3.5rem;

    --space-1: 0.25rem; --space-2: 0.5rem;  --space-3: 0.75rem;
    --space-4: 1rem;    --space-6: 1.5rem;  --space-8: 2rem;
    --space-10: 2.5rem; --space-12: 3rem;   --space-16: 4rem;
    --space-20: 5rem;   --space-24: 6rem;   --space-32: 8rem;

    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-full: 9999px;

    --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
    --shadow-md: 0 4px 16px rgba(15, 23, 42, 0.06);
    --shadow-lg: 0 16px 40px rgba(15, 23, 42, 0.08);

    --duration: 200ms;
    --ease: cubic-bezier(0.4, 0, 0.2, 1);

    --container-max: 1200px;
  }

  /* ============ Reset ============ */
  *, *::before, *::after { box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  body {
    margin: 0;
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--gray-900);
    background: var(--surface-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }
  h1, h2, h3, h4 { margin: 0; line-height: 1.2; font-weight: 600; letter-spacing: -0.01em; }
  p { margin: 0; }
  ul { margin: 0; padding: 0; list-style: none; }
  a { color: inherit; text-decoration: none; transition: color var(--duration) var(--ease); }
  button { font-family: inherit; cursor: pointer; border: none; background: none; }
  img, svg { display: block; max-width: 100%; }

  /* ============ Focus (a11y) ============ */
  :focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 3px;
    border-radius: var(--radius-sm);
  }

  /* ============ Layout primitives ============ */
  .container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-6);
  }
  section { padding: var(--space-24) 0; }
  .section-head { text-align: center; max-width: 720px; margin: 0 auto var(--space-16); }
  .section-eyebrow {
    display: inline-block;
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-primary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: var(--space-3);
  }
  .section-title { font-size: var(--text-3xl); margin-bottom: var(--space-4); }
  .section-subtitle { font-size: var(--text-lg); color: var(--gray-500); }

  /* ============ Buttons ============ */
  .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    font-size: var(--text-base);
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: all var(--duration) var(--ease);
    min-height: 44px;
    white-space: nowrap;
  }
  .btn-primary { background: var(--color-primary); color: #fff; }
  .btn-primary:hover { background: var(--color-primary-hover); transform: translateY(-1px); box-shadow: var(--shadow-md); }
  .btn-ghost { color: var(--gray-900); border: 1px solid var(--gray-200); background: #fff; }
  .btn-ghost:hover { border-color: var(--color-primary); color: var(--color-primary); }

  /* ============ Header ============ */
  .site-header {
    position: sticky; top: 0; z-index: 50;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: saturate(180%) blur(16px);
    -webkit-backdrop-filter: saturate(180%) blur(16px);
    border-bottom: 1px solid var(--gray-100);
  }
  .header-inner {
    display: flex; align-items: center; justify-content: space-between;
    height: 64px;
  }
  .brand {
    display: flex; align-items: center; gap: var(--space-2);
    font-size: var(--text-lg); font-weight: 600; color: var(--gray-900);
  }
  .brand-mark {
    width: 28px; height: 28px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    border-radius: var(--radius-md);
  }
  .nav-list {
    display: none;
    gap: var(--space-8);
    align-items: center;
  }
  .nav-list a { color: var(--gray-700); font-size: var(--text-sm); font-weight: 500; }
  .nav-list a:hover { color: var(--color-primary); }
  .header-actions { display: flex; align-items: center; gap: var(--space-3); }
  .nav-toggle {
    display: inline-flex; align-items: center; justify-content: center;
    width: 40px; height: 40px;
    color: var(--gray-700);
  }
  .nav-toggle:hover { color: var(--color-primary); }

  @media (min-width: 768px) {
    .nav-list { display: flex; }
    .nav-toggle { display: none; }
  }

  /* Mobile menu */
  .mobile-nav {
    display: none;
    padding: var(--space-4) 0 var(--space-6);
    border-top: 1px solid var(--gray-100);
  }
  .mobile-nav.is-open { display: block; }
  .mobile-nav ul { display: flex; flex-direction: column; gap: var(--space-2); }
  .mobile-nav a {
    display: block;
    padding: var(--space-3);
    color: var(--gray-700);
    font-size: var(--text-base);
    border-radius: var(--radius-sm);
  }
  .mobile-nav a:hover { background: var(--gray-100); color: var(--color-primary); }
  @media (min-width: 768px) { .mobile-nav { display: none !important; } }

  /* ============ Hero ============ */
  .hero {
    position: relative;
    padding: var(--space-32) 0 var(--space-24);
    overflow: hidden;
    background:
      radial-gradient(ellipse 60% 50% at 50% 0%, rgba(79, 70, 229, 0.12), transparent 70%),
      linear-gradient(180deg, #fafbff 0%, #ffffff 100%);
  }
  .hero::before {
    content: '';
    position: absolute; inset: 0;
    background-image:
      linear-gradient(rgba(79, 70, 229, 0.04) 1px, transparent 1px),
      linear-gradient(90deg, rgba(79, 70, 229, 0.04) 1px, transparent 1px);
    background-size: 48px 48px;
    mask-image: radial-gradient(ellipse 60% 60% at 50% 40%, #000 30%, transparent 80%);
    -webkit-mask-image: radial-gradient(ellipse 60% 60% at 50% 40%, #000 30%, transparent 80%);
    pointer-events: none;
  }
  .hero-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(65px);
    opacity: 0.5;
    pointer-events: none;
    will-change: transform;
  }
  .hero-orb-1 {
    width: 470px; height: 470px;
    top: -140px; left: -100px;
    background: radial-gradient(circle, rgba(79, 70, 229, 0.55), transparent 70%);
    animation: heroOrbDrift1 28s ease-in-out infinite;
  }
  .hero-orb-2 {
    width: 410px; height: 410px;
    bottom: -120px; right: -80px;
    background: radial-gradient(circle, rgba(6, 182, 212, 0.5), transparent 70%);
    animation: heroOrbDrift2 34s ease-in-out infinite;
  }
  @keyframes heroOrbDrift1 {
    0%, 100% { transform: translate(0, 0) scale(1); }
    50%      { transform: translate(95px, 60px) scale(1.15); }
  }
  @keyframes heroOrbDrift2 {
    0%, 100% { transform: translate(0, 0) scale(1); }
    50%      { transform: translate(-80px, -55px) scale(1.12); }
  }
  .hero-canvas {
    position: absolute; inset: 0;
    width: 100%; height: 100%;
    pointer-events: none;
    opacity: 0.65;
    mix-blend-mode: multiply;
  }
  .hero-inner {
    position: relative;
    text-align: center;
    max-width: 820px; margin: 0 auto;
  }
  .hero-eyebrow {
    display: inline-flex; align-items: center; gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: var(--color-primary-subtle);
    color: var(--color-primary);
    border-radius: var(--radius-full);
    font-size: var(--text-sm); font-weight: 500;
    margin-bottom: var(--space-6);
  }
  .hero-eyebrow::before {
    content: '';
    width: 6px; height: 6px;
    background: var(--color-primary);
    border-radius: var(--radius-full);
  }
  .hero-title {
    font-size: clamp(var(--text-3xl), 6vw, var(--text-4xl));
    margin-bottom: var(--space-6);
    letter-spacing: -0.02em;
  }
  .hero-title .accent {
    background: linear-gradient(120deg, var(--color-primary), var(--color-accent));
    -webkit-background-clip: text; background-clip: text;
    -webkit-text-fill-color: transparent; color: transparent;
  }
  .hero-subtitle {
    font-size: var(--text-lg);
    color: var(--gray-500);
    margin-bottom: var(--space-10);
    max-width: 620px; margin-left: auto; margin-right: auto;
  }
  .hero-cta { display: flex; flex-wrap: wrap; gap: var(--space-3); justify-content: center; }

  /* ============ Capability Overview (2-col) ============ */
  .capabilities {
    background: var(--surface-raised);
  }
  .cap-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
  @media (min-width: 768px) {
    .cap-grid { grid-template-columns: 1fr 1fr; gap: var(--space-8); }
  }
  .cap-card {
    background: #fff;
    padding: var(--space-10);
    border-radius: var(--radius-lg);
    border: 1px solid var(--gray-100);
    transition: all var(--duration) var(--ease);
  }
  .cap-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-2px); border-color: var(--gray-200); }
  .cap-tag {
    display: inline-block;
    padding: var(--space-1) var(--space-3);
    background: var(--color-primary-subtle);
    color: var(--color-primary);
    font-size: var(--text-xs); font-weight: 600;
    border-radius: var(--radius-full);
    letter-spacing: 0.05em;
    margin-bottom: var(--space-4);
  }
  .cap-card h3 { font-size: var(--text-2xl); margin-bottom: var(--space-3); }
  .cap-card p { color: var(--gray-500); }

  /* ============ Service Grid (4-card) ============ */
  .svc-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
  @media (min-width: 640px) {
    .svc-grid { grid-template-columns: repeat(2, 1fr); }
  }
  @media (min-width: 1024px) {
    .svc-grid { grid-template-columns: repeat(4, 1fr); }
  }
  .svc-card {
    padding: var(--space-8);
    background: #fff;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    transition: all var(--duration) var(--ease);
  }
  .svc-card:hover { border-color: var(--color-primary); transform: translateY(-2px); box-shadow: var(--shadow-md); }
  .svc-icon {
    width: 44px; height: 44px;
    display: flex; align-items: center; justify-content: center;
    background: var(--color-primary-subtle);
    color: var(--color-primary);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-4);
  }
  .svc-card h3 { font-size: var(--text-lg); margin-bottom: var(--space-2); }
  .svc-card p { color: var(--gray-500); font-size: var(--text-sm); }

  /* IT section variant: dark accent */
  .it-services { background: var(--gray-900); color: #fff; }
  .it-services .section-eyebrow { color: var(--color-accent); }
  .it-services .section-subtitle { color: var(--gray-400); }
  .it-services .svc-card {
    background: rgba(255, 255, 255, 0.03);
    border-color: rgba(255, 255, 255, 0.08);
  }
  .it-services .svc-card:hover { border-color: var(--color-accent); background: rgba(255, 255, 255, 0.05); }
  .it-services .svc-icon {
    background: rgba(6, 182, 212, 0.12);
    color: var(--color-accent);
  }
  .it-services .svc-card p { color: var(--gray-400); }

  /* ============ Process ============ */
  .process { background: var(--surface-raised); }
  .process-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-6);
    counter-reset: step;
  }
  @media (min-width: 768px) {
    .process-grid { grid-template-columns: repeat(4, 1fr); }
  }
  .step {
    position: relative;
    padding: var(--space-8);
    background: #fff;
    border-radius: var(--radius-lg);
    border: 1px solid var(--gray-100);
    counter-increment: step;
  }
  .step::before {
    content: counter(step, decimal-leading-zero);
    display: block;
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--space-4);
    letter-spacing: -0.02em;
  }
  .step h3 { font-size: var(--text-lg); margin-bottom: var(--space-2); }
  .step p { color: var(--gray-500); font-size: var(--text-sm); }

  /* ============ About ============ */
  .about-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-12);
    align-items: center;
  }
  @media (min-width: 1024px) {
    .about-grid { grid-template-columns: 1fr 1fr; gap: var(--space-20); }
  }
  .about-text h2 { font-size: var(--text-3xl); margin-bottom: var(--space-6); }
  .about-text p { color: var(--gray-500); margin-bottom: var(--space-4); }
  .about-values { display: grid; gap: var(--space-4); margin-top: var(--space-8); }
  .value {
    display: flex; gap: var(--space-4); align-items: flex-start;
    padding: var(--space-4) 0;
    border-top: 1px solid var(--gray-100);
  }
  .value-num {
    flex-shrink: 0;
    font-size: var(--text-sm); font-weight: 600;
    color: var(--color-primary);
    font-variant-numeric: tabular-nums;
  }
  .value h4 { font-size: var(--text-base); margin-bottom: var(--space-1); }
  .value p { font-size: var(--text-sm); color: var(--gray-500); margin: 0; }

  .about-visual {
    aspect-ratio: 4 / 5;
    background:
      radial-gradient(ellipse at 30% 20%, rgba(79, 70, 229, 0.4), transparent 50%),
      radial-gradient(ellipse at 70% 80%, rgba(6, 182, 212, 0.35), transparent 50%),
      var(--gray-900);
    border-radius: var(--radius-lg);
    position: relative;
    overflow: hidden;
  }
  .about-visual::before {
    content: '';
    position: absolute; inset: 0;
    background-image:
      linear-gradient(rgba(255, 255, 255, 0.06) 1px, transparent 1px),
      linear-gradient(90deg, rgba(255, 255, 255, 0.06) 1px, transparent 1px);
    background-size: 32px 32px;
  }
  .about-canvas {
    position: absolute; inset: 0;
    width: 100%; height: 100%;
    display: block;
  }

  /* ============ Contact ============ */
  .contact { background: var(--surface-raised); }
  .contact-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-12);
  }
  @media (min-width: 1024px) {
    .contact-grid { grid-template-columns: 1fr 1.2fr; gap: var(--space-16); }
  }
  .contact-info h2 { font-size: var(--text-3xl); margin-bottom: var(--space-4); }
  .contact-info > p { color: var(--gray-500); margin-bottom: var(--space-8); }
  .contact-list { display: grid; gap: var(--space-6); }
  .contact-item {
    display: flex; gap: var(--space-4); align-items: flex-start;
  }
  .contact-icon {
    flex-shrink: 0;
    width: 40px; height: 40px;
    display: flex; align-items: center; justify-content: center;
    background: var(--color-primary-subtle);
    color: var(--color-primary);
    border-radius: var(--radius-md);
  }
  .contact-item-label { font-size: var(--text-xs); color: var(--gray-500); text-transform: uppercase; letter-spacing: 0.08em; }
  .contact-item-value { font-size: var(--text-base); color: var(--gray-900); font-weight: 500; }

  .contact-form {
    background: #fff;
    padding: var(--space-10);
    border-radius: var(--radius-lg);
    border: 1px solid var(--gray-200);
  }
  .form-row { display: grid; gap: var(--space-4); margin-bottom: var(--space-4); }
  @media (min-width: 640px) { .form-row.split { grid-template-columns: 1fr 1fr; } }
  .form-field { display: flex; flex-direction: column; gap: var(--space-2); }
  .form-field label { font-size: var(--text-sm); font-weight: 500; color: var(--gray-700); }
  .form-field input,
  .form-field textarea {
    font-family: inherit;
    font-size: var(--text-base);
    padding: var(--space-3) var(--space-4);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    background: #fff;
    color: var(--gray-900);
    transition: border-color var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
    min-height: 44px;
  }
  .form-field textarea { min-height: 120px; resize: vertical; }
  .form-field input:focus,
  .form-field textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-subtle);
  }
  .form-submit { width: 100%; margin-top: var(--space-2); }

  /* ============ Footer ============ */
  .site-footer {
    background: var(--gray-900);
    color: var(--gray-400);
    padding: var(--space-16) 0 var(--space-8);
  }
  .footer-top {
    display: grid; gap: var(--space-8);
    grid-template-columns: 1fr;
    padding-bottom: var(--space-12);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }
  @media (min-width: 768px) {
    .footer-top { grid-template-columns: 2fr 1fr 1fr 1fr; }
  }
  .footer-brand { color: #fff; font-size: var(--text-lg); font-weight: 600; margin-bottom: var(--space-3); }
  .footer-tag { font-size: var(--text-sm); color: var(--gray-400); max-width: 320px; }
  .footer-col h5 { color: #fff; font-size: var(--text-sm); margin-bottom: var(--space-4); font-weight: 600; }
  .footer-col ul { display: flex; flex-direction: column; gap: var(--space-2); }
  .footer-col a { font-size: var(--text-sm); color: var(--gray-400); }
  .footer-col a:hover { color: #fff; }
  .footer-bottom {
    display: flex; flex-wrap: wrap; justify-content: space-between; gap: var(--space-4);
    padding-top: var(--space-8);
    font-size: var(--text-sm);
    color: var(--gray-500);
  }

  /* ============ Language Switcher ============ */
  .lang-switcher { position: relative; }
  .lang-switcher > summary {
    list-style: none;
    cursor: pointer;
    display: inline-flex; align-items: center; gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-sm);
    color: var(--gray-700);
    background: transparent;
    border-radius: var(--radius-sm);
    min-height: 36px;
    transition: all var(--duration) var(--ease);
    user-select: none;
  }
  .lang-switcher > summary::-webkit-details-marker { display: none; }
  .lang-switcher > summary::marker { display: none; }
  .lang-switcher > summary:hover { color: var(--color-primary); background: var(--gray-100); }
  .lang-icon { color: var(--gray-500); flex-shrink: 0; }
  .lang-switcher > summary:hover .lang-icon { color: var(--color-primary); }
  .lang-caret { color: var(--gray-400); transition: transform var(--duration) var(--ease); flex-shrink: 0; }
  .lang-switcher[open] > summary .lang-caret { transform: rotate(180deg); }
  .lang-current { font-weight: 500; }

  .lang-menu {
    position: absolute;
    top: calc(100% + 4px);
    right: 0;
    min-width: 160px;
    background: #fff;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: var(--space-2);
    z-index: 100;
    list-style: none;
    margin: 0;
  }
  .lang-menu button {
    width: 100%;
    text-align: left;
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-sm);
    color: var(--gray-700);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--duration) var(--ease);
    min-height: 36px;
  }
  .lang-menu button:hover { background: var(--gray-100); color: var(--color-primary); }
  .lang-menu button[aria-current="true"] {
    background: var(--color-primary-subtle);
    color: var(--color-primary);
    font-weight: 500;
  }

  .btn-sm { padding: var(--space-2) var(--space-4); min-height: 36px; font-size: var(--text-sm); }

  @media (max-width: 640px) {
    .lang-current { display: none; }
    .lang-switcher > summary { padding: var(--space-2); }
  }

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