/* ========================================
   TokenSource · 数道源科技 — Company Website
   ======================================== */

/* ---- Reset & Base ---- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --clr-primary: #2563eb;
  --clr-primary-dark: #1d4ed8;
  --clr-primary-light: #60a5fa;
  --clr-accent: #06b6d4;
  --clr-dark: #0f172a;
  --clr-dark-2: #1e293b;
  --clr-gray-100: #f1f5f9;
  --clr-gray-200: #e2e8f0;
  --clr-gray-400: #94a3b8;
  --clr-gray-500: #64748b;
  --clr-gray-600: #475569;
  --clr-white: #ffffff;
  --ff: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max-w: 1200px;
  --nav-h: 72px;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 20px rgba(0,0,0,.08);
  --shadow-lg: 0 12px 48px rgba(0,0,0,.12);
  --transition: 350ms cubic-bezier(.22,1,.36,1);
}

html { scroll-behavior: smooth; }
body {
  font-family: var(--ff);
  color: var(--clr-dark);
  background: var(--clr-white);
  line-height: 1.6;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---- Typography ---- */
.section {
  padding: 100px 0;
}
.section-dark {
  background: var(--clr-dark);
  color: var(--clr-white);
}
.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 64px;
}
.section-tag {
  display: inline-block;
  padding: 6px 18px;
  border-radius: 100px;
  font-size: .85rem;
  font-weight: 600;
  letter-spacing: .5px;
  color: var(--clr-primary);
  background: rgba(37,99,235,.10);
  margin-bottom: 16px;
}
.section-dark .section-tag {
  color: var(--clr-primary-light);
  background: rgba(96,165,250,.12);
}
.section-title {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
}
.section-desc {
  font-size: 1.05rem;
  color: var(--clr-gray-500);
  line-height: 1.7;
}
.section-dark .section-desc {
  color: var(--clr-gray-400);
}

/* ---- Nav Domain ---- */
.nav-domain {
  font-size: .8rem;
  font-weight: 500;
  color: var(--clr-gray-400);
  padding: 4px 12px;
  border-radius: 6px;
  border: 1px solid rgba(255,255,255,.12);
  transition: var(--transition);
  margin-left: -12px;
}
.site-header.scrolled .nav-domain {
  color: var(--clr-primary);
  border-color: rgba(37,99,235,.2);
}
.site-header.scrolled .nav-domain:hover {
  background: rgba(37,99,235,.06);
}
.site-header:not(.scrolled) .nav-domain {
  color: rgba(255,255,255,.7);
  border-color: rgba(255,255,255,.15);
}
.site-header:not(.scrolled) .nav-domain:hover {
  color: var(--clr-white);
  border-color: rgba(255,255,255,.3);
}

/* ---- Hero Domain Wrap ---- */
.hero-domain-wrap {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 28px;
  padding: 8px 18px 8px 14px;
  border-radius: 100px;
  background: linear-gradient(135deg, rgba(37,99,235,.2), rgba(6,182,212,.12));
  border: 1px solid rgba(96,165,250,.25);
  width: fit-content;
  backdrop-filter: blur(6px);
}
.hero-domain-icon {
  font-size: 1rem;
  line-height: 1;
}
.hero-domain-wrap a {
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: .3px;
  transition: var(--transition);
}
.hero-domain-wrap a:hover {
  color: var(--clr-primary-light);
  text-decoration: underline;
  text-underline-offset: 3px;
}
@media (max-width: 1024px) {
  .hero-domain-wrap { margin: 0 auto 28px; }
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 100px;
  font-size: .95rem;
  font-weight: 600;
  font-family: var(--ff);
  border: none;
  cursor: pointer;
  transition: var(--transition);
}
.btn-primary {
  background: var(--clr-primary);
  color: var(--clr-white);
}
.btn-primary:hover {
  background: var(--clr-primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(37,99,235,.35);
}
.btn-outline {
  background: transparent;
  color: var(--clr-white);
  border: 2px solid rgba(255,255,255,.3);
}
.btn-outline:hover {
  border-color: var(--clr-white);
  background: rgba(255,255,255,.08);
  transform: translateY(-2px);
}

/* ====================================
   HEADER / NAV
   ==================================== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-h);
  transition: var(--transition);
}
.site-header.scrolled {
  background: rgba(255,255,255,.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 1px 0 var(--clr-gray-200);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: 6px;
  font-weight: 700;
  font-size: 1.15rem;
}
.logo-icon {
  color: var(--clr-primary);
  font-size: 1.4rem;
  line-height: 1;
}
.logo-text { color: var(--clr-dark); }
.site-header.scrolled .logo-text { color: var(--clr-dark); }
.site-header:not(.scrolled) .logo-text { color: var(--clr-white); }
.site-header:not(.scrolled) .logo-cn { color: rgba(255,255,255,.7); }
.logo-divider {
  color: var(--clr-gray-400);
  font-weight: 300;
  margin: 0 4px;
}
.logo-cn {
  font-weight: 400;
  font-size: .9rem;
  color: var(--clr-gray-500);
}

/* Nav links */
.nav {
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav a {
  font-size: .9rem;
  font-weight: 500;
  position: relative;
  transition: color var(--transition);
}
.site-header:not(.scrolled) .nav a { color: rgba(255,255,255,.8); }
.site-header:not(.scrolled) .nav a:hover { color: var(--clr-white); }
.site-header.scrolled .nav a { color: var(--clr-gray-600); }
.site-header.scrolled .nav a:hover { color: var(--clr-primary); }
.nav a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 2px;
  background: var(--clr-primary);
  transition: width var(--transition);
  border-radius: 2px;
}
.nav a:hover::after { width: 100%; }

/* Hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--clr-dark);
  border-radius: 2px;
  transition: var(--transition);
}
.site-header:not(.scrolled) .nav-toggle span { background: var(--clr-white); }
.nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ====================================
   HERO
   ==================================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: var(--clr-dark);
  color: var(--clr-white);
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 600px 400px at 20% 50%, rgba(37,99,235,.25), transparent),
    radial-gradient(ellipse 500px 500px at 80% 60%, rgba(6,182,212,.15), transparent),
    radial-gradient(ellipse 400px 400px at 60% 20%, rgba(99,102,241,.12), transparent);
  pointer-events: none;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  padding-top: var(--nav-h);
}
.hero-content { position: relative; z-index: 2; }
.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 100px;
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .5px;
  background: rgba(96,165,250,.15);
  color: var(--clr-primary-light);
  margin-bottom: 24px;
}
.hero-title {
  font-size: clamp(2rem, 4.5vw, 3.2rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 20px;
}
.hero-title-line { display: block; }
.hero-title-line.accent {
  background: linear-gradient(135deg, var(--clr-primary-light), var(--clr-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-desc {
  font-size: 1.05rem;
  line-height: 1.8;
  color: rgba(255,255,255,.65);
  margin-bottom: 36px;
  max-width: 540px;
}
.hero-desc strong { color: rgba(255,255,255,.9); }
.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* Hero visual (abstract shapes) */
.hero-visual {
  position: relative;
  height: 400px;
}
.hero-shape {
  position: absolute;
  border-radius: 50%;
  opacity: .4;
}
.shape-1 {
  width: 280px; height: 280px;
  top: 10%; right: 10%;
  background: radial-gradient(circle, rgba(37,99,235,.5), transparent 70%);
  animation: float 8s ease-in-out infinite;
}
.shape-2 {
  width: 180px; height: 180px;
  top: 50%; right: 30%;
  background: radial-gradient(circle, rgba(6,182,212,.4), transparent 70%);
  animation: float 10s ease-in-out infinite reverse;
}
.shape-3 {
  width: 120px; height: 120px;
  top: 20%; right: 55%;
  background: radial-gradient(circle, rgba(99,102,241,.3), transparent 70%);
  animation: float 6s ease-in-out infinite 2s;
}

@keyframes float {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-30px) scale(1.05); }
}

/* Scroll hint */
.hero-scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: rgba(255,255,255,.4);
  font-size: .75rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  animation: fadeInUp 1s ease-out 1s both;
}
.scroll-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--clr-primary-light);
  animation: scrollBounce 2s ease-in-out infinite;
}
@keyframes scrollBounce {
  0%, 100% { transform: translateY(0); opacity: 1; }
  50% { transform: translateY(8px); opacity: .3; }
}

/* ====================================
   ABOUT
   ==================================== */
.about-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}
.about-card {
  padding: 40px 32px;
  border-radius: var(--radius);
  background: var(--clr-gray-100);
  transition: var(--transition);
}
.about-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}
.about-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}
.about-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.about-card p {
  color: var(--clr-gray-600);
  line-height: 1.7;
  font-size: .95rem;
}

/* ====================================
   BUSINESS (flip cards)
   ==================================== */
.business-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  perspective: 1200px;
}
.business-card {
  cursor: pointer;
  height: 380px;
  perspective: 1200px;
}
.business-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform .6s cubic-bezier(.22,1,.36,1);
  transform-style: preserve-3d;
}
.business-card.flipped .business-card-inner {
  transform: rotateY(180deg);
}
.business-card-front,
.business-card-back {
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}
.business-card-front {
  background: linear-gradient(145deg, var(--clr-dark-2), #0f172a);
  border: 1px solid rgba(255,255,255,.06);
  align-items: center;
  text-align: center;
  justify-content: center;
}
.business-icon-wrap {
  width: 72px; height: 72px;
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  background: hsla(var(--card-hue, 210), 60%, 50%, .15);
  border: 1px solid hsla(var(--card-hue, 210), 60%, 50%, .25);
  margin-bottom: 20px;
}
.business-card-front h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 10px;
}
.business-card-front p {
  color: var(--clr-gray-400);
  font-size: .9rem;
  line-height: 1.6;
}
.business-hint {
  margin-top: 20px;
  font-size: .8rem;
  color: var(--clr-gray-500);
  transition: var(--transition);
}
.business-card:hover .business-hint { color: var(--clr-primary-light); }

.business-card-back {
  background: linear-gradient(145deg, #1e293b, #0f172a);
  border: 1px solid rgba(255,255,255,.08);
  transform: rotateY(180deg);
  justify-content: center;
}
.business-card-back h4 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--clr-primary-light);
}
.business-card-back li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 10px;
  font-size: .9rem;
  color: var(--clr-gray-300);
  line-height: 1.5;
}
.business-card-back li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--clr-primary-light);
  font-weight: 600;
}

/* ====================================
   ADVANTAGES
   ==================================== */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}
.advantage-item {
  text-align: center;
  padding: 40px 24px;
  border-radius: var(--radius);
  background: var(--clr-gray-100);
  transition: var(--transition);
}
.advantage-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.advantage-number {
  font-size: 3rem;
  font-weight: 800;
  color: var(--clr-primary);
  line-height: 1;
  margin-bottom: 8px;
}
.advantage-number::after {
  content: '+';
  color: var(--clr-accent);
}
.advantage-info h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 6px;
}
.advantage-info p {
  font-size: .85rem;
  color: var(--clr-gray-500);
  line-height: 1.5;
}

/* ====================================
   CONTACT
   ==================================== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 48px;
  align-items: start;
}
.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  margin-bottom: 28px;
}
.contact-item-icon {
  flex-shrink: 0;
  width: 44px; height: 44px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  background: rgba(255,255,255,.06);
}
.contact-item h4 {
  font-size: .85rem;
  font-weight: 600;
  color: var(--clr-gray-400);
  margin-bottom: 4px;
}
.contact-item p,
.contact-item a {
  font-size: .95rem;
  color: var(--clr-white);
}
.contact-item a:hover { color: var(--clr-primary-light); }

/* Form */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255,255,255,.1);
  background: rgba(255,255,255,.05);
  color: var(--clr-white);
  font-family: var(--ff);
  font-size: .95rem;
  transition: var(--transition);
}
.contact-form input::placeholder,
.contact-form textarea::placeholder { color: var(--clr-gray-500); }
.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--clr-primary);
  background: rgba(255,255,255,.08);
  box-shadow: 0 0 0 3px rgba(37,99,235,.15);
}
.contact-form .btn-primary {
  align-self: flex-start;
  padding: 14px 40px;
}

/* ====================================
   FOOTER
   ==================================== */
.site-footer {
  background: var(--clr-dark-2);
  color: var(--clr-white);
  padding: 60px 0 32px;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 48px;
}
.footer-brand .logo {
  margin-bottom: 12px;
}
.footer-brand .logo .logo-text {
  color: var(--clr-white);
}
.footer-brand p {
  color: var(--clr-gray-400);
  font-size: .9rem;
  max-width: 300px;
  margin-bottom: 12px;
}
.footer-domain {
  font-size: .85rem;
  font-weight: 500;
  color: var(--clr-primary-light);
  transition: var(--transition);
}
.footer-domain:hover {
  color: var(--clr-white);
}
.footer-links {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}
.footer-col h5 {
  font-size: .8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--clr-gray-500);
  margin-bottom: 16px;
}
.footer-col a {
  display: block;
  font-size: .9rem;
  color: var(--clr-gray-400);
  margin-bottom: 10px;
  transition: color var(--transition);
}
.footer-col a:hover { color: var(--clr-white); }
.footer-bottom {
  grid-column: 1 / -1;
  padding-top: 32px;
  border-top: 1px solid rgba(255,255,255,.06);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: .8rem;
  color: var(--clr-gray-500);
}
.footer-icp a {
  color: var(--clr-gray-500);
}
.footer-icp a:hover { color: var(--clr-gray-400); }

/* ====================================
   RESPONSIVE
   ==================================== */
@media (max-width: 1024px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-desc { margin: 0 auto 36px; }
  .hero-actions { justify-content: center; }
  .hero-visual { display: none; }
  .business-grid { grid-template-columns: repeat(2, 1fr); }
  .about-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .section { padding: 72px 0; }

  /* Mobile nav */
  .nav {
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--clr-white);
    padding: 16px 24px;
    box-shadow: var(--shadow-lg);
    transform: translateY(-120%);
    opacity: 0;
    transition: var(--transition);
    border-radius: 0 0 var(--radius) var(--radius);
  }
  .nav.open {
    transform: translateY(0);
    opacity: 1;
  }
  .nav a {
    display: block;
    padding: 14px 0;
    color: var(--clr-dark) !important;
    border-bottom: 1px solid var(--clr-gray-100);
  }
  .nav-toggle { display: flex; }
  .nav-domain { display: none; }

  .hero { min-height: 90vh; }
  .hero-scroll-hint { display: none; }

  .about-grid,
  .business-grid,
  .advantages-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .form-row { grid-template-columns: 1fr; }

  .contact-form .btn-primary { align-self: stretch; text-align: center; }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .business-card { height: 340px; }
  .advantage-number { font-size: 2.4rem; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; }
}

/* ====================================
   ANIMATIONS (on scroll)
   ==================================== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity .6s ease, transform .6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ====================================
   FAVICON (inline fallback)
   ==================================== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}