/* ============================================
   DELINK TECHNOLOGY LIMITED — PayPal-Inspired Style
   ============================================ */

/* --- CSS Variables --- */
:root {
  /* Color Palette — PayPal-inspired */
  --color-primary: #003087;
  --color-primary-dark: #001c64;
  --color-primary-light: #0047ab;
  --color-accent: #009cde;
  --color-accent-light: #e6f4ff;

  --color-bg-dark: #001435;
  --color-bg-white: #ffffff;
  --color-bg-light: #f7f8fa;
  --color-bg-card: #ffffff;

  --color-text-primary: #1a1a1a;
  --color-text-secondary: #5f6368;
  --color-text-light: #ffffff;
  --color-text-muted: rgba(255,255,255,0.7);

  --color-border: #e0e2e6;
  --color-footer-bg: #001435;

  /* Typography */
  --font-family: 'Inter', 'Noto Sans TC', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang TC', 'PingFang SC', 'Microsoft YaHei', '微軟雅黑', sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3.25rem;

  /* Spacing */
  --section-padding: 100px 0;
  --container-max: 1140px;
  --gutter: 24px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,48,135,0.10);
  --shadow-card: 0 2px 8px rgba(0,0,0,0.06), 0 1px 3px rgba(0,0,0,0.04);
  --shadow-card-hover: 0 12px 40px rgba(0,48,135,0.12);

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text-primary);
  background: var(--color-bg-white);
  overflow-x: hidden;
}

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

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

/* --- Container --- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* ============================================
   NAVIGATION
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: all 0.3s ease;
  background: transparent;
}

.navbar.scrolled {
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
  padding: 10px 0;
}

.navbar.scrolled .nav-logo {
  color: var(--color-primary);
}

.navbar.scrolled .nav-link {
  color: var(--color-text-primary);
}

.navbar.scrolled .nav-link:hover {
  color: var(--color-primary);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
}

.nav-logo-img {
  height: 32px;
  width: auto;
  display: block;
  filter: brightness(0) invert(1);
  transition: filter 0.3s ease;
}

.navbar.scrolled .nav-logo-img {
  filter: none;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* --- Language Switcher --- */
.lang-switcher {
  display: flex;
  gap: 2px;
  background: rgba(255,255,255,0.1);
  border-radius: var(--radius-full);
  padding: 3px;
}

.scrolled .lang-switcher {
  background: var(--color-bg-light);
}

.lang-btn {
  font-family: var(--font-family);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.5px;
  padding: 4px 10px;
  border: none;
  background: transparent;
  color: var(--color-text-muted);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all 0.2s ease;
}

.lang-btn:hover {
  color: var(--color-text-light);
  background: rgba(255,255,255,0.1);
}

.scrolled .lang-btn:hover {
  color: var(--color-text-primary);
  background: var(--color-border);
}

.lang-btn.active {
  background: rgba(255,255,255,0.2);
  color: var(--color-text-light);
}

.scrolled .lang-btn.active {
  background: var(--color-primary);
  color: #fff;
}

.nav-links {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 8px;
}

.nav-link {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  transition: all 0.25s ease;
  letter-spacing: 0.3px;
}

.nav-link:hover {
  color: var(--color-text-light);
  background: rgba(255,255,255,0.1);
}

.nav-cta {
  background: rgba(255,255,255,0.15) !important;
  padding: 8px 24px !important;
  border-radius: var(--radius-full);
  font-weight: 600;
  margin-left: 8px;
  border: 1px solid rgba(255,255,255,0.25);
}

.nav-cta:hover {
  background: var(--color-text-light) !important;
  color: var(--color-primary-dark) !important;
}

.scrolled .nav-link {
  color: var(--color-text-secondary);
}

.scrolled .nav-link:hover {
  color: var(--color-primary);
  background: rgba(0,48,135,0.06);
}

.scrolled .nav-cta {
  background: var(--color-primary) !important;
  color: #fff !important;
  border-color: var(--color-primary);
}

.scrolled .nav-cta:hover {
  background: var(--color-primary-dark) !important;
  color: #fff !important;
}

/* Mobile toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  z-index: 1001;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text-light);
  border-radius: 2px;
  transition: all 0.3s ease;
}

.scrolled .nav-toggle span {
  background: var(--color-text-primary);
}

/* ============================================
   HERO
   ============================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--color-bg-dark) 0%, var(--color-primary-dark) 50%, var(--color-primary) 100%);
  overflow: hidden;
  padding: 120px 0 80px;
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(0,156,222,0.10) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 20%, rgba(0,156,222,0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 50% 80%, rgba(0,156,222,0.06) 0%, transparent 50%);
  pointer-events: none;
}

.hero-container {
  position: relative;
  z-index: 2;
  width: 100%;
}

.hero-content {
  max-width: 760px;
}

.hero-title {
  font-size: var(--font-size-5xl);
  font-weight: 800;
  line-height: 1.15;
  color: var(--color-text-light);
  margin-bottom: 16px;
  letter-spacing: -1px;
}

.hero-title-accent {
  background: linear-gradient(135deg, #4fc3f7, #009cde);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 12px;
  letter-spacing: 0.5px;
}

.hero-desc {
  font-size: var(--font-size-lg);
  color: var(--color-text-muted);
  max-width: 580px;
  margin-bottom: 36px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-wave {
  position: absolute;
  bottom: -1px;
  left: 0;
  right: 0;
  height: 120px;
  z-index: 2;
}

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

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  font-weight: 600;
  letter-spacing: 0.5px;
  border-radius: var(--radius-full);
  transition: all 0.25s ease;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 4px 14px rgba(0,156,222,0.35);
}

.btn-primary:hover {
  background: #0088c4;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0,156,222,0.45);
}

.btn-outline {
  background: transparent;
  color: var(--color-text-light);
  border: 1.5px solid rgba(255,255,255,0.3);
}

.btn-outline:hover {
  border-color: rgba(255,255,255,0.6);
  background: rgba(255,255,255,0.08);
  transform: translateY(-2px);
}

.btn-full {
  width: 100%;
}

/* ============================================
   SECTIONS
   ============================================ */
.section {
  padding: var(--section-padding);
}

.section-light {
  background: var(--color-bg-white);
}

.section-dark {
  background: linear-gradient(135deg, var(--color-bg-dark) 0%, var(--color-primary-dark) 100%);
  color: var(--color-text-light);
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 60px;
}

.section-label {
  display: inline-block;
  font-size: var(--font-size-xs);
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--color-accent);
  background: var(--color-accent-light);
  padding: 6px 16px;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
}

.section-label-light {
  background: rgba(0,156,222,0.15);
  color: var(--color-accent);
}

.section-title {
  font-size: var(--font-size-4xl);
  font-weight: 800;
  line-height: 1.2;
  color: var(--color-text-primary);
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.section-title-light {
  color: var(--color-text-light);
}

.section-desc {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.section-desc-light {
  color: var(--color-text-muted);
}

/* ============================================
   SERVICES
   ============================================ */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.service-card {
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
  padding: 40px 32px;
  box-shadow: var(--shadow-card);
  transition: all 0.3s ease;
  border: 1px solid var(--color-border);
}

.service-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-card-hover);
  border-color: transparent;
}

.service-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-accent-light), #f0f8ff);
  border-radius: var(--radius-sm);
  margin-bottom: 24px;
  color: var(--color-primary);
}

.service-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.4;
  color: var(--color-text-primary);
}

.service-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ============================================
   WHY DELINK
   ============================================ */
.why-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 36px;
}

.why-item {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-md);
  padding: 36px 32px;
  transition: all 0.3s ease;
}

.why-item:hover {
  background: rgba(255,255,255,0.08);
  border-color: rgba(0,156,222,0.3);
  transform: translateY(-3px);
}

.why-number {
  font-size: var(--font-size-3xl);
  font-weight: 800;
  color: rgba(0,156,222,0.4);
  margin-bottom: 12px;
  line-height: 1;
  letter-spacing: -1px;
}

.why-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--color-text-light);
}

.why-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ============================================
   CLIENTS
   ============================================ */
.clients-content {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
}

.clients-statement {
  padding: 40px;
}

.clients-icon {
  color: var(--color-primary);
  opacity: 0.15;
  margin-bottom: 24px;
}

.clients-text {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: 28px;
}

.clients-badge {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.badge {
  font-size: var(--font-size-xs);
  font-weight: 600;
  letter-spacing: 0.5px;
  padding: 8px 18px;
  background: var(--color-accent-light);
  color: var(--color-primary);
  border-radius: var(--radius-full);
}

/* ============================================
   CONTACT
   ============================================ */
.section-contact {
  background: linear-gradient(135deg, var(--color-bg-dark) 0%, var(--color-primary-dark) 100%);
  position: relative;
}

.contact-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  max-width: 920px;
  margin: 0 auto;
  align-items: start;
}

.contact-form {
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
  padding: 40px;
  box-shadow: var(--shadow-lg);
}

.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-primary);
  margin-bottom: 6px;
}

.form-input {
  width: 100%;
  padding: 12px 16px;
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  color: var(--color-text-primary);
  background: var(--color-bg-light);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: all 0.25s ease;
  outline: none;
}

.form-input:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(0,156,222,0.12);
  background: var(--color-bg-white);
}

.form-input::placeholder {
  color: #9ca3af;
}

.form-textarea {
  resize: vertical;
  min-height: 100px;
}

.contact-info {
  padding-top: 12px;
}

.contact-info-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 28px;
}

.contact-info-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,156,222,0.12);
  border-radius: var(--radius-sm);
  color: var(--color-accent);
  flex-shrink: 0;
}

.contact-info-label {
  font-size: var(--font-size-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--color-text-muted);
  margin-bottom: 4px;
}

.contact-info-value {
  font-size: var(--font-size-base);
  color: var(--color-text-light);
  font-weight: 500;
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
  background: var(--color-footer-bg);
  padding: 48px 0 32px;
  color: var(--color-text-muted);
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-logo {
  font-size: var(--font-size-xl);
  font-weight: 800;
  letter-spacing: 2px;
  color: var(--color-text-light);
}

.footer-logo-img {
  height: 26px;
  width: auto;
  display: block;
  margin-bottom: 6px;
  filter: brightness(0) invert(1);
  opacity: 0.8;
}

.footer-tagline {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-top: 4px;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-link {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  transition: color 0.2s;
}

.footer-link:hover {
  color: var(--color-text-light);
}

.footer-divider {
  height: 1px;
  background: rgba(255,255,255,0.08);
  margin: 28px 0;
}

.footer-copy {
  font-size: var(--font-size-xs);
  text-align: center;
  color: rgba(255,255,255,0.3);
}

/* ============================================
   SUCCESS MESSAGE (for form submission)
   ============================================ */
.form-success {
  display: none;
  text-align: center;
  padding: 40px 24px;
}

.form-success.show {
  display: block;
}

.form-success-icon {
  width: 64px;
  height: 64px;
  background: #10b981;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  color: #fff;
}

.form-success-text {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 6px;
}

.form-success-sub {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

/* ============================================
   ANIMATIONS
   ============================================ */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.service-card:nth-child(2) { transition-delay: 0.1s; }
.service-card:nth-child(3) { transition-delay: 0.2s; }

.why-item:nth-child(2) { transition-delay: 0.1s; }
.why-item:nth-child(3) { transition-delay: 0.2s; }
.why-item:nth-child(4) { transition-delay: 0.3s; }

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 968px) {
  :root {
    --font-size-5xl: 2.5rem;
    --font-size-4xl: 2rem;
    --section-padding: 72px 0;
  }

  .services-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .why-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .contact-wrapper {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .hero-title {
    font-size: var(--font-size-5xl);
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    flex-direction: column;
    background: var(--color-bg-white);
    padding: 80px 32px 32px;
    gap: 4px;
    box-shadow: -8px 0 30px rgba(0,0,0,0.1);
    transition: right 0.3s ease;
    align-items: flex-start;
  }

  .nav-links.open {
    right: 0;
  }

  .nav-link {
    color: var(--color-text-primary) !important;
    font-size: var(--font-size-base);
    padding: 12px 16px;
    width: 100%;
  }

  .nav-link:hover {
    background: var(--color-bg-light) !important;
  }

  .nav-cta {
    background: var(--color-primary) !important;
    color: #fff !important;
    border: none;
    text-align: center;
    margin-left: 0;
    margin-top: 8px;
  }

  .nav-cta:hover {
    background: var(--color-primary-dark) !important;
  }

  .hero-title {
    font-size: 2rem;
  }

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

  .btn {
    width: 100%;
    text-align: center;
  }

  .contact-form {
    padding: 28px 24px;
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .hero-wave {
    height: 60px;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 1.75rem;
  }

  .hero-subtitle {
    font-size: var(--font-size-base);
  }

  .section-title {
    font-size: 1.75rem;
  }

  .section {
    padding: 56px 0;
  }
}