/* ============================================================
   液态金属风 (Liquid Metal) — Custom Styles
   ============================================================ */

/* --- CSS Variables --- */
:root {
  --chrome-silver: #c0c0c0;
  --chrome-light: #e8e8e8;
  --gunmetal-dark: #1a1a1e;
  --gunmetal-mid: #2c2c30;
  --mercury: #d4d4d4;
  --brushed-steel: #8a8a8e;
  --accent-blue: #3b82f6;
  --accent-blue-light: #60a5fa;
  --white: #ffffff;
  --black: #000000;
  --transition-speed: 0.35s;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Noto Sans SC', sans-serif;
  background-color: var(--gunmetal-dark);
  color: var(--chrome-light);
  margin: 0;
  padding: 0;
  overflow-x: hidden;
  line-height: 1.6;
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Rajdhani', sans-serif;
  font-weight: 700;
  letter-spacing: 0.02em;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color var(--transition-speed);
}

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

/* --- Utility: Metallic Gradient Text --- */
.metallic-text {
  background: linear-gradient(135deg, #e8e8e8 0%, #c0c0c0 25%, #ffffff 50%, #a0a0a0 75%, #e8e8e8 100%);
  background-size: 200% 200%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: metallicShimmer 4s ease-in-out infinite;
}

@keyframes metallicShimmer {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

/* --- Utility: Chrome Gradient Numbers --- */
.chrome-number {
  background: linear-gradient(180deg, #ffffff 0%, #c0c0c0 40%, #e8e8e8 60%, #8a8a8e 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* --- Utility: Silver Gradient Border --- */
.silver-border {
  position: relative;
  background: var(--gunmetal-mid);
  border-radius: 16px;
}
.silver-border::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 16px;
  padding: 1px;
  background: linear-gradient(135deg, #c0c0c0, #8a8a8e, #c0c0c0);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

/* --- Navbar --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(26, 26, 30, 0.92);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(192, 192, 192, 0.12);
  transition: all var(--transition-speed) ease;
}

.navbar.scrolled {
  background: rgba(26, 26, 30, 0.98);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.5);
}

.nav-link {
  position: relative;
  color: var(--chrome-silver);
  font-family: 'Rajdhani', sans-serif;
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  transition: color var(--transition-speed);
  padding: 4px 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #c0c0c0, #e8e8e8, #c0c0c0);
  transition: width var(--transition-speed) ease;
  border-radius: 1px;
}

.nav-link:hover,
.nav-link.active {
  color: var(--white);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* Mobile Menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: 60px;
  left: 0;
  right: 0;
  background: rgba(26, 26, 30, 0.98);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(192, 192, 192, 0.12);
  z-index: 999;
  padding: 1.5rem;
  flex-direction: column;
  gap: 1rem;
}

.mobile-menu.open {
  display: flex;
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--chrome-silver);
  border-radius: 1px;
  transition: all 0.3s ease;
}

.hamburger.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.hamburger.open span:nth-child(2) {
  opacity: 0;
}
.hamburger.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* --- Animated Wave Shapes (Hero) --- */
.wave-container {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 200px;
  overflow: hidden;
  pointer-events: none;
}

.wave {
  position: absolute;
  bottom: 0;
  left: -50%;
  width: 200%;
  height: 200px;
  opacity: 0.25;
}

.wave-1 {
  background: linear-gradient(180deg, transparent 0%, rgba(59, 130, 246, 0.15) 100%);
  border-radius: 40%;
  animation: waveDrift 12s ease-in-out infinite;
}

.wave-2 {
  background: linear-gradient(180deg, transparent 0%, rgba(192, 192, 192, 0.12) 100%);
  border-radius: 45%;
  animation: waveDrift 15s ease-in-out infinite reverse;
  bottom: -20px;
}

.wave-3 {
  background: linear-gradient(180deg, transparent 0%, rgba(138, 138, 142, 0.1) 100%);
  border-radius: 35%;
  animation: waveDrift 18s ease-in-out infinite;
  bottom: -40px;
}

@keyframes waveDrift {
  0%, 100% { transform: translateX(0) translateY(0); }
  25% { transform: translateX(3%) translateY(-8px); }
  50% { transform: translateX(-2%) translateY(-4px); }
  75% { transform: translateX(4%) translateY(-12px); }
}

/* --- Liquid Metal Blobs --- */
.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.12;
  pointer-events: none;
}

.blob-1 {
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, var(--accent-blue), transparent);
  top: -100px;
  right: -50px;
  animation: blobFloat 8s ease-in-out infinite;
}

.blob-2 {
  width: 250px;
  height: 250px;
  background: radial-gradient(circle, var(--chrome-silver), transparent);
  bottom: -80px;
  left: -40px;
  animation: blobFloat 10s ease-in-out infinite reverse;
}

@keyframes blobFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(20px, -30px) scale(1.08); }
  66% { transform: translate(-15px, 15px) scale(0.94); }
}

/* --- Feature Cards --- */
.feature-card {
  position: relative;
  background: var(--gunmetal-mid);
  border-radius: 16px;
  padding: 2rem;
  transition: all var(--transition-speed) ease;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 16px;
  padding: 1px;
  background: linear-gradient(135deg, rgba(192, 192, 192, 0.3), rgba(138, 138, 142, 0.15), rgba(192, 192, 192, 0.3));
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(192, 192, 192, 0.08);
}

.feature-card .icon-circle {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(192, 192, 192, 0.12), rgba(59, 130, 246, 0.12));
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  font-size: 1.4rem;
  color: var(--chrome-silver);
  transition: all var(--transition-speed) ease;
}

.feature-card:hover .icon-circle {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.2), rgba(192, 192, 192, 0.15));
  color: var(--accent-blue-light);
  box-shadow: 0 0 24px rgba(59, 130, 246, 0.15);
}

/* --- Stats Cards --- */
.stat-card {
  background: var(--gunmetal-mid);
  border-radius: 16px;
  padding: 2rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  transition: all var(--transition-speed) ease;
  border: 1px solid rgba(192, 192, 192, 0.08);
}

.stat-card:hover {
  border-color: rgba(192, 192, 192, 0.2);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.3);
}

/* --- Testimonial Cards --- */
.testimonial-card {
  background: var(--gunmetal-mid);
  border-radius: 16px;
  padding: 2rem;
  border-left: 3px solid;
  border-image: linear-gradient(180deg, var(--chrome-silver), var(--accent-blue)) 1;
  position: relative;
  transition: all var(--transition-speed) ease;
}

.testimonial-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.3);
}

/* Prevent border-image from overriding left border style */
.testimonial-card {
  border-left: 3px solid var(--chrome-silver);
  border-image: none;
}

/* --- FAQ Accordion --- */
.faq-item {
  border-bottom: 1px solid rgba(192, 192, 192, 0.1);
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  color: var(--chrome-light);
  font-family: 'Rajdhani', sans-serif;
  font-size: 1.1rem;
  font-weight: 600;
  padding: 1.25rem 0;
  text-align: left;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: color var(--transition-speed);
  letter-spacing: 0.03em;
}

.faq-question:hover {
  color: var(--accent-blue-light);
}

.faq-question i {
  transition: transform 0.35s ease;
  color: var(--chrome-silver);
  font-size: 0.85rem;
}

.faq-question.open i {
  transform: rotate(180deg);
  color: var(--accent-blue-light);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}

.faq-answer.open {
  max-height: 300px;
  padding-bottom: 1.25rem;
}

.faq-answer p {
  color: var(--mercury);
  line-height: 1.8;
  margin: 0;
}

/* --- CTA Section --- */
.cta-section {
  background: linear-gradient(135deg, #1a1a1e 0%, #2c2c30 40%, #3b3b42 70%, #2c2c30 100%);
  position: relative;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 30% 20%, rgba(59, 130, 246, 0.12) 0%, transparent 50%),
    radial-gradient(ellipse at 70% 80%, rgba(192, 192, 192, 0.08) 0%, transparent 50%);
  pointer-events: none;
}

/* --- Footer --- */
.footer {
  background: var(--gunmetal-dark);
  border-top: 1px solid rgba(192, 192, 192, 0.08);
}

.footer a {
  color: var(--brushed-steel);
  transition: color var(--transition-speed);
}

.footer a:hover {
  color: var(--chrome-silver);
}

/* --- Buttons --- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: linear-gradient(135deg, var(--accent-blue), #2563eb);
  color: #fff;
  font-family: 'Rajdhani', sans-serif;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.85rem 2rem;
  border-radius: 50px;
  border: none;
  cursor: pointer;
  transition: all var(--transition-speed);
  font-size: 1rem;
}

.btn-primary:hover {
  box-shadow: 0 8px 24px rgba(59, 130, 246, 0.35);
  transform: translateY(-2px);
}

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: transparent;
  color: var(--chrome-silver);
  font-family: 'Rajdhani', sans-serif;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.85rem 2rem;
  border-radius: 50px;
  border: 2px solid rgba(192, 192, 192, 0.3);
  cursor: pointer;
  transition: all var(--transition-speed);
  font-size: 1rem;
}

.btn-outline:hover {
  border-color: var(--chrome-silver);
  color: var(--white);
  box-shadow: 0 8px 24px rgba(192, 192, 192, 0.1);
  transform: translateY(-2px);
}

/* --- Floating CS Button --- */
.float-cs-btn {
  position: fixed;
  bottom: 80px;
  right: 24px;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-blue), #2563eb);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  cursor: pointer;
  z-index: 900;
  border: none;
  box-shadow: 0 4px 20px rgba(59, 130, 246, 0.3);
  transition: all var(--transition-speed);
}

.float-cs-btn:hover {
  transform: scale(1.1);
  box-shadow: 0 8px 28px rgba(59, 130, 246, 0.45);
}

/* --- Back to Top --- */
.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gunmetal-mid);
  color: var(--chrome-silver);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  cursor: pointer;
  z-index: 900;
  border: 1px solid rgba(192, 192, 192, 0.2);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-speed);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--accent-blue);
  color: #fff;
  border-color: var(--accent-blue);
}

/* --- Intersection Observer Animations --- */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

.animate-on-scroll.fade-left {
  transform: translateX(-30px);
}

.animate-on-scroll.fade-left.visible {
  transform: translateX(0);
}

.animate-on-scroll.fade-right {
  transform: translateX(30px);
}

.animate-on-scroll.fade-right.visible {
  transform: translateX(0);
}

/* --- Count Up --- */
.counter-value {
  font-family: 'Rajdhani', sans-serif;
  font-weight: 700;
  font-size: 3rem;
  background: linear-gradient(180deg, #ffffff 0%, #c0c0c0 40%, #e8e8e8 60%, #8a8a8e 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* --- Section Titles --- */
.section-badge {
  display: inline-block;
  font-family: 'Rajdhani', sans-serif;
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-blue-light);
  border: 1px solid rgba(59, 130, 246, 0.3);
  padding: 0.35rem 1.25rem;
  border-radius: 50px;
  margin-bottom: 1rem;
  background: rgba(59, 130, 246, 0.06);
}

.section-title {
  font-family: 'Rajdhani', sans-serif;
  font-weight: 700;
  font-size: 2.5rem;
  color: var(--chrome-light);
  margin-bottom: 0.75rem;
  letter-spacing: 0.02em;
}

.section-subtitle {
  color: var(--brushed-steel);
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
}

/* --- About Page Specific --- */
.about-hero {
  background: linear-gradient(180deg, var(--gunmetal-dark) 0%, var(--gunmetal-mid) 100%);
  position: relative;
  overflow: hidden;
}

.about-value-card {
  background: var(--gunmetal-mid);
  border-radius: 16px;
  padding: 2rem;
  text-align: center;
  border: 1px solid rgba(192, 192, 192, 0.08);
  transition: all var(--transition-speed);
}

.about-value-card:hover {
  border-color: rgba(192, 192, 192, 0.2);
  transform: translateY(-4px);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.3);
}

/* --- Contact Page Specific --- */
.contact-input {
  width: 100%;
  background: var(--gunmetal-dark);
  border: 1px solid rgba(192, 192, 192, 0.15);
  border-radius: 10px;
  padding: 0.85rem 1.25rem;
  color: var(--chrome-light);
  font-family: 'Noto Sans SC', sans-serif;
  font-size: 0.95rem;
  transition: all var(--transition-speed);
  outline: none;
}

.contact-input:focus {
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.12);
}

.contact-input::placeholder {
  color: var(--brushed-steel);
}

textarea.contact-input {
  resize: vertical;
  min-height: 140px;
}

.contact-info-card {
  background: var(--gunmetal-mid);
  border-radius: 16px;
  padding: 1.5rem;
  border: 1px solid rgba(192, 192, 192, 0.08);
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  transition: all var(--transition-speed);
}

.contact-info-card:hover {
  border-color: rgba(192, 192, 192, 0.2);
}

.contact-info-icon {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.15), rgba(192, 192, 192, 0.08));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-blue-light);
  font-size: 1.1rem;
  flex-shrink: 0;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .section-title {
    font-size: 2rem;
  }
}

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

  .desktop-nav {
    display: none;
  }

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

  .counter-value {
    font-size: 2.25rem;
  }

  .feature-card {
    padding: 1.5rem;
  }
}

@media (max-width: 480px) {
  .section-title {
    font-size: 1.5rem;
  }

  .counter-value {
    font-size: 1.75rem;
  }

  .btn-primary,
  .btn-outline {
    padding: 0.7rem 1.5rem;
    font-size: 0.9rem;
  }
}