@import url('https://fonts.googleapis.com/css2?family=Hind+Siliguri:wght@300;400;500;600;700&family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
  /* Colors - Light Theme (Default) */
  --bg-primary: #f5f7fa;
  --bg-secondary: rgba(255, 255, 255, 0.7);
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --accent-primary: #d946ef; /* Magenta */
  --accent-secondary: #3b82f6; /* Blue */
  --border-color: rgba(15, 23, 42, 0.05);
  
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 8px 16px -4px rgb(0 0 0 / 0.05), 0 4px 6px -2px rgb(0 0 0 / 0.02);
  --shadow-lg: 0 20px 40px -5px rgb(0 0 0 / 0.1), 0 10px 20px -5px rgb(0 0 0 / 0.04);
  --shadow-glow: 0 0 30px 0 rgba(217, 70, 239, 0.4);

  --glass-bg: rgba(255, 255, 255, 0.4);
  --glass-border: rgba(255, 255, 255, 0.6);
  --glass-spotlight: rgba(255, 255, 255, 0.8);

  --font-bengali: 'Hind Siliguri', sans-serif;
  --font-english: 'Inter', sans-serif;

  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-primary: #050505;
  --bg-secondary: rgba(15, 15, 20, 0.5);
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #475569;
  --accent-primary: #c026d3; /* Vibrant Magenta/Purple */
  --accent-secondary: #06b6d4; /* Vivid Cyan */
  --border-color: rgba(255, 255, 255, 0.08);

  --shadow-md: 0 8px 16px -4px rgb(0 0 0 / 0.5), 0 4px 6px -2px rgb(0 0 0 / 0.3);
  --shadow-lg: 0 25px 50px -12px rgb(0 0 0 / 0.6);
  --shadow-glow: 0 0 40px 0 rgba(6, 182, 212, 0.4);

  --glass-bg: rgba(20, 20, 25, 0.4);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-spotlight: rgba(255, 255, 255, 0.05);
}

/* Premium Cinematic Animated Tech Background */
.aurora-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -2;
  overflow: hidden;
  background-color: var(--bg-primary);
  transition: background-color var(--transition-slow);
}

/* Subtle Animated Rotating Gradient Beams */
.aurora-bg::before {
  content: "";
  position: absolute;
  top: -50%; 
  left: -50%;
  width: 200%; 
  height: 200%;
  background: conic-gradient(
    from 180deg at 50% 50%,
    transparent 0deg,
    rgba(6, 182, 212, 0.1) 40deg,
    transparent 90deg,
    rgba(168, 85, 247, 0.1) 135deg,
    transparent 180deg,
    rgba(59, 130, 246, 0.1) 220deg,
    transparent 270deg,
    rgba(217, 70, 239, 0.1) 310deg,
    transparent 360deg
  );
  animation: spin-aurora 25s linear infinite;
  z-index: 0;
}

[data-theme="light"] .aurora-bg::before {
  background: conic-gradient(
    from 180deg at 50% 50%,
    transparent 0deg,
    rgba(59, 130, 246, 0.08) 40deg,
    transparent 90deg,
    rgba(168, 85, 247, 0.08) 135deg,
    transparent 180deg,
    rgba(6, 182, 212, 0.08) 220deg,
    transparent 270deg,
    rgba(217, 70, 239, 0.08) 310deg,
    transparent 360deg
  );
}

/* Premium Tech Grid Overlay */
.aurora-bg::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  z-index: 1;
  pointer-events: none;
  /* Mask grid so it only shows subtly in the center/where needed */
  -webkit-mask-image: radial-gradient(circle at center, black 10%, transparent 80%);
  mask-image: radial-gradient(ellipse at center, black 10%, transparent 80%);
}

[data-theme="dark"] .aurora-bg::after {
  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);
}

/* Floating Light Blobs */
.aurora-blob {
  position: absolute;
  filter: blur(120px);
  border-radius: 50%;
  animation: drift-blob 20s infinite ease-in-out alternate;
  pointer-events: none;
  z-index: 2;
  mix-blend-mode: screen;
}

[data-theme="light"] .aurora-blob {
  mix-blend-mode: multiply;
  opacity: 0.15;
}

[data-theme="dark"] .aurora-blob {
  opacity: 0.25;
}

.aurora-blob:nth-child(1) {
  top: 10%; 
  left: -5%;
  width: 40vw; 
  height: 40vw;
  background: var(--accent-secondary); 
  animation-delay: 0s;
}

.aurora-blob:nth-child(2) {
  bottom: 0%; 
  right: -5%;
  width: 50vw; 
  height: 50vw;
  background: var(--accent-primary); 
  animation-delay: -7s;
}

@keyframes spin-aurora {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes drift-blob {
  0% { transform: translate(0, 0) scale(1) rotate(0deg); }
  33% { transform: translate(15vw, 15vh) scale(1.2) rotate(90deg); }
  66% { transform: translate(-10vw, 20vh) scale(0.9) rotate(180deg); }
  100% { transform: translate(5vw, -5vh) scale(1.1) rotate(270deg); }
}

/* Global Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--font-bengali);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

body[data-lang="en"] {
  font-family: var(--font-english);
}

ul {
  list-style: none;
}

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

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
}

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

/* Layout Utilities */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 2rem;
}

.section {
  padding: 5rem 0;
}

.section-head {
  text-align: center;
  margin-bottom: 4rem;
}

.section-head h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  background: linear-gradient(to right, var(--accent-primary), var(--accent-secondary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.section-head p {
  color: var(--text-secondary);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 2.2rem;
  border-radius: 9999px;
  font-weight: 600;
  font-size: 1.05rem;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
  z-index: 1;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0; left: 0; width: 100%; height: 100%;
  background: linear-gradient(to right, var(--accent-primary), var(--accent-secondary));
  z-index: -1;
  transition: opacity var(--transition-normal);
  opacity: 1;
}

.btn-primary {
  color: #ffffff;
  box-shadow: var(--shadow-md);
  border: none;
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: var(--shadow-glow);
}

.btn-primary:hover::before {
  opacity: 0.85;
}

.btn-outline {
  color: var(--text-primary);
  background: transparent;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.btn-outline::before {
  content: '';
  position: absolute;
  inset: 2px;
  background: var(--bg-primary);
  border-radius: 9999px;
  z-index: -1;
  transition: background var(--transition-normal), opacity var(--transition-normal);
}

.btn-outline::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(to right, var(--accent-primary), var(--accent-secondary));
  border-radius: 9999px;
  z-index: -2;
}

.btn-outline:hover {
  color: #ffffff;
  transform: translateY(-3px) scale(1.02);
  box-shadow: var(--shadow-glow);
}

.btn-outline:hover::before {
  opacity: 0;
}

/* Header Wrapper (Haptic Theme Style) */
.header-wrapper {
  position: fixed;
  top: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  width: calc(100% - 3rem);
  max-width: 1200px;
  z-index: 50;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
}

.header-wrapper.scrolled .top-bar {
  opacity: 0;
  transform: translateY(-20px);
  pointer-events: none;
  height: 0;
  padding: 0;
  margin-bottom: 0;
}

.top-bar {
  background: linear-gradient(to right, var(--accent-secondary), var(--accent-primary));
  border-radius: 40px 40px 0 0;
  padding: 0.75rem 2.5rem 1.75rem 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: white;
  font-size: 0.875rem;
  font-weight: 600;
  margin: 0 2rem;
  transform: translateY(1.2rem);
  z-index: 1;
  transition: all var(--transition-normal);
  overflow: hidden;
}

[data-theme="dark"] .top-bar {
  background: linear-gradient(to right, var(--accent-primary), #a855f7);
}

.top-bar-left, .top-bar-right {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.top-bar-left span {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.top-bar-right a {
  color: white;
  font-size: 1.25rem;
  transition: opacity var(--transition-fast);
}

.top-bar-right a:hover {
  opacity: 0.8;
}

.main-header {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 100px;
  box-shadow: 0 15px 35px rgba(0,0,0,0.1);
  position: relative;
  z-index: 2;
  transition: all var(--transition-normal);
}

[data-theme="dark"] .main-header {
  box-shadow: 0 15px 35px rgba(0,0,0,0.4);
}

.header-wrapper.scrolled .main-header {
  box-shadow: var(--shadow-lg);
  background: var(--glass-bg);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
  padding: 0 2rem;
  transition: height var(--transition-normal);
}

.header-wrapper.scrolled .nav {
  height: 70px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo span {
  color: var(--accent-primary);
}

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

.nav-link {
  font-weight: 500;
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background-color: var(--accent-primary);
  transition: width var(--transition-fast);
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.icon-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  font-size: 1.25rem;
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  background: var(--accent-primary);
  color: #fff;
  border-color: var(--accent-primary);
}

/* Mobile Menu Toggle */
.mobile-toggle {
  display: none;
  font-size: 1.5rem;
  color: var(--text-primary);
}

/* Hero Section */
.hero {
  padding: 12rem 0 8rem;
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  background-size: cover;
  background-position: center;
  opacity: 0.1;
}

[data-theme="dark"] .hero-bg {
  opacity: 0.3;
}

.hero-content {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.5rem;
}

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

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 2.5rem;
}

.hero-btns {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

/* Hero Digital Network Animation */
#digital-network {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.cursor-glow {
  position: absolute;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(217,70,239,0.15) 0%, rgba(255,255,255,0) 70%);
  border-radius: 50%;
  pointer-events: none;
  transform: translate(-50%, -50%);
  transition: opacity 0.3s ease;
  z-index: 2;
  mix-blend-mode: screen;
}

[data-theme="dark"] .cursor-glow {
  background: radial-gradient(circle, rgba(217,70,239,0.2) 0%, rgba(0,0,0,0) 70%);
}

/* Page Header for Inner Pages */
.page-header {
  padding: 12rem 0 6rem;
  background: linear-gradient(135deg, rgba(217, 70, 239, 0.05), rgba(59, 130, 246, 0.1));
  text-align: center;
  border-bottom: 1px solid var(--border-color);
}

.page-title {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 1rem;
  background: linear-gradient(to right, var(--accent-primary), var(--accent-secondary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.page-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* Cards / Services */
.grid {
  display: grid;
  gap: 2rem;
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  padding: 2.5rem;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transform-style: preserve-3d;
  will-change: transform;
}

/* Mouse Spotlight Hover on Card */
.card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(800px circle at var(--mouse-x) var(--mouse-y), var(--glass-spotlight), transparent 40%);
  opacity: 0;
  transition: opacity var(--transition-normal);
  pointer-events: none;
  z-index: 0;
}

.card:hover::after {
  opacity: 1;
}

.card > * {
  position: relative;
  z-index: 1;
  /* To help avoid z-index collision with spotlight */
  transform: translateZ(20px);
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(to right, var(--accent-primary), var(--accent-secondary));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-normal);
  z-index: 2;
}

.card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: var(--shadow-lg);
  border-color: rgba(255, 255, 255, 0.2);
}

.card:hover::before {
  transform: scaleX(1);
}

.card-icon {
  width: 64px;
  height: 64px;
  border-radius: 1rem;
  background: rgba(79, 70, 229, 0.1);
  color: var(--accent-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  margin-bottom: 1.5rem;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.card-text {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Angled & Geometric Sections (Proactive Style) */
.section-angled {
  position: relative;
  background: var(--bg-secondary);
  padding: 8rem 0;
  margin-top: -4rem;
  z-index: 1;
  clip-path: polygon(0 4rem, 100% 0, 100% calc(100% - 4rem), 0 100%);
}

.section-angled-alt {
  position: relative;
  background: linear-gradient(135deg, rgba(217, 70, 239, 0.05), rgba(59, 130, 246, 0.05));
  padding: 8rem 0;
  margin-top: -4rem;
  z-index: 2;
  clip-path: polygon(0 0, 100% 4rem, 100% 100%, 0 calc(100% - 4rem));
}

[data-theme="dark"] .section-angled-alt {
  background: linear-gradient(135deg, rgba(217, 70, 239, 0.08), rgba(59, 130, 246, 0.08));
}

/* Geometric Divider Lines */
.geo-line-top {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(to right, var(--accent-primary), var(--accent-secondary));
  z-index: 10;
  transform: skewY(-2deg);
  transform-origin: top left;
}

/* Scroll Animations */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.8s ease-out;
}

.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* Footer */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 4rem 0 2rem;
  margin-top: 5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-about p {
  color: var(--text-secondary);
  margin-top: 1rem;
}

.footer-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.footer-links li {
  margin-bottom: 0.75rem;
}

.footer-links a {
  color: var(--text-secondary);
}

.footer-links a:hover {
  color: var(--accent-primary);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.875rem;
}

/* Language Visibility */
[data-lang="bn"] .en { display: none !important; }
[data-lang="en"] .bn { display: none !important; }

/* Responsive */
@media (max-width: 768px) {
  .header {
    width: calc(100% - 1rem);
    top: 1rem;
    border-radius: 50px;
  }
  
  
  .nav-links {
    display: flex;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: var(--glass-bg);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    padding: 8rem 2rem 2rem;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    border: none;
    box-shadow: none;
    border-radius: 0;
    z-index: -1;
    opacity: 0;
    pointer-events: none;
    transform: translateY(-20px);
    transition: all var(--transition-normal);
  }
  
  .nav-links.active {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
  }

  .nav-links a {
    font-size: 1.5rem;
    margin-bottom: 2rem;
  }

  .mobile-toggle {
    display: block;
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .section-angled, .section-angled-alt {
    padding: 6rem 0;
    clip-path: polygon(0 2rem, 100% 0, 100% calc(100% - 2rem), 0 100%);
    margin-top: -2rem;
  }
  .section-angled-alt {
    clip-path: polygon(0 0, 100% 2rem, 100% 100%, 0 calc(100% - 2rem));
  }

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

/* Vanta JS Birds Hero Animation */
#vanta-bg {
  animation: vanta-zoom-out 4s cubic-bezier(0.2, 0.8, 0.2, 1) forwards !important;
  transform-origin: center center;
  opacity: 0;
}

@keyframes vanta-zoom-out {
  0% { transform: scale(2); opacity: 0; filter: blur(10px); }
  100% { transform: scale(1); opacity: 1; filter: blur(0px); }
}

/* Premium Custom Mouse Cursor (Ring Only, Native Pointer) */
.custom-cursor-outline {
  position: fixed;
  top: 0; left: 0;
  width: 40px; height: 40px;
  border: 1.5px solid rgba(255, 255, 255, 0.8);
  border-radius: 50%;
  pointer-events: none;
  z-index: 9998;
  transition: width 0.2s cubic-bezier(0.2, 0.8, 0.2, 1), 
              height 0.2s cubic-bezier(0.2, 0.8, 0.2, 1), 
              background-color 0.2s, 
              border-color 0.2s,
              transform 0.1s;
  mix-blend-mode: difference;
}

[data-theme="light"] .custom-cursor-outline {
  border-color: var(--accent-secondary);
  mix-blend-mode: normal;
}

.custom-cursor-outline.hovering {
  width: 75px;
  height: 75px;
  background-color: rgba(255, 255, 255, 0.1);
  border-color: transparent;
}

[data-theme="light"] .custom-cursor-outline.hovering {
  background-color: rgba(59, 130, 246, 0.1);
}

/* Click Animation Class */
.custom-cursor-outline.clicked {
  width: 20px;
  height: 20px;
  border-width: 4px;
  background-color: rgba(255, 255, 255, 0.3);
}

@media (pointer: coarse) {
  .custom-cursor-outline {
    display: none !important;
  }
}

.card-icon {
  width: 70px;
  height: 70px;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: flex-start;
}

/* Interactive Storytelling Narratives */
.story-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 4rem;
  margin-bottom: 5rem;
}

.story-block.reverse {
  grid-template-columns: 1fr 1fr;
  direction: rtl;
}

.story-block.reverse > * {
  direction: ltr; /* Reset text direction inside */
}

.story-content h3 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  line-height: 1.2;
}

.story-content p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 1.5rem;
}

.story-lottie {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 2rem;
  background: radial-gradient(circle at center, rgba(var(--accent-primary), 0.05), transparent 70%);
  border-radius: 2rem;
}

@media (max-width: 900px) {
  .story-block, .story-block.reverse {
    grid-template-columns: 1fr;
    gap: 2rem;
    direction: ltr;
  }
}