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

:root {
  --ff-heading: 'Orbitron', sans-serif;
  --ff-body: 'Inter', sans-serif;
  
  --fw-light: 300;
  --fw-regular: 400;
  --fw-medium: 500;
  --fw-semibold: 600;
  --fw-bold: 700;
  
  --fs-300: 0.875rem;   /* 14px */
  --fs-400: 1rem;       /* 16px - Base */
  --fs-500: 1.125rem;   /* 18px */
  --fs-600: 1.25rem;    /* 20px */
  --fs-700: 1.5rem;     /* 24px */
  --fs-800: 2rem;       /* 32px */
  --fs-900: 2.5rem;     /* 40px */
  --fs-hero: 3rem;      /* 48px */
  
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-xxl: 5rem;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--ff-body);
  font-weight: var(--fw-regular);
  font-size: var(--fs-400);
  background-color: #0c1c2c;
  color: #e0f7ff;
  scroll-behavior: smooth;
  line-height: 1.6;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--ff-heading);
  font-weight: var(--fw-bold);
  line-height: 1.2;
  color: #00b4d8;
  text-align: center;
  margin-top: 0;
}

h1 {
  font-size: var(--fs-hero);
  margin-bottom: var(--space-lg);
  letter-spacing: 0.02em;
}

h2 {
  font-size: var(--fs-800);
  margin-bottom: var(--space-md);
  letter-spacing: 0.01em;
}

h3 {
  font-size: var(--fs-600);
  margin-bottom: var(--space-sm);
}

p {
  text-align: center;
  max-width: 800px;
  margin: 0 auto 1em;
}

section {
  padding: 4em 2em;
  text-align: center;
}

/* --- HEADER & NAVIGATION --- */
header {
  background-color: #06101a;
  padding: 1em 2em;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.logo {
  height: 100px;
  width: auto;
  display: flex;
}

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

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

nav a {
  margin-left: 1em;
  color: #e0f7ff;
  text-decoration: none;
  font-weight: bold;
  transition: color 0.3s ease;
}

nav a:hover, nav a.active {
  color: #00b4d8;
}

.mobile-nav-toggle {
  display: none;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0.5em;
  z-index: 1001;
}

.hamburger {
  width: 24px;
  height: 3px;
  background-color: #e0f7ff;
  position: relative;
  transition: background-color 0.3s;
}

.hamburger::before,
.hamburger::after {
  content: '';
  position: absolute;
  width: 24px;
  height: 3px;
  background-color: #e0f7ff;
  transition: transform 0.3s;
}

.hamburger::before {
  top: -8px;
}

.hamburger::after {
  top: 8px;
}

.mobile-nav-toggle[aria-expanded="true"] .hamburger {
  background-color: transparent;
}

.mobile-nav-toggle[aria-expanded="true"] .hamburger::before {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-nav-toggle[aria-expanded="true"] .hamburger::after {
  transform: rotate(-45deg) translate(5px, -5px);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* --- HERO SECTION --- */
#hero {
  position: relative;
  height: 90vh;
  min-height: 500px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  flex-wrap: wrap;
  /* background: #06101a; */
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 1;
  opacity: 0.6;
  filter: brightness(0.7) blur(1px);
  flex: 1 1 100%;
}

.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(120deg, rgba(0, 180, 216, 0.3) 0%, rgba(6, 16, 26, 0.8) 100%);
  z-index: 2;
}

.hero-text {
  position: relative;
  z-index: 3;
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
  color: #fff;
  padding: 2em;
  background: rgba(6, 16, 26, 0.5);
  border-radius: 16px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.25);
}

.hero-text h1 {
  font-size: var(--fs-hero);
  font-weight: 700;
  margin-bottom: 1em;
  letter-spacing: 1px;
  text-transform: uppercase;
  background: linear-gradient(90deg, #ffffff, #00b4d8);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-text p {
  font-size: 1.3rem;
  margin-bottom: 1.5em;
}

/* --- CTA BUTTONS --- */
.cta {
  display: inline-block;
  margin-top: 1em;
  padding: 0.9em 2em;
  background: linear-gradient(90deg, #00b4d8 60%, #007ea7 100%);
  color: white;
  border-radius: 8px;
  text-decoration: none;
  font-weight: bold;
  font-size: 1.1rem;
  box-shadow: 0 2px 8px rgba(0, 180, 216, 0.15);
  transition: background 0.2s, transform 0.2s;
  position: relative;
  overflow: hidden;
}

.cta:hover {
  background: linear-gradient(90deg, #007ea7 60%, #00b4d8 100%);
  transform: translateY(-2px) scale(1.04);
}

.cta::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.7s;
}

.cta:hover::after {
  left: 100%;
}

/* --- ARTICLES SECTION --- */
#articles {
  background: #0e2236;
  padding: 4em 2em;
}

.articles-list {
  display: flex;
  flex-wrap: wrap;
  gap: 2em;
  justify-content: center;
  margin-top: 2em;
}

.articles-list article {
  background: #14263a;
  border-radius: 14px;
  box-shadow: 0 4px 24px rgba(0, 180, 216, 0.08);
  padding: 2em 1.5em;
  max-width: 320px;
  min-width: 260px;
  flex: 1 1 260px;
  transition: transform 0.18s, box-shadow 0.18s;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.articles-list article:hover {
  transform: translateY(-6px) scale(1.03);
  box-shadow: 0 8px 32px rgba(0, 180, 216, 0.18);
}

.articles-list h3 {
  color: #00b4d8;
  margin-bottom: 0.7em;
  font-size: 1.25rem;
  font-weight: 600;
}

.articles-list p {
  color: #e0f7ff;
  font-size: 1rem;
  margin-bottom: 1.2em;
  text-align: left;
}

.read-more {
  color: #00b4d8;
  text-decoration: none;
  font-weight: bold;
  margin-top: auto;
  transition: color 0.2s;
}

.read-more:hover {
  color: #fff;
  text-decoration: underline;
}

/* --- CHARTS SECTION --- */
.charts-section {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin: 2rem auto;
  max-width: 1000px;
}

.chart-block {
  background: #14263a;
  border-radius: 14px;
  padding: 1.5rem;
  box-shadow: 0 4px 24px rgba(0, 180, 216, 0.08);
  max-width: 100%;
  overflow: hidden;
}

.chart-block h3 {
  margin-bottom: 1rem;
  color: #00b4d8;
}

.chart-block canvas {
  width: 100% !important;
  height: 250px !important;
  max-height: 250px !important;
}

/* --- FOOTER --- */
footer {
  background-color: #06101a;
  padding: 2em;
  text-align: center;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1em;
}

.footer-logo {
  height: 40px;
  width: auto;
  margin-bottom: 1em;
}

/* --- ANIMATIONS --- */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

.animate-on-scroll {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

.tech-images img:hover {
  animation: pulse 1s infinite;
}

/* --- RESPONSIVE DESIGN --- */
@media (min-width: 768px) {
  :root {
    --fs-700: 1.75rem;  /* 28px */
    --fs-800: 2.25rem;  /* 36px */
    --fs-900: 3rem;     /* 48px */
    --fs-hero: 3.5rem;  /* 56px */
  }
  
  .charts-section {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .mobile-nav-toggle {
    display: block;
  }
  
  nav {
    position: fixed;
    inset: 0 0 0 30%;
    background: rgba(6, 16, 26, 0.95);
    backdrop-filter: blur(1rem);
    padding: min(30vh, 10rem) 2em;
    z-index: 1000;
    transform: translateX(100%);
    transition: transform 350ms ease-out;
    flex-direction: column;
    align-items: flex-start;
  }
  
  nav[data-visible="true"] {
    transform: translateX(0%);
  }
  
  nav a {
    display: block;
    margin: 1em 0;
    font-size: 1.5rem;
  }
  
  .hero-text h1 {
    font-size: 2rem;
  }
  
  .chart-block canvas {
    height: 200px !important;
  }
}

@media (max-width: 900px) {
  .articles-list {
    flex-direction: column;
    align-items: center;
  }
}