/* ======================================
   Helionics – Scientific Theme Stylesheet (Enhanced Contrast Version)
   ====================================== */

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

/* Root Variables */
:root {
  --color-navy: #002147;
  --color-orange: #f47c26;
  --color-lightblue: #d9e6f2;
  --color-text-dark: #1a1a1a;
  --color-text-muted: #444;
  --color-bg-light: #ffffff;
  --color-alert: #c0392b;

  --color-bg: var(--color-bg-light);
  --color-text: var(--color-text-dark);
  --color-muted: var(--color-text-muted);
  --color-accent-bg: var(--color-lightblue);
  --color-link: var(--color-navy);
}

/* Dark Theme Support */
@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f1117;
    --color-text: #e0e0e0;
    --color-muted: #aaaaaa;
    --color-accent-bg: #1e1f26;
    --color-link: #66b2ff;
    --color-navy: #6ab0ff;
  }

  h2, h3 {
    color: #ffffff;
  }

  nav a {
    color: #ffffff;
  }

  .hero {
    background: linear-gradient(135deg, #1a2a44 0%, #2e4e75 100%);
  }

  .hero::before {
    background-color: rgba(0, 21, 48, 0.75);
  }

  .highlight {
    color: #ffae6d;
  }
}

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

body {
  font-family: 'Inter', 'Segoe UI', Tahoma, sans-serif;
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
}

/* Header & Nav */
header {
  background-color: var(--color-navy);
  color: #ffffff;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}

header h1 {
  font-size: 1.8rem;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

nav a {
  color: #ffffff;
  text-decoration: none;
  font-weight: 600;
}

nav a:hover {
  text-decoration: underline;
}

/* Hero Section */
.hero {
  position: relative;
  background: linear-gradient(135deg, #002147 0%, #003b6f 100%);
  background-image: url("data:image/svg+xml,%3Csvg width='160' height='140' viewBox='0 0 160 140' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' stroke='%2300346b' stroke-width='1.5'%3E%3Cpath d='M80 0l80 46v48l-80 46-80-46V46z'/%3E%3Cpath d='M0 46l80 46 80-46' stroke-opacity='0.2'/%3E%3C/g%3E%3C/svg%3E");
  background-size: 220px;
  background-repeat: repeat;
  background-position: center;
  color: #ffffff;
  text-align: center;
  padding: 4rem 2rem;
  z-index: 0;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 33, 71, 0.85);
  z-index: 1;
}

.hero h1,
.hero p,
.hero a {
  position: relative;
  z-index: 2;
}

.hero h1 {
  font-size: 2.7rem;
  margin-bottom: 0.5rem;
  text-shadow: 1px 1px 4px rgba(0, 0, 0, 0.6);
}

.hero p {
  font-size: 1.2rem;
  color: #f2f2f2;
  margin-bottom: 1.5rem;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.5);
}

/* Sections */
section {
  padding: 2rem 1rem;
  max-width: 960px;
  margin: auto;
}

.section-soft {
  background-color: var(--color-accent-bg);
}

h2 {
  color: var(--color-navy);
  font-size: 1.8rem;
  margin-bottom: 1rem;
}

h3 {
  color: var(--color-navy);
  margin-top: 2rem;
  margin-bottom: 0.8rem;
}

p {
  margin-bottom: 1rem;
}

ul {
  padding-left: 1.2rem;
  margin-bottom: 1.5rem;
}

li {
  margin-bottom: 0.5rem;
}

/* Callout */
.callout {
  background-color: var(--color-accent-bg);
  border-left: 6px solid var(--color-orange);
  padding: 1.5rem;
  margin: 2rem 0;
  font-style: italic;
  font-size: 1.1rem;
}

/* Highlighted Text */
.highlight {
  color: var(--color-orange);
  font-weight: bold;
}

/* Footer */
footer {
  background-color: var(--color-navy);
  color: #ffffff;
  text-align: center;
  padding: 1rem;
  margin-top: 3rem;
}

/* Animations */
.fade-in {
  animation: fadeIn 1s ease-in-out both;
}

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

/* Responsive Design */
@media (max-width: 768px) {
  header {
    flex-direction: column;
    align-items: flex-start;
  }

  nav ul {
    flex-direction: column;
    gap: 10px;
    margin-top: 1rem;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero p {
    font-size: 1rem;
  }

  .button {
    font-size: 0.95rem;
    padding: 0.75rem 1.4rem;
  }
}