/*
 * Portfolio website stylesheet for Atharva Gupta
 *
 * This stylesheet defines a clean, dark themed layout inspired by
 * modern developer portfolios. It leverages CSS variables to
 * centralize colors and spacing values and uses flexible grid
 * layouts for the experience and project sections. Responsiveness
 * is accomplished via media queries so the site adapts gracefully
 * to smaller screens without the need for JavaScript-driven
 * breakpoints. Where possible, semantic element selectors are
 * preferred over heavy class names to aid readability.
 */

:root {
  /* Colour palette derived from ocean blues and neon green accents. */
  --bg-color: #0a192f;
  --primary-color: #112240;
  --accent-color: #64ffda;
  --light-accent: rgba(100, 255, 218, 0.1);
  --text-color: #ccd6f6;
  --heading-color: #e6f1ff;
  --card-bg: #112240;
  --border-radius: 8px;
  --max-width: 1080px;
  --transition-duration: 0.3s;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: Arial, Helvetica, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
}

a {
  color: var(--accent-color);
  text-decoration: none;
  transition: color var(--transition-duration) ease;
}

a:hover {
  color: #9affee;
  text-decoration: underline;
}

/* Navigation bar */
header {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  backdrop-filter: blur(12px);
}

nav.navbar {
  background-color: rgba(10, 25, 47, 0.85);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

nav .logo {
  font-weight: bold;
  color: var(--accent-color);
  font-size: 1.5rem;
}

nav ul.nav-links {
  list-style: none;
  display: flex;
  gap: 2rem;
}

nav ul.nav-links a {
  color: var(--text-color);
  font-weight: 500;
  letter-spacing: 0.5px;
  padding-bottom: 0.2rem;
  transition: border-bottom var(--transition-duration) ease;
}

nav ul.nav-links a.active,
nav ul.nav-links a:hover {
  border-bottom: 2px solid var(--accent-color);
  color: var(--accent-color);
}

/* Hero section */
section.hero {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  height: 100vh;
  color: var(--heading-color);
  text-align: center;
  overflow: hidden;
}

section.hero img.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  z-index: -1;
  filter: brightness(60%);
}

section.hero .hero-content {
  max-width: var(--max-width);
  padding: 0 1.5rem;
}

section.hero h1 {
  font-size: 3rem;
  margin-bottom: 0.5rem;
}

section.hero h2 {
  font-size: 1.5rem;
  color: var(--accent-color);
  margin-bottom: 1rem;
}

section.hero p {
  font-size: 1.1rem;
  margin-bottom: 2rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

section.hero .cta-button {
  display: inline-block;
  background-color: transparent;
  border: 2px solid var(--accent-color);
  color: var(--accent-color);
  padding: 0.7rem 1.5rem;
  border-radius: var(--border-radius);
  font-weight: bold;
  transition: background-color var(--transition-duration) ease,
              color var(--transition-duration) ease;
}

section.hero .cta-button:hover {
  background-color: var(--accent-color);
  color: var(--bg-color);
}

/* Main content common styles */
main section {
  padding: 5rem 1.5rem 4rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

main section h2 {
  color: var(--heading-color);
  font-size: 2rem;
  margin-bottom: 2rem;
  border-bottom: 2px solid var(--light-accent);
  display: inline-block;
  padding-bottom: 0.5rem;
}

/* Experience */
.experience-section .experience-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.experience-section .experience-item {
  background-color: var(--card-bg);
  padding: 1.5rem;
  border-radius: var(--border-radius);
  box-shadow: 0 2px 4px rgba(0,0,0,0.3);
  transition: transform var(--transition-duration) ease;
}

.experience-section .experience-item:hover {
  transform: translateY(-5px);
}

.experience-section .experience-item h3 {
  font-size: 1.3rem;
  margin-bottom: 0.5rem;
  color: var(--accent-color);
}

.experience-section .experience-item .date-location {
  font-size: 0.9rem;
  color: #8892b0;
  margin-bottom: 0.8rem;
}

.experience-section .experience-item ul {
  list-style-type: disc;
  padding-left: 1.2rem;
  color: #8892b0;
}

.experience-section .experience-item li {
  margin-bottom: 0.5rem;
}

/* Projects */
.projects-section .projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.projects-section .project-card {
  background-color: var(--card-bg);
  padding: 1.5rem;
  border-radius: var(--border-radius);
  box-shadow: 0 2px 4px rgba(0,0,0,0.3);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform var(--transition-duration) ease;
}

.projects-section .project-card:hover {
  transform: translateY(-5px);
}

.projects-section .project-card h3 {
  color: var(--accent-color);
  margin-bottom: 0.5rem;
}

.projects-section .project-card p {
  font-size: 0.95rem;
  color: #8892b0;
  margin-bottom: 1rem;
}

.projects-section .project-card a {
  align-self: flex-start;
  margin-top: auto;
  font-weight: bold;
  color: var(--accent-color);
  border-bottom: 2px solid transparent;
  transition: border-color var(--transition-duration) ease;
}

.projects-section .project-card a:hover {
  border-color: var(--accent-color);
}

/* Contact */
.contact-section {
  text-align: center;
}

.contact-section .contact-info {
  margin-top: 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.8rem;
  font-size: 1rem;
}

.contact-section .contact-info a {
  color: var(--accent-color);
  transition: color var(--transition-duration) ease;
}

.contact-section .contact-info a:hover {
  color: #9affee;
}

/* Footer */
footer {
  background-color: var(--primary-color);
  text-align: center;
  padding: 1rem 0;
  color: #8892b0;
  font-size: 0.8rem;
}

/* Responsive adjustments */
@media (min-width: 768px) {
  .experience-section .experience-list {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 1024px) {
  .experience-section .experience-list {
    grid-template-columns: 1fr 1fr 1fr;
  }
}