/*
 * Stylesheet for Akash Banerjee’s portfolio website.
 *
 * The design uses translucent panels, blurred backgrounds and smooth animations.
 * A light tonal backdrop along with a cool blue accent highlights interactive
 * elements. The style aims to reflect and refract surrounding colours while
 * drawing focus to content. Colour schemes rely on neutral bases such as grays
 * and beiges, with accent hues derived from background colours.
 */

:root {
  /* Light base colour with a subtle blue tint. */
  --background-color: #e6f4ff;
  /* Glass panel colours with higher opacity for readability on light backgrounds. */
  --card-bg: rgba(255, 255, 255, 0.6);
  --card-bg-light: rgba(255, 255, 255, 0.8);
  /* Crisp blue accent colour */
  --accent-color: #0a84ff;
  /* Hover state for accent colour – slightly lighter */
  --accent-color-hover: #57a3ff;
  /* Text colours */
  --text-color: #1d1d1f;
  --text-muted: #555;
}

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

html,
body {
  height: 100%;
  width: 100%;
}

body {
  font-family:
    "Inter",
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    Oxygen,
    Ubuntu,
    Cantarell,
    "Open Sans",
    "Helvetica Neue",
    sans-serif;
  background-color: var(--background-color);
  color: var(--text-color);
  overflow-x: hidden;
  line-height: 1.6;
  position: relative;
  height: 100vh;
  touch-action: pan-y;
  overscroll-behavior-y: contain;
  scroll-behavior: smooth;
}

#fluid-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

.sections {
  position: fixed;
  inset: 0;
  overflow: hidden;
  z-index: 1;
}

.panel {
  position: absolute;
  inset: 0;
  overflow-y: auto;
  opacity: 0;
  pointer-events: none;
  transform: scale(0.95);
  transition:
    opacity 0.4s cubic-bezier(0.4, 0, 0.2, 1),
    transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  padding-top: 6rem;
  padding-bottom: 6rem;
}

.panel:first-of-type {
  opacity: 1;
  pointer-events: auto;
  transform: scale(1);
}

/* Animated gradient background */

/* Navigation bar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background: var(--card-bg);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  z-index: 1000;
}

.navbar .brand {
  font-size: 1.4rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--text-color);
  transition: color 0.3s;
  display: flex;
  align-items: center;
  white-space: nowrap;
}

.brand-short {
  display: none;
}

.brand-full {
  display: inline;
}

.navbar .brand:hover {
  color: var(--accent-color);
}

.navbar nav a {
  margin-left: 1.5rem;
  text-decoration: none;
  color: var(--text-muted);
  font-size: 1rem;
  transition: color 0.3s;
}

.navbar nav a:hover {
  color: var(--accent-color);
}

/* Hero section */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 6rem 1rem 4rem; /* top padding accounts for nav height */
}

.profile-photo {
  width: 160px;
  height: 160px;
  object-fit: cover;
  border-radius: 50%;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  margin-bottom: 1rem;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  margin-bottom: 0.5rem;
  font-weight: 700;
}

.hero p {
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
  color: var(--text-muted);
}

.cta-button {
  padding: 0.8rem 2rem;
  font-size: 1rem;
  background: var(--accent-color);
  color: #fff;
  text-decoration: none;
  display: inline-block;
  border: none;
  border-radius: 30px;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  transition:
    transform 0.3s ease,
    box-shadow 0.3s ease,
    background 0.3s;
}

.cta-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.4);
  background: var(--accent-color-hover);
}

/* Arrow linking to next section */
.down-arrow {
  position: fixed;
  left: 50%;
  bottom: 2rem;
  transform: translate(-50%, 0);
  width: 28px;
  height: 28px;
  display: flex;
  color: var(--accent-color);
  opacity: 0.7;
  z-index: 5;
  animation: arrow-bounce 2s infinite;
  transition: opacity 0.3s;
}

.down-arrow:hover {
  opacity: 1;
}

.down-arrow svg {
  width: 100%;
  height: 100%;
}

.down-arrow.hidden {
  opacity: 0;
  pointer-events: none;
}

@media (min-width: 600px) {
  .down-arrow {
    bottom: 3rem;
  }
}

@keyframes arrow-bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translate(-50%, 0);
  }
  40% {
    transform: translate(-50%, 6px);
  }
  60% {
    transform: translate(-50%, 3px);
  }
}

/* Global section styles */
section {
  padding: 4rem 1rem;
}

section h2 {
  font-size: 2.2rem;
  margin-bottom: 2rem;
  text-align: center;
  font-weight: 600;
}

/* Projects */
.projects .project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
}

.project-card {
  background: var(--card-bg-light);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-radius: 20px;
  padding: 2rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  transition:
    transform 0.4s ease,
    box-shadow 0.4s ease;
}

.project-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
}

.project-card h3 {
  margin-top: 0;
  margin-bottom: 0.4rem;
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--accent-color);
}

.project-card small {
  display: block;
  margin-bottom: 0.8rem;
  font-size: 0.8rem;
  color: var(--accent-color);
  font-weight: 600;
  letter-spacing: 0.5px;
}

.project-card p {
  font-size: 0.9rem;
  line-height: 1.5;
  margin-bottom: 1rem;
  color: var(--text-muted);
}

.project-card a {
  font-size: 0.9rem;
  text-decoration: none;
  color: var(--accent-color);
  font-weight: 600;
  transition: color 0.3s;
}

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

/* About */

.about {
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  align-items: center;
  padding-left: 1rem;
  padding-right: 1rem;
}

.about-panel {
  background: var(--card-bg-light);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-radius: 20px;
  padding: 2rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  transition:
    transform 0.4s ease,
    box-shadow 0.4s ease;
  max-width: 800px;
  width: 100%;
}

.about-panel:hover {
  transform: translateY(-6px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
}

.about-content p {
  margin-bottom: 1.2rem;
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Skills */
.skills .skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 2rem;
  max-width: 1000px;
  margin: 0 auto;
  justify-content: center;
}

.skill-category {
  background: var(--card-bg-light);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-radius: 20px;
  padding: 1.5rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  transition:
    transform 0.4s ease,
    box-shadow 0.4s ease;
}

.skill-category:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
}

.skill-category h3 {
  margin-bottom: 1rem;
  color: var(--accent-color);
  font-weight: 600;
  font-size: 1.2rem;
}

.skill-category ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.skill-category li {
  margin-bottom: 0.6rem;
  font-size: 0.9rem;
  color: var(--text-muted);
  position: relative;
  padding-left: 1.1rem;
}

.skill-category li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.5rem;
  width: 0.5rem;
  height: 0.5rem;
  background: var(--accent-color);
  border-radius: 50%;
  opacity: 0.7;
}

/* Contact */
.contact {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.contact-form {
  width: 100%;
  max-width: 600px;
  display: flex;
  flex-direction: column;
}

.contact-form input,
.contact-form textarea {
  margin-bottom: 1rem;
  padding: 0.8rem 1rem;
  background: var(--card-bg);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 10px;
  color: var(--text-color);
  font-size: 0.9rem;
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: var(--text-muted);
}

.contact-form button {
  padding: 0.8rem 2rem;
  background: var(--accent-color);
  color: #fff;
  border: none;
  border-radius: 30px;
  font-size: 1rem;
  cursor: pointer;
  align-self: flex-end;
  transition:
    background 0.3s,
    transform 0.3s;
}

.contact-form button:hover {
  background: var(--accent-color-hover);
  transform: translateY(-2px);
}

.contact-info {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 3rem;
  margin-top: 3rem;
  text-align: center;
}

.contact-info div h3 {
  margin-bottom: 0.5rem;
  color: var(--accent-color);
  font-size: 1.1rem;
  font-weight: 600;
}

.contact-info div p {
  margin: 0;
  color: var(--text-muted);
  line-height: 1.5;
  font-size: 0.9rem;
}
.email a {
  color: #000;
}


.social-icons {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1.5rem;
  margin-top: 0.5rem;
}

.social-icons a {
  color: var(--text-muted);
  transition: color 0.3s;
}

.social-icons a:hover {
  color: var(--accent-color);
}

/* Footer */
.footer {
  text-align: center;
  padding: 2rem 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: auto;
}

/* Fade in animation using IntersectionObserver. Elements with class
 * `fade-in` are initially hidden and slide up into view when scrolled
 * into the viewport. */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition:
    opacity 0.8s ease,
    transform 0.8s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Panels with shadow-fade start with no shadow and fade it in when visible */
.shadow-fade {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0);
  transition: box-shadow 0.4s ease;
}

.shadow-fade.visible {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.shadow-fade.visible:hover {
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
}

@media (max-width: 600px) {
  /* Hide the navigation bar on small screens to remove the sidebar */
  .navbar {
    display: none;
  }
  .hero h1 {
    font-size: 2.5rem;
  }
  .projects .project-grid {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  }
  .skills .skills-grid {
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  }
  .contact-info {
    flex-direction: column;
    gap: 2rem;
  }
  .about {
    align-items: center;
  }
}