/* HERO */
.hero {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70vh;
  padding: 0 5%;
  overflow: hidden;
  z-index: 2;
}

.hero-text {
  position: relative;
  z-index: 2; 
  color: white;
  max-width: 600px;
}

.hero-text h1 {
  font-size: 4.7rem;
  z-index: 2; 
  line-height: 1.;
  margin-bottom: 1.5rem;
}
.hero-text .buttons {
  z-index: 2; 
  display: flex;
  gap: 1rem;
}
.hero-text .buttons a {
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.3s ease, transform 0.2s ease;
}

/* Primary / Secondary buttons */
.btn-primary {
  background: #2563eb;
  color: white;
  z-index: 1;
}

.btn-primary:hover {
  background-color: #181f30;
  transform: translateY(-2px);
}

.btn-secondary {
  background: rgba(255,255,255,0.1);
  color: #fff;
}

.btn-secondary:hover {
  background: rgba(255,255,255,0.25);
  transform: translateY(-2px);
}

/* Device container */
#device-container {
  position: absolute;
  top: 70%;
  left: 70%;
  transform: translate(-50%, -50%);
  aspect-ratio: 16/9;  
  z-index: -100;
}

/* PARTICLES BACKGROUND */
.particles-section {
  position: relative;
  overflow: hidden;
}

#particles-js {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%; 
  background: linear-gradient(to bottom, #131724 10%, #121212 90%);
  z-index: -99;
}



/* === Features Section === */
#features, 
.features {
  padding: 5rem 2rem;
  color: #fff;
  text-align: center;
  font-family: "Inter", sans-serif;
  background: transparent; /* keep gradient from particles */
}

/* === Features Heading (side by side) === */
.features-heading {
  display: flex;
  justify-content: center;
  align-items: baseline; 
  gap: 1rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap; 
}

.features-heading h2 {
  font-size: 2rem;
  font-weight: 700;
  color: #fff;
  margin: 0;
  flex-shrink: 0; 
}

.features-heading h3 {
  font-size: 1.6rem;
  font-weight: 500;
  color: #fff;
  margin: 0;
  white-space: nowrap; 
  opacity: 0.85;
}

/* === Feature Tabs (Carousel Controls) === */
.feature-carousel {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.feature-tab {
  background: #121212;
  border: 1px solid rgba(255,255,255,0.15);
  color: #fff;
  font-size: 1.4rem;
  padding: 0.75rem 1.25rem;
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 3px 8px rgba(0,0,0,0.5);
}

.feature-tab:hover {
  background: #1c1c1c;
  transform: translateY(-2px);
}

.feature-tab.active {
  background: #2563eb;
  border-color: #2563eb;
  color: #fff;
  box-shadow: 0 4px 12px rgba(0,0,0,0.6);
}

.feature-tab img {
  width: 40px;  /* adjust size as needed */
  height: 40px; /* maintain uniform square */
  object-fit: contain;
  transition: transform 0.2s;
}

.feature-tab.active img,
.feature-tab:hover img {
  transform: scale(1.1); /* small zoom effect on hover/active */
}

/* === Feature Content === */
.feature-content {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  justify-content: center;
  align-items: stretch;
  max-width: 1100px;
  margin: 0 auto;
  text-align: left;
  position: relative;
}

/* === Feature Columns === */
.feature-col {
  flex: 1 1 350px;
  background: #121212;
  padding: 2rem;
  border-radius: 18px;
  box-shadow: 0 6px 18px rgba(0,0,0,0.5);
  transition: transform 0.3s ease, background 0.3s ease;
}

.feature-col:hover {
  transform: translateY(-5px);
  background: #1c1c1c;
}

.feature-col h3 {
  font-size: 1.4rem;
  margin-bottom: 1rem;
  color: #fff;
}

.feature-col p, 
.feature-col li {
  font-size: 1rem;
  line-height: 1.7;
  color: #fff;
  opacity: 0.85;
}

.feature-col ul {
  list-style: disc;
  padding-left: 1.5rem;
}

/* Fade animation */
.fade {
  opacity: 0;
  transition: opacity 0.5s ease;
}

.fade.show {
  opacity: 1;
}

/* --- Mobile Responsive --- */
@media (max-width: 768px) {
  .feature-content {
    flex-direction: column;
  }

  .feature-tab {
    font-size: 1.1rem;
    padding: 0.6rem 0.9rem;
  }

  .features-heading {
    flex-direction: column;
    text-align: center;
  }
}

/* === Hardware Section === */
.hardware-section {
  background-color: #121212;
  color: #ffffff;
  padding: 80px 20px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hardware-container {
  display: flex;
  flex-wrap: wrap;
  max-width: 1200px;
  gap: 60px;
  align-items: center;
}

.hardware-visual {
  flex: 1 1 400px;
  min-width: 300px;
  height: 400px;
  display: flex;
  justify-content: center;
  align-items: center;
  perspective: 1000px;
}

/* Placeholder box if 3D not yet added */
#retrowalker-3d {
  width: 300px;
  height: 300px;
  background-color: #1e1e1e;
  border-radius: 12px;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #888;
  font-size: 14px;
  text-align: center;
}

.hardware-info {
  flex: 1 1 400px;
  min-width: 300px;
}

.hardware-info h2 {
  font-family: 'Poppins', sans-serif;
  font-size: 2rem;
  margin-bottom: 20px;
}

.hardware-description {
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

.hardware-specs {
  list-style: none;
  padding: 0;
  margin-bottom: 30px;
}

.hardware-specs li {
  margin-bottom: 10px;
  font-size: 1rem;
}

.btn-primary {
  background-color: #2563eb;
  color: #fff;
  padding: 12px 28px;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
  transition: 0.3s ease;
}

.btn-primary:hover {
  background-color: #181f30;
}

/* Responsive */
@media (max-width: 900px) {
  .hardware-container {
    flex-direction: column;
    gap: 40px;
  }
}

/* === Use case & Mission Section === */
.use-cases-section {
  padding: 60px 20px;
  text-align: center;
  background-color: #121212; /* match site theme */
  color: #fff;
}

.use-cases-container {
  display: flex;
  justify-content: center;
  gap: 30px;
  flex-wrap: wrap;
  margin-top: 40px;
}

.use-case-card {
  background: #1a1a1a;
  border-radius: 12px;
  padding: 20px;
  width: 300px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.5);
  transition: transform 0.2s ease;
}

.use-case-card:hover {
  transform: translateY(-5px);
}

.use-case-card img {
  width: 100%;
  border-radius: 8px;
  margin-bottom: 15px;
}

.use-case-card h3 {
  margin: 10px 0;
  font-size: 1.2rem;
}

.use-case-card p {
  font-size: 0.95rem;
  line-height: 1.4;
}

/* === FAQ Section === */
.faq-section {
  padding: 80px 20px;
  background: linear-gradient(to top, #131724 20%, #121212 80%);
  color: #fff;
  text-align: center;
  z-index: 1;
}

.faq-section h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 2.5rem;
}

.faq-container {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  text-align: left;
}

.faq-item {
  background: #1a1a1a;
  border-radius: 12px;
  padding: 1rem 1.25rem;
  box-shadow: 0 4px 10px rgba(0,0,0,0.5);
  transition: background 0.3s ease, transform 0.2s ease;
}

.faq-item:hover {
  background: #1c1c1c;
  transform: translateY(-2px);
}

.faq-question {
  width: 100%;
  font-weight: 600;
  font-size: 1.1rem;
  background: none;
  border: none;
  color: #fff;
  cursor: pointer;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.4s ease, opacity 0.3s ease;
  margin-top: 0.5rem;
}

.faq-item.active .faq-answer {
  opacity: 1;
  /* max-height is set dynamically with JS */
}

.faq-footer {
  margin-top: 3rem;
  text-align: center;
  font-size: 0.95rem;
  opacity: 0.85;
}

.hardware-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.retrowalker-img {
  width: 360px;        /* adjusts size nicely */
  height: auto;
  border-radius: 14px; 
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
  object-fit: contain;
}

/* =========================================================
   FULL RESPONSIVE UPGRADE (MOBILE-FIRST)
   Add this AFTER your existing CSS
   ========================================================= */

/* --- Global Scaling --- */
* {
  box-sizing: border-box;
}

html {
  font-size: 15px;
}

@media (max-width: 480px) {
  html {
    font-size: 14px;
  }
}

/* --- HERO Section --- */
@media (max-width: 1024px) {
  .hero {
    height: auto;
    padding: 4rem 5% 6rem;
    flex-direction: column;
    text-align: center;
    gap: 2rem;
  }

  #device-container {
    position: static;
    transform: none;
    margin: 1rem auto 0;
    width: 90%;
    max-width: 400px;
  }
}

@media (max-width: 600px) {
  .hero-text h1 {
    font-size: 2.8rem;
    line-height: 1.15;
  }

  .hero-text .buttons {
    flex-direction: column;
  }

  .hero-text .buttons a {
    width: 100%;
    text-align: center;
  }
}

/* --- Feature Tabs --- */
@media (max-width: 900px) {
  .feature-tab {
    padding: 0.5rem 0.75rem;
    width: 55px;
    height: 55px;
  }

  .feature-tab img {
    width: 30px;
    height: 30px;
  }
}

@media (max-width: 600px) {
  .features-heading h2 {
    font-size: 1.6rem;
  }

  .features-heading h3 {
    font-size: 1.15rem;
  }
}

/* --- Feature Content Columns --- */
@media (max-width: 992px) {
  .feature-content {
    flex-direction: column;
    gap: 1.5rem;
  }

  .feature-col {
    padding: 1.5rem;
    flex: 1 1 auto;
  }
}

@media (max-width: 480px) {
  .feature-col h3 {
    font-size: 1.2rem;
  }

  .feature-col p,
  .feature-col li {
    font-size: 0.95rem;
  }
}

/* --- Hardware Section --- */
@media (max-width: 1024px) {
  .hardware-container {
    flex-direction: column;
    text-align: center;
  }

  .hardware-info {
    order: 2;
  }

  .hardware-visual {
    order: 1;
  }
}

@media (max-width: 600px) {
  .retrowalker-img {
    width: 260px;
  }

  .hardware-info h2 {
    font-size: 1.7rem;
  }

  .hardware-description {
    font-size: 0.95rem;
  }
}

/* --- Use Cases --- */
@media (max-width: 900px) {
  .use-cases-container {
    gap: 20px;
  }

  .use-case-card {
    width: 90%;
    max-width: 330px;
  }
}

@media (max-width: 480px) {
  .use-case-card {
    width: 100%;
    padding: 15px;
  }

  .use-case-card h3 {
    font-size: 1.05rem;
  }
}

/* --- FAQ --- */
@media (max-width: 768px) {
  .faq-section {
    padding: 60px 15px;
  }

  .faq-item {
    padding: 0.9rem 1rem;
  }

  .faq-question {
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  .faq-section h2 {
    font-size: 1.6rem;
  }

  .faq-answer {
    font-size: 0.95rem;
  }
}

/* --- Buttons --- */
@media (max-width: 600px) {
  .btn-primary,
  .btn-secondary {
    width: 100%;
    text-align: center;
    padding: 0.8rem;
    font-size: 1rem;
  }
}

/* --- Extra Touches (safe zones) --- */
@media (max-width: 480px) {
  section,
  .hardware-section,
  .features,
  .use-cases-section,
  .faq-section {
    padding-left: 5%;
    padding-right: 5%;
  }
}

/* ================================
   RESPONSIVE HEADER — FINAL VERSION
   ================================ */

/* container styling */
.nav-container {
  width: 100%;
  padding: 1rem 5%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative; /* IMPORTANT */
  z-index: 1000;
}

.nav-container .logo img {
  height: 70px;
}

/* desktop menu */
.nav-menu {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  list-style: none;
}

.nav-menu a {
  color: white;
  text-decoration: none;
}

/* dropdown (desktop) */
.dropdown-menu {
  display: none;
  position: absolute;
  background: #111;
  padding: 10px 0;
  list-style: none;
  border-radius: 4px;
}

.dropdown:hover .dropdown-menu {
  display: block;
}

/* hamburger button */
.hamburger {
  display: none;
  font-size: 2rem;
  color: white;
  background: none;
  border: none;
  cursor: pointer;
}

/* ================================
   MOBILE MODE
   ================================ */
@media (max-width: 900px) {

  /* show hamburger */
  .hamburger {
    display: block !important;
  }

  /* shrink logo */
  .nav-container .logo img {
    height: 50px;
  }

  /* hide desktop menu */
  .nav-menu {
    display: none !important;
    position: absolute;
    top: 100%;          /* drop directly BELOW the nav */
    left: 0;            /* align full-width */
    width: 100%;
    background: rgba(0,0,0,0.9);
    flex-direction: column;
    padding: 1.5rem 0;
    gap: 1rem;
    text-align: center;
  }

  /* show mobile menu */
  .nav-menu.show {
    display: flex !important;
  }

  /* mobile dropdowns */
  .dropdown-menu {
    position: static;
    background: transparent;
    padding: 0;
    display: none;
    flex-direction: column;
  }

  .dropdown.open .dropdown-menu {
    display: flex;
  }

  .dropdown-menu li a {
    padding: 8px 0;
    display: block;
  }
}