/* ===== Base Styles ===== */
:root {
  --primary-color: #4361ee;
  --primary-dark: #3a56d4;
  --secondary-color: #3f37c9;
  --accent-color: #4895ef;
  --light-color: #f8f9fa;
  --dark-color: #212529;
  --gray-color: #6c757d;
  --light-gray: #e9ecef;
  --success-color: #4bb543;
  --warning-color: #f0ad4e;
  --danger-color: #d9534f;
  --border-radius: 8px;
  --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
}

/* Dark Theme Variables */
[data-theme="dark"] {
  --primary-color: #4895ef;
  --primary-dark: #3f37c9;
  --secondary-color: #4361ee;
  --light-color: #212529;
  --dark-color: #f8f9fa;
  --gray-color: #adb5bd;
  --light-gray: #343a40;
  --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Poppins', sans-serif;
  line-height: 1.6;
  color: var(--dark-color);
  background-color: var(--light-color);
  transition: var(--transition);
}

a {
  text-decoration: none;
  color: var(--primary-color);
  transition: var(--transition);
}

a:hover {
  color: var(--primary-dark);
}

img {
  max-width: 100%;
  height: auto;
}

ul {
  list-style: none;
}

/* ===== Header Styles ===== */
header {
  background-color: var(--light-color);
  box-shadow: var(--box-shadow);
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: var(--transition);
}

.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--primary-color);
}

.theme-toggle {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  margin-left: auto;
  margin-right: 1.5rem;
  transition: var(--transition);
}

.theme-toggle:hover {
  transform: scale(1.1);
}

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

.hamburger {
  display: none;
  font-size: 1.8rem;
  cursor: pointer;
  color: var(--dark-color);
}

.nav-links {
  display: flex;
  gap: 1.5rem;
}

.nav-links li a {
  color: var(--dark-color);
  font-weight: 500;
  padding: 0.5rem 0;
  position: relative;
}

.nav-links li a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-color);
  transition: var(--transition);
}

.nav-links li a:hover::after {
  width: 100%;
}

.nav-links li a.active {
  color: var(--primary-color);
  font-weight: 600;
}

/* ===== Main Content Styles ===== */
main.course-detail {
  padding: 3rem 0;
}

.course-detail h2 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: var(--primary-color);
  text-align: center;
}

.meta {
  text-align: center;
  color: var(--gray-color);
  margin-bottom: 2rem;
  font-size: 1.1rem;
}

.course-detail p {
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
  line-height: 1.8;
}

.course-detail h3 {
  font-size: 1.8rem;
  margin: 2rem 0 1rem;
  color: var(--secondary-color);
}

.course-detail ul {
  margin-bottom: 2rem;
  padding-left: 1.5rem;
}

.course-detail ul li {
  margin-bottom: 0.8rem;
  position: relative;
  list-style-type: disc;
  color: var(--gray-color);
}

.course-detail ul li::marker {
  color: var(--primary-color);
}

.course-detail ul li strong {
  color: var(--dark-color);
}

/* Video Teaser Styles */
.video-teaser {
  margin: 2rem 0;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--box-shadow);
}

.video-teaser iframe {
  width: 100%;
  height: 500px;
  border: none;
}

/* Timeline Styles */
.timeline {
  margin: 3rem 0;
  position: relative;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 100%;
  background-color: var(--primary-color);
  border-radius: 10px;
}

.phase {
  padding: 1.5rem;
  margin-bottom: 2rem;
  background-color: var(--light-gray);
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  position: relative;
  width: calc(50% - 2rem);
  transition: var(--transition);
}

.phase:hover {
  transform: translateY(-5px);
}

.phase:nth-child(odd) {
  margin-right: auto;
}

.phase:nth-child(even) {
  margin-left: auto;
}

.phase h4 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.phase::before {
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background-color: var(--primary-color);
  top: 1.5rem;
}

.phase:nth-child(odd)::before {
  right: -30px;
}

.phase:nth-child(even)::before {
  left: -30px;
}

/* USP Grid Styles */
.usp-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.usp-card {
  background-color: var(--light-gray);
  padding: 1.5rem;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
}

.usp-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.usp-card h4 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

/* Tech Stack Styles */
.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  justify-content: center;
  margin: 2rem 0;
}

.tech-stack img {
  height: 60px;
  width: auto;
  filter: grayscale(100%);
  opacity: 0.7;
  transition: var(--transition);
}

.tech-stack img:hover {
  filter: grayscale(0%);
  opacity: 1;
  transform: scale(1.1);
}

/* CTA Section Styles */
.cta-section {
  text-align: center;
  padding: 3rem;
  margin: 3rem 0;
  background-color: var(--primary-color);
  color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
}

.cta-section h2 {
  color: white;
  margin-bottom: 1rem;
}

.cta-section p {
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 1.5rem;
}

.enroll-button {
  display: inline-block;
  background-color: white;
  color: var(--primary-color);
  padding: 0.8rem 2rem;
  border-radius: 50px;
  font-weight: 600;
  transition: var(--transition);
  border: none;
  cursor: pointer;
  font-size: 1.1rem;
}

.enroll-button:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.guarantee {
  font-style: italic;
  margin-top: 1rem;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
}

/* ===== Footer Styles ===== */
footer {
  background-color: var(--dark-color);
  color: var(--light-color);
  padding: 3rem 0 0;
}

.footer {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.footer-info h3 {
  font-size: 1.8rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.footer-links ul li {
  margin-bottom: 0.8rem;
}

.footer-links ul li a {
  color: var(--light-color);
  transition: var(--transition);
}

.footer-links ul li a:hover {
  color: var(--primary-color);
  padding-left: 5px;
}

.footer-contact p {
  margin-bottom: 0.8rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.footer-contact a {
  color: var(--light-color);
  transition: var(--transition);
}

.footer-contact a:hover {
  color: var(--primary-color);
}

/* Subscription Panel Styles */
.subscription-panel {
  background-color: var(--light-gray);
  padding: 2rem;
  margin: 2rem auto;
  max-width: 800px;
  border-radius: var(--border-radius);
  text-align: center;
}

.subscription-panel h3 {
  color: var(--primary-color);
  margin-bottom: 1rem;
}

#subscriptionForm {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-top: 1.5rem;
}

#subscriberEmail {
  padding: 0.8rem 1rem;
  border: 2px solid var(--gray-color);
  border-radius: 50px;
  width: 60%;
  max-width: 400px;
  font-size: 1rem;
  transition: var(--transition);
  background-color: var(--light-color);
  color: var(--dark-color);
}

#subscriberEmail:focus {
  outline: none;
  border-color: var(--primary-color);
}

.btn {
  padding: 0.8rem 1.5rem;
  border-radius: 50px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  border: none;
}

.primary-btn {
  background-color: var(--primary-color);
  color: white;
}

.primary-btn:hover {
  background-color: var(--primary-dark);
  transform: translateY(-2px);
}

#subscriptionMessage {
  margin-top: 1rem;
  color: var(--success-color);
}

.bottom-footer {
  text-align: center;
  padding: 1.5rem 0;
  background-color: rgba(0, 0, 0, 0.2);
  margin-top: 2rem;
}

/* ===== Scroll Reveal Animation ===== */
.scroll-reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.scroll-reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive Styles ===== */
@media (max-width: 992px) {
  .video-teaser iframe {
    height: 400px;
  }

  .timeline::before {
    left: 30px;
  }

  .phase {
    width: calc(100% - 4rem);
    margin-left: 4rem !important;
  }

  .phase::before {
    left: -30px !important;
  }
}

@media (max-width: 768px) {
  .hamburger {
    display: block;
  }

  .nav-links {
    position: fixed;
    top: 80px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 80px);
    background-color: var(--light-color);
    flex-direction: column;
    align-items: center;
    padding: 2rem 0;
    transition: var(--transition);
    z-index: 999;
  }

  .nav-links.active {
    left: 0;
  }

  .video-teaser iframe {
    height: 300px;
  }

  .cta-section {
    padding: 2rem 1rem;
  }

  #subscriptionForm {
    flex-direction: column;
    align-items: center;
  }

  #subscriberEmail {
    width: 100%;
  }
}

@media (max-width: 576px) {
  .course-detail h2 {
    font-size: 2rem;
  }

  .video-teaser iframe {
    height: 200px;
  }

  .tech-stack img {
    height: 40px;
  }

  .enroll-button {
    padding: 0.6rem 1.5rem;
  }
}

/* ===== Dark/Light Theme Toggle Functionality ===== */
body.dark-theme {
  background-color: #121212;
  color: #f8f9fa;
}

/* ===== JavaScript Interaction Styles ===== */
/* These styles will be applied when JavaScript interacts with elements */
.nav-links.active {
  left: 0;
}

/* Animation for theme toggle */
@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.theme-toggle.spin {
  animation: spin 0.5s ease-in-out;
}