@import url("https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;700&display=swap");

:root {
  --primary: #6c5ce7; /* Purple */
  --secondary: #fdcb6e; /* Gold */
  --dark: #2d3436;
  --light: #f9f9f9;
  --gray: #636e72;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Outfit", sans-serif;
  text-decoration: none;
  list-style: none;
  scroll-behavior: smooth;
}

body {
  background: var(--light);
  color: var(--dark);
}

/* --- Navbar --- */
nav {
  background: white;
  padding: 15px 5%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
}
.logo {
  font-size: 26px;
  font-weight: 800;
  color: var(--primary);
}
.logo span {
  color: var(--secondary);
}
.nav-links a {
  margin-left: 30px;
  color: var(--dark);
  font-weight: 500;
  transition: 0.3s;
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
}
.btn {
  padding: 10px 25px;
  background: var(--primary);
  color: white;
  border-radius: 5px;
  transition: 0.3s;
  border: none;
  cursor: pointer;
}
.btn:hover {
  background: #5649c0;
  transform: translateY(-3px);
}

/* --- Hero --- */
.hero {
  height: 80vh;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 5%;
  background: linear-gradient(135deg, #fff 50%, #f0edff 50%);
}
.hero-text h1 {
  font-size: 50px;
  line-height: 1.2;
  margin-bottom: 20px;
}
.hero-text span {
  color: var(--primary);
}
.hero-img img {
  width: 500px;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-20px);
  }
}

/* --- Course Cards --- */
.container {
  padding: 80px 5%;
}
.section-header {
  text-align: center;
  margin-bottom: 50px;
}
.grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 30px;
}

.course-card {
  background: white;
  border-radius: 15px;
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
  transition: 0.3s;
  position: relative;
}
.course-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}
.thumb {
  height: 180px;
  width: 100%;
  object-fit: cover;
}

.badge {
  position: absolute;
  top: 15px;
  left: 15px;
  background: var(--secondary);
  color: var(--dark);
  padding: 5px 10px;
  font-size: 12px;
  font-weight: 700;
  border-radius: 5px;
}

.course-info {
  padding: 20px;
}
.meta {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  color: var(--gray);
  margin-bottom: 10px;
}
.price {
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
  display: block;
  margin-top: 10px;
}

/* --- Tabs System (Course Detail) --- */
.tabs {
  display: flex;
  border-bottom: 2px solid #eee;
  margin-bottom: 20px;
}
.tab-btn {
  padding: 15px 30px;
  background: none;
  border: none;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  color: var(--gray);
  position: relative;
}
.tab-btn.active {
  color: var(--primary);
}
.tab-btn.active::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--primary);
}
.tab-content {
  display: none;
  padding: 20px 0;
  animation: fadeIn 0.5s;
}
.tab-content.active {
  display: block;
}
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* --- Accordion (Syllabus) --- */
.accordion-item {
  border: 1px solid #eee;
  margin-bottom: 10px;
  border-radius: 5px;
  overflow: hidden;
}
.accordion-header {
  background: #f8f8f8;
  padding: 15px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  font-weight: 600;
}
.accordion-body {
  padding: 15px;
  display: none;
  background: white;
  border-top: 1px solid #eee;
}
.accordion-item.open .accordion-body {
  display: block;
}

/* --- Progress Bar (Dashboard) --- */
.progress-bg {
  height: 8px;
  background: #eee;
  border-radius: 10px;
  margin: 10px 0;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--secondary);
  width: 0%;
  transition: width 1s ease;
}

/* --- Video Player Page --- */
.video-wrapper {
  width: 100%;
  height: 500px;
  background: black;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  border-radius: 10px;
}
.playlist {
  height: 500px;
  overflow-y: auto;
  background: white;
  border: 1px solid #eee;
  border-radius: 10px;
}
.lesson-item {
  padding: 15px;
  border-bottom: 1px solid #eee;
  cursor: pointer;
  display: flex;
  gap: 10px;
  transition: 0.2s;
}
.lesson-item:hover,
.lesson-item.active {
  background: #f0edff;
}

/* Responsive */
@media (max-width: 768px) {
  .hero {
    flex-direction: column-reverse;
    text-align: center;
    height: auto;
    padding: 50px 5%;
  }
  .hero-img img {
    width: 80%;
    margin-bottom: 30px;
  }
  .video-wrapper {
    height: 300px;
  }
  .playlist {
    height: auto;
    max-height: 300px;
    margin-top: 20px;
  }
}