/* ============================================
   KHÓA HỌC - STYLES
   ============================================ */

/* ===== COURSES HERO ===== */
.courses-hero {
  position: relative;
  background: linear-gradient(145deg, #e67e22 0%, #d35400 50%, #a04000 100%);
  padding: 55px 50px 55px 60px;
  margin-bottom: 45px;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(211, 84, 0, 0.3);
  min-height: 320px;
  border-radius: 0 0 30px 30px;
  transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.courses-hero:hover {
  box-shadow: 0 25px 80px rgba(211, 84, 0, 0.4);
}

/* ===== DECORATION LINE ===== */
.hero-accent-line {
  position: absolute;
  left: 0;
  top: 15%;
  bottom: 15%;
  width: 5px;
  background: linear-gradient(180deg, #ffd700, #f39c12, #ffd700);
  border-radius: 0 5px 5px 0;
  box-shadow: 0 0 30px rgba(255, 215, 0, 0.3);
  animation: accentPulse 2s ease-in-out infinite;
}

@keyframes accentPulse {
  0%,
  100% {
    opacity: 0.8;
    transform: scaleY(1);
  }
  50% {
    opacity: 1;
    transform: scaleY(1.05);
  }
}

/* ===== BACKGROUND PATTERN ===== */
.hero-bg-pattern {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  opacity: 0.06;
  background-image:
    radial-gradient(circle at 20% 50%, #ffffff 2px, transparent 2px),
    radial-gradient(circle at 80% 20%, #ffffff 2px, transparent 2px),
    radial-gradient(circle at 40% 80%, #ffffff 2px, transparent 2px),
    radial-gradient(circle at 70% 70%, #ffffff 2px, transparent 2px);
  background-size: 80px 80px;
  pointer-events: none;
}

/* ===== DECORATION CIRCLES ===== */
.hero-decoration-circle {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
}
.hero-decoration-circle.c1 {
  width: 300px;
  height: 300px;
  bottom: -100px;
  right: -60px;
  background: rgba(255, 255, 255, 0.04);
  border: 2px solid rgba(255, 255, 255, 0.06);
  animation: circleFloat 8s ease-in-out infinite;
}
.hero-decoration-circle.c2 {
  width: 180px;
  height: 180px;
  top: -60px;
  left: 30%;
  background: rgba(255, 255, 255, 0.03);
  border: 2px solid rgba(255, 255, 255, 0.05);
  animation: circleFloat 6s ease-in-out infinite 2s;
}
.hero-decoration-circle.c3 {
  width: 120px;
  height: 120px;
  bottom: 20px;
  left: 5%;
  background: rgba(255, 215, 0, 0.05);
  border: 2px solid rgba(255, 215, 0, 0.08);
  animation: circleFloat 7s ease-in-out infinite 4s;
}

@keyframes circleFloat {
  0%,
  100% {
    transform: translate(0, 0) scale(1);
  }
  50% {
    transform: translate(-10px, -15px) scale(1.05);
  }
}

/* ===== CONTENT WRAPPER ===== */
.hero-content-wrapper {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
}

/* ===== LEFT SIDE ===== */
.hero-left {
  flex: 1;
  min-width: 0;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  padding: 6px 22px;
  border-radius: 30px;
  font-size: 12px;
  font-weight: 600;
  color: #fff5e6;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 14px;
  transition: all 0.3s ease;
}
.hero-badge:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: scale(1.05);
}
.hero-badge i {
  font-size: 14px;
  color: #ffd700;
}

.hero-title {
  font-size: 44px;
  font-weight: 800;
  font-family: "Playfair Display", serif;
  color: #ffffff;
  line-height: 1.15;
  margin-bottom: 8px;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  animation: titleSlide 0.8s ease-out;
}

@keyframes titleSlide {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.hero-title .highlight {
  color: #ffd700;
  text-shadow: 0 4px 30px rgba(255, 215, 0, 0.3);
  position: relative;
  display: inline-block;
}
.hero-title .highlight::after {
  content: "";
  position: absolute;
  bottom: 2px;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #ffd700, #f39c12);
  border-radius: 2px;
  animation: underlineExpand 1s ease-out 0.5s forwards;
  transform: scaleX(0);
  transform-origin: left;
}

@keyframes underlineExpand {
  from {
    transform: scaleX(0);
  }
  to {
    transform: scaleX(1);
  }
}

.hero-subtitle {
  font-size: 17px;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 22px;
  font-weight: 300;
  animation: titleSlide 0.8s ease-out 0.2s both;
}

/* ===== SEARCH ===== */
.hero-search {
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-radius: 50px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 4px;
  max-width: 420px;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  animation: titleSlide 0.8s ease-out 0.4s both;
}
.hero-search:focus-within {
  border-color: #ffd700;
  box-shadow: 0 0 0 4px rgba(255, 215, 0, 0.15);
  background: rgba(255, 255, 255, 0.15);
  transform: scale(1.02);
}
.hero-search i {
  color: rgba(255, 255, 255, 0.5);
  padding: 0 16px;
  font-size: 16px;
  transition: color 0.3s ease;
}
.hero-search:focus-within i {
  color: #ffd700;
}
.hero-search input {
  flex: 1;
  background: transparent;
  border: none;
  padding: 12px 0;
  color: white;
  font-size: 15px;
  outline: none;
}
.hero-search input::placeholder {
  color: rgba(255, 255, 255, 0.4);
}
.hero-search button {
  background: linear-gradient(135deg, #ffd700, #f39c12);
  border: none;
  color: #2c3e50;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero-search button:hover {
  transform: scale(1.1) rotate(5deg);
  box-shadow: 0 4px 25px rgba(255, 215, 0, 0.4);
}
.hero-search button:active {
  transform: scale(0.95);
}

/* ===== RIGHT SIDE ===== */
.hero-right {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 16px;
  animation: fadeInRight 0.8s ease-out 0.3s both;
}

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* ===== STATS ===== */
.hero-stats-wrapper {
  display: flex;
  gap: 16px;
}
.hero-stat {
  display: flex;
  align-items: center;
  gap: 12px;
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(10px);
  padding: 12px 20px;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.06);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: default;
  position: relative;
  overflow: hidden;
}

.hero-stat::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 215, 0, 0.1),
    transparent
  );
  transition: left 0.6s ease;
}
.hero-stat:hover::before {
  left: 100%;
}

.hero-stat:hover {
  background: rgba(255, 255, 255, 0.12);
  transform: translateY(-4px) scale(1.02);
  border-color: rgba(255, 215, 0, 0.2);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

.stat-icon {
  width: 42px;
  height: 42px;
  min-width: 42px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 215, 0, 0.15);
  color: #ffd700;
  font-size: 18px;
  transition: all 0.3s ease;
}
.hero-stat:hover .stat-icon {
  background: rgba(255, 215, 0, 0.25);
  transform: rotate(-5deg) scale(1.1);
}

.stat-info {
  display: flex;
  flex-direction: column;
}
.stat-number {
  font-size: 22px;
  font-weight: 800;
  color: #ffffff;
  line-height: 1.1;
  transition: all 0.3s ease;
}
.hero-stat:hover .stat-number {
  color: #ffd700;
}
.stat-label {
  font-size: 12px;
  color: rgba(255, 255, 255, 0.5);
  font-weight: 400;
}

/* ===== FLOAT CARDS ===== */
.hero-float-cards {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: flex-end;
}
.hero-float-card {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(15px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 12px;
  padding: 10px 18px;
  color: white;
  font-size: 13px;
  font-weight: 500;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  cursor: default;
}

.hero-float-card:hover {
  background: rgba(255, 255, 255, 0.18);
  transform: translateY(-5px) scale(1.03);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
}
.hero-float-card i {
  font-size: 18px;
  color: #ffd700;
  transition: all 0.3s ease;
}
.hero-float-card:hover i {
  transform: rotate(15deg) scale(1.1);
}

.card-1 {
  animation: cardFloat 4s ease-in-out infinite 0s;
}
.card-2 {
  animation: cardFloat 4s ease-in-out infinite 1.3s;
}
.card-3 {
  animation: cardFloat 4s ease-in-out infinite 2.6s;
}

@keyframes cardFloat {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-8px);
  }
}

/* ============================================
   FILTER TABS - HIỆU ỨNG MỚI
   ============================================ */
.courses-container {
  max-width: 1300px;
  margin: 0 auto;
  padding: 30px 20px 60px;
}

.filter-tabs {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 40px;
  flex-wrap: wrap;
  padding: 8px;
  background: #f8f9fa;
  border-radius: 50px;
  box-shadow: 0 2px 15px rgba(0, 0, 0, 0.04);
}

.filter-tab {
  padding: 10px 30px;
  border-radius: 40px;
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  color: #666;
  background: transparent;
  border: none;
  position: relative;
}

/* Hiệu ứng hover */
.filter-tab:hover {
  color: #e67e22;
  transform: translateY(-2px);
}

/* Hiệu ứng active */
.filter-tab.active {
  background: linear-gradient(135deg, #e67e22, #d35400);
  color: white;
  box-shadow: 0 8px 25px rgba(230, 126, 34, 0.3);
  transform: translateY(-3px);
}

/* Hiệu ứng ripple khi click */
.filter-tab:active {
  transform: scale(0.92);
}

/* ============================================
   COURSES GRID
   ============================================ */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 30px;
  align-items: stretch;
}

/* ============================================
   COURSE CARD - HIỆU ỨNG MỚI
   ============================================ */
.course-card {
  background: white;
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.06);
  transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: 1px solid #f0f0f0;
  display: flex;
  flex-direction: column;
  height: 100%;
  position: relative;
}

/* Hiệu ứng hover card */
.course-card:hover {
  transform: translateY(-10px) scale(1.01);
  box-shadow: 0 20px 50px rgba(230, 126, 34, 0.15);
  border-color: #e67e22;
}

/* Hiệu ứng glow khi hover */
.course-card::before {
  content: "";
  position: absolute;
  top: -2px;
  left: -2px;
  right: -2px;
  bottom: -2px;
  border-radius: 22px;
  opacity: 0;
  transition: opacity 0.5s ease;
  z-index: -1;
  background-size: 200% 200%;
  animation: gradientMove 3s ease infinite;
}

.course-card:hover::before {
  opacity: 1;
}

@keyframes gradientMove {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}

/* Card Image */
.card-image {
  height: 200px;
  overflow: hidden;
  position: relative;
  flex-shrink: 0;
}

.card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.course-card:hover .card-image img {
  transform: scale(1.08);
}

/* Card Badge */
.card-badge {
  position: absolute;
  top: 15px;
  right: 15px;
  background: linear-gradient(135deg, #e67e22, #d35400);
  color: white;
  padding: 4px 16px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  box-shadow: 0 4px 15px rgba(230, 126, 34, 0.3);
  animation: badgePulse 2s ease-in-out infinite;
}

@keyframes badgePulse {
  0%,
  100% {
    box-shadow: 0 4px 15px rgba(230, 126, 34, 0.3);
  }
  50% {
    box-shadow: 0 4px 25px rgba(230, 126, 34, 0.5);
  }
}

/* Card Body */
.card-body {
  padding: 20px 20px 25px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.card-category {
  display: inline-block;
  background: #e67e2210;
  color: #e67e22;
  padding: 3px 14px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  margin-bottom: 10px;
  align-self: flex-start;
  transition: all 0.3s ease;
}

.course-card:hover .card-category {
  background: #e67e22;
  color: white;
}

.card-title {
  font-size: 18px;
  font-weight: 700;
  color: #2c3e50;
  margin-bottom: 6px;
  min-height: 28px;
  transition: color 0.3s ease;
}

.course-card:hover .card-title {
  color: #e67e22;
}

.card-description {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
  flex: 1;
  margin-bottom: 15px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Card Meta */
.card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 15px;
  border-top: 1px solid #eee;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: auto;
  flex-shrink: 0;
  transition: border-color 0.3s ease;
}

.course-card:hover .card-meta {
  border-color: #e67e22;
}

.card-price {
  font-weight: 700;
  color: #e67e22;
  font-size: 17px;
  transition: all 0.3s ease;
}

.course-card:hover .card-price {
  transform: scale(1.05);
}

.card-duration {
  color: #999;
  font-size: 13px;
}
.card-duration i {
  margin-right: 4px;
}

/* Button Detail */
.btn-detail {
  background: linear-gradient(135deg, #e67e22, #d35400);
  color: white;
  padding: 6px 20px;
  border-radius: 30px;
  border: none;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  font-size: 13px;
  flex-shrink: 0;
}

.btn-detail:hover {
  transform: scale(1.08);
  box-shadow: 0 4px 20px rgba(230, 126, 34, 0.4);
}

.course-card:hover .btn-detail {
  animation: btnPulse 1.5s ease-in-out infinite;
}

@keyframes btnPulse {
  0%,
  100% {
    box-shadow: 0 4px 15px rgba(230, 126, 34, 0.3);
  }
  50% {
    box-shadow: 0 4px 30px rgba(230, 126, 34, 0.5);
  }
}

/* ============================================
   EMPTY STATE
   ============================================ */
.empty-courses {
  text-align: center;
  padding: 80px 20px;
  background: #f8f9fa;
  border-radius: 20px;
  grid-column: 1/-1;
}
.empty-courses h3 {
  font-size: 24px;
  color: #666;
  margin-bottom: 15px;
}

.empty-search {
  background: white;
  border-radius: 20px;
  padding: 40px;
  box-shadow: 0 2px 15px rgba(0, 0, 0, 0.05);
}
.empty-search button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(230, 126, 34, 0.3);
}

.search-result-info {
  animation: fadeIn 0.3s ease;
}
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 1024px) {
  .courses-hero {
    border-radius: 0 0 20px 20px;
    padding: 40px 30px 40px 40px;
  }
  .hero-content-wrapper {
    flex-direction: column;
    align-items: stretch;
    gap: 24px;
  }
  .hero-right {
    align-items: stretch;
    width: 100%;
  }
  .hero-stats-wrapper {
    justify-content: center;
  }
  .hero-float-cards {
    justify-content: center;
  }
  .hero-title {
    font-size: 38px;
  }
  .courses-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .courses-hero {
    border-radius: 0 0 16px 16px;
    padding: 30px 20px;
    min-height: auto;
  }
  .hero-title {
    font-size: 30px;
    text-align: center;
  }
  .hero-subtitle {
    font-size: 15px;
    text-align: center;
  }
  .hero-badge {
    margin: 0 auto 14px;
    display: inline-flex;
  }
  .hero-left {
    text-align: center;
  }
  .hero-search {
    max-width: 100%;
    margin: 0 auto;
  }
  .hero-stats-wrapper {
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
  }
  .hero-stat {
    flex: 1;
    min-width: 80px;
    justify-content: center;
    padding: 10px 14px;
  }
  .hero-float-cards {
    justify-content: center;
    gap: 8px;
  }
  .hero-float-card {
    font-size: 12px;
    padding: 8px 14px;
  }
  .stat-number {
    font-size: 18px;
  }
  .stat-icon {
    width: 34px;
    height: 34px;
    min-width: 34px;
    font-size: 15px;
  }
  .filter-tabs {
    border-radius: 30px;
    gap: 6px;
    padding: 6px;
  }
  .filter-tab {
    padding: 8px 18px;
    font-size: 13px;
  }
  .courses-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .card-image {
    height: 180px;
  }
}

@media (max-width: 480px) {
  .courses-hero {
    border-radius: 0 0 12px 12px;
    padding: 24px 16px;
  }
  .hero-title {
    font-size: 24px;
  }
  .hero-subtitle {
    font-size: 14px;
  }
  .hero-badge {
    font-size: 10px;
    padding: 4px 14px;
  }
  .hero-search input {
    font-size: 13px;
    padding: 8px 0;
  }
  .hero-search button {
    width: 38px;
    height: 38px;
  }
  .hero-stat {
    min-width: 60px;
    padding: 6px 10px;
    gap: 8px;
  }
  .stat-number {
    font-size: 16px;
  }
  .stat-label {
    font-size: 10px;
  }
  .stat-icon {
    width: 28px;
    height: 28px;
    min-width: 28px;
    font-size: 12px;
  }
  .hero-float-card {
    font-size: 11px;
    padding: 6px 12px;
  }
  .hero-float-card i {
    font-size: 14px;
  }
  .filter-tabs {
    gap: 4px;
    padding: 4px;
    border-radius: 20px;
  }
  .filter-tab {
    padding: 6px 14px;
    font-size: 12px;
  }
  .card-image {
    height: 160px;
  }
  .card-title {
    font-size: 16px;
  }
}