:root {
  --color-bg: #f5f5f7;
  --color-surface: #ffffff;
  --color-text: #1e1e1e;
  --color-text-secondary: #6e6e73;
  --color-accent: #656f77;
  --color-border: rgba(0, 0, 0, 0.08);
  --color-border-hover: rgba(0, 0, 0, 0.15);
  --font-heading: Georgia, 'Times New Roman', serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --radius-lg: 16px;
  --radius-md: 12px;
  --shadow-soft: 0 2px 20px rgba(0, 0, 0, 0.06);
  --shadow-hover: 0 8px 40px rgba(0, 0, 0, 0.12);
}

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

html, body {
  overflow-x: hidden;
  width: 100%;
  max-width: 100vw;
}

body {
  font-family: var(--font-body);
  margin: 0;
  padding: 0;
}

.selector-body {
  min-height: 100vh;
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  background: var(--color-bg);
  position: relative;
  overflow: hidden;
  padding: 40px 20px;
}

.selector-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
}

.selector-background .floating-icon {
  position: absolute;
  width: 60px;
  height: 60px;
  background: rgba(101, 111, 119, 0.04);
  border: 1px solid rgba(101, 111, 119, 0.06);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: floatSubtle 8s ease-in-out infinite;
}

.selector-background .floating-icon svg {
  width: 28px;
  height: 28px;
  color: rgba(101, 111, 119, 0.15);
  stroke-width: 1.5;
}

.selector-background .icon-1 {
  top: 12%;
  left: 8%;
  animation-delay: 0s;
}

.selector-background .icon-2 {
  top: 18%;
  right: 12%;
  animation-delay: 2s;
}

.selector-background .icon-3 {
  bottom: 22%;
  left: 12%;
  animation-delay: 4s;
}

.selector-background .icon-4 {
  bottom: 18%;
  right: 8%;
  animation-delay: 6s;
}

@keyframes floatSubtle {
  0%, 100% {
    transform: translateY(0) rotate(0deg);
    opacity: 0.6;
  }
  50% {
    transform: translateY(-12px) rotate(3deg);
    opacity: 0.8;
  }
}

.back-button {
  position: fixed;
  top: 24px;
  left: 24px;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
  z-index: 1000;
  box-shadow: var(--shadow-soft);
}

.back-button:hover {
  border-color: rgba(147, 161, 173, 0.55);
  transform: translateX(-2px);
  box-shadow: var(--shadow-hover);
}

.back-button i, .back-button svg {
  width: 20px;
  height: 20px;
  stroke-width: 1.5;
}

.selector-wrapper {
  position: relative;
  z-index: 1;
  max-width: 900px;
  width: 100%;
  animation: fadeIn 0.6s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

.selector-header {
  display: none;
}

.selector-title {
  text-align: center;
  margin-bottom: 40px;
}

.selector-title h2 {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3vw + 0.5rem, 2rem);
  font-weight: 400;
  color: var(--color-text);
  margin-bottom: 8px;
  letter-spacing: -0.5px;
}

.selector-title p {
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--color-text-secondary);
  font-weight: 400;
}

.selector-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-bottom: 40px;
}

.selector-card {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  cursor: pointer;
  min-height: 380px;
  display: flex;
  align-items: flex-end;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-soft);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.selector-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(147, 161, 173, 0.55);
}

.card-background {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: url('../../images/STOCK3.webp');
  background-size: cover;
  background-position: center;
  z-index: 1;
  transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.card-background::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(to top, rgba(30, 30, 30, 0.85) 0%, rgba(30, 30, 30, 0.4) 50%, rgba(30, 30, 30, 0.2) 100%);
  z-index: 1;
}

.card-background::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  backdrop-filter: blur(2px);
  -webkit-backdrop-filter: blur(2px);
  transition: backdrop-filter 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 2;
}

.selector-card:hover .card-background::after {
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.classroom-bg {
  background-image: url('../../images/STOCK4.jpg');
}

.card-content {
  position: relative;
  z-index: 3;
  padding: 32px 28px;
  color: #ffffff;
  width: 100%;
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.selector-card:hover .card-content {
  transform: translateY(-4px);
}

.card-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto 24px;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(10px);
  transition: all 0.3s ease;
}

.selector-card:hover .card-icon {
  background: rgba(255, 255, 255, 0.2);
  transform: scale(1.05);
  border-color: rgba(147, 161, 173, 0.75);
}

.card-icon svg {
  width: 40px;
  height: 40px;
  color: white;
  stroke-width: 1.5;
}

.card-content h3 {
  text-align: center;
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3vw + 0.5rem, 2.5rem);
  font-weight: 400;
  margin-bottom: 8px;
  letter-spacing: -0.3px;
}

.card-content > p {
  font-family: var(--font-body);
  font-size: 0.9rem;
  line-height: 1.5;
  opacity: 0.85;
  margin-bottom: 20px;
}

.card-features {
  list-style: none;
  margin-bottom: 24px;
  padding: 0;
}

.card-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
  font-size: 0.85rem;
  opacity: 0.8;
  transition: all 0.2s ease;
}

.selector-card:hover .card-features li {
  opacity: 0.95;
}

.card-features li svg {
  width: 16px;
  height: 16px;
  stroke-width: 2;
  opacity: 0.9;
}

.card-action {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 20px;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.9rem;
  color: white;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
}

.selector-card:hover .card-action {
  background: rgba(255, 255, 255, 0.18);
  border-color: rgba(147, 161, 173, 0.65);
}

.card-action svg {
  width: 18px;
  height: 18px;
  transition: transform 0.3s ease;
  stroke-width: 2;
}

.selector-card:hover .card-action svg {
  transform: translateX(4px);
}

.selector-footer {
  text-align: center;
}

.btn-back {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 28px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.9rem;
  text-decoration: none;
  box-shadow: var(--shadow-soft);
  transition: all 0.2s ease;
}

.btn-back:hover {
  border-color: rgba(147, 161, 173, 0.55);
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.btn-back svg {
  width: 18px;
  height: 18px;
  stroke-width: 1.5;
  transition: transform 0.2s ease;
}

.btn-back:hover svg {
  transform: translateX(-3px);
}

@media (max-width: 768px) {
  .selector-body {
    padding: 30px 16px;
    align-items: flex-start;
    padding-top: 80px;
  }

  .selector-title {
    margin-bottom: 28px;
  }

  .selector-title h2 {
    font-size: 1.6rem;
  }

  .selector-title p {
    font-size: 0.95rem;
  }

  .selector-cards {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .selector-card {
    min-height: 340px;
  }

  .card-content {
    padding: 28px 24px;
  }

  .card-content h3 {
    font-size: 1.35rem;
  }

  .selector-background .floating-icon {
    display: none;
  }

  .back-button {
    top: 20px;
    left: 16px;
  }
}

@media (max-width: 480px) {
  .selector-body {
    padding: 24px 14px;
    padding-top: 72px;
  }

  .selector-title h2 {
    font-size: 1.4rem;
  }

  .selector-card {
    min-height: 320px;
    border-radius: 14px;
  }

  .card-content {
    padding: 24px 20px;
  }

  .card-icon {
    width: 48px;
    height: 48px;
    margin-bottom: 16px;
  }

  .card-icon svg {
    width: 24px;
    height: 24px;
  }

  .card-content h3 {
    font-size: 1.25rem;
  }

  .card-content > p {
    font-size: 0.85rem;
    margin-bottom: 16px;
  }

  .card-features {
    margin-bottom: 20px;
  }

  .card-features li {
    font-size: 0.8rem;
    margin-bottom: 8px;
  }

  .card-action {
    padding: 11px 18px;
    font-size: 0.85rem;
    width: 100%;
    justify-content: center;
  }

  .btn-back {
    width: 100%;
    justify-content: center;
    padding: 14px 24px;
  }
}

@media (hover: none) and (pointer: coarse) {
  .selector-card:hover {
    transform: none;
  }

  .selector-card:active {
    transform: scale(0.98);
  }

  .selector-card:hover .card-content {
    transform: none;
  }

  .selector-card:hover .card-icon {
    transform: none;
  }

  .selector-card:hover .card-action svg {
    transform: none;
  }
}