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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #2c3e50 0%, #3498db 100%);
  color: #f0f0f0;
  height: 100vh;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
}

header {
  position: fixed;
  top: 0;
  left: 0;
  padding: 0;
  margin: 0;
  z-index: 10;
}

#site-icon {
  width: 500px;
  height: auto; 
  display: block;
  margin: 0;
  padding: 0;
  cursor: default;
  filter: drop-shadow(0 0 5px rgba(0,0,0,0.7));
}

main {
  flex-grow: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 0 20px;
  text-align: center;
  flex-direction: column;
}

.tabs-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 40px;
  min-height: 500px; 
}

.tabs-container {
  display: flex;
  gap: 40px;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
}

.hidden {
  display: none !important;
}

.big-tab {
  background: #34495e;
  width: 540px;
  height: 320px;
  border-radius: 20px;
  cursor: pointer;
  overflow: hidden;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
  transition: box-shadow 0.3s ease, transform 0.2s ease;
  display: block;
  position: relative;
}


.big-tab:hover {
  box-shadow: 0 10px 26px rgba(0, 180, 180, 0.3);
  transform: translateY(-7px);
}

.big-tab img {
  width: 70px;
  height: 70px;
  margin: 0;
  filter: drop-shadow(0 0 4px rgba(0,0,0,0.8));
}

.big-tab span {
  font-weight: 600;
}

.small-tab {
  width: 300px;
  height: 180px;
  border-radius: 15px;
  overflow: hidden;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.35);
  transition: box-shadow 0.3s ease, transform 0.2s ease;
}

.small-tab:hover {
  box-shadow: 0 8px 20px rgba(0, 180, 180, 0.3);
  transform: translateY(-6px);
}

.smaller-tab {
  width: 250px;
  height: 150px;
  border-radius: 12px;
  overflow: hidden;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  transition: box-shadow 0.3s ease, transform 0.2s ease;
}

.smaller-tab:hover {
  box-shadow: 0 6px 18px rgba(0, 180, 180, 0.3);
  transform: translateY(-5px);
}


.small-tab img,
.smaller-tab img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  display: block;
  pointer-events: none;
  user-select: none;
  border-radius: inherit;
}

.back-btn {
  position: fixed;         
  top: 20px;              
  left: 50%;               
  transform: translateX(-50%);
  
  background: rgba(255, 255, 255, 0.15);
  border: none;
  color: #f0f0f0;
  padding: 14px 28px;
  font-size: 2rem;
  cursor: pointer;
  border-radius: 16px;
  user-select: none;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
  transition: background 0.3s ease, box-shadow 0.3s ease;
  font-weight: 600;

  display: block;
  margin: 0;              
  z-index: 1000;        
}

.back-btn:hover {
  background: rgba(255, 255, 255, 0.35);
  box-shadow: 0 8px 22px rgba(255, 255, 255, 0.5);
}

.big-tab img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  border-radius: inherit;
  pointer-events: none;
  user-select: none;
}
.small-tab img {
width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  border-radius: inherit;
  pointer-events: none;
  user-select: none;
}
.smaller-tab img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block; 
  border-radius: inherit;
}


.big-tab,
.small-tab,
.smaller-tab {
  padding: 0 !important;
  gap: 0 !important;
  color: transparent;      
  overflow: hidden;        
}
.smaller-tab span {
  display: none;
}
.small-tab span {
  display: none;
}

@media (max-width: 600px) {
  #site-icon {
    display: block;
    width: 80vw;
    max-width: 300px;
    height: auto;
    margin: 20px auto;
  }

  #main-tabs {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
    width: 100%;
    padding: 0 10px;
  }

  .big-tab {
    width: 100% !important;
    max-width: 400px;
    height: auto;
    margin-bottom: 15px;
  }

  .back-btn {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    top: auto;
    z-index: 1000;
  }
}