body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: #fff;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  color: #333;
}

/* Hlavička */
header {
  background-color: transparent;
  color: #333;
  padding: 20px 0;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  transition: background-color 0.3s ease;
  position: relative;
  text-align: center;
}

header:hover {
  background-color: transparent;
}

/* Hlavní obsah */
main {
  max-width: 1000px;
  margin: 60px auto;
  padding: 30px;
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
  flex-grow: 1;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* Patička */
footer {
  background-color: #3eb489;
  color: #fff;
  text-align: center;
  padding: 20px;
  margin-top: 50px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.15);
}

/* Obecný kontejner */
.container {
  max-width: 1200px;
  margin: auto;
  padding: 60px 20px;
  text-align: center;
}

/* Kategorie tlačítek */
.category-buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 30px;
}
/* --- Mobilní hamburger menu --- */
/* Hamburger je defaultně skrytý */
.mobile-header {
  display: none;
}

/* --- Mobilní hamburger menu --- */
@media (max-width: 768px) {
  .mobile-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.7em 1em;
    background: transparent;
    border-bottom: 1px solid transparent;
    z-index: 1002;
    position: relative;
  }

  .hamburger {
    background: none;
    border: none;
    padding: 0.5em;
    cursor: pointer;
    z-index: 1003;
    display: flex;
    flex-direction: column;
    gap: 5px;
  }
  .hamburger span {
    display: block;
    width: 28px;
    height: 3px;
    background: #222;
    border-radius: 2px;
    transition: all 0.3s;
  }

  #main-nav {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: 100vw;
    pointer-events: none;
    z-index: 1001;
  }
  #main-nav ul {
    position: fixed;
    top: 0;
    left: -100vw;
    width: 80vw;
    max-width: 200px;
    height: 70vh;
    background: #fff;
    box-shadow: 0 8px 32px rgba(62,180,137,0.18);
    border-radius: 0 22px 22px 0;
    flex-direction: column;
    align-items: flex-start;
    padding: 3em 2em 2em 2em;
    gap: 1.2em;
    display: flex;
    transition: left 0.3s cubic-bezier(.4,0,.2,1);
    pointer-events: auto;
    z-index: 1002;
  }
  #main-nav ul.show {
    left: 0;
  }

  #main-nav ul li {
    margin: 0;
    width: 100%;
  }
  #main-nav ul li a {
    font-size: 1.18em;
    color: #222;
    text-decoration: none;
    font-weight: 600;
    padding: 0.7em 0;
    display: block;
    width: 100%;
    border: none;
    background: transparent;
    border-radius: 10px;
    position: relative;
    transition: background 0.18s, color 0.18s;
    letter-spacing: 0.01em;
    outline: none;
  }
  #main-nav ul li a::after {
    content: '';
    display: block;
    margin: 7px 0 0 0;
    width: 0;
    height: 3px;
    background: linear-gradient(90deg, #3eb489 60%, #34b68a 100%);
    border-radius: 2px;
    transition: width 0.22s;
  }
  #main-nav ul li a:hover,
  #main-nav ul li a:focus {
    background: #e6f7f2;
    color: #3eb489;
  }
  #main-nav ul li a:hover::after,
  #main-nav ul li a:focus::after {
    width: 60%;
  }

  /* Overlay */
  #overlay {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0; top: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.45);
    transition: opacity 0.3s;
  }
  #overlay.open {
    display: block;
  }
}

@media (min-width: 769px) {
  #main-nav ul {
    display: flex;
    flex-direction: row;
    gap: 36px;
    align-items: center;
    justify-content: center;
    background: transparent;
    box-shadow: none;
    border-radius: 0;
    padding: 0;
    margin: 0;
  }
  #main-nav ul li {
    margin: 0;
    width: auto;
  }
  #main-nav ul li a {
    font-size: 1.08em;
    color: #222;
    text-decoration: none;
    font-weight: 500;
    padding: 0.7em 1.3em;
    border-radius: 18px;
    background: transparent;
    transition: background 0.18s, color 0.18s;
  }
  #main-nav ul li a:hover,
  #main-nav ul li a:focus {
    background: #e6f7f2;
    color: #3eb489;
  }
}