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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: #4f6bcd;
  min-height: 100vh;
  min-height: 100dvh;
  min-height: 100svh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.container {
  width: 100%;
  max-width: 600px;
  padding: 5px;
  margin-bottom: 30px;
}

.screen {
  display: none;
  text-align: center;
}

.screen.active {
  display: block;
}

h1,
h2 {
  color: white;
  margin-bottom: 10px;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

/* Menu Screen */
.hamburger-menu {
  position: absolute;
  top: 10px;
  right: 10px;
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  font-size: 24px;
  width: 40px;
  height: 40px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
  z-index: 100;
}

.hamburger-menu:hover {
  background: rgba(255, 255, 255, 0.3);
}

.dropdown-menu {
  position: absolute;
  top: 55px;
  right: 10px;
  background: white;
  border-radius: 8px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
  display: none;
  z-index: 99;
}

.dropdown-menu.active {
  display: block;
}

.menu-item {
  display: block;
  padding: 12px 20px;
  color: #333;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.2s ease;
}

.menu-item:hover {
  background: #f0f0f0;
  border-radius: 8px;
}

#message-screen {
  color: white;
}

#message-screen p {
  font-size: 18px;
  margin-bottom: 10px;
}

.level-filter {
  margin-bottom: 15px;
  text-align: center;
  color: white;
}

.level-filter span {
  font-size: 16px;
  font-weight: 500;
  margin-right: 0px;
}

.level-btn {
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  padding: 8px 8px;
  border-radius: 20px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s ease;
  margin: 0 5px;
}

.level-btn:hover {
  background: rgba(255, 255, 255, 0.3);
}

.level-btn.active {
  background: rgba(255, 255, 255, 0.4);
  border-color: rgba(255, 255, 255, 0.6);
  border-width: 2px;
  font-weight: bold;
}

.favorites-link {
  margin-bottom: 15px;
  text-align: center;
}

.favorites-btn {
  background: rgba(255, 255, 255, 0.3);
  border: 1px solid rgba(255, 255, 255, 0.4);
  color: white;
  padding: 10px 20px;
  border-radius: 20px;
  font-size: 16px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.favorites-btn:hover {
  background: rgba(255, 255, 255, 0.4);
}

/* Set List */
.set-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.set-item {
  background: white;
  padding: 8px;
  border-radius: 15px;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.set-item:hover {
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.set-title {
  font-size: 17px;
  font-weight: bold;
  margin-bottom: 4px;
  color: #333;
}

.set-levels {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
}

.level-select-btn {
  flex: 1;
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  padding: 5px 16px;
  border-radius: 12px;
  font-size: 12px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.level-select-btn:hover {
  transform: translateY(-1px);
  filter: brightness(0.95);
}

/* Level Colors */
.level-select-btn.level-L1,
.nav-link.level-L1 {
  background: #c8f5c8;
  color: #2d5016;
  border-color: #90ee90;
}

.level-select-btn.level-L2,
.nav-link.level-L2 {
  background: #fffacd;
  color: #6b5e00;
  border-color: #fff59d;
}

.level-select-btn.level-L3,
.nav-link.level-L3 {
  background: #ffd9d9;
  color: #8b0000;
  border-color: #ffb3b3;
}

/* Card Screen */
.header {
  margin-bottom: 5px;
  color: white;
}

.header-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header-buttons {
  display: flex;
  gap: 5px;
}

.progress {
  font-size: 18px;
  font-weight: 500;
}

.menu-btn {
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.card-container {
  margin-bottom: 15px;
  perspective: 1000px;
}

.card {
  background: white;
  border-radius: 20px;
  min-height: 300px;
  padding: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
  transition: transform 0.2s ease;
  position: relative;
}

.card:active {
  transform: translateY(2px);
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

.card-content {
  padding: 5px;
  font-size: 24px;
  line-height: 1.6;
  text-align: center;
  width: 100%;
  font-weight: bold;
}

.card-bottom-content {
  padding: 5px;
  font-size: 12px;
  line-height: 1.4;
  text-align: center;
  position: absolute;
  bottom: 0;
  width: 100%;
}

.favorite-star {
  position: absolute;
  top: 8px;
  right: 15px;
  font-size: 28px;
  background: none;
  border: none;
  cursor: pointer;
  color: #b0b0b0;
  transition: all 0.2s ease;
  z-index: 10;
}

.favorite-star:hover {
  transform: scale(1.2);
}

.favorite-star.active {
  color: #ffd700;
}

/* Controls */
.controls {
  display: flex;
  gap: 10px;
  justify-content: center;
}

.btn {
  background: white;
  border: none;
  padding: 0px;
  border-radius: 25px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  width: 160px;
  height: 54px;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

#prev-btn {
  width: 100px;
  font-size: 14px;
}

#next-btn {
  width: 200px;
  font-size: 16px;
}

/* Complete Screen */
#complete-screen {
  color: white;
}

#complete-screen p {
  margin-bottom: 10px;
  font-size: 18px;
}

#completed-set-name {
  font-size: 20px;
  font-weight: 500;
  margin-bottom: 20px;
  color: #fff;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.navigation-links {
  margin-top: 30px;
  color: white;
}

.navigation-links h3 {
  margin-bottom: 15px;
  font-size: 18px;
}

.nav-section {
  margin-bottom: 20px;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.nav-link {
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  padding: 5px 16px;
  border-radius: 15px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
  width: 160px;
}

.theme-nav-section {
  display: flex;
  gap: 10px;
  justify-content: center;
  margin-top: 20px;
}

/* Favorites Screen */
.favorites-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 20px;
}

.favorites-buttons {
  text-align: center;
}

.favorites-warning {
  color: white;
  font-size: 14px;
  margin-top: 20px;
  margin-bottom: 5px;
  opacity: 0.9;
}

.reset-btn {
  background: #ffebee;
  color: #c62828;
  font-size: 12px;
}

.reset-btn:hover {
  background: #ffcdd2;
}

.favorite-item {
  background: white;
  padding: 15px;
  border-radius: 15px;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.favorite-item:hover {
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
  transform: translateY(-2px);
}

.favorite-content {
  text-align: left;
}

.favorite-set {
  font-size: 12px;
  color: #666;
  margin-bottom: 5px;
}

.favorite-text {
  font-size: 16px;
  font-weight: 500;
  color: #333;
}

.no-favorites {
  color: white;
  font-size: 16px;
  margin: 20px 0;
}