/* ==========================================
   Modern CSS Reset & Theme Declarations (oklch)
   ========================================== */

@layer base {
  :root {
    /* Fonts */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

    /* Light Theme Default Variables */
    --bg-color: oklch(96% 0.015 240);
    --bg-gradient: radial-gradient(circle at top left, oklch(98% 0.01 240), oklch(94% 0.02 245));
    --text-color: oklch(25% 0.02 240);
    --text-secondary: oklch(50% 0.02 240);
    --card-bg: oklch(100% 0 0);
    --card-border: oklch(90% 0.01 240);
    --card-shadow: 
      0 4px 6px -1px rgba(0, 0, 0, 0.05),
      0 10px 15px -3px rgba(0, 0, 0, 0.07),
      0 20px 25px -5px rgba(0, 0, 0, 0.05);
    
    --btn-bg: linear-gradient(135deg, oklch(60% 0.22 250), oklch(45% 0.22 265));
    --btn-hover-bg: linear-gradient(135deg, oklch(65% 0.22 250), oklch(50% 0.22 265));
    --btn-shadow: 0 10px 20px -5px oklch(55% 0.22 250 / 40%);
    --btn-text: oklch(99% 0.005 240);

    /* Lotto Ball Gradients */
    --ball-gold-gradient: linear-gradient(135deg, oklch(85% 0.16 85), oklch(68% 0.15 75));
    --ball-blue-gradient: linear-gradient(135deg, oklch(65% 0.15 235), oklch(48% 0.16 250));
    --ball-red-gradient: linear-gradient(135deg, oklch(65% 0.19 25), oklch(48% 0.21 20));
    --ball-gray-gradient: linear-gradient(135deg, oklch(60% 0.08 285), oklch(43% 0.10 295));
    --ball-green-gradient: linear-gradient(135deg, oklch(68% 0.16 145), oklch(51% 0.17 155));
    --ball-border: rgba(255, 255, 255, 0.35);
    --ball-shadow: 0 4px 8px rgba(0, 0, 0, 0.15), inset 0 -4px 6px rgba(0, 0, 0, 0.2), inset 0 4px 6px rgba(255, 255, 255, 0.4);

    --toggle-bg: oklch(88% 0.02 240);
    --toggle-thumb: oklch(100% 0 0);
    --toggle-border: oklch(82% 0.02 240);
    
    --ambient-glow: oklch(60% 0.22 250 / 8%);
  }

  /* Dark Theme Override */
  [data-theme="dark"] {
    --bg-color: oklch(14% 0.02 245);
    --bg-gradient: radial-gradient(circle at top right, oklch(18% 0.02 240), oklch(12% 0.02 250));
    --text-color: oklch(93% 0.015 240);
    --text-secondary: oklch(68% 0.015 240);
    --card-bg: oklch(21% 0.025 245);
    --card-border: oklch(28% 0.02 245);
    --card-shadow: 
      0 4px 12px rgba(0, 0, 0, 0.4),
      0 12px 24px -4px rgba(0, 0, 0, 0.5),
      inset 0 1px 0 rgba(255, 255, 255, 0.05);
    
    --btn-bg: linear-gradient(135deg, oklch(68% 0.18 190), oklch(52% 0.18 205));
    --btn-hover-bg: linear-gradient(135deg, oklch(73% 0.18 190), oklch(57% 0.18 205));
    --btn-shadow: 0 10px 25px -5px oklch(62% 0.18 195 / 50%);
    --btn-text: oklch(12% 0.02 245);

    --ball-border: rgba(255, 255, 255, 0.2);
    --ball-shadow: 0 6px 12px rgba(0, 0, 0, 0.4), inset 0 -4px 6px rgba(0, 0, 0, 0.3), inset 0 4px 6px rgba(255, 255, 255, 0.3);

    --toggle-bg: oklch(30% 0.02 245);
    --toggle-thumb: oklch(85% 0.15 85);
    --toggle-border: oklch(38% 0.02 245);

    --ambient-glow: oklch(68% 0.18 190 / 12%);
  }
}

/* ==========================================
   Base Layout & Typography
   ========================================== */

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

body {
  font-family: var(--font-family);
  background: var(--bg-gradient);
  background-color: var(--bg-color);
  color: var(--text-color);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px 15px;
  transition: background 0.4s ease, background-color 0.4s ease, color 0.4s ease;
  position: relative;
  overflow-x: hidden;
}

/* Ambient glow effect */
body::before {
  content: "";
  position: absolute;
  top: -10%;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: var(--ambient-glow);
  filter: blur(120px);
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
}

/* Texture overlay for visual tactile richness */
body::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: radial-gradient(oklch(100% 0 0 / 1.5%) 1px, transparent 0);
  background-size: 24px 24px;
  pointer-events: none;
  z-index: 0;
}

/* ==========================================
   Main Application Container Card
   ========================================== */

.app-wrapper {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 680px;
}

.container {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 28px;
  padding: 35px 30px;
  box-shadow: var(--card-shadow);
  text-align: center;
  transition: background-color 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
}

/* Header with Title and Mode Toggle */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
  padding-bottom: 20px;
  border-bottom: 1px dashed var(--card-border);
}

.header h1 {
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--text-color), var(--text-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Beautiful Interactive Toggle Switch */
.theme-switch-container {
  display: flex;
  align-items: center;
  gap: 10px;
}

.theme-toggle-btn {
  background: var(--toggle-bg);
  border: 1px solid var(--toggle-border);
  border-radius: 30px;
  width: 64px;
  height: 34px;
  position: relative;
  cursor: pointer;
  outline: none;
  transition: background-color 0.3s ease, border-color 0.3s ease;
  display: flex;
  align-items: center;
  padding: 3px;
}

.theme-toggle-btn:focus-visible {
  box-shadow: 0 0 0 3px oklch(60% 0.22 250 / 40%);
}

.toggle-thumb {
  background-color: var(--toggle-thumb);
  border-radius: 50%;
  width: 26px;
  height: 26px;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1), background-color 0.3s ease;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

[data-theme="dark"] .toggle-thumb {
  transform: translateX(30px);
}

.toggle-thumb svg {
  width: 15px;
  height: 15px;
  fill: currentColor;
  transition: transform 0.4s ease;
}

/* Sun and moon specific styles */
.toggle-thumb .sun-icon {
  color: oklch(75% 0.17 75);
}

.toggle-thumb .moon-icon {
  color: oklch(25% 0.02 240);
  display: none;
}

[data-theme="dark"] .toggle-thumb .sun-icon {
  display: none;
}

[data-theme="dark"] .toggle-thumb .moon-icon {
  display: block;
  color: oklch(90% 0.18 190);
}

/* ==========================================
   Lotto Set Container & Item Styles
   ========================================== */

#lotto-sets-container {
  margin-bottom: 35px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

/* Empty state / Introduction text */
.empty-state {
  padding: 40px 10px;
  color: var(--text-secondary);
}

.empty-state svg {
  width: 48px;
  height: 48px;
  stroke: var(--text-secondary);
  opacity: 0.6;
  margin-bottom: 12px;
}

.empty-state p {
  font-size: 1.05rem;
  font-weight: 500;
  line-height: 1.5;
}

/* A Single Lotto Set Row Card */
.lotto-set-row {
  background: oklch(100% 0 0 / 2%);
  border: 1px solid var(--card-border);
  border-radius: 18px;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 15px;
  transition: transform 0.3s ease, border-color 0.3s ease, background-color 0.3s ease;
}

.lotto-set-row:hover {
  transform: translateY(-2px);
  background-color: oklch(100% 0 0 / 4%);
}

.lotto-set-label {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  min-width: 50px;
  text-align: left;
}

.lotto-balls-group {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
  flex-wrap: wrap;
}

/* ==========================================
   Lotto Ball Styles
   ========================================== */

.number {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 1.15rem;
  font-weight: 800;
  border: 1px solid var(--ball-border);
  box-shadow: var(--ball-shadow);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
  user-select: none;
  opacity: 0;
  transform: scale(0.3) rotate(-180deg);
  animation: pop-in 0.5s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

@keyframes pop-in {
  to {
    opacity: 1;
    transform: scale(1) rotate(0deg);
  }
}

/* Beautiful Lotto Ball Colors based on Range */
.ball-gold {
  background: var(--ball-gold-gradient);
}

.ball-blue {
  background: var(--ball-blue-gradient);
}

.ball-red {
  background: var(--ball-red-gradient);
}

.ball-gray {
  background: var(--ball-gray-gradient);
}

.ball-green {
  background: var(--ball-green-gradient);
}

/* ==========================================
   Generate Button with Glowing Aesthetics
   ========================================== */

#generate-btn {
  background: var(--btn-bg);
  border: none;
  border-radius: 18px;
  color: var(--btn-text);
  font-size: 1.15rem;
  font-weight: 800;
  padding: 16px 36px;
  cursor: pointer;
  box-shadow: var(--btn-shadow);
  transition: all 0.25s cubic-bezier(0.25, 0.8, 0.25, 1);
  display: inline-flex;
  align-items: center;
  gap: 10px;
  outline: none;
}

#generate-btn:hover {
  background: var(--btn-hover-bg);
  transform: translateY(-2px);
  box-shadow: 0 14px 28px -5px oklch(55% 0.22 250 / 45%);
}

#generate-btn:active {
  transform: translateY(1px);
  box-shadow: 0 6px 12px -5px oklch(55% 0.22 250 / 40%);
}

#generate-btn svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
  transition: transform 0.4s ease;
}

#generate-btn:hover svg {
  transform: rotate(30deg) scale(1.1);
}

/* Footer / Disclaimer style */
.footer-note {
  margin-top: 25px;
  font-size: 0.8rem;
  color: var(--text-secondary);
  opacity: 0.8;
}

/* ==========================================
   Responsive Breakpoints
   ========================================== */

@media (max-width: 520px) {
  .header h1 {
    font-size: 1.35rem;
  }
  
  .container {
    padding: 25px 18px;
    border-radius: 20px;
  }
  
  .lotto-set-row {
    flex-direction: column;
    align-items: stretch;
    padding: 15px 12px;
    gap: 12px;
  }
  
  .lotto-set-label {
    text-align: center;
    border-bottom: 1px solid var(--card-border);
    padding-bottom: 8px;
  }
  
  .lotto-balls-group {
    justify-content: center;
    gap: 8px;
  }
  
  .number {
    width: 38px;
    height: 38px;
    font-size: 1rem;
  }
  
  #generate-btn {
    width: 100%;
    justify-content: center;
  }
}