:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  
  /* Indigo default */
  --bg-base: #090d16;
  --bg-surface: rgba(255, 255, 255, 0.04);
  --bg-surface-hover: rgba(255, 255, 255, 0.08);
  --border-color: rgba(255, 255, 255, 0.1);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  
  --accent: #6366f1;
  --accent-hover: #4f46e5;
  --accent-glow: rgba(99, 102, 241, 0.45);
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #d946ef 100%);
}

.theme-emerald {
  --bg-base: #06140e;
  --accent: #10b981;
  --accent-hover: #059669;
  --accent-glow: rgba(16, 185, 129, 0.45);
  --accent-gradient: linear-gradient(135deg, #10b981 0%, #14b8a6 50%, #06b6d4 100%);
}

.theme-sunset {
  --bg-base: #18090d;
  --accent: #f43f5e;
  --accent-hover: #e11d48;
  --accent-glow: rgba(244, 63, 94, 0.45);
  --accent-gradient: linear-gradient(135deg, #f43f5e 0%, #fb923c 50%, #facc15 100%);
}

.theme-amber {
  --bg-base: #140d04;
  --accent: #f59e0b;
  --accent-hover: #d97706;
  --accent-glow: rgba(245, 158, 11, 0.45);
  --accent-gradient: linear-gradient(135deg, #f59e0b 0%, #ea580c 100%);
}

.theme-obsidian {
  --bg-base: #030304;
  --accent: #38bdf8;
  --accent-hover: #0284c7;
  --accent-glow: rgba(56, 189, 248, 0.4);
  --accent-gradient: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-base);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow-x: hidden;
  transition: background-color 0.4s ease;
}

.button-stage {
  position: relative;
  width: 100%;
  max-width: 720px;
  min-height: 100vh;
  padding: 2.5rem 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  z-index: 1;
}

/* Background ambient glow */
.stage-ambient {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--accent-glow) 0%, rgba(0, 0, 0, 0) 70%);
  opacity: 0.35;
  filter: blur(80px);
  pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease;
  z-index: -1;
}

.stage-ambient.active {
  opacity: 0.7;
  transform: translate(-50%, -50%) scale(1.15);
}

/* Header */
.stage-header {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 9999px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-muted);
  backdrop-filter: blur(8px);
}

.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--accent);
  box-shadow: 0 0 8px var(--accent);
}

.combo-badge {
  background: linear-gradient(135deg, #f59e0b, #ef4444);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  padding: 0.3rem 0.9rem;
  border-radius: 9999px;
  box-shadow: 0 4px 14px rgba(239, 68, 68, 0.4);
  animation: pulse 1s infinite alternate;
}

@keyframes pulse {
  0% { transform: scale(1); }
  100% { transform: scale(1.06); }
}

/* Hero Button Container */
.hero-button-container {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 0;
  width: 100%;
}

.hero-button {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.85rem;
  padding: 1.25rem 2.75rem;
  font-family: inherit;
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: #ffffff;
  background: var(--accent-gradient);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 9999px;
  cursor: pointer;
  outline: none;
  overflow: hidden;
  user-select: none;
  box-shadow: 0 10px 30px var(--accent-glow), 0 2px 8px rgba(0, 0, 0, 0.4);
  transform: translateY(0);
  transition: transform 0.12s ease, box-shadow 0.15s ease, filter 0.2s ease;
}

.hero-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 40px var(--accent-glow), 0 4px 12px rgba(0, 0, 0, 0.5);
}

.hero-button.is-pressed,
.hero-button:active {
  transform: translateY(2px) scale(0.97);
  box-shadow: 0 4px 16px var(--accent-glow), 0 1px 4px rgba(0, 0, 0, 0.4);
}

.hero-button.super-glow {
  animation: rainbow-glow 1.5s linear infinite;
}

@keyframes rainbow-glow {
  0% { filter: drop-shadow(0 0 15px #f43f5e); }
  50% { filter: drop-shadow(0 0 25px #38bdf8); }
  100% { filter: drop-shadow(0 0 15px #f43f5e); }
}

.hero-button:focus-visible {
  box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.4), 0 10px 30px var(--accent-glow);
}

.hero-button-icon {
  font-size: 1.25rem;
  transition: transform 0.3s ease;
}

.hero-button:hover .hero-button-icon {
  transform: rotate(180deg);
}

/* Ripple */
.ripple {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.45);
  transform: scale(0);
  animation: ripple-animation 0.6s linear;
  pointer-events: none;
}

@keyframes ripple-animation {
  to {
    transform: scale(2.5);
    opacity: 0;
  }
}

/* Floating Click Effects */
.floating-text {
  position: absolute;
  pointer-events: none;
  font-size: 0.95rem;
  font-weight: 700;
  color: #ffffff;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.8), 0 0 12px var(--accent);
  transform: translate(-50%, -50%);
  animation: float-up 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  z-index: 10;
  white-space: nowrap;
}

@keyframes float-up {
  0% {
    opacity: 1;
    transform: translate(-50%, 0) scale(0.85);
  }
  100% {
    opacity: 0;
    transform: translate(-50%, -60px) scale(1.15);
  }
}

/* Dashboard Grid */
.dashboard-grid {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  width: 100%;
}

.stats-card,
.controls-card,
.achievements-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.25rem;
  backdrop-filter: blur(12px);
}

/* Stats */
.stats-card {
  display: flex;
  align-items: center;
  justify-content: space-around;
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
}

.stat-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  font-weight: 600;
}

.stat-value {
  font-family: var(--font-mono);
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--text-main);
  transition: transform 0.1s ease;
}

.stat-value.highlight {
  color: var(--accent);
}

.stat-divider {
  width: 1px;
  height: 36px;
  background: var(--border-color);
}

/* Controls */
.controls-card {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.control-title {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.segmented-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.segment-btn {
  flex: 1;
  min-width: 65px;
  padding: 0.45rem 0.6rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.segment-btn:hover {
  background: var(--bg-surface-hover);
  color: var(--text-main);
}

.segment-btn.active {
  background: var(--accent);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 2px 10px var(--accent-glow);
}

.control-row {
  display: flex;
  gap: 0.75rem;
  margin-top: 0.25rem;
}

.action-btn {
  flex: 1;
  padding: 0.6rem 1rem;
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: all 0.2s ease;
}

.action-btn.secondary {
  background: var(--bg-surface-hover);
  color: var(--text-main);
}

.action-btn.secondary:hover {
  background: rgba(255, 255, 255, 0.15);
}

.action-btn.danger {
  background: #ef4444;
  color: #fff;
  border-color: #ef4444;
  box-shadow: 0 2px 10px rgba(239, 68, 68, 0.4);
}

/* Achievements */
.achievements-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.85rem;
}

.achievements-count {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  background: rgba(255, 255, 255, 0.08);
  padding: 0.15rem 0.5rem;
  border-radius: 9999px;
  color: var(--text-main);
}

.achievements-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.6rem;
}

.achievement-badge {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.5rem 0.75rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  transition: all 0.2s ease;
}

.achievement-badge.unlocked {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.2);
}

.achievement-badge.locked {
  opacity: 0.4;
  filter: grayscale(1);
}

.achievement-icon {
  font-size: 1.25rem;
}

.achievement-info {
  display: flex;
  flex-direction: column;
}

.achievement-title {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-main);
}

.achievement-desc {
  font-size: 0.65rem;
  color: var(--text-muted);
}

/* Footer */
.stage-footer {
  text-align: center;
}

.subtle-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
}

kbd {
  display: inline-block;
  padding: 0.15rem 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border-color);
  border-radius: 4px;
}

@media (max-width: 480px) {
  .hero-button {
    padding: 1rem 1.75rem;
    font-size: 1rem;
    width: 100%;
  }

  .stats-card {
    padding: 1rem 0.5rem;
  }

  .stat-value {
    font-size: 1.4rem;
  }
}