:root {
  font-family: system-ui, Avenir, Helvetica, Arial, sans-serif;
  line-height: 1.5;
  font-weight: 400;

  color-scheme: light dark;

  /* --- Default Dark Theme Variables --- */
  --bg-gradient: radial-gradient(circle at center, #444 0%, #000000 100%);
  --glass-bg: rgba(255, 255, 255, 0.1);
  --glass-border: rgba(255, 255, 255, 0.2);
  --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  --text-color: #ffffff;
  --text-strong: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.85);
  --text-muted: rgba(255, 255, 255, 0.7);
  --accent-cyan: #00f2fe;
  --accent-purple: #4facfe;
  --primary-accent: #00f2fe;
  --title-glow: rgba(0, 255, 255, 0.2);
  --toggle-bg: rgba(255, 255, 255, 0.08);
  --toggle-border: rgba(255, 255, 255, 0.2);
  --toggle-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
  --toggle-btn-border: rgba(255, 255, 255, 0.2);
  --toggle-hover-border: #ffffff;
  --toggle-active-shadow: 0 0 10px rgba(0, 242, 255, 0.3);
  --panel-bg: rgba(0, 0, 0, 0.4);
  --panel-border: rgba(255, 255, 255, 0.1);
  --panel-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
  --button-bg: rgba(255, 255, 255, 0.1);
  --button-border: rgba(255, 255, 255, 0.2);
  --button-text: #ffffff;
  --button-hover-bg: rgba(255, 255, 255, 0.25);
  --button-hover-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  --button-active-shadow: 0 0 20px rgba(79, 172, 254, 0.4);
  --title-gradient: linear-gradient(45deg, #00f2fe, #4facfe);
  --ripple-color: rgba(255, 255, 255, 0.3);
  --nav-item-weight: 400;

  color: var(--text-color);
  background-color: #242424; /* Fallback */
  background: var(--bg-gradient);
  background-attachment: fixed;

  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

:root[data-theme="light"] {
  --bg-gradient: radial-gradient(circle at center, #ffffff 0%, #cccccc 100%);
  --glass-bg: rgba(255, 255, 255, 0.75);
  --glass-border: rgba(15, 23, 42, 0.12);
  --glass-shadow: 0 8px 32px 0 rgba(15, 23, 42, 0.12);
  --text-color: #000000;
  --text-strong: #000000;
  --text-secondary: #000000;
  --text-muted: rgba(0, 0, 0, 0.7);
  --accent-cyan: #0ea5e9;
  --accent-purple: #6366f1;
  --primary-accent: #0ea5e9;
  --title-glow: rgba(14, 165, 233, 0.35);
  --toggle-bg: rgba(255, 255, 255, 0.85);
  --toggle-border: rgba(15, 23, 42, 0.12);
  --toggle-shadow: 0 8px 20px rgba(15, 23, 42, 0.12);
  --toggle-btn-border: rgba(15, 23, 42, 0.18);
  --toggle-hover-border: rgba(15, 23, 42, 0.5);
  --toggle-active-shadow: 0 0 12px rgba(14, 165, 233, 0.25);
  --panel-bg: rgba(255, 255, 255, 0.7);
  --panel-border: rgba(15, 23, 42, 0.12);
  --panel-shadow: 0 12px 24px rgba(15, 23, 42, 0.12);
  --button-bg: rgba(255, 255, 255, 0.85);
  --button-border: rgba(15, 23, 42, 0.16);
  --button-text: #0f172a;
  --button-hover-bg: rgba(0, 0, 0, 0.05);
  --button-hover-shadow: 0 6px 18px rgba(15, 23, 42, 0.18);
  --button-active-shadow: 0 0 18px rgba(14, 165, 233, 0.25);
  --title-gradient: linear-gradient(45deg, #0ea5e9, #6366f1);
  --ripple-color: rgba(0, 0, 0, 0.1);
}

body {
  margin: 0;
  display: flex;
  min-width: 320px;
  min-height: 100vh;
}

#app {
  width: 100%;
  height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Common UI Element Styles */
.glass-panel {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
}

.btn-neon {
  background: var(--button-bg);
  border: 1px solid var(--button-border);
  color: var(--button-text);
  padding: 8px 16px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  outline: none; /* Remove focus outline */
}

/* Remove focus outline for all buttons */
button:focus {
  outline: none;
}

.btn-neon:hover {
  background: var(--button-hover-bg);
  transform: translateY(-2px);
  box-shadow: var(--button-hover-shadow);
  border-color: var(--accent-cyan);
}

.btn-neon:active {
  transform: translateY(1px);
  box-shadow: var(--button-active-shadow);
}

.icon-only {
  padding: 8px;
  border-radius: 50%;
  width: 40px;
  height: 40px;
}

.unselectable {
  user-select: none;
  -webkit-user-select: none;
}

/* Ripple Effect */
span.ripple {
  position: absolute;
  border-radius: 50%;
  transform: scale(0);
  animation: ripple 600ms linear;
  background-color: var(--ripple-color);
  pointer-events: none;
}

@keyframes ripple {
  to {
    transform: scale(4);
    opacity: 0;
  }
}