@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=Outfit:wght@400;600;700;800&display=swap');

:root {
  /* HSL Color System */
  --bg-dark: hsl(224, 71%, 4%);
  --bg-dark-accent: hsl(224, 71%, 6%);
  
  /* State Accents: Ready/Paused (Violet), Work (Coral/Orange), Rest (Emerald) */
  --accent-ready-start: hsl(262, 83%, 64%);
  --accent-ready-end: hsl(245, 80%, 60%);
  --accent-work-start: hsl(14, 100%, 63%);
  --accent-work-end: hsl(35, 100%, 55%);
  --accent-rest-start: hsl(150, 80%, 48%);
  --accent-rest-end: hsl(165, 80%, 40%);
  
  /* Glassmorphism Tokens */
  --glass-bg: rgba(255, 255, 255, 0.03);
  --glass-bg-hover: rgba(255, 255, 255, 0.06);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-border-focus: rgba(255, 255, 255, 0.2);
  --glass-shadow: rgba(0, 0, 0, 0.4);
  
  /* Typography Tokens */
  --font-display: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  
  /* Dynamic Active Accents (Modified dynamically by JS state machine) */
  --active-start: var(--accent-ready-start);
  --active-end: var(--accent-ready-end);
  --active-shadow: rgba(130, 80, 223, 0.3);
  
  --transition-smooth: all 0.5s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-fast: all 0.2s ease;
}

/* Base resets & adjustments for iOS Safari */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent; /* Disable flash tap on iOS */
  user-select: none; /* Prevent text selection during workouts */
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-dark);
  background-image: 
    radial-gradient(circle at 10% 20%, rgba(93, 88, 223, 0.1) 0%, transparent 40%),
    radial-gradient(circle at 90% 80%, rgba(255, 110, 80, 0.08) 0%, transparent 40%);
  background-attachment: fixed;
  color: #ffffff;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 2rem 1.5rem calc(2rem + env(safe-area-inset-bottom)) 1.5rem; /* iOS viewport safe areas */
  overflow: hidden;
}

/* Header UI */
header {
  text-align: center;
  margin-bottom: 1.5rem;
  z-index: 10;
}

header h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.8rem, 5vw, 2.5rem);
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, #ffffff 40%, rgba(255, 255, 255, 0.7));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.25rem;
}

header p {
  font-size: clamp(0.85rem, 3vw, 1rem);
  color: rgba(255, 255, 255, 0.5);
  font-weight: 400;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* Main glass timer card */
.timer-container {
  position: relative;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px); /* Webkit/Safari blur support */
  border: 1px solid var(--glass-border);
  border-radius: 32px;
  width: 100%;
  max-width: 420px;
  aspect-ratio: 1 / 1.1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  box-shadow: 0 24px 64px var(--glass-shadow);
  z-index: 5;
  transition: var(--transition-smooth);
}

.timer-container::before {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: 32px;
  padding: 1px;
  background: linear-gradient(135deg, var(--active-start), transparent 60%);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
  opacity: 0.6;
  transition: var(--transition-smooth);
}

/* Circular Visual Progress Display */
.progress-ring-container {
  position: relative;
  width: clamp(200px, 60vw, 290px);
  height: clamp(200px, 60vw, 290px);
  display: flex;
  align-items: center;
  justify-content: center;
}

.progress-ring {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg); /* Start progress at the top */
}

.progress-ring__circle {
  transition: stroke-dashoffset 0.1s linear, stroke 0.5s ease;
  stroke-linecap: round;
}

.progress-ring__bg {
  stroke: rgba(255, 255, 255, 0.03);
}

/* Display text within the progress ring */
.timer-display {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.time-left {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(4.5rem, 15vw, 6.5rem);
  line-height: 1;
  letter-spacing: -0.05em;
  font-variant-numeric: tabular-nums; /* Prevents shifting during countdown */
  text-shadow: 0 0 30px var(--active-shadow);
  transition: var(--transition-smooth);
}

.timer-label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(0.9rem, 3.5vw, 1.2rem);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: #ffffff;
  margin-top: -0.5rem;
  opacity: 0.9;
  transition: var(--transition-smooth);
}

/* Quick Status indicators (Next Phase / Total sets) */
.timer-stats {
  display: flex;
  justify-content: space-around;
  width: 100%;
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

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

.stat-val {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  color: #ffffff;
}

.stat-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: rgba(255, 255, 255, 0.4);
}

/* Timer Control Buttons styling */
.controls-container {
  display: flex;
  flex-direction: column;
  width: 100%;
  max-width: 420px;
  gap: 1rem;
  margin-top: 2rem;
  z-index: 10;
}

.main-controls {
  display: flex;
  gap: 1rem;
  width: 100%;
}

.btn {
  border: none;
  outline: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  border-radius: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: var(--transition-fast);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
  height: 58px;
}

.btn-primary {
  flex: 2;
  background: linear-gradient(135deg, var(--active-start), var(--active-end));
  color: #ffffff;
  font-size: 1.1rem;
  box-shadow: 0 12px 30px var(--active-shadow);
}

.btn-primary:active {
  transform: scale(0.97);
  box-shadow: 0 6px 15px var(--active-shadow);
  filter: brightness(0.95);
}

.btn-secondary {
  flex: 1;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  color: rgba(255, 255, 255, 0.85);
}

.btn-secondary:active {
  transform: scale(0.97);
  background: var(--glass-bg-hover);
}

/* Secondary controls (Audio state toggles / Screen lock status) */
.sub-controls {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 0.5rem;
}

.icon-btn {
  background: none;
  border: none;
  outline: none;
  cursor: pointer;
  color: rgba(255, 255, 255, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  transition: var(--transition-fast);
}

.icon-btn:active {
  transform: scale(0.92);
  background: var(--glass-bg-hover);
}

.icon-btn.active {
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.1);
  box-shadow: 0 0 12px rgba(255, 255, 255, 0.05);
}

.icon-btn svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
  transition: var(--transition-fast);
}

/* Dynamic Wake Lock Badge */
.wakelock-badge {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.4);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  padding: 0.35rem 0.75rem;
  border-radius: 100px;
  align-self: center;
  transition: var(--transition-fast);
}

.wakelock-badge.active {
  color: #10b981;
  background: rgba(16, 185, 129, 0.08);
  border-color: rgba(16, 185, 129, 0.2);
}

.wakelock-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: currentColor;
}

.wakelock-badge.active .wakelock-dot {
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0% { transform: scale(0.9); opacity: 0.6; }
  50% { transform: scale(1.3); opacity: 1; }
  100% { transform: scale(0.9); opacity: 0.6; }
}

/* Presets panel */
.presets-panel {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  width: 100%;
}

.preset-chip {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  padding: 0.4rem 0.8rem;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.6);
  cursor: pointer;
  transition: var(--transition-fast);
}

.preset-chip.active {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.35);
  color: #ffffff;
}

/* Animations for subtle visual pop */
@keyframes pulse-pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.02); }
  100% { transform: scale(1); }
}

.pulse {
  animation: pulse-pulse 0.4s ease-out;
}