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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background: linear-gradient(135deg, #1e1e2f, #2a2a40);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
}

.container {
  text-align: center;
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(12px);
  border-radius: 32px;
  padding: 40px 48px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.08);
  max-width: 480px;
  width: 90%;
}

h1 {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 28px;
  letter-spacing: -0.5px;
  color: #f0f0f5;
}

/* Mode Selector */
.mode-selector {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 32px;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 14px;
  padding: 4px;
}

.mode-btn {
  background: transparent;
  color: rgba(255, 255, 255, 0.5);
  border: none;
  padding: 10px 20px;
  border-radius: 10px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
  flex: 1;
}

.mode-btn:hover {
  color: rgba(255, 255, 255, 0.8);
}

.mode-btn.active {
  background: #ff6b6b;
  color: #fff;
  box-shadow: 0 4px 15px rgba(255, 107, 107, 0.4);
}

/* Timer Ring */
.timer-ring {
  position: relative;
  width: 220px;
  height: 220px;
  margin: 0 auto 28px;
}

.timer-ring svg {
  transform: rotate(-90deg);
  width: 220px;
  height: 220px;
}

.bg-circle {
  fill: none;
  stroke: rgba(255, 255, 255, 0.08);
  stroke-width: 6;
}

.progress-circle {
  fill: none;
  stroke: #ff6b6b;
  stroke-width: 6;
  stroke-linecap: round;
  stroke-dasharray: 628.32;
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 0.3s ease, stroke 0.4s ease;
}

.timer-display {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 3.5rem;
  font-weight: 700;
  letter-spacing: 2px;
  font-variant-numeric: tabular-nums;
  color: #f0f0f5;
}

/* Controls */
.controls {
  display: flex;
  justify-content: center;
  gap: 14px;
  margin-bottom: 20px;
}

#startBtn {
  background: #ff6b6b;
  color: #fff;
  border: none;
  padding: 14px 48px;
  border-radius: 14px;
  font-size: 1.05rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s ease;
  letter-spacing: 0.5px;
  box-shadow: 0 6px 20px rgba(255, 107, 107, 0.35);
}

#startBtn:hover {
  background: #ff5252;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(255, 107, 107, 0.45);
}

#startBtn:active {
  transform: translateY(0);
}

#startBtn.running {
  background: #ffa94d;
  box-shadow: 0 6px 20px rgba(255, 169, 77, 0.35);
}

#startBtn.running:hover {
  background: #ff922b;
}

#resetBtn {
  background: rgba(255, 255, 255, 0.08);
  color: rgba(255, 255, 255, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 14px 28px;
  border-radius: 14px;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

#resetBtn:hover {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
}

/* Session Info */
.session-info {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.45);
  margin-top: 8px;
}

/* States */
.progress-circle.break-mode {
  stroke: #51cf66;
}

.progress-circle.longbreak-mode {
  stroke: #339af0;
}

#startBtn.running.break {
  background: #51cf66;
  box-shadow: 0 6px 20px rgba(81, 207, 102, 0.35);
}

#startBtn.running.longbreak {
  background: #339af0;
  box-shadow: 0 6px 20px rgba(51, 154, 240, 0.35);
}

/* Responsive */
@media (max-width: 480px) {
  .container {
    padding: 28px 20px;
    border-radius: 24px;
  }

  h1 {
    font-size: 1.3rem;
  }

  .timer-ring {
    width: 180px;
    height: 180px;
  }

  .timer-ring svg {
    width: 180px;
    height: 180px;
  }

  .timer-display {
    font-size: 2.8rem;
  }

  #startBtn {
    padding: 12px 36px;
    font-size: 0.95rem;
  }

  #resetBtn {
    padding: 12px 20px;
    font-size: 0.95rem;
  }
}