:root {
  --bg: radial-gradient(1200px 600px at 10% 10%, #fff5e6 0%, #ffffff 40%, #fefefe 100%);
  --calc-ar: 4 / 6;
}

html, body {
  height: 100%;
}

body {
  background: var(--bg);
}

html body {
  padding-top: 0;
}

.calc-wrap {
  aspect-ratio: var(--calc-ar);
  width: min(100vw, calc(100vh * var(--calc-ar)));
  height: auto;
}

.card, .card-body {
  height: 100%;
}

.card-body {
  display: flex;
  flex-direction: column;
}

.timer-display-container {
  position: relative;
  width: 100%;
  max-width: 300px;
  margin: 0 auto 2rem;
}

.timer-circle {
  width: 100%;
  height: auto;
  transform: rotate(-90deg);
}

.timer-circle-bg {
  fill: none;
  stroke: #e9ecef;
  stroke-width: 8;
}

.timer-circle-progress {
  fill: none;
  stroke: #0d6efd;
  stroke-width: 8;
  stroke-linecap: round;
  transition: stroke-dashoffset 1s linear, stroke 0.3s ease;
}

.timer-display {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 3rem;
  font-weight: 700;
  color: #212529;
  font-family: 'Courier New', monospace;
}

.timer-controls {
  display: flex;
  gap: 10px;
  justify-content: center;
}

.timer-controls .btn {
  min-width: 100px;
}

.form-container {
  flex: 1;
  overflow-y: auto;
}

.preset-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.preset-btn {
  flex: 1 1 calc(33.333% - 8px);
  min-width: 80px;
}

.custom-time-inputs {
  display: flex;
  align-items: center;
  gap: 8px;
  justify-content: center;
}

.time-input-group {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.time-input-group input {
  width: 70px;
  text-align: center;
  font-size: 1.2rem;
  font-weight: 600;
}

.time-separator {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0 5px;
  padding-bottom: 20px;
}

@media (max-width: 575.98px) {
  .calc-wrap {
    width: 100vw;
    height: 100vh;
    aspect-ratio: auto;
  }

  .timer-display-container {
    max-width: 250px;
    margin-bottom: 1.5rem;
  }

  .timer-display {
    font-size: 2.5rem;
  }

  .timer-controls .btn {
    min-width: 80px;
    padding: 0.5rem 0.75rem;
  }

  .time-input-group input {
    width: 60px;
    font-size: 1rem;
  }

  .preset-btn {
    flex: 1 1 calc(50% - 8px);
    font-size: 0.875rem;
  }
}

@media (min-width: 576px) and (max-width: 991.98px) {
  :root { 
    --calc-ar: 5 / 7; 
  }
}

@media (min-width: 992px) {
  :root { 
    --calc-ar: 4 / 6; 
  }
}