body {
  background: #111a2b !important;
  color: #e0e6ed !important;
  min-height: 100vh;
  margin: 0;
  font-family: 'Inter', Arial, sans-serif;
}
header, .site-header {
  padding: 24px 0 16px 0 !important;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent !important;
}
header img, .site-header img {
  height: 40px !important;
  margin-right: 16px;
}
header h1, .site-header h1 {
  font-size: 2rem;
  margin: 0;
  color: #e0e6ed !important;
}
.timer-display {
  font-family: 'Roboto Mono', 'Consolas', monospace;
  font-size: 5rem;
  color: #00ffe7;
  background: rgba(20, 30, 50, 0.85);
  border-radius: 16px;
  padding: 32px 64px;
  box-shadow: 0 0 32px #00ffe7bb;
  text-align: center;
  margin: 60px auto 40px auto;
  width: fit-content;
}
.start-btn {
  display: block;
  margin: 0 auto;
  padding: 18px 48px;
  font-size: 1.3rem;
  font-weight: 600;
  color: #111a2b;
  background: linear-gradient(90deg, #00ffe7 30%, #39ff14 100%);
  border: none;
  border-radius: 32px;
  box-shadow: 0 0 16px #00ffe7cc, 0 0 32px #39ff14aa;
  cursor: pointer;
  transition: transform 0.1s, box-shadow 0.2s;
}
.start-btn:hover, .start-btn:focus {
  transform: scale(1.06);
  box-shadow: 0 0 32px #00ffe7ee, 0 0 64px #39ff14cc;
  outline: none;
}
.center-content {
  min-height: 80vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}