:root {
  --bg: linear-gradient(135deg, #667eea, #764ba2);
  --glass: rgba(255, 255, 255, 0.18);
  --border: rgba(255, 255, 255, 0.25);
  --accent: #4caf50;
  --text: #ffffff;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Poppins", sans-serif;
}

body {
  min-height: 100vh;
  background: var(--bg);
  display: flex;
  justify-content: center;
  align-items: center;
  color: var(--text);
}

#app {
  width: 100%;
  max-width: 420px;
  padding: 25px;
  border-radius: 18px;
  background: var(--glass);
  backdrop-filter: blur(18px);
  border: 1px solid var(--border);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
  animation: fadeIn 0.6s ease;
}

header {
  text-align: center;
  margin-bottom: 15px;
}

#timer {
  text-align: center;
  margin: 15px 0;
}

#time {
  font-size: 3.5rem;
  font-weight: bold;
  letter-spacing: 2px;
}

.mode-selector {
  display: flex;
  gap: 10px;
  margin-bottom: 15px;
}

.mode {
  flex: 1;
  padding: 10px;
  border-radius: 10px;
  border: none;
  background: rgba(255, 255, 255, 0.25);
  color: #fff;
  cursor: pointer;
  transition: all 0.3s ease;
}

.mode.active {
  background: var(--accent);
  font-weight: bold;
}

.controls {
  display: flex;
  gap: 10px;
  margin-bottom: 15px;
}

button {
  flex: 1;
  padding: 10px;
  border-radius: 10px;
  border: none;
  background: rgba(255, 255, 255, 0.25);
  color: #fff;
  cursor: pointer;
  transition: all 0.3s ease;
}

button:hover {
  background: rgba(255, 255, 255, 0.4);
  transform: translateY(-2px);
}

#progress {
  text-align: center;
  margin-bottom: 15px;
}

#progress-bar {
  width: 100%;
  height: 10px;
  margin: 8px 0;
}

progress::-webkit-progress-bar {
  background: rgba(255, 255, 255, 0.3);
  border-radius: 6px;
}

progress::-webkit-progress-value {
  background: var(--accent);
  border-radius: 6px;
}

progress::-moz-progress-bar {
  background: var(--accent);
  border-radius: 6px;
}

#settings {
  margin-top: 10px;
}

#settings h3 {
  margin-bottom: 10px;
}

#settings form {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

#settings label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.9rem;
}

#settings input,
#settings select {
  width: 80px;
  padding: 6px;
  border-radius: 8px;
  border: none;
  outline: none;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@media (max-width: 480px) {
  #time {
    font-size: 2.5rem;
  }

  button {
    padding: 8px;
    font-size: 0.9rem;
  }
}