/* Root Variables */
:root {
  --bg-color-day: #ffffff;
  --text-color-day: #000000;
  --bg-color-night: #202520;
  --text-color-night: #f5f5f5;
  --box-color: #ddd;
  --highlight-color: #007bff;
}

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

body[data-theme='day'] {
  background-color: var(--bg-color-day);
  color: var(--text-color-day);
}

body[data-theme='night'] {
  background-color: var(--bg-color-night);
  color: var(--text-color-night);
}

body {
  font-family: 'Segoe UI', sans-serif;
  line-height: 1.6;
  padding: 1rem;
}

/* Header */
header, footer {
  text-align: center;
  padding: 1rem 0;
}

/* Container Layout */
.container {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

/* Theme Toggle Block */
.parent {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 1rem;
  background: var(--box-color);
  border-radius: 8px;
}

.child {
  background-color: whitesmoke;
  padding: 3.5rem;
  margin-top: 0.5rem;
  border: 4px dashed #030000;
}

/* Logger Block */
.runtime-logger {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  align-items: center;
  padding: 1rem;
  border: 1px solid #ccc;
  border-radius: 6px;
}

#phaseSelect, #logPhaseBtn {
  padding: 0.4rem;
  font-size: 1rem;
}

#phaseOutput {
  margin-top: 0.5rem;
  font-family: monospace;
  background: #f2f2f2;
  padding: 0.5rem;
  border-radius: 4px;
}

/* Flex Grid */
.grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
}

.grid-item {
  flex: 1 0 calc(33.33% - 1rem);
  text-align: center;
  padding: 1rem;
  background: #eaeaea;
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.6s ease;
}

.grid-item:hover {
  background: var(--highlight-color);
  color: white;
}

/* Footer */
.footer {
  text-align: center;
  font-size: 0.9rem;
  padding: 1rem 0;
}

/* Responsive Layouts */
@media (max-width: 768px) {
  .grid-item {
    flex: 1 0 calc(50% - 1rem);
  }

  .parent, .runtime-logger {
    width: 100%;
  }
}

@media (max-width: 480px) {
  .grid-item {
    flex: 1 0 100%;
  }

  body {
    padding: 0.5rem;
  }

  header h1 {
    font-size: 1.5rem;
  }

  .runtime-logger {
    padding: 4.5rem;
  }
}