:root {
  --bg-color: #f0f2f5;
  --text-color: #1c1e21;
  --card-bg: #ffffff;
  --btn-bg: #4CAF50;
  --btn-hover: #45a049;
  --btn-text: #ffffff;
}

[data-theme='dark'] {
  --bg-color: #18191a;
  --text-color: #e4e6eb;
  --card-bg: #242526;
  --btn-bg: #2db84c;
  --btn-hover: #26a041;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
}

#app {
    text-align: center;
    padding: 2rem;
    background-color: var(--card-bg);
    border-radius: 1rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transition: background-color 0.3s;
    width: 90%;
    max-width: 500px;
}

h1 {
    margin-bottom: 2rem;
}

#generator-btn {
    padding: 12px 24px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    border-radius: 0.5rem;
    background-color: var(--btn-bg);
    color: var(--btn-text);
    margin-bottom: 1.5rem;
    transition: background-color 0.3s, transform 0.1s;
}

#generator-btn:hover {
    background-color: var(--btn-hover);
}

#generator-btn:active {
    transform: scale(0.98);
}

#theme-toggle {
    position: fixed;
    top: 1rem;
    right: 1rem;
    padding: 0.5rem 1rem;
    cursor: pointer;
    background-color: var(--card-bg);
    border: 1px solid var(--text-color);
    border-radius: 0.5rem;
    color: var(--text-color);
    font-weight: 500;
    transition: all 0.3s;
}