:root {
    --primary-blue: #4A90E2;
    --secondary-blue: #e6ecfe;
    --light-blue: #C8DFF9;
    --secondary-green: #4ebf7d;
    --accent-gray: #F5F7FA;
    --dark-text: #2C3E50;
    --light-text: #7F8C8D;
    --background-white: #FFFFFF;
}

body {
    font-family: "Roboto Mono", monospace;
    margin: 0;
    padding: 20px;
    color: var(--dark-text);
}

.display-3 {
    text-align: center;
    color: var(--primary-blue);
    font-weight: bold;
    margin-bottom: 10px;
}

.timer-display {
    text-align: center;
    color: var(--primary-blue);
    background-color: var(--light-blue);
    border: 2px solid var(--primary-blue);
    border-radius: 20px;
    padding: 10px;
    font-size: 2rem;
    margin: 0 auto 15px auto;
    max-width: 400px;
}

.timer-display h2 {
    font-size: 6rem;
    font-weight: bold;
    margin: 0;
    line-height: 1;
    text-align: center;
}

.session-description {
    text-align: center;
    color: var(--dark-text);
    background-color: var(--secondary-blue);
    border: 2px solid var(--primary-blue);
    border-radius: 15px;
    padding: 10px;
    margin: 0 auto 20px auto;
    max-width: 500px;
}

.timer-options button, .control-buttons button {
    margin: 0 5px 5px 0;
}

.toast-notification {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: var(--secondary-green);
    color: white;
    padding: 12px 20px;
    border-radius: 8px;
    font-family: "Roboto Mono", monospace;
    font-size: 0.9rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    opacity: 0;
    transform: translateX(100%);
    transition: all 0.3s ease;
    z-index: 1000;
    border-left: 4px solid var(--primary-blue);
}

.toast-notification.show {
    opacity: 1;
    transform: translateX(0);
}

.toast-notification.hide {
    opacity: 0;
    transform: translateX(100%);
}

.footer {
    text-align: center;
    font-size: 0.75rem;
    color: var(--light-text);
    margin-top: 10px;
    padding-top: 8px;
    border-top: 1px solid var(--accent-gray);
}

.footer p {
    margin: 2px 0;
}