:root {
    --primary-color: #4a90e2;
    --background-color: #fff;
    --text-color: #333;
    --circle-color: #a8d0e6;
    --circle-growth-color: #8ab9e3;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 0;
    margin: 40px 0 0 0;
    background-color: var(--background-color);
    color: var(--text-color);
}

.app-container {
    text-align: center;
    padding: 30px;
    border-radius: 15px;
    background-color: white;
    /* box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1); */
    width: 90%;
    max-width: 400px;
}

.breathing-circle-container {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 30px auto;
}

.breathing-circle {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background-color: var(--circle-color);
    transition: transform 6s ease-in-out, background-color 1s;
    transform: scale(1);
}

.breathing-circle.inhale {
    transform: scale(1.25);
    background-color: var(--circle-growth-color);
}

.breathing-circle.exhale {
    transform: scale(0.9);
    background-color: var(--circle-color);
}

.breathing-circle.finished {
    background-color: #4CAF50; /* A nice green color */
    transform: scale(1.2);
}

.phase-timer {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 2.5rem;
    font-weight: bold;
}

.phase-name {
    font-size: 1.5rem;
    margin-bottom: 10px;
    font-weight: 500;
}

.total-timer {
    font-size: 1rem;
    margin-bottom: 20px;
    color: #666;
}

.controls button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 25px;
    font-size: 1rem;
    cursor: pointer;
    margin: 5px;
    transition: background-color 0.3s, transform 0.2s;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.controls button:hover {
    background-color: #357abd;
}

.controls button:active {
    transform: scale(0.98);
}

.duration-slider-container {
    margin-top: 30px;
}

.phase-duration-slider-container {
    margin-top: 30px;
}

.duration-slider-container label,
.phase-duration-slider-container label {
    display: block;
    margin-bottom: 10px;
    font-size: 0.9rem;
    color: #555;
}

#duration-slider,
#phase-duration-slider {
    width: 80%;
    cursor: pointer;
}

#duration-label,
#phase-duration-label {
    display: block;
    margin-top: 5px;
    font-weight: 500;
}

.sound-toggle-container {
    margin-top: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.sound-toggle-container label {
    margin-left: 8px;
    cursor: pointer;
}

#sound-toggle {
    cursor: pointer;
}

.donation-container {
    margin-top: 30px;
    font-size: 0.9rem;
}

.donation-container a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s;
}

.donation-container a:hover {
    color: #357abd;
    text-decoration: underline;
}

@media (max-width: 480px) {
    .app-container {
        padding-top: 0;
    }
}