:root {
    --bg-color: #224c5e;
    --text: #e0f7fa;
    --circle-color: #80deea;
    --gradient-color: rgba(128, 222, 234, 0.3);
}

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

body {
    font-family: 'Quicksand', sans-serif;
    background-color: var(--bg-color);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    transition: background-color 2s ease;
}

.container {
    text-align: center;
    width: 100%;
    max-width: 600px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    height: 100vh;
    justify-content: space-between;
}

header {
    margin-top: 2rem;
    z-index: 10;
}

h1 {
    font-size: 2.5rem;
    font-weight: 300;
    margin-bottom: 1.5rem;
    letter-spacing: 2px;
}

.highlight {
    font-weight: 700;
}

.controls {
    display: flex;
    justify-content: center;
    gap: 1rem;
    align-items: center;
}

select {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-family: inherit;
    outline: none;
    cursor: pointer;
}

select option {
    background: var(--bg-color);
    color: white;
}

.icon-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.2s;
}

.icon-btn:hover {
    opacity: 1;
}

.icon-btn.active {
    opacity: 1;
    text-shadow: 0 0 10px white;
}

/* Visualizer */
.visualizer-container {
    position: relative;
    height: 300px;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-grow: 1;
}

.circle-container {
    position: relative;
    width: 300px;
    height: 300px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.circle {
    width: 100%;
    height: 100%;
    background-color: var(--text);
    border-radius: 50%;
    position: absolute;
    z-index: 1;
    transform: scale(0.3);
    /* Initial state */
}

.gradient-circle {
    width: 120%;
    height: 120%;
    background: radial-gradient(circle, var(--gradient-color) 0%, rgba(0, 0, 0, 0) 70%);
    border-radius: 50%;
    position: absolute;
    z-index: 0;
    transform: scale(0.3);
}

#instruction-text {
    position: absolute;
    z-index: 2;
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--bg-color);
    pointer-events: none;
}

footer {
    margin-bottom: 2rem;
    opacity: 0.6;
    font-size: 0.9rem;
}