:root {
    --bg-color: #d6d6d6;
    --dark-shadow: #a3a3a3;
    --light-shadow: #f5f5f5;
    --accent: #5b7cff;
    --text: #2f2f2f;
}

body.dark {
    --bg-color: #1f2430;
    --dark-shadow: #11141c;
    --light-shadow: #32394a;
    --accent: #8ea2ff;
    --text: #f1f1f1;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    transition: background 0.3s ease, color 0.3s ease;
}

.main-container {
    display: flex;
    flex-direction: row;
    gap: 60px;
    align-items: center;
    max-width: 1100px;
    width: 100%;
}

.preview-panel {
    flex: 1;
    display: flex;
    justify-content: center;
}

.target-element {
    width: 250px;
    height: 250px;
    background: var(--bg-color);
    border-radius: 40px;
    transition: all 0.3s ease;
    box-shadow: 20px 20px 40px var(--dark-shadow),
                -20px -20px 40px var(--light-shadow);
}

.controls-panel {
    flex: 1;
    background: var(--bg-color);
    padding: 40px;
    border-radius: 40px;
    box-shadow: 20px 20px 60px var(--dark-shadow), 
                -20px -20px 60px var(--light-shadow);
}

.top-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1 {
    font-size: 1.8rem;
    margin-bottom: 8px;
}

.subtitle {
    font-size: 0.9rem;
    margin-bottom: 30px;
    opacity: 0.75;
}

.control-group {
    margin-bottom: 35px;
}

label {
    font-weight: 600;
}

.label-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 18px;
    font-size: 0.9rem;
    font-weight: 600;
}

input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    background: transparent;
}

input[type="range"]::-webkit-slider-runnable-track {
    width: 100%;
    height: 12px;
    background: var(--bg-color);
    border-radius: 10px;
    box-shadow: inset 4px 4px 8px var(--dark-shadow), 
                inset -4px -4px 8px var(--light-shadow);
    border: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    height: 24px;
    width: 24px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    margin-top: -6px;
    box-shadow: 3px 3px 6px var(--dark-shadow);
    border: 2px solid var(--bg-color);
}

.radius-buttons,
.preset-buttons {
    display: flex;
    gap: 10px;
    margin-top: 14px;
}

button {
    flex: 1;
    padding: 12px;
    border: none;
    background: var(--bg-color);
    border-radius: 12px;
    cursor: pointer;
    font-weight: 600;
    color: var(--text);
    box-shadow: 4px 4px 8px var(--dark-shadow), 
                -4px -4px 8px var(--light-shadow);
    transition: all 0.2s;
}

button:hover {
    transform: translateY(-2px);
}

button:active {
    box-shadow: inset 3px 3px 6px var(--dark-shadow), 
                inset -3px -3px 6px var(--light-shadow);
    transform: scale(0.98);
}

.icon-btn {
    max-width: 50px;
    padding: 10px;
}

.color-picker-row {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-top: 12px;
}

input[type="color"] {
    width: 55px;
    height: 40px;
    border: none;
    border-radius: 10px;
    background: transparent;
    cursor: pointer;
    box-shadow: 4px 4px 8px var(--dark-shadow),
                -4px -4px 8px var(--light-shadow);
}

#color-value {
    font-weight: 600;
    font-size: 0.9rem;
}

.code-box {
    margin-top: 30px;
    padding: 15px;
    background: #2d2d2d;
    border-radius: 15px;
}

pre {
    color: #a6e22e;
    font-size: 0.75rem;
    white-space: pre-wrap;
    font-family: 'Courier New', monospace;
}

#copy-btn,
#download-btn,
#save-history-btn {
    margin-top: 10px;
    width: 100%;
    padding: 8px;
    font-size: 0.8rem;
    background: #444;
    color: white;
    box-shadow: none;
}

.history-box {
    margin-top: 28px;
}

.history-box h2 {
    font-size: 1rem;
    margin-bottom: 15px;
}

.history-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    padding: 12px;
    margin-bottom: 12px;
    border-radius: 14px;
    background: var(--bg-color);
    box-shadow: 4px 4px 8px var(--dark-shadow),
                -4px -4px 8px var(--light-shadow);
    font-size: 0.8rem;
}

.history-item button {
    max-width: 90px;
    padding: 8px;
    font-size: 0.75rem;
}

@media (max-width: 800px) {
    .main-container {
        flex-direction: column;
        gap: 30px;
    }

    .target-element {
        width: 180px;
        height: 180px;
    }

    .controls-panel {
        padding: 28px;
    }
}