* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: #f5f7fa;
    font-family: 'Roboto', sans-serif;
    color: #333;
    display: flex;
    justify-content: center;
    padding: 20px;
}

.container {
    max-width: 900px;
    width: 100%;
    background: white;
    padding: 20px 30px;
    border-radius: 8px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
}

h1 {
    margin-bottom: 20px;
    font-weight: 700;
    text-align: center;
    color: #222;
}

fieldset {
    border: 1px solid #ddd;
    padding: 15px 20px 20px 20px;
    border-radius: 6px;
    margin-bottom: 20px;
}

legend {
    padding: 0 10px;
    font-weight: 600;
    color: #555;
}

label {
    display: inline-block;
    min-width: 100px;
    margin-bottom: 10px;
    font-weight: 500;
    color: #444;
}

.input-number{
    width: 100px;
    text-align: left;
}

.input-select,
.input-number {
    padding: 6px 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 15px;
    outline-offset: 2px;
    transition: border-color 0.25s ease;
    margin-right: 10px;
}

.input-select:focus,
.input-number:focus {
    border-color: #4a90e2;
    outline: none;
}

.btn-primary,
.btn-danger {
    padding: 8px 16px;
    border: none;
    border-radius: 4px;
    font-weight: 600;
    cursor: pointer;
    user-select: none;
    transition: background-color 0.25s ease, color 0.25s ease;
    margin-left: 10px;
    font-size: 15px;
}

.btn-primary {
    background-color: #4a90e2;
    color: white;
}

.btn-primary:hover,
.btn-primary:focus {
    background-color: #357ABD;
}

.btn-danger {
    background-color: #e94e4e;
    color: white;
}

.btn-danger:hover,
.btn-danger:focus {
    background-color: #c63636;
}

.canvas-container {
    text-align: center;
    margin-bottom: 20px;
}

#drawingCanvas {
    border: 2px solid #4a90e2;
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(74,144,226,0.3);
    background: white;
    cursor: crosshair;
    max-width: 100%;
}

.shape-info {
    border: 1px solid #ddd;
    border-radius: 6px;
    padding: 15px 20px;
    background: #fafafa;
    max-height: 220px;
    overflow-y: auto;
    font-family: monospace;
    font-size: 14px;
}

.shape-item {
    margin-bottom: 6px;
    padding: 4px 8px;
    border-radius: 4px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.shape-item.selected {
    background-color: #dbe9ff;
}

.shape-item span {
    flex-grow: 1;
    cursor: pointer;
}

.shape-item span:hover {
    text-decoration: underline;
}

.shape-item span:last-child {
    flex-grow: 0;
    margin-left: 10px;
    cursor: pointer;
}

.input-file {
    padding: 6px 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 14px;
    margin-left: 5px;
    vertical-align: middle;
}

.file-label {
    display: inline-block;
    width: 120px;
    font-weight: 500;
    color: #444;
}

.input-range {
    vertical-align: middle;
    width: 120px;
    margin-left: 5px;
    cursor: pointer;
}

#opacityValue {
    margin-left: 10px;
    font-weight: 500;
    color: #444;
}