:root {
    --bg-color: #F4F1EA;
    --primary-color: #3D3D3D;
    --secondary-color: #8A8A8A;
    --accent-color: #EAE7E0;
    --border-color: #EAE7E0;
    --hover-color: #E0DACE;
    --font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--primary-color);
    min-height: 100vh;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    background: #ffffff;
    color: var(--primary-color);
    border-radius: 20px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    overflow: hidden;
    display: grid;
    grid-template-columns: 320px 1fr 320px;
}

h1 {
    text-align: center;
    padding: 30px 0;
    font-size: 1.8em;
    font-weight: 600;
    letter-spacing: -0.5px;
    margin-bottom: 0;
    grid-column: 1 / -1;
    background-color: #ffffff;
    border-bottom: 1px solid var(--border-color);
}

.generator-section {
    display: contents;
}

.input-section {
    padding: 30px;
    background-color: #ffffff;
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.output-section {
    padding: 40px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background-color: #fafafa;
}

.customization-section {
    padding: 30px;
    background-color: #ffffff;
    border-left: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 20px;
}

h3 {
    font-size: 1.2em;
    font-weight: 600;
    margin-bottom: 10px;
}

label {
    font-weight: 500;
    color: var(--secondary-color);
    font-size: 0.9em;
    margin-bottom: 8px;
    display: block;
}

input[type="text"] {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #dcdcdc;
    background-color: #ffffff;
    color: var(--primary-color);
    border-radius: 8px;
    font-size: 15px;
    transition: all 0.3s ease;
}

input[type="text"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(61, 61, 61, 0.1);
}

.preset-section {
    margin-top: 10px;
}

.preset-buttons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

.preset-btn {
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: #ffffff;
    color: var(--primary-color);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.preset-btn:hover {
    background: var(--accent-color);
    border-color: var(--accent-color);
}

.preset-btn.active {
    background: var(--primary-color);
    color: #ffffff;
    border-color: var(--primary-color);
}

button {
    width: 100%;
    padding: 15px;
    background: var(--primary-color);
    color: #ffffff;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

button:hover {
    background: #555555;
    transform: translateY(-1px);
}

#download-btn {
    margin-top: 10px;
    background: var(--accent-color);
    color: var(--primary-color);
}

#download-btn:hover {
    background: var(--hover-color);
}

#qr-display {
    width: 100%;
    max-width: 350px;
    height: auto;
    background: white;
    border-radius: 15px;
    padding: 20px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.08);
    margin-bottom: 20px;
}

#qr-canvas {
    width: 100%;
    height: 100%;
    border-radius: 8px;
}

#url-display {
    word-break: break-all;
    text-align: center;
    color: var(--secondary-color);
    font-size: 14px;
    max-width: 100%;
}

#url-display.error {
    color: #e74c3c;
}

.color-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

input[type="color"] {
    width: 30px;
    height: 30px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    background-color: transparent;
}

.color-value {
    font-family: monospace;
    font-size: 13px;
    color: var(--secondary-color);
}

.size-control {
    display: flex;
    align-items: center;
    gap: 15px;
}

input[type="range"] {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 4px;
    border-radius: 2px;
    background: var(--accent-color);
    outline: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    box-shadow: 0 0 5px rgba(0, 0, 0, 0.2);
}

.style-group select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid #dcdcdc;
    border-radius: 6px;
    background: white;
    font-size: 14px;
    cursor: pointer;
    transition: border-color 0.3s ease;
}

.style-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.gradient-toggle label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
}

input[type="file"] {
    width: 100%;
    font-size: 13px;
}

@media (max-width: 992px) {
    .container {
        grid-template-columns: 1fr;
    }
    .input-section, .customization-section {
        border: none;
    }
    .output-section {
        order: -1;
    }
}