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

:root {
    --primary-color: #4a90e2;
    --secondary-color: #2c3e50;
    --accent-color: #e74c3c;
    --bg-color: #f5f7fa;
    --text-color: #333;
    --border-color: #ddd;
    --success-color: #27ae60;
    --shadow: 0 2px 10px rgba(0,0,0,0.1);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

.navbar {
    background-color: var(--secondary-color);
    padding: 0;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.logo h1 {
    color: white;
    font-size: 1.5rem;
    padding: 1rem 0;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 0;
}

.nav-item {
    position: relative;
}

.nav-link {
    color: white;
    text-decoration: none;
    padding: 1.5rem 1.2rem;
    display: block;
    transition: background-color 0.3s;
}

.nav-link:hover {
    background-color: rgba(255,255,255,0.1);
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: white;
    min-width: 200px;
    box-shadow: var(--shadow);
    list-style: none;
    border-radius: 0 0 4px 4px;
}

.dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown-menu li a {
    color: var(--text-color);
    padding: 0.8rem 1.2rem;
    display: block;
    text-decoration: none;
    transition: background-color 0.3s;
}

.dropdown-menu li a:hover {
    background-color: var(--bg-color);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: white;
    transition: 0.3s;
}

.container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 20px;
}

.hero {
    text-align: center;
    padding: 3rem 0;
    background: white;
    border-radius: 8px;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.hero h2 {
    color: var(--primary-color);
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    color: #666;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.feature-card ul {
    list-style: none;
}

.feature-card li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
}

.feature-card li:last-child {
    border-bottom: none;
}

.tool-container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.tool-container h2 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--secondary-color);
}

.form-group input[type="file"],
.form-group input[type="text"],
.form-group input[type="number"],
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group textarea {
    min-height: 200px;
    font-family: 'Courier New', monospace;
    resize: vertical;
}

.btn {
    padding: 0.8rem 2rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: #3a7bc8;
}

.btn:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

.btn-success {
    background-color: var(--success-color);
}

.btn-success:hover {
    background-color: #229954;
}

.btn-group {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.result-area {
    margin-top: 2rem;
    padding: 1.5rem;
    background-color: var(--bg-color);
    border-radius: 4px;
    border: 2px solid var(--border-color);
}

.result-area pre {
    background-color: white;
    padding: 1rem;
    border-radius: 4px;
    overflow-x: auto;
    max-height: 500px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
}

.alert {
    padding: 1rem;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.alert-success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-info {
    background-color: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

.canvas-container {
    margin: 1rem 0;
    border: 2px dashed var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    position: relative;
    background-color: #f9f9f9;
}

.canvas-container canvas {
    display: block;
    max-width: 100%;
}

.image-preview {
    max-width: 100%;
    margin: 1rem 0;
    border-radius: 4px;
}

.compare-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-top: 1rem;
}

.compare-panel {
    background: white;
    padding: 1rem;
    border-radius: 4px;
    border: 2px solid var(--border-color);
}

.compare-panel h3 {
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
}

.compare-panel pre {
    background-color: var(--bg-color);
    padding: 1rem;
    border-radius: 4px;
    overflow-x: auto;
    max-height: 400px;
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
}

.diff-line {
    padding: 2px 4px;
}

.diff-add {
    background-color: #d4edda;
    color: #155724;
}

.diff-remove {
    background-color: #f8d7da;
    color: #721c24;
}

.diff-unchanged {
    background-color: white;
}

footer {
    background-color: var(--secondary-color);
    color: white;
    text-align: center;
    padding: 2rem;
    margin-top: 3rem;
}

@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: absolute;
        top: 100%;
        left: -100%;
        flex-direction: column;
        background-color: var(--secondary-color);
        width: 100%;
        transition: 0.3s;
        box-shadow: var(--shadow);
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-item {
        width: 100%;
    }

    .nav-link {
        width: 100%;
    }

    .dropdown-menu {
        position: static;
        display: none;
        background-color: rgba(0,0,0,0.1);
    }

    .dropdown.active .dropdown-menu {
        display: block;
    }

    .hero h2 {
        font-size: 2rem;
    }

    .features {
        grid-template-columns: 1fr;
    }

    .compare-container {
        grid-template-columns: 1fr;
    }

    .btn-group {
        flex-direction: column;
    }

    .btn-group .btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .hero h2 {
        font-size: 1.5rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .tool-container {
        padding: 1rem;
    }
}