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

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #64748b;
    --secondary-hover: #475569;
    --background: #f8fafc;
    --surface: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --success-color: #22c55e;
    --drop-zone-bg: #f1f5f9;
    --drop-zone-border: #cbd5e1;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 1rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
}

main {
    flex: 1;
}

/* Upload Section */
.upload-section {
    margin-bottom: 2rem;
}

.drop-zone {
    background: var(--surface);
    border: 2px dashed var(--drop-zone-border);
    border-radius: var(--radius-xl);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.drop-zone:hover,
.drop-zone.drag-over {
    border-color: var(--primary-color);
    background: var(--drop-zone-bg);
}

.drop-zone.drag-over {
    transform: scale(1.01);
}

.drop-zone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
}

.upload-icon {
    width: 48px;
    height: 48px;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.drop-text {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--text-primary);
}

.drop-text-alt {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.file-input-label {
    display: inline-flex;
    align-items: center;
    padding: 0.625rem 1.25rem;
    background: var(--primary-color);
    color: white;
    border-radius: var(--radius-md);
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s ease;
}

.file-input-label:hover {
    background: var(--primary-hover);
}

/* Result Section */
.result-section {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.image-preview-container,
.image-info-container,
.data-url-container {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.image-preview-container h2,
.image-info-container h2,
.data-url-container h2 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.image-preview {
    display: flex;
    justify-content: center;
    align-items: center;
    background: var(--drop-zone-bg);
    border-radius: var(--radius-md);
    padding: 1rem;
    min-height: 200px;
    max-height: 400px;
    overflow: hidden;
}

.image-preview img {
    max-width: 100%;
    max-height: 380px;
    object-fit: contain;
    border-radius: var(--radius-sm);
}

/* Info Grid */
.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.info-item {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    padding: 0.75rem;
    background: var(--drop-zone-bg);
    border-radius: var(--radius-md);
}

.info-label {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.info-value {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-primary);
    word-break: break-all;
}

/* Data URL Container */
.data-url-wrapper {
    margin-bottom: 1rem;
}

#dataUrlOutput {
    width: 100%;
    height: 150px;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.8125rem;
    resize: vertical;
    background: var(--drop-zone-bg);
    color: var(--text-primary);
    line-height: 1.5;
}

#dataUrlOutput:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* Action Buttons */
.action-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn svg {
    width: 18px;
    height: 18px;
}

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

.btn-primary:hover {
    background: var(--primary-hover);
}

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

.btn-secondary:hover {
    background: var(--secondary-hover);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-outline:hover {
    background: var(--drop-zone-bg);
    border-color: var(--secondary-color);
}

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--text-primary);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

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

/* Footer */
footer {
    text-align: center;
    padding: 2rem 0 1rem;
    margin-top: auto;
}

footer p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

footer a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Responsive Styles */
@media (max-width: 768px) {
    .container {
        padding: 1.5rem 1rem;
    }

    header h1 {
        font-size: 1.5rem;
    }

    .subtitle {
        font-size: 0.875rem;
    }

    .drop-zone {
        padding: 2rem 1rem;
    }

    .upload-icon {
        width: 40px;
        height: 40px;
    }

    .drop-text {
        font-size: 1rem;
    }

    .image-preview-container,
    .image-info-container,
    .data-url-container {
        padding: 1rem;
    }

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

    .action-buttons {
        flex-direction: column;
    }

    .btn {
        justify-content: center;
        width: 100%;
    }

    #dataUrlOutput {
        height: 120px;
        font-size: 0.75rem;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.25rem;
    }

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

    .image-preview {
        min-height: 150px;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-section:not([hidden]) {
    animation: fadeIn 0.3s ease;
}