:root {
            --c-primary: #3B82F6;
            --c-primary-hover: #2563EB;
            --c-danger: #EF4444;
            --c-danger-hover: #DC2626;
            --c-bg: #F3F4F6;
            --c-card-bg: #FFFFFF;
            --c-text-dark: #1F2937;
            --c-text-light: #6B7280;
            --c-border: #D1D5DB;
            --border-radius: 16px;
            --shadow: 0 6px 24px rgba(0, 0, 0, 0.07);
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            margin: 0;
            padding: 40px;
            background-color: var(--c-bg);
            color: var(--c-text-dark);
            display: flex;
            justify-content: center;
            align-items: flex-start;
            min-height: 100vh;
        }

        #container {
            width: 100%;
            max-width: 800px;
            padding: 30px;
            background-color: var(--c-card-bg);
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            transition: all 0.3s ease-out;
        }

        h1 {
            color: var(--c-text-dark);
            text-align: center;
            font-size: 2rem;
            font-weight: 700;
            margin-bottom: 2.5rem;
        }

        #fileInput {
            opacity: 0;
            position: absolute;
            z-index: -1;
            width: 0;
            height: 0;
        }

        #dropZone {
            border: 2px dashed var(--c-border);
            border-radius: var(--border-radius);
            padding: 40px;
            text-align: center;
            cursor: pointer;
            transition: background-color 0.2s ease-in-out, border-color 0.2s ease-in-out;
        }
        #dropZone.drag-over {
            border-color: var(--c-primary);
            background-color: #EFF6FF;
        }
        #dropZone .icon {
            font-size: 3rem;
            color: var(--c-primary);
            margin-bottom: 1rem;
        }
        #dropZone p {
            margin: 0;
            color: var(--c-text-light);
            font-weight: 500;
        }
        #dropZone p span {
            color: var(--c-primary);
            font-weight: 600;
        }
        #fileInfo {
            margin-top: 1.5rem;
            font-weight: 600;
            color: var(--c-text-dark);
            text-align: center;
        }

        .button-group {
            display: flex;
            gap: 1rem;
            margin-top: 2rem;
        }

        button {
            flex: 1;
            padding: 12px;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-size: 1rem;
            font-weight: 600;
            transition: background-color 0.2s ease;
        }

        #copyButton {
            background-color: var(--c-primary);
            color: white;
        }
        #copyButton:hover {
            background-color: var(--c-primary-hover);
        }
        #clearButton {
            background-color: var(--c-danger);
            color: white;
        }
        #clearButton:hover {
            background-color: var(--c-danger-hover);
        }

        #output-container {
            margin-top: 1.5rem;
        }
        #output {
            padding: 15px;
            border: 1px solid var(--c-border);
            border-radius: 8px;
            background-color: #F9FAFB;
            white-space: pre-wrap;
            word-wrap: break-word;
            min-height: 200px;
            font-family: "Menlo", "Monaco", "Consolas", "Courier New", monospace;
            font-size: 0.9rem;
            line-height: 1.6;
        }