:root {
    --primary-color: #3b82f6; /* Blue */
    --primary-hover: #2563eb;
    --bg-color: #ffffff;
    --text-color: #1f2937;
    --border-color: #e5e7eb;
    --light-gray: #f9fafb;
    --sky-blue: #0ea5e9; /* Sky blue for button as requested */
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 600px;
    padding: 2rem;
    text-align: center;
}

header {
    margin-bottom: 3rem;
}

h1 {
    font-weight: 600;
    font-size: 2rem;
    margin-bottom: 0.5rem;
    color: #111827;
}

.subtitle {
    color: #6b7280;
    font-weight: 300;
}

.upload-area {
    border: 1px solid var(--border-color); /* Thin border as requested */
    border-radius: 12px;
    padding: 3rem 2rem;
    background-color: var(--light-gray);
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 1.5rem;
}

.upload-area:hover, .upload-area.dragover {
    border-color: var(--primary-color);
    background-color: #eff6ff;
}

.icon-container {
    margin-bottom: 1rem;
}

.upload-text {
    font-weight: 600;
    color: #374151;
    margin-bottom: 0.25rem;
}

.upload-subtext {
    color: #9ca3af;
    font-size: 0.875rem;
}

.btn-primary {
    background-color: var(--sky-blue); /* Sky blue as requested */
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s;
    width: 100%;
}

.btn-primary:hover:not(:disabled) {
    background-color: #0284c7;
}

.btn-primary:disabled {
    background-color: #cbd5e1;
    cursor: not-allowed;
}

.result-container {
    margin-top: 2rem;
    text-align: left;
    border: 1px solid var(--border-color); /* Light border as requested */
    border-radius: 8px;
    padding: 1.5rem;
    background-color: #fff;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.result-container.hidden {
    display: none;
}

.result-container h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: #374151;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

pre {
    background-color: #f3f4f6;
    padding: 1rem;
    border-radius: 6px;
    overflow-x: auto;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
    color: #333;
}

footer {
    margin-top: 3rem;
    color: #9ca3af;
    font-size: 0.8rem;
}