:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #f3f4f6;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --error-color: #ef4444;
    --background-color: #f9fafb;
    --card-background: #ffffff;
    --header-bg: #f1f5f9;
    --header-border: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 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);
}

[data-theme="dark"] {
    --primary-color: #60a5fa;
    --primary-light: #93c5fd;
    --secondary-color: #1f2937;
    --text-color: #e0f2fe;
    --text-color-light: #9ca3af;
    --border-color: #374151;
    --background-color: #111827;
    --message-bg-user: #2563eb;
    --message-bg-bot: #1f2937;
    --shadow-color: rgba(37, 99, 235, 0.3);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    transition: background-color 0.3s, color 0.3s, transform 0.2s;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    width: 100%;
    max-width: 1200px;
    padding: 2rem;
}

.upload-card {
    background-color: var(--card-background);
    border-radius: 1rem;
    padding: 2.5rem;
    box-shadow: var(--shadow-lg);
}

.upload-header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.upload-header i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.upload-header h1 {
    font-size: 1.875rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

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

.textarea-container {
    margin-bottom: 1.5rem;
    position: relative;
}

textarea {
    width: 100%;
    padding: 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: 0.75rem;
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
    font-size: 0.875rem;
    line-height: 1.5;
    resize: vertical;
    min-height: 200px;
    transition: all 0.2s ease;
    background-color: var(--card-background);
    color: var(--text-color);
    white-space: pre;
    overflow-wrap: normal;
    overflow-x: scroll;
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

textarea::placeholder {
    color: var(--text-light);
}

/* Header row styling */
textarea::first-line {
    background-color: var(--header-bg);
    color: var(--primary-color);
    font-weight: 600;
    padding: 0.75rem 1.25rem;
    border-bottom: 2px solid var(--header-border);
    display: block;
    margin: -1.25rem -1.25rem 0.75rem -1.25rem;
    border-radius: 0.5rem 0.5rem 0 0;
    letter-spacing: 0.025em;
    text-transform: uppercase;
    font-size: 0.75rem;
}

.submit-btn {
    width: 100%;
    padding: 1rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 0.75rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
}

.submit-btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

.status-message {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 0.75rem;
    font-size: 0.875rem;
    text-align: center;
}

.status-message.success {
    background-color: #dcfce7;
    color: var(--success-color);
}

.status-message.error {
    background-color: #fee2e2;
    color: var(--error-color);
}

@media (max-width: 640px) {
    .container {
        padding: 1rem;
    }
    
    .upload-card {
        padding: 1.5rem;
    }
}

/* Utility Classes */
.hidden {
    display: none;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--secondary-color);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-color-light);
}