:root {
    /* Slate Palette (Tailwind Match) */
    --slate-50: #f8fafc;
    --slate-100: #f1f5f9;
    --slate-200: #e2e8f0;
    --slate-300: #cbd5e1;
    --slate-400: #94a3b8;
    --slate-500: #64748b;
    --slate-600: #475569;
    --slate-700: #334155;
    --slate-800: #1e293b;
    --slate-900: #0f172a;

    --indigo-600: #4f46e5;
    --indigo-700: #4338ca;
    --indigo-50: #eef2ff;

    /* Diff Colors (Light) */
    --diff-added-bg: #d1e7dd;
    --diff-added-text: #0f5132;
    --diff-removed-bg: #f8d7da;
    --diff-removed-text: #842029;
    --diff-modified-bg: #fff3cd;
    --diff-modified-text: #664d03;

    /* Light Mode Bootstrap Overrides */
    --bs-body-bg: var(--slate-50);
    --bs-body-color: var(--slate-900);
}

[data-bs-theme="dark"] {
    /* Dark Mode Overrides */
    --bs-body-bg: var(--slate-900);
    --bs-body-color: var(--slate-100);
    --bs-border-color: var(--slate-700);

    /* Diff Colors (Dark) */
    --diff-added-bg: #0a3622;
    --diff-added-text: #75b798;
    --diff-removed-bg: #2c0b0e;
    --diff-removed-text: #ea868f;
    --diff-modified-bg: #332701;
    --diff-modified-text: #ffda6a;
}

body {
    font-family: 'Roboto', sans-serif;
    background-color: var(--bs-body-bg);
    color: var(--bs-body-color);
}

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

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--slate-300);
    border-radius: 4px;
}

[data-bs-theme="dark"] ::-webkit-scrollbar-thumb {
    background: var(--slate-600);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--slate-400);
}

/* Header Styling */
.app-header {
    background-color: #667eea;
    color: white;
    padding: 2rem 1rem;
    text-align: center;
    position: relative;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

[data-bs-theme="dark"] .app-header {
    background-color: #1a1a2e;
}

/* Theme Toggle Fab */
.theme-fab {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    padding: 0.5rem;
    border-radius: 50%;
    color: rgba(255, 255, 255, 0.7);
    background: transparent;
    border: none;
    cursor: pointer;
    z-index: 10;
    transition: all 0.2s;
}

.theme-fab:hover {
    color: white;
    background: rgba(255, 255, 255, 0.1);
}

.theme-fab:focus {
    outline: none;
    box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.5);
}

/* Card / Containers */
.card-custom {
    background-color: white;
    border: 1px solid var(--slate-200);
    border-radius: 0;
    /* Squared edges as requested */
    box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

[data-bs-theme="dark"] .card-custom {
    background-color: var(--slate-800);
    border-color: var(--slate-700);
}

.card-header-custom {
    padding: 1rem;
    border-bottom: 1px solid var(--slate-200);
    background-color: rgba(248, 250, 252, 0.5);
    /* Slate 50 with opacity */
    display: flex;
    justify-content: space-between;
    align-items: center;
}

[data-bs-theme="dark"] .card-header-custom {
    border-color: var(--slate-700);
    background-color: var(--slate-800);
}

/* Textareas */
.diff-textarea {
    width: 100%;
    min-height: 500px;
    /* Requested height */
    resize: vertical;
    border: none;
    padding: 1rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    background: transparent;
    color: var(--slate-800);
    outline: none;
    display: block;
}

[data-bs-theme="dark"] .diff-textarea {
    color: var(--slate-200);
}

.diff-textarea:focus {
    box-shadow: none;
    outline: none;
}

/* Controls Bar */
.controls-bar {
    background-color: white;
    border-bottom: 1px solid var(--slate-200);
    padding: 0.75rem 1rem;
    position: sticky;
    top: 0;
    z-index: 40;
}

[data-bs-theme="dark"] .controls-bar {
    background-color: var(--slate-800);
    border-color: var(--slate-700);
}

/* Custom Toggle Switch (Checkbox lookalike) */
.form-check-custom {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.375rem 0.75rem;
    border: 1px solid var(--slate-300);
    border-radius: 0.375rem;
    font-size: 0.875rem;
    background-color: var(--slate-50);
    cursor: pointer;
    transition: background-color 0.2s;
}

.form-check-custom:hover {
    background-color: var(--slate-100);
}

[data-bs-theme="dark"] .form-check-custom {
    border-color: var(--slate-600);
    background-color: var(--slate-700);
    color: var(--slate-100);
}

[data-bs-theme="dark"] .form-check-custom:hover {
    background-color: var(--slate-600);
}

/* Unified/Split Toggle Group */
.view-toggle-group {
    border: 1px solid var(--indigo-600);
    border-radius: 9999px;
    overflow: hidden;
    display: flex;
    background-color: white;
}

[data-bs-theme="dark"] .view-toggle-group {
    background-color: var(--slate-800);
}

.view-toggle-label {
    padding: 0.375rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--indigo-600);
    cursor: pointer;
    transition: all 0.2s;
}

[data-bs-theme="dark"] .view-toggle-label {
    color: #818cf8;
    /* Indigo 400 */
}

.view-toggle-input:checked+.view-toggle-label {
    background-color: var(--indigo-600);
    color: white;
}

/* Buttons */
.btn-primary-custom {
    background-color: var(--indigo-600);
    color: white;
    border-radius: 9999px;
    padding: 0.625rem 2rem;
    font-weight: 500;
    border: none;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    transition: all 0.2s;
}

.btn-primary-custom:hover {
    background-color: var(--indigo-700);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    color: white;
}

.btn-primary-custom:active {
    transform: scale(0.95);
}

.btn-upload {
    color: var(--indigo-600);
    font-size: 0.875rem;
    font-weight: 500;
    background: transparent;
    border: none;
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    transition: background 0.2s;
}

.btn-upload:hover {
    background-color: var(--indigo-50);
}

[data-bs-theme="dark"] .btn-upload {
    color: #818cf8;
}

[data-bs-theme="dark"] .btn-upload:hover {
    background-color: rgba(79, 70, 229, 0.3);
}

/* Diff Styling */
.diff-container {
    border: 1px solid var(--slate-200);
    border-radius: 0.75rem;
    /* Only results card has radius, or should it be squared? Keeping it slightly rounded as per previous 'rounded-xl' was for input, results usually match. Let's make it rounded-xl (0.75rem) to better contain the diff list */
    border-radius: 0.75rem;
    overflow: hidden;
    background-color: white;
}

[data-bs-theme="dark"] .diff-container {
    background-color: var(--slate-800);
    border-color: var(--slate-700);
}

.diff-line {
    display: grid;
    grid-template-columns: 40px 30px 1fr;
    font-family: 'JetBrains Mono', monospace;
    font-size: 13px;
    line-height: 1.6;
    /* Removed border-bottom as requested */
}

.side-by-side .diff-line {
    grid-template-columns: 40px 30px 1fr 40px 30px 1fr;
}

.line-num,
.line-label,
.line-txt {
    border-right: 1px solid var(--slate-200);
}

[data-bs-theme="dark"] .line-num,
[data-bs-theme="dark"] .line-label,
[data-bs-theme="dark"] .line-txt {
    border-color: var(--slate-700);
}

.line-txt:last-child {
    border-right: none;
}

.line-num {
    text-align: right;
    padding: 0 0.75rem;
    user-select: none;
    color: var(--slate-500);
}

[data-bs-theme="dark"] .line-num {
    color: var(--slate-400);
}

.line-label {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    user-select: none;
    color: var(--slate-500);
}

[data-bs-theme="dark"] .line-label {
    color: var(--slate-400);
}

.line-txt {
    padding: 0 0.75rem;
    white-space: pre-wrap;
    word-break: break-all;
}

/* Diff Colors */
.diff-added {
    background-color: var(--diff-added-bg);
    color: var(--diff-added-text);
}

.diff-removed {
    background-color: var(--diff-removed-bg);
    color: var(--diff-removed-text);
}

.diff-modified {
    background-color: var(--diff-modified-bg);
    color: var(--diff-modified-text);
}

/* Footer */
footer {
    margin-top: 4rem;
    padding: 1.5rem 1rem;
    /* Reduced padding (py-6 approx) */
    background-color: transparent;
    border-top: 1px solid var(--slate-200);
    text-align: center;
    font-size: 0.875rem;
    color: var(--slate-500);
}

[data-bs-theme="dark"] footer {
    border-color: var(--slate-700);
}

.footer-link {
    color: var(--slate-500);
    text-decoration: none;
    margin: 0 0.75rem;
    transition: color 0.2s;
    background: none;
    border: none;
    padding: 0;
    cursor: pointer;
}

.footer-link:hover {
    color: var(--indigo-600);
}

[data-bs-theme="dark"] .footer-link {
    color: var(--slate-400);
}

[data-bs-theme="dark"] .footer-link:hover {
    color: #818cf8;
}

/* Modal Theme Overrides */
[data-bs-theme="dark"] .modal-content {
    background-color: var(--slate-800);
    border-color: var(--slate-700);
    color: var(--slate-200);
}

[data-bs-theme="dark"] .modal-header,
[data-bs-theme="dark"] .modal-footer {
    border-color: var(--slate-700);
}

[data-bs-theme="dark"] .btn-close {
    filter: invert(1) grayscale(100%) brightness(200%);
}