:root {
    --color-dark: #1a1a1a;
    --color-dark-green: #2a442a;
    --color-light-text: #e0e0e0;
    --color-light-green: #90EE90;
    --color-lighter-green: #98FB98;
    --color-dark-hover: #333;
    --color-dark-active: #3a3a3a;
}

body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: linear-gradient(to right, var(--color-dark), var(--color-dark-green), var(--color-dark));
    color: var(--color-light-text);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    text-align: center;
}

h1 {
    color: var(--color-light-green);
    margin-bottom: 30px;
}

.main-content {
    display: flex;
    justify-content: center;
    align-items: stretch;
    gap: 30px;
    margin: 20px auto;
    width: 100%;
    max-width: 900px;
    padding: 0 20px;
}

.upload-section, .controls-section {
    flex: 1 0 350px;
    width: 350px;
    display: flex;
    flex-direction: column;
    min-width: 0;
    min-height: 250px;
    background-color: var(--color-dark);
    border-radius: 8px;
}

.upload-section {
    padding: 0;
    margin: 20px;
}

.controls-section {
    border: 1px solid var(--color-light-green);
    padding: 20px;
    gap: 20px;
    justify-content: center;
    margin: 20px;
}

.upload-area {
    border: 2px dashed var(--color-light-green);
    padding: 30px;
    border-radius: 8px;
    background-color: var(--color-dark);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    height: 100%;
    justify-content: center;
    margin: 0;
}

.upload-area.files-added {
    padding: 15px;
    min-height: 150px;
}

.upload-area p {
    margin: 0;
    font-size: 1.1em;
    color: var(--color-light-green);
}

.hidden {
    display: none !important;
}

.after-upload-text, .initial-text {
    transition: opacity 0.3s ease;
}

.upload-area:hover {
    border-color: var(--color-lighter-green);
    background-color: var(--color-dark-hover);
}

.upload-area.dragover {
    background-color: var(--color-dark-active);
    border-color: var(--color-lighter-green);
}

.upload-area button {
    margin: 0;
    min-width: 150px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 1em;
}

#uploadButton {
    margin-top: 5px;
}

.button-pairs {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.sort-buttons, .action-buttons {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.sort-buttons button, .action-buttons button {
    flex: 1;
    max-width: 150px;
}

.button-group {
    display: flex;
    flex-direction: column;
    gap: 15px;
    width: 100%;
}

.filename-input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
    width: 100%;
}

.filename-input-group label {
    color: var(--color-light-green);
    text-align: left;
}

#fileNameInput {
    width: 100%;
    padding: 8px 12px;
    background-color: var(--color-dark);
    border: 1px solid rgba(144, 238, 144, 0.3);
    border-radius: 4px;
    color: var(--color-light-text);
    font-size: 1em;
    box-sizing: border-box;
    transition: all 0.3s ease;
}

#fileNameInput:hover {
    border-color: rgba(144, 238, 144, 0.5);
}

#fileNameInput:focus {
    outline: none;
    border-color: var(--color-light-green);
    box-shadow: 0 0 5px rgba(144, 238, 144, 0.2);
}

button {
    padding: 8px 12px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9em;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

button:hover {
    background-color: #45a049;
    transform: translateY(-1px);
}

button:disabled {
    background-color: #404040;
    cursor: not-allowed;
    transform: none;
}

#pdfInput {
    display: none;
}

.pdf-list-container {
    width: 100%;
    display: flex;
    justify-content: center;
    padding: 20px 0;
}

#pdfList {
    list-style: none;
    padding: 0;
    margin: 0;
    width: 100%;
    max-width: 800px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
}

#pdfList li {
    padding: 10px 15px;
    margin: 8px 0;
    background-color: var(--color-dark);
    border: 1px solid rgba(144, 238, 144, 0.3);
    border-radius: 4px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background-color 0.3s ease, border-color 0.3s ease;
    cursor: move;
    min-width: 0;
}

#pdfList li:hover {
    background-color: var(--color-dark-active);
    border-color: rgba(144, 238, 144, 0.5);
}

#pdfList li.dragging {
    opacity: 0.5;
    background-color: var(--color-dark-active);
    border: 2px dotted #4488ff;
}

.sortable-ghost {
    border: 2px dotted #4488ff !important;
    background-color: rgba(68, 136, 255, 0.1) !important;
    opacity: 0.7;
}

#pdfList li:nth-child(even) {
    background-color: #333333;
}

#pdfList li:nth-child(even):hover {
    background-color: var(--color-dark-active);
}

.file-info {
    display: flex;
    align-items: center;
    gap: 12px;
    flex: 1;
    min-width: 0;
}

.file-number {
    color: var(--color-light-green);
    font-weight: bold;
    min-width: 25px;
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.fa-file-pdf {
    color: var(--color-light-green);
    font-size: 1.1em;
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.file-name {
    color: var(--color-light-text);
    margin: 0;
    display: flex;
    align-items: center;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    min-width: 0;
}

.file-actions {
    display: flex;
    gap: 10px;
    align-items: center;
}

.remove-button {
    background-color: transparent;
    border: none;
    color: #ff4444;
    cursor: pointer;
    padding: 8px;
    margin-left: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    flex-shrink: 0;
    border-radius: 50%;
    width: 32px;
    height: 32px;
}

.remove-button:hover {
    color: #ff0000;
    background-color: rgba(255, 0, 0, 0.1);
    transform: scale(1.1);
}

.remove-button:active {
    transform: scale(0.95);
    background-color: rgba(255, 0, 0, 0.2);
}

.remove-button i {
    font-size: 1.1em;
    transition: transform 0.3s ease;
}

.remove-button:hover i {
    transform: rotate(90deg);
}

.move-buttons {
    display: flex;
    gap: 5px;
}

.move-buttons button {
    width: auto;
    margin: 0;
    padding: 5px 10px;
    font-size: 14px;
}

.fa-file-pdf, .fa-object-group, .fa-sort-alpha-down,
.fa-sort-alpha-up, .fa-plus, .fa-redo {
    font-size: 1.1em;
}

li {
    background-color: var(--color-dark);
    margin-bottom: 5px;
    padding: 8px 15px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-radius: 4px;
    cursor: move;
    transition: background-color 0.1s ease;
    font-size: 14px;
}

li:nth-child(even) {
    background-color: #333333;
}

li:hover {
    background-color: var(--color-dark-active);
}

li.dragging {
    opacity: 0.5;
    background-color: var(--color-dark-active);
}

input[type="file"] {
    display: none;
}

ul {
    list-style-type: none;
    padding: 0;
}

#mergeButton {
    width: 100%;
    padding: 12px;
    font-size: 1.1em;
    box-sizing: border-box;
}