/* Reset và Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #4361ee;
    --primary-dark: #3a56d4;
    --secondary-color: #7209b7;
    --success-color: #4cc9f0;
    --warning-color: #f72585;
    --danger-color: #f72585;
    --home-color: #10b981;
    --home-dark: #0da271;
    --light-color: #f8f9fa;
    --dark-color: #212529;
    --gray-100: #f8f9fa;
    --gray-200: #e9ecef;
    --gray-300: #dee2e6;
    --gray-400: #ced4da;
    --gray-500: #adb5bd;
    --gray-600: #6c757d;
    --gray-700: #495057;
    --gray-800: #343a40;
    --gray-900: #212529;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    --box-shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--dark-color);
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow-lg);
    overflow: hidden;
    min-height: 90vh;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 20px 30px 40px 30px;
    text-align: center;
    position: relative;
}

/* Header Top - Nút Về trang chủ trên cùng */
.header-top {
    display: flex;
    justify-content: flex-end;
    margin-bottom: 20px;
}

.home-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 500;
    font-size: 0.9rem;
    transition: var(--transition);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.home-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.home-icon {
    font-size: 1.1rem;
}

.logo-section {
    max-width: 600px;
    margin: 0 auto;
}

.logo-icon {
    font-size: 48px;
    margin-bottom: 15px;
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    width: 80px;
    height: 80px;
    line-height: 80px;
    border-radius: 50%;
    backdrop-filter: blur(10px);
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    letter-spacing: -0.5px;
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    font-weight: 300;
}

/* Main Content */
.main-content {
    padding: 30px;
}

/* Note Section */
.note {
    background: linear-gradient(135deg, #e3f2fd, #f3e5f5);
    border-radius: var(--border-radius-sm);
    padding: 25px;
    margin-bottom: 30px;
    border-left: 4px solid var(--primary-color);
}

.note-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
}

.note-icon {
    font-size: 24px;
}

.note-body ul {
    list-style: none;
    padding: 0;
}

.note-body li {
    padding: 8px 0;
    position: relative;
    padding-left: 25px;
}

.note-body li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

.highlight {
    background: linear-gradient(120deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 600;
    padding: 2px 6px;
    border-radius: 4px;
}

/* Upload Section */
.upload-section {
    margin-bottom: 30px;
    position: relative;
}

/* Upload area */
.upload-area {
    border: 3px dashed var(--gray-300);
    border-radius: var(--border-radius);
    padding: 60px 40px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    background: var(--gray-100);
    position: relative;
    overflow: hidden;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: white;
    transform: translateY(-2px);
    box-shadow: var(--box-shadow);
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(67, 97, 238, 0.1), rgba(114, 9, 183, 0.1));
}

.upload-icon {
    font-size: 60px;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.upload-area h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--gray-800);
}

.upload-area p {
    color: var(--gray-600);
    margin-bottom: 20px;
}

.file-requirements {
    margin-top: 20px;
    padding: 10px;
    background: white;
    border-radius: var(--border-radius-sm);
    display: inline-block;
    font-size: 0.9rem;
    color: var(--gray-600);
}

/* File info */
.file-info {
    margin-top: 15px;
    padding: 15px;
    background: var(--gray-100);
    border-radius: var(--border-radius-sm);
    display: none;
}

.file-info.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.file-info-content {
    display: flex;
    align-items: center;
    gap: 15px;
}

.file-info-icon {
    font-size: 32px;
    flex-shrink: 0;
}

.file-info-details {
    flex: 1;
}

.file-info-name {
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 5px;
}

.file-info-size {
    color: var(--gray-600);
    font-size: 0.9rem;
}

.file-info-close {
    background: none;
    border: none;
    font-size: 20px;
    color: var(--gray-600);
    cursor: pointer;
    padding: 5px;
    border-radius: 50%;
    transition: var(--transition);
}

.file-info-close:hover {
    background: var(--gray-200);
    color: var(--gray-800);
}

/* Control Section */
.control-section {
    margin-bottom: 30px;
}

.buttons {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.btn {
    padding: 14px 28px;
    border: none;
    border-radius: var(--border-radius-sm);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    min-width: 140px;
    text-decoration: none;
    text-align: center;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
}

.btn-secondary {
    background: var(--gray-200);
    color: var(--gray-700);
}

.btn-success {
    background: linear-gradient(135deg, var(--success-color), #4895ef);
    color: white;
}

/* Nút Về trang chủ trong control buttons */
.btn-home {
    background: linear-gradient(135deg, var(--home-color), var(--home-dark));
    color: white;
}

.btn-home:hover {
    background: linear-gradient(135deg, var(--home-dark), #0c8a62);
}

.btn-icon {
    font-size: 20px;
}

.table-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
    padding: 20px;
    background: var(--gray-100);
    border-radius: var(--border-radius-sm);
}

.rows-per-page {
    display: flex;
    align-items: center;
    gap: 10px;
}

select {
    padding: 10px 15px;
    border: 2px solid var(--gray-300);
    border-radius: var(--border-radius-sm);
    background: white;
    color: var(--gray-700);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

select:hover {
    border-color: var(--primary-color);
}

select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
}

.results-info {
    font-weight: 600;
    color: var(--gray-700);
}

/* Data Section */
.data-section {
    background: var(--gray-100);
    border-radius: var(--border-radius-sm);
    padding: 20px;
    margin-bottom: 30px;
}

.table-container {
    overflow-x: auto;
    background: white;
    border-radius: var(--border-radius-sm);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.empty-state {
    padding: 60px 20px;
    text-align: center;
    color: var(--gray-500);
}

.empty-icon {
    font-size: 60px;
    margin-bottom: 20px;
    opacity: 0.5;
}

table {
    width: 100%;
    border-collapse: collapse;
    min-width: 600px;
}

thead {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
}

th {
    padding: 18px 20px;
    text-align: left;
    color: white;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.9rem;
}

td {
    padding: 16px 20px;
    border-bottom: 1px solid var(--gray-200);
    color: var(--gray-700);
}

tbody tr {
    transition: var(--transition);
}

tbody tr:hover {
    background: var(--gray-100);
    transform: translateX(5px);
}

/* Pagination */
.pagination-container {
    margin-top: 30px;
    display: flex;
    justify-content: center;
}

.pagination {
    display: flex;
    gap: 8px;
    align-items: center;
}

.pagination button {
    padding: 10px 18px;
    border: 2px solid var(--gray-300);
    background: white;
    color: var(--gray-700);
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
    min-width: 45px;
}

.pagination button:hover:not(:disabled) {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
}

.pagination button:disabled {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border-color: var(--primary-color);
    cursor: default;
}

.pagination span {
    color: var(--gray-500);
    padding: 0 10px;
}

/* Alert Messages */
.alert {
    padding: 20px;
    border-radius: var(--border-radius-sm);
    margin: 20px 0;
    display: flex;
    align-items: flex-start;
    gap: 15px;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.alert-warning {
    background: linear-gradient(135deg, #fff3e0, #ffecb3);
    border-left: 4px solid var(--warning-color);
    color: #856404;
}

.alert-success {
    background: linear-gradient(135deg, #e8f5e9, #c8e6c9);
    border-left: 4px solid var(--success-color);
    color: #155724;
}

.alert-icon {
    font-size: 24px;
    flex-shrink: 0;
}

.alert-content {
    flex: 1;
}

.alert-content ul {
    margin-top: 10px;
    padding-left: 20px;
}

.alert-content li {
    margin-bottom: 5px;
}

/* Footer */
.footer {
    background: var(--gray-900);
    color: white;
    padding: 30px;
    text-align: center;
}

.stats {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--gray-400);
    margin-top: 5px;
}

.footer-bottom {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.copyright {
    color: var(--gray-500);
    font-size: 0.9rem;
    margin-bottom: 10px;
}

.footer-home-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--home-color);
    text-decoration: none;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: 20px;
    background: rgba(16, 185, 129, 0.1);
    transition: var(--transition);
}

.footer-home-link:hover {
    background: rgba(16, 185, 129, 0.2);
    transform: translateY(-2px);
}

.footer-home-link span {
    font-size: 1.2rem;
}

/* Ad Container */
.ad-container {
    max-width: 1200px;
    margin: 20px auto;
    padding: 20px;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        margin: 10px;
        border-radius: 10px;
    }
    
    .header {
        padding: 15px 20px 30px 20px;
    }
    
    .header-top {
        margin-bottom: 15px;
    }
    
    .home-btn {
        padding: 8px 16px;
        font-size: 0.85rem;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .main-content {
        padding: 20px;
    }
    
    .buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .upload-area {
        padding: 40px 20px;
    }
    
    .table-controls {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
    }
    
    .rows-per-page {
        justify-content: center;
    }
    
    .stats {
        gap: 20px;
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 15px;
    }
}

@media (max-width: 480px) {
    body {
        padding: 10px;
    }
    
    .header {
        padding: 10px 15px 20px 15px;
    }
    
    h1 {
        font-size: 1.8rem;
    }
    
    .upload-icon {
        font-size: 48px;
    }
    
    th, td {
        padding: 12px 15px;
    }
    
    .pagination button {
        padding: 8px 12px;
        min-width: 40px;
    }
    
    .home-btn {
        padding: 6px 12px;
        font-size: 0.8rem;
    }
    
    .footer-home-link {
        font-size: 0.9rem;
        padding: 6px 12px;
    }
}