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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #333;
    min-height: 100vh;
}

.container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: 280px;
    background: linear-gradient(180deg, #1a1a2e 0%, #16213e 100%);
    color: white;
    padding: 24px;
    position: fixed;
    height: 100vh;
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.1);
}

.logo {
    font-size: 26px;
    font-weight: 700;
    margin-bottom: 40px;
    color: #4ecca3;
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo::before {
    content: "🎓";
    font-size: 32px;
}

.nav {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.nav-btn {
    background: transparent;
    border: none;
    color: rgba(255, 255, 255, 0.7);
    padding: 14px 18px;
    text-align: left;
    cursor: pointer;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 12px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-btn:hover {
    background: rgba(78, 204, 163, 0.15);
    color: white;
    transform: translateX(4px);
}

.nav-btn.active {
    background: linear-gradient(135deg, #4ecca3 0%, #45b892 100%);
    color: #1a1a2e;
    box-shadow: 0 4px 15px rgba(78, 204, 163, 0.4);
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: 280px;
    padding: 40px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
}

.section {
    display: none;
    animation: fadeIn 0.3s ease-in-out;
}

.section.active {
    display: block;
}

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

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 32px;
    padding-bottom: 20px;
    border-bottom: 2px solid #e0e0e0;
}

.section-header h2 {
    font-size: 32px;
    color: #1a1a2e;
    font-weight: 700;
}

/* Buttons */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: linear-gradient(135deg, #4ecca3 0%, #45b892 100%);
    color: #1a1a2e;
    box-shadow: 0 4px 15px rgba(78, 204, 163, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(78, 204, 163, 0.4);
}

.btn-secondary {
    background: #f0f0f0;
    color: #333;
}

.btn-secondary:hover {
    background: #e0e0e0;
    transform: translateY(-2px);
}

.btn-danger {
    background: linear-gradient(135deg, #ff6b6b 0%, #ff5252 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(255, 107, 107, 0.3);
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 107, 107, 0.4);
}

.btn-success {
    background: linear-gradient(135deg, #4ecca3 0%, #45b892 100%);
    color: white;
}

.btn-sm {
    padding: 8px 16px;
    font-size: 13px;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.modal.active {
    display: flex;
    animation: modalFadeIn 0.3s ease-in-out;
}

@keyframes modalFadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.modal-content {
    background: white;
    border-radius: 16px;
    width: 90%;
    max-width: 900px;
    max-height: 90vh;
    overflow-y: auto;
    padding: 36px;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.25);
    animation: modalSlideIn 0.3s ease-in-out;
}

@keyframes modalSlideIn {
    from {
        transform: translateY(-20px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 2px solid #e0e0e0;
}

.modal-header h3 {
    font-size: 26px;
    color: #1a1a2e;
    font-weight: 700;
}

.close-btn {
    background: #f0f0f0;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #666;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
}

.close-btn:hover {
    background: #e0e0e0;
    color: #333;
    transform: rotate(90deg);
}

/* Form */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #1a1a2e;
    font-size: 14px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 14px;
    transition: all 0.3s;
    background: #fafafa;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: #4ecca3;
    background: white;
    box-shadow: 0 0 0 3px rgba(78, 204, 163, 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
}

.form-section {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    padding: 24px;
    border-radius: 12px;
    margin-bottom: 24px;
    border: 1px solid #e0e0e0;
}

.form-section h4 {
    margin-bottom: 16px;
    color: #1a1a2e;
    font-size: 18px;
    font-weight: 600;
}

.form-actions {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
    margin-top: 24px;
    padding-top: 20px;
    border-top: 2px solid #e0e0e0;
}

.image-preview {
    margin-top: 12px;
}

.image-preview img {
    max-width: 250px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* Items Grid */
.items-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}

.item-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid #e0e0e0;
}

.item-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
}

.item-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 12px;
    margin-bottom: 16px;
}

.item-card h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: #1a1a2e;
    font-weight: 700;
}

.item-card p {
    color: #666;
    font-size: 14px;
    margin-bottom: 12px;
    line-height: 1.5;
}

.item-card .meta {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 16px;
}

.item-card .badge {
    background: linear-gradient(135deg, #e0f2f1 0%, #b2dfdb 100%);
    color: #00695c;
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.item-card .price {
    font-size: 24px;
    font-weight: 700;
    color: #4ecca3;
    margin-bottom: 16px;
}

.item-card .actions {
    display: flex;
    gap: 12px;
}

.item-card .actions button {
    flex: 1;
}

/* Table */
.table-container {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    border: 1px solid #e0e0e0;
}

table {
    width: 100%;
    border-collapse: collapse;
}

thead {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    color: white;
}

th {
    padding: 16px 20px;
    text-align: left;
    font-weight: 600;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

td {
    padding: 16px 20px;
    border-bottom: 1px solid #e0e0e0;
}

tr:hover {
    background: #f8f9fa;
}

.status-badge {
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.status-pending {
    background: linear-gradient(135deg, #fff3cd 0%, #ffeaa7 100%);
    color: #856404;
}

.status-confirmed {
    background: linear-gradient(135deg, #d1ecf1 0%, #a8d8ea 100%);
    color: #0c5460;
}

.status-completed {
    background: linear-gradient(135deg, #d4edda 0%, #b8e6b8 100%);
    color: #155724;
}

.status-cancelled {
    background: linear-gradient(135deg, #f8d7da 0%, #f5b7b1 100%);
    color: #721c24;
}

.filters select {
    padding: 10px 16px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 14px;
    background: white;
    cursor: pointer;
    transition: all 0.3s;
}

.filters select:focus {
    outline: none;
    border-color: #4ecca3;
}

.status-select {
    padding: 6px 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 12px;
    background: white;
    cursor: pointer;
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        width: 70px;
        padding: 16px 12px;
    }

    .logo {
        font-size: 0;
        margin-bottom: 24px;
    }

    .logo::before {
        font-size: 28px;
    }

    .nav-btn span:first-child {
        font-size: 22px;
    }

    .nav-btn span:last-child {
        display: none;
    }

    .main-content {
        margin-left: 70px;
        padding: 20px;
    }

    .section-header {
        flex-direction: column;
        gap: 16px;
        align-items: flex-start;
    }

    .section-header h2 {
        font-size: 24px;
    }

    .table-container {
        overflow-x: auto;
    }

    .items-grid {
        grid-template-columns: 1fr;
    }

    .modal-content {
        padding: 24px;
        margin: 20px;
    }
}