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

:root {
    --primary-blue: #4A90E2;
    --light-blue: #E8F4FD;
    --dark-blue: #2E5C8A;
    --white: #FFFFFF;
    --light-gray: #F5F7FA;
    --border-gray: #E1E8ED;
    --text-dark: #2C3E50;
    --text-gray: #7F8C9B;
    --success: #27AE60;
    --danger: #E74C3C;
    --warning: #F39C12;
    --sidebar-width: 280px;
    --top-bar-height: 70px;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--light-gray);
    color: var(--text-dark);
    line-height: 1.6;
}

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

.sidebar {
    width: var(--sidebar-width);
    background: linear-gradient(180deg, var(--primary-blue) 0%, var(--dark-blue) 100%);
    color: var(--white);
    position: fixed;
    right: 0;
    top: 0;
    height: 100vh;
    overflow-y: auto;
    box-shadow: -4px 0 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
    z-index: 1000;
}

.sidebar::-webkit-scrollbar {
    width: 6px;
}

.sidebar::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.1);
}

.sidebar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
}

.sidebar-header {
    padding: 25px 20px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.sidebar-header h1 {
    font-size: 22px;
    font-weight: 600;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--white);
    font-size: 24px;
    cursor: pointer;
}

.sidebar-nav {
    padding: 10px 0;
}

.nav-item {
    display: flex;
    align-items: center;
    padding: 14px 20px;
    color: var(--white);
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
    border-right: 3px solid transparent;
}

.nav-item:hover {
    background: rgba(255, 255, 255, 0.1);
    border-right-color: var(--white);
}

.nav-item.active {
    background: rgba(255, 255, 255, 0.2);
    border-right-color: var(--white);
    font-weight: 600;
}

.nav-item .icon {
    font-size: 20px;
    margin-left: 12px;
}

.nav-parent {
    justify-content: space-between;
}

.nav-parent .arrow {
    font-size: 12px;
    transition: transform 0.3s ease;
}

.nav-parent.active .arrow {
    transform: rotate(180deg);
}

.nav-submenu {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    background: rgba(0, 0, 0, 0.2);
}

.nav-submenu.open {
    max-height: 500px;
}

.nav-submenu .nav-item {
    padding-right: 52px;
    font-size: 14px;
}

.main-content {
    flex: 1;
    margin-right: var(--sidebar-width);
    transition: margin-right 0.3s ease;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.top-bar {
    height: var(--top-bar-height);
    background: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 30px;
    position: sticky;
    top: 0;
    z-index: 100;
}

.menu-toggle-mobile {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-dark);
}

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

.user-info span {
    color: var(--text-dark);
    font-weight: 500;
}

.btn-icon {
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: background 0.3s ease;
}

.btn-icon:hover {
    background: var(--light-gray);
}

.content-area {
    padding: 30px;
    flex: 1;
}

.page-header {
    margin-bottom: 30px;
}

.page-header h2 {
    color: var(--text-dark);
    font-size: 28px;
    margin-bottom: 8px;
}

.page-header p {
    color: var(--text-gray);
    font-size: 14px;
}

.card {
    background: var(--white);
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    margin-bottom: 25px;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--light-blue);
}

.card-header h3 {
    color: var(--text-dark);
    font-size: 20px;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: var(--primary-blue);
    color: var(--white);
}

.btn-primary:hover {
    background: var(--dark-blue);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(74, 144, 226, 0.3);
}

.btn-success {
    background: var(--success);
    color: var(--white);
}

.btn-success:hover {
    background: #229954;
}

.btn-danger {
    background: var(--danger);
    color: var(--white);
}

.btn-danger:hover {
    background: #C0392B;
}

.btn-secondary {
    background: var(--light-gray);
    color: var(--text-dark);
}

.btn-secondary:hover {
    background: var(--border-gray);
}

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

.dashboard-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--dark-blue) 100%);
    color: var(--white);
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.2);
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
}

.stat-card .icon {
    font-size: 36px;
    margin-bottom: 10px;
    opacity: 0.9;
}

.stat-card h4 {
    font-size: 14px;
    font-weight: 400;
    opacity: 0.9;
    margin-bottom: 8px;
}

.stat-card .value {
    font-size: 32px;
    font-weight: 700;
}

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

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

thead {
    background: var(--light-blue);
}

thead th {
    padding: 15px;
    text-align: right;
    font-weight: 600;
    color: var(--text-dark);
    font-size: 14px;
}

tbody td {
    padding: 15px;
    border-bottom: 1px solid var(--border-gray);
    color: var(--text-dark);
}

tbody tr {
    transition: background 0.2s ease;
}

tbody tr:hover {
    background: var(--light-gray);
}

.badge {
    display: inline-block;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}

.badge-success {
    background: #D5F5E3;
    color: var(--success);
}

.badge-danger {
    background: #FADBD8;
    color: var(--danger);
}

.badge-warning {
    background: #FCF3CF;
    color: var(--warning);
}

.action-buttons {
    display: flex;
    gap: 8px;
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-dark);
    font-weight: 500;
    font-size: 14px;
}

.form-group label.required::after {
    content: " *";
    color: var(--danger);
}

.form-control {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid var(--border-gray);
    border-radius: 8px;
    font-size: 14px;
    transition: all 0.3s ease;
    background: var(--white);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--white);
    border-radius: 12px;
    max-width: 900px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.modal-header {
    padding: 20px 25px;
    border-bottom: 2px solid var(--light-blue);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    color: var(--text-dark);
    font-size: 22px;
}

.modal-close {
    background: none;
    border: none;
    font-size: 28px;
    cursor: pointer;
    color: var(--text-gray);
    transition: color 0.3s ease;
}

.modal-close:hover {
    color: var(--danger);
}

.modal-body {
    padding: 25px;
}

.invoice-items {
    margin-top: 20px;
}

.invoice-item {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    padding: 15px;
    background: var(--light-gray);
    border-radius: 8px;
    margin-bottom: 15px;
    position: relative;
}

.btn-remove-item {
    position: absolute;
    top: 10px;
    left: 10px;
    background: var(--danger);
    color: var(--white);
    border: none;
    border-radius: 50%;
    width: 30px;
    height: 30px;
    cursor: pointer;
    font-size: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.invoice-total {
    text-align: left;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 2px solid var(--border-gray);
}

.invoice-total h3 {
    font-size: 24px;
    color: var(--primary-blue);
}

.search-box {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.search-box input {
    flex: 1;
}

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

.empty-state .icon {
    font-size: 64px;
    margin-bottom: 20px;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 20px;
    margin-bottom: 10px;
}

@media (max-width: 1024px) {
    :root {
        --sidebar-width: 250px;
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(100%);
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .main-content {
        margin-right: 0;
    }

    .menu-toggle-mobile {
        display: block;
    }

    .menu-toggle {
        display: block;
    }

    .content-area {
        padding: 20px;
    }

    .dashboard-stats {
        grid-template-columns: 1fr;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .table-container {
        font-size: 12px;
    }

    thead th, tbody td {
        padding: 10px;
    }

    .user-info span {
        display: none;
    }

    .modal-content {
        max-width: 100%;
    }
}

@media (max-width: 480px) {
    .sidebar-header h1 {
        font-size: 18px;
    }

    .page-header h2 {
        font-size: 22px;
    }

    .btn {
        padding: 10px 18px;
        font-size: 13px;
    }

    .stat-card .value {
        font-size: 24px;
    }
}

.loading {
    text-align: center;
    padding: 40px;
    color: var(--text-gray);
}

.loading::after {
    content: "...";
    animation: loading 1.5s infinite;
}

@keyframes loading {
    0%, 20% { content: "."; }
    40% { content: ".."; }
    60%, 100% { content: "..."; }
}

.alert {
    padding: 15px 20px;
    border-radius: 8px;
    margin-bottom: 20px;
}

.alert-success {
    background: #D5F5E3;
    color: var(--success);
    border-right: 4px solid var(--success);
}

.alert-danger {
    background: #FADBD8;
    color: var(--danger);
    border-right: 4px solid var(--danger);
}

.alert-info {
    background: var(--light-blue);
    color: var(--primary-blue);
    border-right: 4px solid var(--primary-blue);
}

.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 20px;
}

.login-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    max-width: 1200px;
    width: 100%;
    background: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    animation: slideIn 0.5s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-left {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 60px 40px;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
}

.login-branding {
    text-align: center;
}

.login-icon {
    font-size: 80px;
    margin-bottom: 20px;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

.login-branding h1 {
    font-size: 32px;
    margin-bottom: 15px;
    font-weight: 700;
}

.login-description {
    font-size: 16px;
    line-height: 1.8;
    margin-bottom: 40px;
    opacity: 0.95;
}

.login-features {
    text-align: right;
    margin-top: 40px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 20px;
    font-size: 15px;
}

.feature-icon {
    width: 28px;
    height: 28px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    flex-shrink: 0;
}

.login-right {
    padding: 60px 50px;
    background: white;
    display: flex;
    align-items: center;
    justify-content: center;
}

.login-form-container {
    width: 100%;
    max-width: 400px;
}

.login-form-container h2 {
    font-size: 28px;
    color: var(--text-dark);
    margin-bottom: 10px;
}

.login-subtitle {
    color: var(--text-gray);
    margin-bottom: 35px;
    font-size: 15px;
}

.login-form .form-group {
    margin-bottom: 25px;
}

.login-form label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-dark);
    font-weight: 500;
    font-size: 14px;
}

.input-with-icon {
    position: relative;
    display: flex;
    align-items: center;
}

.input-with-icon .input-icon {
    position: absolute;
    right: 15px;
    font-size: 18px;
    color: var(--text-gray);
    pointer-events: none;
}

.input-with-icon .form-control {
    padding-right: 45px;
    padding-left: 45px;
}

.toggle-password {
    position: absolute;
    left: 15px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 18px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.6;
    transition: opacity 0.3s;
}

.toggle-password:hover {
    opacity: 1;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 14px;
    color: var(--text-dark);
    user-select: none;
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--primary-blue);
}

.login-error {
    padding: 12px 15px;
    background: #FADBD8;
    color: var(--danger);
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14px;
    border-right: 4px solid var(--danger);
    animation: shake 0.5s;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

.btn-login {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-login:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

.btn-login:active {
    transform: translateY(0);
}

.login-footer {
    margin-top: 30px;
    text-align: center;
    font-size: 13px;
    color: var(--text-gray);
}

.nav-logout {
    margin-top: auto;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding-top: 15px !important;
}

.nav-logout:hover {
    background: rgba(231, 76, 60, 0.2) !important;
}

@media (max-width: 968px) {
    .login-container {
        grid-template-columns: 1fr;
    }

    .login-left {
        padding: 40px 30px;
    }

    .login-branding h1 {
        font-size: 26px;
    }

    .login-icon {
        font-size: 60px;
    }

    .login-right {
        padding: 40px 30px;
    }
}

@media (max-width: 576px) {
    .login-page {
        padding: 10px;
    }

    .login-left {
        padding: 30px 20px;
    }

    .login-right {
        padding: 30px 20px;
    }

    .login-form-container h2 {
        font-size: 24px;
    }
}

.app-footer {
    background: var(--white);
    border-top: 1px solid var(--border-gray);
    padding: 20px 30px;
    text-align: center;
    color: var(--text-gray);
    font-size: 14px;
    margin-top: auto;
}

.app-footer p {
    margin: 5px 0;
}

.app-footer strong {
    color: var(--primary-blue);
    font-weight: 600;
}

.profile-container {
    max-width: 600px;
    margin: 0 auto;
}

.profile-header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
    background: var(--light-gray);
    border-radius: 12px;
}

.profile-image-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.profile-image {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--primary-blue);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.profile-info {
    margin-top: 20px;
    padding: 20px;
    background: var(--light-blue);
    border-radius: 8px;
    border-right: 4px solid var(--primary-blue);
}

.profile-info p {
    margin: 10px 0;
    color: var(--text-dark);
    font-size: 14px;
}

.profile-info strong {
    color: var(--primary-blue);
    margin-left: 8px;
}