:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --info-color: #3b82f6;
    --light-bg: #f9fafb;
    --dark-text: #1f2937;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --transition: all 0.3s ease;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.25;
    margin-bottom: 0.75rem;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Forms */
input, select, textarea, button {
    font-family: inherit;
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="number"],
input[type="date"],
input[type="tel"],
select,
textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    background-color: white;
}

input:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

textarea {
    resize: vertical;
    min-height: 120px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    text-decoration: none;
    user-select: none;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover:not(:disabled) {
    background-color: #d1d5db;
}

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

.btn-success:hover:not(:disabled) {
    opacity: 0.9;
}

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

.btn-danger:hover:not(:disabled) {
    opacity: 0.9;
}

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

.btn-warning:hover:not(:disabled) {
    opacity: 0.9;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-block {
    width: 100%;
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.alert-success {
    background-color: #d1fae5;
    color: #065f46;
    border-left: 4px solid var(--success-color);
}

.alert-danger {
    background-color: #fee2e2;
    color: #991b1b;
    border-left: 4px solid var(--danger-color);
}

.alert-warning {
    background-color: #fef3c7;
    color: #92400e;
    border-left: 4px solid var(--warning-color);
}

.alert-info {
    background-color: #dbeafe;
    color: #0c2d6b;
    border-left: 4px solid var(--info-color);
}

.alert-close {
    margin-left: auto;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0.7;
}

.alert-close:hover {
    opacity: 1;
}

/* Cards */
.card {
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 1.5rem;
}

.card-body {
    padding: 1.5rem;
}

.card-footer {
    background-color: var(--light-bg);
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--border-color);
}

/* Tables */
.table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    margin-bottom: 1.5rem;
}

.table thead {
    background-color: var(--light-bg);
    border-bottom: 2px solid var(--border-color);
}

.table th {
    padding: 1rem;
    text-align: left;
    font-weight: 600;
}

.table td {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border-color);
}

.table tbody tr:hover {
    background-color: var(--light-bg);
}

/* Grid Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.row {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 1.5rem;
}

.col-1 { grid-column: span 1; }
.col-2 { grid-column: span 2; }
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-6 { grid-column: span 6; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }

/* Utilities */
.text-center {
    text-align: center;
}

.text-right {
    text-align: right;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }

.d-none {
    display: none;
}

.d-block {
    display: block;
}

.d-inline {
    display: inline;
}

.d-flex {
    display: flex;
}

.flex-between {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.flex-center {
    display: flex;
    justify-content: center;
    align-items: center;
}

.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }

/* Loading Spinner */
.spinner {
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Progress Bar */
.progress {
    width: 100%;
    height: 8px;
    background-color: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 1rem;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    transition: width 0.3s ease;
}

/* Badges */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.875rem;
    font-weight: 600;
}

.badge-primary {
    background-color: #dbeafe;
    color: #0c2d6b;
}

.badge-success {
    background-color: #d1fae5;
    color: #065f46;
}

.badge-danger {
    background-color: #fee2e2;
    color: #991b1b;
}

.badge-warning {
    background-color: #fef3c7;
    color: #92400e;
}

/* Navigation */
.navbar {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    text-decoration: none;
}

.navbar-menu {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.navbar-menu a {
    color: white;
    transition: var(--transition);
}

.navbar-menu a:hover {
    color: #f0f0f0;
    text-decoration: none;
}

/* Sidebar */
.sidebar {
    background: white;
    width: 250px;
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    height: 100vh;
    overflow-y: auto;
    position: fixed;
    left: 0;
    top: 0;
}

.sidebar-menu {
    list-style: none;
}

.sidebar-menu li {
    margin-bottom: 0.5rem;
}

.sidebar-menu a {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--dark-text);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.sidebar-menu a:hover,
.sidebar-menu a.active {
    background-color: var(--light-bg);
    color: var(--primary-color);
}

/* Dashboard */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.stat-card-title {
    color: #6b7280;
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    margin-bottom: 0.5rem;
}

.stat-card-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

/* Login Page */
.login-container {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 1rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
}

.login-card {
    width: 100%;
    max-width: 450px;
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.login-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 2rem;
    text-align: center;
}

.login-header i {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.login-body {
    padding: 2rem;
}

.login-form-group {
    margin-bottom: 1.5rem;
}

.login-form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.form-help {
    font-size: 0.875rem;
    color: #6b7280;
    margin-top: 0.25rem;
}

.forgot-password {
    text-align: right;
    margin-top: 0.5rem;
}

.forgot-password a {
    font-size: 0.875rem;
}

.login-divider {
    text-align: center;
    margin: 1.5rem 0;
    position: relative;
}

.login-divider::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    width: 100%;
    height: 1px;
    background-color: var(--border-color);
}

.login-divider span {
    background: white;
    padding: 0 1rem;
    color: #6b7280;
    position: relative;
}

.social-login {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.social-login-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: white;
    cursor: pointer;
    transition: var(--transition);
}

.social-login-btn:hover {
    border-color: var(--primary-color);
    background-color: var(--light-bg);
}

.login-footer {
    background-color: var(--light-bg);
    padding: 1rem;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

.login-footer a {
    font-weight: 600;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    :root {
        font-size: 14px;
    }

    h1 { font-size: 1.5rem; }
    h2 { font-size: 1.25rem; }
    h3 { font-size: 1.125rem; }

    .row {
        grid-template-columns: repeat(6, 1fr);
    }

    .col-4 { grid-column: span 6; }
    .col-8 { grid-column: span 6; }

    .navbar-menu {
        gap: 1rem;
        font-size: 0.875rem;
    }

    .dashboard-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    }

    .stat-card-value {
        font-size: 1.5rem;
    }

    .table {
        font-size: 0.875rem;
    }

    .table th,
    .table td {
        padding: 0.5rem;
    }

    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
    }

    .navbar {
        flex-direction: column;
        gap: 1rem;
    }

    .login-card {
        max-width: 100%;
    }

    .login-header {
        padding: 1.5rem;
    }

    .login-body {
        padding: 1.5rem;
    }

    .btn {
        padding: 0.75rem;
        font-size: 0.875rem;
    }

    .social-login {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .row {
        grid-template-columns: 1fr;
    }

    .col-1, .col-2, .col-3, .col-4, .col-6, .col-8, .col-12 {
        grid-column: span 1;
    }

    .navbar-menu {
        flex-direction: column;
        gap: 0.5rem;
    }

    .container {
        padding: 0 0.75rem;
    }

    .card {
        border-radius: var(--radius-md);
    }

    .card-header,
    .card-body {
        padding: 1rem;
    }

    .btn {
        padding: 0.625rem 1rem;
        font-size: 0.8rem;
    }

    .btn-sm {
        padding: 0.4rem 0.75rem;
        font-size: 0.75rem;
    }

    .stat-card {
        padding: 1rem;
    }

    .stat-card-value {
        font-size: 1.25rem;
    }
}

/* Print Styles */
@media print {
    .navbar,
    .sidebar,
    .btn,
    .btn-group {
        display: none;
    }

    body {
        background: white;
    }

    .card {
        box-shadow: none;
        border: 1px solid var(--border-color);
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
    :root {
        --dark-text: #f3f4f6;
        --light-bg: #1f2937;
        --border-color: #374151;
    }

    body {
        background-color: #111827;
    }

    input, select, textarea {
        background-color: #1f2937;
        color: #f3f4f6;
        border-color: #374151;
    }

    .card,
    .table,
    .sidebar {
        background-color: #1f2937;
        color: #f3f4f6;
    }

    .table thead {
        background-color: #111827;
    }
}