/* ============================================
   CSS VARIABLES & RESET
   ============================================ */
:root {
    /* Colors */
    --primary-color: #667eea;
    --primary-dark: #5568d3;
    --secondary-color: #764ba2;
    --success-color: #48bb78;
    --warning-color: #f6ad55;
    --danger-color: #f56565;
    --info-color: #4299e1;

    --dark-color: #2d3748;
    --dark-light: #4a5568;
    --light-color: #f7fafc;
    --border-color: #e2e8f0;
    --gray-color: #718096;

    /* Layout */
    --sidebar-width: 260px;
    --header-height: 64px;
    --footer-height: 50px;

    /* Spacing */
    --spacing-xs: 5px;
    --spacing-sm: 10px;
    --spacing-md: 15px;
    --spacing-lg: 20px;
    --spacing-xl: 30px;

    /* Border Radius */
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.15);
}

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

html {
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 14px;
    line-height: 1.6;
    color: var(--dark-color);
    background-color: var(--light-color);
    min-height: 100vh;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: var(--spacing-md);
    color: var(--dark-color);
}

h1 { font-size: 28px; }
h2 { font-size: 24px; }
h3 { font-size: 20px; }
h4 { font-size: 18px; }
h5 { font-size: 16px; }
h6 { font-size: 14px; }

p {
    margin-bottom: var(--spacing-md);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--primary-dark);
}

/* ============================================
   LAYOUT
   ============================================ */
.wrapper {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* Top Navigation */
.top-nav {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    height: var(--header-height);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.top-nav .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

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

.logo-text {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.user-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.warehouse-badge {
    background: rgba(255, 255, 255, 0.2);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.user-name {
    font-weight: 500;
    font-size: 15px;
}

.btn-logout {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    background: rgba(255, 255, 255, 0.15);
    color: white;
    padding: 8px 16px;
    border-radius: var(--border-radius-sm);
    font-weight: 500;
    font-size: 14px;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
}

.btn-logout:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-1px);
}

/* Main Container */
.main-container {
    display: flex;
    flex: 1;
    background-color: var(--light-color);
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: white;
    border-right: 1px solid var(--border-color);
    height: calc(100vh - var(--header-height));
    position: sticky;
    top: var(--header-height);
    overflow-y: auto;
    z-index: 900;
    box-shadow: var(--shadow-sm);
}

.sidebar-nav ul {
    list-style: none;
    padding: var(--spacing-lg) 0;
}

.sidebar-nav li {
    margin-bottom: 4px;
}

.sidebar-nav li.section-title {
    padding: var(--spacing-md) var(--spacing-lg) var(--spacing-xs);
    font-size: 11px;
    font-weight: 700;
    color: var(--gray-color);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: var(--spacing-lg);
}

.sidebar-nav a {
    display: flex;
    align-items: center;
    padding: 12px var(--spacing-lg);
    color: var(--dark-light);
    text-decoration: none;
    transition: all 0.2s;
    gap: var(--spacing-md);
    border-left: 3px solid transparent;
}

.sidebar-nav a:hover {
    background: #edf2f7;
    color: var(--primary-color);
    border-left-color: var(--primary-color);
}

.sidebar-nav a.active {
    background: linear-gradient(90deg, rgba(102, 126, 234, 0.1), transparent);
    color: var(--primary-color);
    border-left-color: var(--primary-color);
    font-weight: 600;
}

.sidebar-nav .icon {
    font-size: 20px;
    min-width: 24px;
    text-align: center;
}

.sidebar-nav .text {
    font-weight: 500;
    font-size: 15px;
}

/* Content Area */
.content {
    flex: 1;
    padding: var(--spacing-xl) var(--spacing-lg);
    overflow-y: auto;
    height: calc(100vh - var(--header-height));
}

/* Footer */
.main-footer {
    background: var(--dark-color);
    color: white;
    height: var(--footer-height);
    padding: var(--spacing-sm) 0;
    margin-top: auto;
    box-shadow: var(--shadow-md);
}

.main-footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.main-footer p {
    margin: 0;
    font-size: 14px;
    opacity: 0.9;
}

.main-footer .version {
    font-size: 12px;
    opacity: 0.7;
}

/* ============================================
   PAGE ELEMENTS
   ============================================ */
.page-header {
    margin-bottom: var(--spacing-xl);
}

.page-header h1 {
    font-size: 32px;
    margin-bottom: 8px;
}

.page-header p {
    color: var(--gray-color);
    font-size: 16px;
    margin-bottom: 0;
}

/* ============================================
   CARDS & GRID
   ============================================ */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.card {
    background: white;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.card-header {
    padding: var(--spacing-lg) var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    background: #f8fafc;
}

.card-header h3 {
    font-size: 18px;
    font-weight: 700;
    margin: 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.card-body {
    padding: var(--spacing-lg);
}

/* Card Variants */
.card-warning .card-header {
    background: linear-gradient(90deg, #fff8e6, #ffecb3);
    border-bottom-color: #ffd54f;
}

.card-info .card-header {
    background: linear-gradient(90deg, #e3f2fd, #bbdefb);
    border-bottom-color: #90caf9;
}

.card-span {
    grid-column: 1 / -1;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

.stat-item {
    text-align: center;
    padding: var(--spacing-md);
    background: #f8fafc;
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--border-color);
}

.stat-value {
    font-size: 28px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 4px;
}

.stat-label {
    font-size: 12px;
    color: var(--gray-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
}

/* ============================================
   TABLES
   ============================================ */
.table-responsive {
    overflow-x: auto;
    margin-top: var(--spacing-md);
}

.table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: var(--border-radius-sm);
    overflow: hidden;
}

.table thead {
    background: #f8fafc;
}

.table th {
    padding: 14px var(--spacing-md);
    text-align: left;
    font-weight: 700;
    color: var(--dark-light);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-bottom: 2px solid var(--border-color);
}

.table td {
    padding: 12px var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
    font-size: 14px;
    color: var(--dark-color);
}

.table tbody tr:hover {
    background: #f8fafc;
}

.table tbody tr:last-child td {
    border-bottom: none;
}

/* ============================================
   BADGES
   ============================================ */
.badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.badge.draft {
    background: #e2e8f0;
    color: #4a5568;
}

.badge.shipped {
    background: #bee3f8;
    color: #2b6cb0;
}

.badge.received {
    background: #c6f6d5;
    color: #276749;
}

.badge.warning {
    background: #feebc8;
    color: #92400e;
}

.badge.danger {
    background: #fed7d7;
    color: #9b2c2c;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: 10px 20px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius-sm);
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
    box-shadow: var(--shadow-sm);
}

.btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background: #718096;
}

.btn-secondary:hover {
    background: #4a5568;
}

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

.btn-success:hover {
    background: #38a169;
}

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

.btn-warning:hover {
    background: #ed8936;
}

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

.btn-danger:hover {
    background: #e53e3e;
}

.btn-small {
    padding: 6px 12px;
    font-size: 13px;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

/* ============================================
   ALERTS
   ============================================ */
.alert {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: 14px var(--spacing-lg);
    border-radius: var(--border-radius-md);
    margin-bottom: var(--spacing-lg);
    font-weight: 500;
    box-shadow: var(--shadow-sm);
}

.alert-icon {
    font-size: 20px;
    min-width: 24px;
}

.alert-success {
    background: #f0fff4;
    color: #22543d;
    border: 1px solid #9ae6b4;
}

.alert-error {
    background: #fff5f5;
    color: #c53030;
    border: 1px solid #fed7d7;
}

.alert-warning {
    background: #fffaf0;
    color: #92400e;
    border: 1px solid #fbd38d;
}

.alert-info {
    background: #ebf8ff;
    color: #2c5282;
    border: 1px solid #90cdf4;
}

/* ============================================
   FORMS
   ============================================ */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--dark-color);
    font-size: 14px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    font-size: 15px;
    font-family: inherit;
    transition: all 0.2s;
    background: white;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

.form-group input.error {
    border-color: var(--danger-color);
    background: #fff5f5;
}

/* ============================================
   ACTIVITY LIST
   ============================================ */
.activity-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.activity-item {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: #f8fafc;
    border-radius: var(--border-radius-sm);
    border-left: 3px solid var(--primary-color);
    transition: all 0.2s;
}

.activity-item:hover {
    background: #edf2f7;
    transform: translateX(3px);
}

.activity-icon {
    font-size: 24px;
    min-width: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.activity-content {
    flex: 1;
}

.activity-text {
    font-weight: 500;
    margin-bottom: 4px;
    font-size: 14px;
    line-height: 1.5;
}

.activity-time {
    font-size: 12px;
    color: var(--gray-color);
}

/* ============================================
   UTILITIES
   ============================================ */
.text-center {
    text-align: center;
}

.mt-20 {
    margin-top: 20px;
}

.mb-20 {
    margin-bottom: 20px;
}

.no-data {
    text-align: center;
    padding: 40px 20px;
    color: var(--gray-color);
}

.no-data-icon {
    font-size: 48px;
    margin-bottom: 10px;
    opacity: 0.6;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 992px) {
    .dashboard-grid {
        grid-template-columns: 1fr;
    }

    .card-span {
        grid-column: 1;
    }
}

@media (max-width: 768px) {
    :root {
        --sidebar-width: 240px;
    }

    .top-nav .container {
        padding: 0 var(--spacing-md);
    }

    .logo-text {
        display: none;
    }

    .user-info {
        gap: var(--spacing-sm);
    }

    .warehouse-badge, .user-name {
        display: none;
    }

    .content {
        padding: var(--spacing-lg);
    }

    .page-header h1 {
        font-size: 26px;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .table-responsive {
        font-size: 13px;
    }

    .table th, .table td {
        padding: 10px 8px;
    }
}

@media (max-width: 480px) {
    :root {
        --sidebar-width: 100%;
    }

    .sidebar {
        position: fixed;
        left: -100%;
        top: var(--header-height);
        height: calc(100vh - var(--header-height));
        z-index: 1000;
        box-shadow: var(--shadow-xl);
    }

    .sidebar.active {
        left: 0;
    }

    .main-container {
        flex-direction: column;
    }

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

    .btn {
        width: 100%;
        justify-content: center;
    }

    .form-group input,
    .form-group select {
        padding: 10px 12px;
        font-size: 14px;
    }
}