/* 
 * Main Stylesheet
 * Professional Task Management System
 */

/* ============================================
   ROOT VARIABLES & RESET
   ============================================ */

:root {
    /* Primary Colors */
    --primary: #4f46e5;
    --primary-dark: #4338ca;
    --primary-light: #e0e7ff;
    --primary-gradient: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
    
    /* Secondary Colors */
    --secondary: #64748b;
    --secondary-dark: #475569;
    --secondary-light: #f1f5f9;
    
    /* Status Colors */
    --success: #10b981;
    --success-light: #d1fae5;
    --success-dark: #047857;
    
    --warning: #f59e0b;
    --warning-light: #fef3c7;
    --warning-dark: #d97706;
    
    --danger: #ef4444;
    --danger-light: #fee2e2;
    --danger-dark: #dc2626;
    
    --info: #3b82f6;
    --info-light: #dbeafe;
    --info-dark: #1d4ed8;
    
    /* Gray Scale */
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --shadow-inner: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Z-index layers */
    --z-dropdown: 10;
    --z-sticky: 20;
    --z-fixed: 30;
    --z-modal: 40;
    --z-popover: 50;
    --z-tooltip: 60;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--gray-50);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.25;
    margin-bottom: 0.5em;
    color: var(--gray-900);
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
}

h2 {
    font-size: 2rem;
}

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);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

small {
    font-size: 0.875rem;
    color: var(--gray-500);
}

strong {
    font-weight: 600;
}

/* ============================================
   LAYOUT & CONTAINERS
   ============================================ */

.container {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.container-fluid {
    width: 100%;
    padding: 0 1.5rem;
}

.section {
    padding: 3rem 0;
}

.section-sm {
    padding: 1.5rem 0;
}

.section-lg {
    padding: 4rem 0;
}

/* ============================================
   BUTTONS
   ============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    line-height: 1.25;
    text-align: center;
    text-decoration: none;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    user-select: none;
    white-space: nowrap;
}

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

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.75rem;
}

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

.btn-block {
    display: block;
    width: 100%;
}

/* Button Variants */
.btn-primary {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: white;
    color: var(--gray-700);
    border-color: var(--gray-300);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--gray-50);
    border-color: var(--gray-400);
    transform: translateY(-1px);
}

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

.btn-success:hover:not(:disabled) {
    background: var(--success-dark);
    border-color: var(--success-dark);
}

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

.btn-danger:hover:not(:disabled) {
    background: var(--danger-dark);
    border-color: var(--danger-dark);
}

.btn-warning {
    background: var(--warning);
    color: var(--gray-900);
    border-color: var(--warning);
}

.btn-warning:hover:not(:disabled) {
    background: var(--warning-dark);
    border-color: var(--warning-dark);
    color: white;
}

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

.btn-info:hover:not(:disabled) {
    background: var(--info-dark);
    border-color: var(--info-dark);
}

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

.btn-outline:hover:not(:disabled) {
    background: var(--primary);
    color: white;
}

.btn-link {
    background: transparent;
    color: var(--primary);
    border: none;
    padding: 0;
    text-decoration: underline;
}

.btn-link:hover:not(:disabled) {
    color: var(--primary-dark);
    text-decoration: none;
}

/* Button Groups */
.btn-group {
    display: inline-flex;
    gap: 0.5rem;
}

/* ============================================
   FORMS
   ============================================ */

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--gray-700);
    font-size: 0.875rem;
}

.form-control {
    display: block;
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    line-height: 1.5;
    color: var(--gray-800);
    background-color: white;
    background-clip: padding-box;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.form-control:focus {
    outline: 0;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.form-control::placeholder {
    color: var(--gray-400);
}

.form-control:disabled,
.form-control[readonly] {
    background-color: var(--gray-100);
    opacity: 1;
}

/* Textarea */
textarea.form-control {
    min-height: 100px;
    resize: vertical;
}

/* Select */
select.form-control {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%2364748b'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'%3E%3C/path%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    background-size: 1.5em;
    padding-right: 2.5rem;
}

/* Checkboxes & Radios */
.form-check {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.form-check-input {
    width: 1.25rem;
    height: 1.25rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-sm);
    background-color: white;
    transition: all var(--transition-fast);
}

.form-check-input:checked {
    background-color: var(--primary);
    border-color: var(--primary);
}

.form-check-label {
    font-size: 0.875rem;
    color: var(--gray-700);
}

/* Form Validation */
.form-control.is-valid {
    border-color: var(--success);
}

.form-control.is-invalid {
    border-color: var(--danger);
}

.valid-feedback {
    display: none;
    width: 100%;
    margin-top: 0.25rem;
    font-size: 0.875rem;
    color: var(--success);
}

.invalid-feedback {
    display: none;
    width: 100%;
    margin-top: 0.25rem;
    font-size: 0.875rem;
    color: var(--danger);
}

.is-valid ~ .valid-feedback {
    display: block;
}

.is-invalid ~ .invalid-feedback {
    display: block;
}

/* ============================================
   CARDS
   ============================================ */

.card {
    background: white;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

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

.card-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--gray-200);
    background-color: var(--gray-50);
}

.card-body {
    padding: 1.5rem;
}

.card-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--gray-200);
    background-color: var(--gray-50);
}

.card-title {
    margin-bottom: 0.75rem;
    font-size: 1.25rem;
    font-weight: 600;
}

.card-subtitle {
    margin-top: -0.375rem;
    margin-bottom: 0.75rem;
    color: var(--gray-500);
}

/* ============================================
   TABLES
   ============================================ */

.table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1rem;
}

.table th,
.table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--gray-200);
}

.table th {
    font-weight: 600;
    color: var(--gray-700);
    background-color: var(--gray-50);
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
}

.table tbody tr:hover {
    background-color: var(--gray-50);
}

.table-striped tbody tr:nth-of-type(odd) {
    background-color: var(--gray-50);
}

.table-bordered {
    border: 1px solid var(--gray-200);
}

.table-bordered th,
.table-bordered td {
    border: 1px solid var(--gray-200);
}

/* ============================================
   ALERTS
   ============================================ */

.alert {
    position: relative;
    padding: 1rem 1.5rem;
    margin-bottom: 1rem;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.alert-icon {
    flex-shrink: 0;
    font-size: 1.25rem;
}

.alert-content {
    flex: 1;
}

.alert-title {
    margin-bottom: 0.25rem;
    font-weight: 600;
}

.alert-dismiss {
    background: none;
    border: none;
    padding: 0;
    font-size: 1.25rem;
    color: inherit;
    opacity: 0.5;
    cursor: pointer;
    transition: opacity var(--transition-fast);
}

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

/* Alert Variants */
.alert-success {
    background-color: var(--success-light);
    border-color: var(--success);
    color: var(--success-dark);
}

.alert-danger {
    background-color: var(--danger-light);
    border-color: var(--danger);
    color: var(--danger-dark);
}

.alert-warning {
    background-color: var(--warning-light);
    border-color: var(--warning);
    color: var(--warning-dark);
}

.alert-info {
    background-color: var(--info-light);
    border-color: var(--info);
    color: var(--info-dark);
}

/* ============================================
   BADGES
   ============================================ */

.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 500;
    line-height: 1;
    border-radius: var(--radius-full);
    white-space: nowrap;
}

/* Badge Variants */
.badge-primary {
    background-color: var(--primary-light);
    color: var(--primary-dark);
}

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

.badge-success {
    background-color: var(--success-light);
    color: var(--success-dark);
}

.badge-danger {
    background-color: var(--danger-light);
    color: var(--danger-dark);
}

.badge-warning {
    background-color: var(--warning-light);
    color: var(--warning-dark);
}

.badge-info {
    background-color: var(--info-light);
    color: var(--info-dark);
}

/* Status Badges */
.badge-status-pending {
    background: var(--warning-light);
    color: var(--warning-dark);
    border: 1px solid var(--warning);
}

.badge-status-in-progress {
    background: var(--info-light);
    color: var(--info-dark);
    border: 1px solid var(--info);
}

.badge-status-completed {
    background: var(--success-light);
    color: var(--success-dark);
    border: 1px solid var(--success);
}

/* Priority Badges */
.badge-priority-high {
    background: var(--danger-light);
    color: var(--danger-dark);
    border: 1px solid var(--danger);
}

.badge-priority-medium {
    background: var(--warning-light);
    color: var(--warning-dark);
    border: 1px solid var(--warning);
}

.badge-priority-low {
    background: var(--success-light);
    color: var(--success-dark);
    border: 1px solid var(--success);
}

/* ============================================
   NAVIGATION
   ============================================ */

.nav {
    display: flex;
    flex-wrap: wrap;
    list-style: none;
}

.nav-item {
    margin-right: 1rem;
}

.nav-link {
    display: block;
    padding: 0.5rem 1rem;
    color: var(--gray-600);
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
    background-color: var(--primary-light);
}

.nav-tabs {
    border-bottom: 1px solid var(--gray-200);
}

.nav-tabs .nav-link {
    border: 1px solid transparent;
    border-bottom: none;
    margin-bottom: -1px;
}

.nav-tabs .nav-link.active {
    background-color: white;
    border-color: var(--gray-200) var(--gray-200) white;
}

/* ============================================
   AVATARS
   ============================================ */

.avatar {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    border-radius: var(--radius-full);
    font-weight: 600;
    color: white;
    background: var(--primary-gradient);
    overflow: hidden;
}

.avatar-sm {
    width: 2rem;
    height: 2rem;
    font-size: 0.875rem;
}

.avatar-lg {
    width: 3rem;
    height: 3rem;
    font-size: 1.25rem;
}

.avatar-xl {
    width: 4rem;
    height: 4rem;
    font-size: 1.5rem;
}

.avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* ============================================
   PROGRESS BARS
   ============================================ */

.progress {
    height: 0.5rem;
    background-color: var(--gray-200);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: var(--primary-gradient);
    border-radius: var(--radius-full);
    transition: width var(--transition-slow);
}

/* ============================================
   MODALS
   ============================================ */

.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: none;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
    background-color: rgba(0, 0, 0, 0.5);
    padding: 1rem;
}

.modal.show {
    display: flex;
}

.modal-dialog {
    width: 100%;
    max-width: 500px;
    margin: 1rem;
}

.modal-content {
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--gray-200);
    display: flex;
    gap: 0.5rem;
    justify-content: flex-end;
}

.modal-title {
    margin: 0;
    font-size: 1.25rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--gray-400);
    cursor: pointer;
    transition: color var(--transition-fast);
}

.modal-close:hover {
    color: var(--gray-700);
}

/* ============================================
   UTILITY CLASSES
   ============================================ */

/* Display */
.d-none { display: none !important; }
.d-block { display: block !important; }
.d-inline { display: inline !important; }
.d-inline-block { display: inline-block !important; }
.d-flex { display: flex !important; }
.d-inline-flex { display: inline-flex !important; }

/* Flexbox */
.flex-row { flex-direction: row !important; }
.flex-column { flex-direction: column !important; }
.flex-wrap { flex-wrap: wrap !important; }
.flex-nowrap { flex-wrap: nowrap !important; }
.justify-start { justify-content: flex-start !important; }
.justify-end { justify-content: flex-end !important; }
.justify-center { justify-content: center !important; }
.justify-between { justify-content: space-between !important; }
.justify-around { justify-content: space-around !important; }
.align-start { align-items: flex-start !important; }
.align-end { align-items: flex-end !important; }
.align-center { align-items: center !important; }
.align-baseline { align-items: baseline !important; }
.align-stretch { align-items: stretch !important; }

/* Spacing */
.m-0 { margin: 0 !important; }
.m-1 { margin: 0.25rem !important; }
.m-2 { margin: 0.5rem !important; }
.m-3 { margin: 1rem !important; }
.m-4 { margin: 1.5rem !important; }
.m-5 { margin: 3rem !important; }

.mt-0 { margin-top: 0 !important; }
.mt-1 { margin-top: 0.25rem !important; }
.mt-2 { margin-top: 0.5rem !important; }
.mt-3 { margin-top: 1rem !important; }
.mt-4 { margin-top: 1.5rem !important; }
.mt-5 { margin-top: 3rem !important; }

.mb-0 { margin-bottom: 0 !important; }
.mb-1 { margin-bottom: 0.25rem !important; }
.mb-2 { margin-bottom: 0.5rem !important; }
.mb-3 { margin-bottom: 1rem !important; }
.mb-4 { margin-bottom: 1.5rem !important; }
.mb-5 { margin-bottom: 3rem !important; }

.p-0 { padding: 0 !important; }
.p-1 { padding: 0.25rem !important; }
.p-2 { padding: 0.5rem !important; }
.p-3 { padding: 1rem !important; }
.p-4 { padding: 1.5rem !important; }
.p-5 { padding: 3rem !important; }

.pt-0 { padding-top: 0 !important; }
.pt-1 { padding-top: 0.25rem !important; }
.pt-2 { padding-top: 0.5rem !important; }
.pt-3 { padding-top: 1rem !important; }
.pt-4 { padding-top: 1.5rem !important; }
.pt-5 { padding-top: 3rem !important; }

.pb-0 { padding-bottom: 0 !important; }
.pb-1 { padding-bottom: 0.25rem !important; }
.pb-2 { padding-bottom: 0.5rem !important; }
.pb-3 { padding-bottom: 1rem !important; }
.pb-4 { padding-bottom: 1.5rem !important; }
.pb-5 { padding-bottom: 3rem !important; }

/* Text */
.text-left { text-align: left !important; }
.text-center { text-align: center !important; }
.text-right { text-align: right !important; }
.text-justify { text-align: justify !important; }

.text-primary { color: var(--primary) !important; }
.text-secondary { color: var(--secondary) !important; }
.text-success { color: var(--success) !important; }
.text-danger { color: var(--danger) !important; }
.text-warning { color: var(--warning) !important; }
.text-info { color: var(--info) !important; }
.text-white { color: white !important; }
.text-gray-500 { color: var(--gray-500) !important; }

.font-weight-light { font-weight: 300 !important; }
.font-weight-normal { font-weight: 400 !important; }
.font-weight-medium { font-weight: 500 !important; }
.font-weight-semibold { font-weight: 600 !important; }
.font-weight-bold { font-weight: 700 !important; }

/* Background */
.bg-primary { background-color: var(--primary) !important; }
.bg-secondary { background-color: var(--secondary) !important; }
.bg-success { background-color: var(--success) !important; }
.bg-danger { background-color: var(--danger) !important; }
.bg-warning { background-color: var(--warning) !important; }
.bg-info { background-color: var(--info) !important; }
.bg-white { background-color: white !important; }
.bg-gray-50 { background-color: var(--gray-50) !important; }

/* Borders */
.border { border: 1px solid var(--gray-200) !important; }
.border-top { border-top: 1px solid var(--gray-200) !important; }
.border-bottom { border-bottom: 1px solid var(--gray-200) !important; }
.border-left { border-left: 1px solid var(--gray-200) !important; }
.border-right { border-right: 1px solid var(--gray-200) !important; }

.border-primary { border-color: var(--primary) !important; }
.border-success { border-color: var(--success) !important; }
.border-danger { border-color: var(--danger) !important; }
.border-warning { border-color: var(--warning) !important; }
.border-info { border-color: var(--info) !important; }

.rounded { border-radius: var(--radius-md) !important; }
.rounded-sm { border-radius: var(--radius-sm) !important; }
.rounded-lg { border-radius: var(--radius-lg) !important; }
.rounded-full { border-radius: var(--radius-full) !important; }

/* Shadows */
.shadow-sm { box-shadow: var(--shadow-sm) !important; }
.shadow-md { box-shadow: var(--shadow-md) !important; }
.shadow-lg { box-shadow: var(--shadow-lg) !important; }
.shadow-xl { box-shadow: var(--shadow-xl) !important; }
.shadow-none { box-shadow: none !important; }

/* Width & Height */
.w-25 { width: 25% !important; }
.w-50 { width: 50% !important; }
.w-75 { width: 75% !important; }
.w-100 { width: 100% !important; }
.w-auto { width: auto !important; }

.h-25 { height: 25% !important; }
.h-50 { height: 50% !important; }
.h-75 { height: 75% !important; }
.h-100 { height: 100% !important; }
.h-auto { height: auto !important; }

/* Position */
.position-static { position: static !important; }
.position-relative { position: relative !important; }
.position-absolute { position: absolute !important; }
.position-fixed { position: fixed !important; }
.position-sticky { position: sticky !important; }

/* Overflow */
.overflow-auto { overflow: auto !important; }
.overflow-hidden { overflow: hidden !important; }
.overflow-visible { overflow: visible !important; }
.overflow-scroll { overflow: scroll !important; }

/* Visibility */
.visible { visibility: visible !important; }
.invisible { visibility: hidden !important; }

/* ============================================
   ANIMATIONS
   ============================================ */

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

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

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

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.animate-fade-in {
    animation: fadeIn var(--transition-base);
}

.animate-slide-in-up {
    animation: slideInUp var(--transition-base);
}

.animate-slide-in-down {
    animation: slideInDown var(--transition-base);
}

.animate-pulse {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

.animate-spin {
    animation: spin 1s linear infinite;
}

/* ============================================
   RESPONSIVE BREAKPOINTS
   ============================================ */

/* Small devices (landscape phones, 576px and up) */
@media (min-width: 576px) {
    .container {
        max-width: 540px;
    }
}

/* Medium devices (tablets, 768px and up) */
@media (min-width: 768px) {
    .container {
        max-width: 720px;
    }
    
    .d-md-none { display: none !important; }
    .d-md-block { display: block !important; }
    .d-md-flex { display: flex !important; }
}

/* Large devices (desktops, 992px and up) */
@media (min-width: 992px) {
    .container {
        max-width: 960px;
    }
    
    .d-lg-none { display: none !important; }
    .d-lg-block { display: block !important; }
    .d-lg-flex { display: flex !important; }
}

/* Extra large devices (large desktops, 1200px and up) */
@media (min-width: 1200px) {
    .container {
        max-width: 1140px;
    }
    
    .d-xl-none { display: none !important; }
    .d-xl-block { display: block !important; }
    .d-xl-flex { display: flex !important; }
}

/* ============================================
   PRINT STYLES
   ============================================ */

@media print {
    .no-print {
        display: none !important;
    }
    
    .container {
        max-width: 100%;
        padding: 0;
    }
    
    .card {
        border: none !important;
        box-shadow: none !important;
    }
    
    .btn {
        display: none !important;
    }
    
    a {
        color: black !important;
        text-decoration: none !important;
    }
    
    .table th,
    .table td {
        border: 1px solid #dee2e6 !important;
    }
}

/* ============================================
   CUSTOM COMPONENTS
   ============================================ */

/* Task Card */
.task-card {
    background: white;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    transition: all var(--transition-base);
    cursor: pointer;
}

.task-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}

.task-card.completed {
    opacity: 0.8;
    background-color: var(--gray-50);
}

.task-card.completed .task-title {
    text-decoration: line-through;
    color: var(--gray-500);
}

.task-card.overdue:not(.completed) {
    border-left: 4px solid var(--danger);
}

.task-card.due-today:not(.completed) {
    border-left: 4px solid var(--warning);
}

.task-title {
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 0.5rem;
}

.task-description {
    color: var(--gray-600);
    margin-bottom: 1rem;
    line-height: 1.5;
}

.task-meta {
    display: flex;
    gap: 1rem;
    font-size: 0.875rem;
    color: var(--gray-500);
}

.task-meta-item {
    display: flex;
    align-items: center;
    gap: 0.375rem;
}

/* Dashboard Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    text-align: center;
}

.stat-icon {
    width: 3rem;
    height: 3rem;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    font-size: 1.5rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 0.25rem;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--gray-500);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* User Profile */
.profile-header {
    background: var(--primary-gradient);
    color: white;
    padding: 3rem 0;
    text-align: center;
    margin-bottom: 2rem;
}

.profile-avatar {
    width: 8rem;
    height: 8rem;
    border-radius: var(--radius-full);
    border: 4px solid white;
    margin: 0 auto 1.5rem;
    overflow: hidden;
}

.profile-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.profile-name {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.profile-role {
    font-size: 1rem;
    opacity: 0.9;
}

/* Loading Spinner */
.spinner {
    width: 2rem;
    height: 2rem;
    border: 3px solid var(--gray-200);
    border-top-color: var(--primary);
    border-radius: var(--radius-full);
    animation: spin 1s linear infinite;
}

.spinner-sm {
    width: 1rem;
    height: 1rem;
    border-width: 2px;
}

.spinner-lg {
    width: 3rem;
    height: 3rem;
    border-width: 4px;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem;
    color: var(--gray-500);
}

.empty-state-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    opacity: 0.5;
}

.empty-state-title {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--gray-700);
}

.empty-state-description {
    max-width: 400px;
    margin: 0 auto 2rem;
}

/* Notification Badge */
.notification-badge {
    position: absolute;
    top: -0.5rem;
    right: -0.5rem;
    background: var(--danger);
    color: white;
    width: 1.25rem;
    height: 1.25rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Search Box */
.search-box {
    position: relative;
    max-width: 400px;
}

.search-box input {
    padding-left: 3rem;
}

.search-box .search-icon {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--gray-400);
    pointer-events: none;
}

/* Filter Panel */
.filter-panel {
    background: white;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.filter-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0.75rem;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--gray-200);
}

.timeline-item {
    position: relative;
    margin-bottom: 1.5rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2rem;
    top: 0.25rem;
    width: 1rem;
    height: 1rem;
    border-radius: var(--radius-full);
    background: var(--primary);
    border: 3px solid white;
}

.timeline-date {
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-bottom: 0.25rem;
}

.timeline-content {
    background: white;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    padding: 1rem;
}

/* ============================================
   ACCESSIBILITY
   ============================================ */

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.skip-to-content {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary);
    color: white;
    padding: 0.5rem 1rem;
    text-decoration: none;
    z-index: var(--z-popover);
    transition: top var(--transition-base);
}

.skip-to-content:focus {
    top: 0;
}

/* Focus Styles */
:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

:focus:not(:focus-visible) {
    outline: none;
}

:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* ============================================
   DARK MODE (Optional)
   ============================================ */

@media (prefers-color-scheme: dark) {
    :root {
        --gray-50: #0f172a;
        --gray-100: #1e293b;
        --gray-200: #334155;
        --gray-300: #475569;
        --gray-400: #64748b;
        --gray-500: #94a3b8;
        --gray-600: #cbd5e1;
        --gray-700: #e2e8f0;
        --gray-800: #f1f5f9;
        --gray-900: #f8fafc;
    }
    
    body {
        background-color: var(--gray-50);
        color: var(--gray-800);
    }
    
    .card,
    .stat-card,
    .filter-panel {
        background-color: var(--gray-100);
        border-color: var(--gray-200);
    }
    
    .form-control {
        background-color: var(--gray-100);
        border-color: var(--gray-300);
        color: var(--gray-800);
    }
    
    .table th {
        background-color: var(--gray-100);
    }
    
    .modal-content {
        background-color: var(--gray-100);
    }
}

/* ============================================
   BROWSER SPECIFIC FIXES
   ============================================ */

/* Firefox scrollbar */
* {
    scrollbar-width: thin;
    scrollbar-color: var(--gray-300) transparent;
}

/* Webkit scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--gray-300);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--gray-400);
}

/* IE 11 Support */
@media all and (-ms-high-contrast: none), (-ms-high-contrast: active) {
    .d-flex {
        display: -ms-flexbox !important;
    }
    
    .justify-between {
        -ms-flex-pack: justify !important;
    }
    
    .align-center {
        -ms-flex-align: center !important;
    }
}

/* Safari specific fixes */
@supports (-webkit-touch-callout: none) {
    .h-100 {
        height: -webkit-fill-available;
    }
}