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

:root {
    /* Color Palette */
    --primary-blue: #2563eb;
    --primary-blue-dark: #1d4ed8;
    --primary-blue-light: #3b82f6;
    --secondary-blue: #60a5fa;
    --accent-blue: #93c5fd;
    
    --black: #000000;
    --dark-gray: #1f1f1f;
    --medium-gray: #4b5563;
    --light-gray: #9ca3af;
    --very-light-gray: #f3f4f6;
    --white: #ffffff;
    
    /* Success/Error Colors */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-base: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Border Radius */
    --border-radius-sm: 0.375rem;
    --border-radius-base: 0.5rem;
    --border-radius-lg: 0.75rem;
    --border-radius-xl: 1rem;
    --border-radius-2xl: 1.5rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-base: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Transitions */
    --transition-fast: 0.15s ease-in-out;
    --transition-base: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;
}

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--dark-gray);
    background-color: var(--white);
    font-size: var(--font-size-base);
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--black);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

/* Links */
a {
    color: var(--primary-blue);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-base) var(--spacing-lg);
    border: 2px solid transparent;
    border-radius: var(--border-radius-lg);
    font-size: var(--font-size-base);
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-base);
    outline: none;
    background: none;
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-blue-dark));
    color: var(--white);
    box-shadow: var(--shadow-base);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-blue-dark), var(--primary-blue));
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: var(--white);
}

.btn-secondary {
    background: var(--white);
    color: var(--primary-blue);
    border-color: var(--primary-blue);
    box-shadow: var(--shadow-base);
}

.btn-secondary:hover {
    background: var(--primary-blue);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

.btn-full {
    width: 100%;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

/* Form Elements */
.form-group {
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
}

label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
    color: var(--dark-gray);
}

input, textarea, select {
    width: 100%;
    padding: var(--spacing-base);
    border: 2px solid var(--light-gray);
    border-radius: var(--border-radius-base);
    font-size: var(--font-size-base);
    font-family: inherit;
    transition: all var(--transition-fast);
    background: var(--white);
}

input:focus, textarea:focus, select:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

textarea {
    resize: vertical;
    min-height: 100px;
}

/* Loading Screen */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-blue), var(--black));
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity var(--transition-slow), visibility var(--transition-slow);
}

.loading-screen.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.2);
    border-left: 4px solid var(--white);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-base);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

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

.logo {
    width: 40px;
    height: 40px;
    border-radius: var(--border-radius-base);
    object-fit: cover;
}

.logo-text {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--black);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-xl);
    align-items: center;
}

.nav-link {
    font-weight: 500;
    color: var(--dark-gray);
    padding: var(--spacing-sm) var(--spacing-base);
    border-radius: var(--border-radius-base);
    transition: all var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
    color: var(--primary-blue);
    background: rgba(37, 99, 235, 0.1);
}

.admin-link, .employee-link {
    background: var(--primary-blue);
    color: var(--white) !important;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--border-radius-lg);
}

.admin-link:hover, .employee-link:hover {
    background: var(--primary-blue-dark);
    transform: translateY(-1px);
}

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.bar {
    width: 25px;
    height: 3px;
    background: var(--dark-gray);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

/* Section Titles */
.section-title {
    text-align: center;
    margin-bottom: var(--spacing-base);
    color: var(--black);
}

.section-subtitle {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    color: var(--medium-gray);
    font-size: var(--font-size-lg);
}

/* Cards */
.card {
    background: var(--white);
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-base);
    padding: var(--spacing-xl);
    transition: all var(--transition-base);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

/* Modals */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal-content {
    background: var(--white);
    margin: 5% auto;
    padding: var(--spacing-2xl);
    border-radius: var(--border-radius-xl);
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
    position: relative;
}

.modal-content.large {
    max-width: 700px;
}

.close {
    position: absolute;
    right: var(--spacing-lg);
    top: var(--spacing-lg);
    font-size: var(--font-size-2xl);
    font-weight: bold;
    cursor: pointer;
    color: var(--medium-gray);
    transition: color var(--transition-fast);
}

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

/* Tables */
.table-container {
    background: var(--white);
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-base);
    overflow: hidden;
    overflow-x: auto;
}

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

.data-table th,
.data-table td {
    padding: var(--spacing-base) var(--spacing-lg);
    text-align: left;
    border-bottom: 1px solid var(--very-light-gray);
}

.data-table th {
    background: var(--very-light-gray);
    font-weight: 600;
    color: var(--black);
    font-size: var(--font-size-sm);
    text-transform: uppercase;
    letter-spacing: 0.025em;
}

.data-table tr:hover {
    background: rgba(37, 99, 235, 0.05);
}

/* Status Badges */
.status-badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-base);
    border-radius: var(--border-radius-lg);
    font-size: var(--font-size-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.status-pending {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning);
}

.status-in-progress {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-blue);
}

.status-completed {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
}

.status-cancelled {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error);
}

/* Priority Badges */
.priority-low {
    background: rgba(156, 163, 175, 0.1);
    color: var(--medium-gray);
}

.priority-normal {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-blue);
}

.priority-high {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning);
}

.priority-urgent {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error);
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.hidden { display: none !important; }
.visible { display: block !important; }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-base { margin-bottom: var(--spacing-base); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-base { margin-top: var(--spacing-base); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.p-sm { padding: var(--spacing-sm); }
.p-base { padding: var(--spacing-base); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
    from { transform: translateX(-100%); }
    to { transform: translateX(0); }
}

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

.fade-in {
    animation: fadeIn 0.6s ease-out;
}

.slide-in {
    animation: slideIn 0.3s ease-out;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: var(--white);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-xl) 0;
        gap: var(--spacing-base);
    }

    .nav-menu.active {
        left: 0;
    }

    .hamburger {
        display: flex;
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .container {
        padding: 0 var(--spacing-base);
    }

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

    .modal-content {
        margin: 10% auto;
        width: 95%;
        padding: var(--spacing-lg);
    }

    .btn {
        padding: var(--spacing-base);
    }
}

@media (max-width: 480px) {
    h1 { font-size: var(--font-size-3xl); }
    h2 { font-size: var(--font-size-2xl); }
    h3 { font-size: var(--font-size-xl); }
    
    .modal-content {
        margin: 5% auto;
        padding: var(--spacing-base);
    }
}

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

/* Focus styles for accessibility */
*:focus-visible {
    outline: 2px solid var(--primary-blue);
    outline-offset: 2px;
}

/* Dark mode support (for future enhancement) */
@media (prefers-color-scheme: dark) {
    /* Dark mode styles can be added here in the future */
}

/* Print styles */
@media print {
    .navbar, .sidebar, .modal, .btn {
        display: none !important;
    }
    
    body {
        background: white !important;
        color: black !important;
    }
}