/* ===================================
   EduTrack Pro - Attendance System
   Professional Styling
   =================================== */

/* CSS Variables for Color Scheme */
:root {
    --primary-color: #1e3a5f;
    --secondary-color: #4a9b9f;
    --accent-color: #e07a5f;
    --background-color: #f5f7fa;
    --card-background: #ffffff;
    --text-primary: #2c3e50;
    --text-secondary: #6c757d;
    --border-color: #dee2e6;
    --success-color: #5cb85c;
    --warning-color: #f0ad4e;
    --danger-color: #d9534f;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.12);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles - Compact Design */
header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #2c4d70 100%);
    color: white;
    padding: 0;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo {
    width: 45px;
    height: 45px;
}

.brand h1 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.1rem;
}

.brand p {
    font-size: 0.75rem;
    opacity: 0.9;
    font-weight: 300;
}

/* Navigation */
nav ul {
    list-style: none;
    display: flex;
    gap: 0.5rem;
}

nav a {
    color: white;
    text-decoration: none;
    padding: 0.6rem 1.2rem;
    border-radius: 6px;
    transition: all 0.3s ease;
    font-weight: 500;
    font-size: 0.95rem;
}

nav a:hover,
nav a.active {
    background-color: rgba(255, 255, 255, 0.15);
}

/* Main Content Area */
main {
    flex: 1;
    max-width: 1400px;
    margin: 2rem auto;
    padding: 0 2rem;
    width: 100%;
}

.page-title {
    color: var(--primary-color);
    font-size: 2rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.page-subtitle {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-size: 1rem;
}

/* Card Components */
.card {
    background: var(--card-background);
    border-radius: 10px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    margin-bottom: 1.5rem;
    transition: box-shadow 0.3s ease;
}

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

.card-header {
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 1rem;
    margin-bottom: 1.5rem;
}

.card-header h2 {
    color: var(--primary-color);
    font-size: 1.4rem;
    font-weight: 600;
}

.card-body {
    color: var(--text-primary);
}

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

.stat-card {
    background: var(--card-background);
    border-radius: 10px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--secondary-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.stat-card.success {
    border-left-color: var(--success-color);
}

.stat-card.warning {
    border-left-color: var(--warning-color);
}

.stat-card.danger {
    border-left-color: var(--danger-color);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 0.5rem;
}

.stat-value {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-info {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

/* Tables */
.table-responsive {
    overflow-x: auto;
}

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

thead {
    background-color: var(--primary-color);
    color: white;
}

th {
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

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

tbody tr {
    transition: background-color 0.2s ease;
}

tbody tr:hover {
    background-color: #f8f9fa;
}

/* Badges */
.badge {
    display: inline-block;
    padding: 0.35rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    text-align: center;
}

.badge.success {
    background-color: #d4edda;
    color: #155724;
}

.badge.warning {
    background-color: #fff3cd;
    color: #856404;
}

.badge.danger {
    background-color: #f8d7da;
    color: #721c24;
}

.badge.info {
    background-color: #d1ecf1;
    color: #0c5460;
}

/* Progress Bar */
.progress-bar {
    width: 100%;
    height: 8px;
    background-color: #e9ecef;
    border-radius: 10px;
    overflow: hidden;
    margin-top: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--secondary-color), var(--success-color));
    border-radius: 10px;
    transition: width 0.5s ease;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.form-control,
.form-select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-control:focus,
.form-select:focus {
    outline: none;
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 3px rgba(74, 155, 159, 0.1);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

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

.btn-primary:hover {
    background-color: #152945;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

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

.btn-secondary:hover {
    background-color: #3a7b7f;
    transform: translateY(-2px);
}

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

.btn-success:hover {
    background-color: #4a9d4a;
}

.btn-group {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

/* Attendance Grid */
.attendance-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 1.5rem;
}

.student-attendance {
    background: var(--card-background);
    padding: 1rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.student-attendance:hover {
    border-color: var(--secondary-color);
    box-shadow: var(--shadow);
}

.student-name {
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

/* Alert Messages */
.alert {
    padding: 1rem 1.5rem;
    border-radius: 6px;
    margin-bottom: 1.5rem;
    border-left: 4px solid;
}

.alert-success {
    background-color: #d4edda;
    border-color: var(--success-color);
    color: #155724;
}

.alert-info {
    background-color: #d1ecf1;
    border-color: #17a2b8;
    color: #0c5460;
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: white;
    text-align: center;
    padding: 1.5rem 2rem;
    margin-top: auto;
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
}

footer p {
    margin: 0.3rem 0;
    font-size: 0.9rem;
}

.footer-links {
    margin-top: 0.5rem;
}

.footer-links a {
    color: white;
    text-decoration: none;
    margin: 0 1rem;
    opacity: 0.9;
    transition: opacity 0.3s ease;
}

.footer-links a:hover {
    opacity: 1;
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    
    nav ul {
        flex-direction: column;
        width: 100%;
    }
    
    nav a {
        display: block;
        text-align: center;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    main {
        padding: 0 1rem;
        margin: 1rem auto;
    }
    
    .page-title {
        font-size: 1.5rem;
    }
    
    table {
        font-size: 0.9rem;
    }
    
    th, td {
        padding: 0.75rem 0.5rem;
    }
}

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

.mt-2 {
    margin-top: 1rem;
}

.mb-2 {
    margin-bottom: 1rem;
}

.text-muted {
    color: var(--text-secondary);
}

.text-success {
    color: var(--success-color);
}

.text-warning {
    color: var(--warning-color);
}

.text-danger {
    color: var(--danger-color);
}