:root {
    --primary-color: #0d6efd;
    --success-color: #198754;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --light-gray: #f8f9fa;
    --dark-gray: #343a40;
    --border-color: #dee2e6;
    --shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
}

* { box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    background-color: var(--light-gray);
    color: #212529;
    line-height: 1.5;
}

/* GENERAL LAYOUT & COMPONENTS */
.main-container { max-width: 960px; margin: 2rem auto; padding: 0 1rem; }
.card { background-color: #fff; border: 1px solid var(--border-color); border-radius: 0.375rem; box-shadow: var(--shadow); margin-bottom: 1.5rem; overflow: hidden; }
.card-header { padding: 1rem 1.25rem; border-bottom: 1px solid var(--border-color); background-color: #fff; display: flex; align-items: center; border-left: 5px solid var(--primary-color); }
.card-body { padding: 1.25rem; }
.card-header.status { border-left-color: #6f42c1; }
.card-header.summary { border-left-color: #fd7e14; }
.card-header.history { border-left-color: #0dcaf0; }
.card-header-icon { width: 24px; height: 24px; margin-right: 0.75rem; color: var(--dark-gray); }
h3 { margin: 0; }
.navbar { background-color: var(--dark-gray); color: white; padding: 0.5rem 1rem; display: flex; justify-content: space-between; align-items: center; box-shadow: 0 2px 4px rgba(0,0,0,0.1); }
.navbar-brand { font-size: 1.25rem; font-weight: bold; color: white; text-decoration: none; }
.navbar-right { display: flex; align-items: center; }
.navbar-text { margin-right: 1rem; }
.text-center { text-align: center; }

/* FORMS & BUTTONS */
form div { margin-bottom: 1rem; }
label { display: block; margin-bottom: 0.5rem; font-weight: bold; }
input[type="text"], input[type="password"], select, textarea, input[type="month"], input[type="date"], input[type="time"] { width: 100%; padding: 0.5rem 0.75rem; font-size: 1rem; border: 1px solid var(--border-color); border-radius: 0.25rem; }
.btn { display: inline-block; font-weight: bold; color: #fff; text-align: center; cursor: pointer; background-color: var(--primary-color); border: 1px solid var(--primary-color); padding: 0.6rem 1.2rem; font-size: 1rem; border-radius: 0.25rem; text-decoration: none; width: auto; }
.btn-outline { background-color: transparent; border: 1px solid #fff; color: #fff; }
.btn-success { background-color: var(--success-color); border-color: var(--success-color); }
.reason-field { display: none; margin-top: 10px; }

/* ALERTS & BADGES */
.alert { padding: 1rem; margin-bottom: 1rem; border: 1px solid transparent; border-radius: 0.25rem; display: flex; align-items: center; font-weight: bold; }
.alert-success { color: #0f5132; background-color: #d1e7dd; border-color: #badbcc; }
.alert-danger { color: #842029; background-color: #f8d7da; border-color: #f5c2c7; }
.alert-icon { width: 20px; height: 20px; margin-right: 0.75rem; }
.badge { display: inline-block; padding: 0.4em 0.7em; font-size: 0.8em; font-weight: 700; line-height: 1; color: #fff; text-align: center; border-radius: 0.375rem; }
.bg-present { background-color: var(--success-color); }
.bg-absent { background-color: var(--danger-color); }
.bg-excused { background-color: var(--warning-color); color: #000; }

/* LOGIN PAGE STYLES */
html, body.login-page { height: 100%; }
body.login-page { display: flex; align-items: center; justify-content: center; flex-direction: column; }
.login-card { width: 100%; max-width: 420px; padding: 2rem; border: 1px solid var(--border-color); border-radius: 0.5rem; background-color: #fff; box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1); }
.login-header { text-align: center; margin-bottom: 2rem; }
.login-header h2 { font-size: 1.8rem; margin: 0; font-weight: 700; }
.login-header p { color: #6c757d; font-size: 1rem; margin-top: 0.5rem; }
.login-card .btn { width: 100%; }
.login-footer { margin-top: 1.5rem; text-align: center; font-size: 0.9rem; color: #6c757d; }
.login-footer p { margin: 0; }

/* MANAGE USERS PAGE STYLES */
.action-buttons { display: flex; justify-content: center; align-items: center; gap: 8px; }
.btn-sm { width: auto; padding: 6px 14px; font-size: 0.9rem; font-weight: bold; text-decoration: none; }
.btn-edit { background-color: var(--warning-color); border-color: var(--warning-color); color: #000; }
.btn-delete { background-color: var(--danger-color); border-color: var(--danger-color); color: #fff; }

/* ADMIN DASHBOARD STYLES */
.admin-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1.5rem; }
.stats-container { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 1rem; }
.stat-card { background-color: #fff; padding: 1.25rem; border-radius: 0.5rem; border-left: 5px solid; box-shadow: var(--shadow); display: flex; align-items: center; gap: 1rem; }
.stat-card-present { border-color: var(--success-color); }
.stat-card-absent { border-color: var(--danger-color); }
.stat-card-excused { border-color: var(--warning-color); }
.stat-card-unresponsive { border-color: #6c757d; }
.stat-icon { width: 48px; height: 48px; flex-shrink: 0; }
.stat-card-present .stat-icon { color: var(--success-color); }
.stat-card-absent .stat-icon { color: var(--danger-color); }
.stat-card-excused .stat-icon { color: var(--warning-color); }
.stat-card-unresponsive .stat-icon { color: #6c757d; }
.stat-info .stat-number { font-size: 2rem; font-weight: 700; line-height: 1; }
.stat-info .stat-label { font-size: 1rem; color: #6c757d; }

/* PARTICIPANT HEATMAP STYLES */
.heatmap-card-body { padding-top: 0.5rem; }
.heatmap-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 8px; margin-bottom: 1.5rem; }
.heatmap-cell { aspect-ratio: 1 / 1; border: 1px solid var(--border-color); border-radius: 4px; position: relative; cursor: pointer; transition: transform 0.2s ease-in-out; }
.heatmap-cell:hover { transform: scale(1.1); border-color: var(--dark-gray); }
.heatmap-present { background-color: var(--success-color); }
.heatmap-absent { background-color: var(--danger-color); }
.heatmap-excused { background-color: var(--warning-color); }
.heatmap-nodata { background-color: #ebedf0; }
.heatmap-legend { display: flex; justify-content: center; align-items: center; gap: 1.5rem; font-size: 0.9rem; color: #6c757d; flex-wrap: wrap; }
.legend-item { display: flex; align-items: center; gap: 6px; }
.legend-color-box { width: 15px; height: 15px; border-radius: 3px; border: 1px solid rgba(0,0,0,0.1); }

/* PARTICIPANT HISTORY GRID STYLES */
.history-grid-container { padding: 0; }
.history-grid-table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
.history-grid-table th, .history-grid-table td { border: 1px solid var(--border-color); padding: 0.75rem; text-align: center; vertical-align: middle; }
.history-grid-table thead th { background-color: var(--light-gray); font-weight: bold; }
.history-grid-table th:first-child, .history-grid-table td:first-child { font-weight: bold; background-color: var(--light-gray); width: 60px; }
.history-legend { margin-top: 1.5rem; padding: 0 1.25rem 1.25rem; font-size: 0.9rem; color: #555; }
.history-legend p { margin: 0.25rem 0; }
.history-grid-table td { font-weight: bold; }
.status-p { color: var(--success-color); }
.status-a { color: var(--danger-color); }
.status-e { color: var(--warning-color); }
/* ... (keep all previous styles) ... */

/* NEW Page Footer Style for Login Page */
.page-footer {
    margin-top: 2rem;
    text-align: center;
    font-size: 0.85rem;
    color: #888; /* A subtle gray color */
}
.page-footer p {
    margin: 0;
}