:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-main: #1f2937;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --success: #10b981;
    --danger: #ef4444;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header & Nav */
header {
    background-color: var(--primary-color);
    color: white;
    padding: 1rem 2rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h2 {
    font-weight: 600;
}

.nav-links {
    display: flex;
    align-items: center;
}

.nav-links a {
    color: white;
    text-decoration: none;
    margin-left: 1.5rem;
    font-weight: 500;
    opacity: 0.9;
    transition: opacity 0.2s;
}

.nav-links a:hover {
    opacity: 1;
}

/* Container */
.container {
    max-width: 1000px;
    margin: 2rem auto;
    padding: 0 1rem;
    flex-grow: 1;
    width: 100%;
}

/* Cards */
.card {
    background: var(--card-bg);
    border-radius: 0.75rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    padding: 2rem;
    margin-bottom: 2rem;
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-main);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

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

label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-main);
}

input[type="text"],
input[type="password"],
input[type="date"] {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    transition: background-color 0.2s, transform 0.1s;
    text-align: center;
}

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

.btn:active {
    transform: scale(0.98);
}

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

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    font-weight: 500;
}

.alert-error {
    background-color: #fef2f2;
    color: var(--danger);
    border: 1px solid #f87171;
}

.alert-success {
    background-color: #ecfdf5;
    color: var(--success);
    border: 1px solid #34d399;
}

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

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

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

th {
    background-color: #f9fafb;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    font-size: 0.875rem;
    letter-spacing: 0.05em;
}

tr:hover {
    background-color: #f9fafb;
}

/* Radio buttons for attendance */
.attendance-radios {
    display: flex;
    gap: 1.5rem;
}

.radio-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.radio-group input[type="radio"] {
    width: 1.25rem;
    height: 1.25rem;
    accent-color: var(--primary-color);
}

/* Dashboard Summary Cards */
.summary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.stat-card {
    background: white;
    border-radius: 0.75rem;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    text-align: center;
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-label {
    color: var(--text-muted);
    font-weight: 500;
    margin-top: 0.5rem;
}

/* Login specific */
.login-container {
    max-width: 400px;
    margin: 4rem auto;
}

.login-logo {
    text-align: center;
    margin-bottom: 2rem;
}

.login-logo h1 {
    color: var(--primary-color);
    font-size: 2rem;
}

/* User Info Badge */
.user-badge {
    background: rgba(255, 255, 255, 0.2);
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-size: 0.875rem;
}

/* Additional Button Styles */
.btn-sm {
    padding: 0.4rem 0.75rem;
    font-size: 0.875rem;
}
.btn-danger {
    background-color: var(--danger);
}
.btn-danger:hover {
    background-color: #dc2626;
}
.btn-secondary {
    background-color: var(--text-muted);
}
.btn-secondary:hover {
    background-color: #4b5563;
}
.action-buttons {
    display: flex;
    gap: 0.5rem;
}