:root {
    --primary-color: #2c3e50;
    --secondary-color: #ecf0f1;
    --accent-color: #3498db;
    --text-color: #333;
    --sidebar-width: 250px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f7f6;
    color: var(--text-color);
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--primary-color);
    color: #fff;
    padding: 20px;
    position: fixed;
    height: 100%;
    overflow-y: auto;
}

.sidebar h2 {
    text-align: center;
    margin-bottom: 30px;
    font-size: 1.5rem;
}

.sidebar ul {
    list-style: none;
}

.sidebar ul li {
    margin-bottom: 15px;
}

.sidebar ul li a {
    color: #bdc3c7;
    text-decoration: none;
    font-size: 1.1rem;
    display: block;
    padding: 10px;
    border-radius: 4px;
    transition: background 0.3s, color 0.3s;
}

.sidebar ul li a:hover, .sidebar ul li a.active {
    background-color: var(--accent-color);
    color: #fff;
}

/* Main Content */
.main-content {
    margin-left: var(--sidebar-width);
    flex: 1;
    padding: 40px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
    border-bottom: 1px solid #ddd;
    padding-bottom: 20px;
}

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

.btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: var(--accent-color);
    color: #fff;
    text-decoration: none;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn:hover {
    background-color: #2980b9;
}

.btn-danger {
    background-color: #e74c3c;
}

.btn-danger:hover {
    background-color: #c0392b;
}

/* Forms */
.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="file"],
select {
    width: 100%;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 1rem;
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

/* Dashboard stat cards */
.stat-grid {
    display: flex;
    gap: 16px;
    align-items: stretch;
    flex-wrap: wrap;
}
.stat-card {
    display: block;
    width: 220px;
    padding: 18px;
    background: linear-gradient(180deg, #ffffff 0%, #fbfdff 100%);
    border-radius: 12px;
    box-shadow: 0 6px 18px rgba(50,50,93,0.08), 0 2px 6px rgba(0,0,0,0.05);
    text-decoration: none;
    color: var(--text-color);
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(50,50,93,0.12), 0 4px 10px rgba(0,0,0,0.06);
}
.stat-card .title {
    font-size: 0.95rem;
    color: #666;
    margin-bottom: 8px;
}
.stat-card .count {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 6px;
}
.stat-card .muted {
    font-size: 0.78rem;
    color: #888;
}


th, td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

th {
    background-color: var(--primary-color);
    color: #fff;
}

tr:hover {
    background-color: #f1f1f1;
}

/* Login Page */
.login-container {
    width: 100%;
    max-width: 400px;
    margin: 100px auto;
    padding: 40px;
    background: #fff;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    border-radius: 8px;
    text-align: center;
}

.login-container h2 {
    margin-bottom: 30px;
    color: var(--primary-color);
}

.login-container .btn {
    width: 100%;
}