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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: #25d366;
    color: white;
    padding: 15px 0;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5em;
    font-weight: bold;
}

.nav {
    display: flex;
    align-items: center;
    gap: 15px;
}

.user-info {
    font-size: 0.9em;
}

/* Main Content */
.main-content {
    min-height: calc(100vh - 150px);
}

/* Footer */
.footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 20px 0;
    margin-top: 50px;
}

/* Buttons */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1em;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s;
}

.btn-primary {
    background: #25d366;
    color: white;
}

.btn-primary:hover {
    background: #128c7e;
}

.btn-secondary {
    background: #fff;
    color: #25d366;
    border: 2px solid #25d366;
}

.btn-secondary:hover {
    background: #25d366;
    color: white;
}

.btn-small {
    padding: 5px 10px;
    font-size: 0.9em;
}

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

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

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: #555;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1em;
    outline: none;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: #25d366;
}

/* Alerts */
.alert {
    padding: 15px;
    border-radius: 5px;
    margin-bottom: 20px;
}

.alert-error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-info {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

.alert-warning {
    background: #fff3cd;
    color: #856404;
    border: 1px solid #ffeaa7;
}

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

.mt-1 { margin-top: 10px; }
.mt-2 { margin-top: 20px; }
.mt-3 { margin-top: 30px; }

.mb-1 { margin-bottom: 10px; }
.mb-2 { margin-bottom: 20px; }
.mb-3 { margin-bottom: 30px; }

.p-1 { padding: 10px; }
.p-2 { padding: 20px; }
.p-3 { padding: 30px; }

/* Responsive */
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 10px;
    }
    
    .nav {
        flex-direction: column;
    }
    
    .logo {
        font-size: 1.2em;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #555;
}