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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f4f4f4;
    padding: 20px;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    background: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

h1 {
    margin-bottom: 30px;
    color: #2c3e50;
}

h2 {
    margin-bottom: 20px;
    font-size: 1.3em;
    color: #34495e;
}

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

label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
    color: #555;
}

input {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
}

input:focus {
    outline: none;
    border-color: #3498db;
}

button {
    padding: 12px 20px;
    background: #3498db;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    font-weight: 500;
}

button:hover {
    background: #2980b9;
}

button:active {
    transform: translateY(1px);
}

select {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
}

select:focus {
    outline: none;
    border-color: #3498db;
}

.header-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

#expense-list-section {
    margin-top: 40px;
}

.expense-item {
    padding: 15px;
    margin-bottom: 10px;
    border: 1px solid #e0e0e0;
    border-radius: 4px;
    background: #fafafa;
}

.expense-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.expense-category {
    font-weight: 600;
    color: #2c3e50;
}

.expense-amount {
    font-size: 1.1em;
    font-weight: 600;
    color: #e74c3c;
}

.expense-details {
    display: flex;
    gap: 15px;
    font-size: 0.9em;
    color: #666;
}

.expense-time {
    font-style: italic;
}

.expense-note {
    color: #555;
}

.empty-state {
    text-align: center;
    color: #999;
    font-style: italic;
    padding: 20px;
}