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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

h1 {
    text-align: center;
    color: white;
    margin-bottom: 30px;
    font-size: 2.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.form-container,
.expenses-container {
    background: white;
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

h2 {
    color: #667eea;
    margin-bottom: 20px;
    font-size: 1.5rem;
}

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

label {
    display: block;
    margin-bottom: 8px;
    color: #333;
    font-weight: 500;
}

input[type="number"],
input[type="text"],
input[type="date"],
select {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s;
}

input:focus,
select:focus {
    outline: none;
    border-color: #667eea;
}

.btn-submit {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-submit:active {
    transform: translateY(0);
}

.message {
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    text-align: center;
    font-weight: 500;
}

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

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

.message.hidden {
    display: none;
}

.total-amount {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 15px;
    border-radius: 8px;
    text-align: center;
    font-size: 1.5rem;
    font-weight: bold;
    margin-bottom: 20px;
}

.grouping-controls {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    justify-content: center;
}

.grouping-btn {
    padding: 10px 20px;
    border: 2px solid #667eea;
    background: white;
    color: #667eea;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.grouping-btn:hover {
    background: #f0f0ff;
    transform: translateY(-2px);
}

.grouping-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.expenses-list {
    max-height: 500px;
    overflow-y: auto;
}

.date-group {
    margin-bottom: 30px;
}

.date-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 12px 20px;
    border-radius: 8px;
    margin-bottom: 15px;
    font-weight: 600;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

.date-title {
    font-size: 1.1rem;
}

.date-total {
    font-size: 1.2rem;
    font-weight: bold;
}

.date-expenses {
    padding-left: 10px;
}

.expense-item {
    background: #f8f9fa;
    border-left: 4px solid #667eea;
    padding: 15px;
    margin-bottom: 12px;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: transform 0.2s;
}

.expense-item:hover {
    transform: translateX(5px);
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
}

.expense-details {
    flex: 1;
}

.expense-amount {
    font-size: 1.5rem;
    font-weight: bold;
    color: #667eea;
}

.expense-category {
    display: inline-block;
    background: #667eea;
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    margin-top: 5px;
}

.expense-description {
    color: #666;
    margin-top: 8px;
}

.expense-date {
    color: #999;
    font-size: 0.9rem;
    margin-top: 5px;
}

.loading {
    text-align: center;
    color: #999;
    padding: 20px;
}

.no-expenses {
    text-align: center;
    color: #999;
    padding: 40px;
    font-style: italic;
}

@media (max-width: 600px) {
    h1 {
        font-size: 2rem;
    }

    .form-container,
    .expenses-container {
        padding: 20px;
    }

    .expense-item {
        flex-direction: column;
        align-items: flex-start;
    }

    .expense-amount {
        margin-bottom: 10px;
    }
}