:root {
    --primary-color: #2ecc71; /* Green */
    --secondary-color: #3498db; /* Blue */
    --accent-color: #f1c40f; /* Yellow */
    --bg-color: #ecf0f1; /* Light Gray */
    --text-color: #34495e; /* Dark Blue-Gray */
    --white-color: #ffffff;
    --border-color: #ccc;
    --border-radius: 12px;
    --shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

[data-theme="dark"] {
    --primary-color: #27ae60; /* Darker Green */
    --secondary-color: #2980b9; /* Darker Blue */
    --accent-color: #f39c12; /* Darker Yellow */
    --bg-color: #2c3e50; /* Dark Slate Blue */
    --text-color: #ecf0f1; /* Light Gray */
    --white-color: #34495e; /* Dark Blue-Gray */
    --border-color: #4a6278;
    --shadow: 0 4px 15px rgba(0, 0, 0, 0.4);
}

body {
    font-family: 'Nunito', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    margin: 0;
    padding-bottom: 60px; /* Footer height */
    transition: background-color 0.3s ease, color 0.3s ease;
}

header {
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    color: var(--white-color);
    padding: 1rem 0;
    text-align: center;
    font-size: 1.2rem;
    border-bottom-left-radius: var(--border-radius);
    border-bottom-right-radius: var(--border-radius);
    box-shadow: var(--shadow);
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    transition: background 0.3s ease;
}

#theme-toggle {
    position: absolute;
    top: 50%;
    right: 20px;
    transform: translateY(-50%);
    background: var(--accent-color);
    color: var(--text-color);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    font-size: 1.5rem;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background-color 0.3s ease, transform 0.3s ease;
}

#theme-toggle:hover {
    transform: translateY(-50%) scale(1.1);
}

nav {
    display: flex;
    justify-content: center;
    margin: 20px 0;
}

.tab-btn {
    font-family: 'Nunito', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    background: none;
    border: 2px solid var(--secondary-color);
    color: var(--secondary-color);
    padding: 10px 20px;
    margin: 0 10px;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-btn.active, .tab-btn:hover {
    background: var(--secondary-color);
    color: var(--white-color);
}

main {
    padding: 0 20px;
    max-width: 800px;
    margin: 0 auto;
}

.tab-content {
    display: none;
    background: var(--white-color);
    padding: 20px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.tab-content.active {
    display: block;
}

#ledger-form {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
    margin-bottom: 30px;
}

#ledger-form input {
    font-family: 'Nunito', sans-serif;
    padding: 10px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-color);
    color: var(--text-color);
    border-radius: 8px;
    flex-grow: 1;
    transition: background-color 0.3s ease, color 0.3s ease;
}

#ledger-form button {
    font-family: 'Nunito', sans-serif;
    background-color: var(--primary-color);
    color: var(--white-color);
    border: none;
    padding: 10px 15px;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    font-weight: 700;
}

#ledger-form button:hover {
    background-color: #27ae60; /* Darker Green */
}

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

#reset-btn {
    background: transparent;
    border: 1px solid #e74c3c;
    color: #e74c3c;
    border-radius: 20px;
    padding: 5px 10px;
    cursor: pointer;
    display: flex;
    align-items: center;
    font-family: 'Nunito', sans-serif;
    font-weight: 700;
    transition: all 0.3s ease;
}

#reset-btn:hover {
    background: #e74c3c;
    color: var(--white-color);
}

.reset-icon {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    margin-right: 8px;
    object-fit: cover;
}

.table-container {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

th, td {
    padding: 12px;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: var(--accent-color);
    color: var(--text-color);
    font-weight: 700;
}

tbody tr:nth-child(even) {
    background-color: rgba(0,0,0,0.05);
}

.income-cell {
    color: #2ecc71; /* Green */
    font-weight: 700;
}

.expense-cell {
    color: #e74c3c; /* Red */
    font-weight: 700;
}

[data-theme="dark"] .income-cell {
    color: #32ff7e;
}

[data-theme="dark"] .expense-cell {
    color: #ff4757;
}


#tips-section ul {
    list-style: '🦓';
    padding-left: 30px;
}

#tips-section li {
    padding-left: 10px;
    margin-bottom: 10px;
}

footer {
    text-align: center;
    padding: 15px 0;
    position: fixed;
    bottom: 0;
    width: 100%;
    background-color: var(--text-color);
    color: var(--white-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}