:root {
    --bg-color: #f8f9fa;
    --text-color: #212529;
    --container-bg: #ffffff;
    --circle-bg: #28a745;
    --circle-text: #ffffff;
    --btn-bg: #007bff;
    --btn-text: #ffffff;
    --nav-bg: #ffffff;
    --nav-text: #212529;
    --accent-color: #007bff;
    --footer-bg: #343a40;
    --footer-text: #f8f9fa;
}

body.dark-mode {
    --bg-color: #121212;
    --text-color: #e9ecef;
    --container-bg: #1e1e1e;
    --circle-bg: #218838;
    --circle-text: #ffffff;
    --btn-bg: #0069d9;
    --btn-text: #ffffff;
    --nav-bg: #1e1e1e;
    --nav-text: #e9ecef;
    --accent-color: #0d6efd;
    --footer-bg: #000000;
}

* {
    box-sizing: border-box;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    transition: background-color 0.3s, color 0.3s;
    line-height: 1.6;
}

.navbar {
    background-color: var(--nav-bg);
    color: var(--nav-text);
    padding: 1rem 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1000px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
    color: var(--accent-color);
}

.nav-links {
    list-style: none;
    display: flex;
    margin: 0;
    padding: 0;
}

.nav-links li {
    margin-left: 20px;
}

.nav-links a {
    text-decoration: none;
    color: var(--nav-text);
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--accent-color);
}

.main-content {
    max-width: 1000px;
    margin: 40px auto;
    padding: 0 20px;
}

.container {
    background-color: var(--container-bg);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    margin-bottom: 40px;
    text-align: center;
}

h1, h2 {
    margin-top: 0;
    color: var(--accent-color);
}

.subtitle {
    color: var(--text-color);
    opacity: 0.8;
    margin-bottom: 2rem;
}

.numbers-container {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    margin: 30px 0;
    min-height: 60px;
}

.placeholder-text {
    color: var(--text-color);
    opacity: 0.5;
    font-style: italic;
}

.number-circle {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background-color: var(--circle-bg);
    color: var(--circle-text);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 28px;
    font-weight: bold;
    margin: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    animation: popIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

@keyframes popIn {
    from { transform: scale(0); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

#generate-button {
    padding: 15px 30px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    border: none;
    border-radius: 8px;
    background-color: var(--btn-bg);
    color: var(--btn-text);
    transition: all 0.2s;
}

#generate-button:hover {
    filter: brightness(1.1);
    transform: translateY(-2px);
}

#generate-button:active {
    transform: translateY(0);
}

/* Tax Calculator */
.calc-form {
    max-width: 400px;
    margin: 0 auto;
    text-align: left;
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
}

.form-group input, .form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid rgba(0,0,0,0.1);
    border-radius: 6px;
    background-color: var(--bg-color);
    color: var(--text-color);
}

#calculate-tax-btn {
    width: 100%;
    padding: 12px;
    background-color: var(--circle-bg);
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: bold;
}

.calc-result {
    margin-top: 20px;
    padding: 15px;
    border-radius: 6px;
    background-color: rgba(0,0,0,0.05);
    display: none;
}

/* Tips Grid */
.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    text-align: left;
}

.tip-card {
    padding: 20px;
    border-left: 4px solid var(--accent-color);
    background-color: rgba(0,0,0,0.02);
}

/* Footer */
.footer {
    background-color: var(--footer-bg);
    color: var(--footer-text);
    padding: 40px 0;
    margin-top: 60px;
    text-align: center;
}

.footer-links {
    margin-top: 20px;
}

.footer-links a {
    color: var(--footer-text);
    margin: 0 15px;
    text-decoration: none;
    opacity: 0.7;
}

.footer-links a:hover {
    opacity: 1;
}

.theme-toggle {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1001;
    background-color: var(--accent-color);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 30px;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

.divider {
    border: 0;
    height: 1px;
    background-color: var(--text-color);
    opacity: 0.1;
    margin: 40px 0;
}

@media (max-width: 600px) {
    .nav-container {
        flex-direction: column;
    }
    .nav-links {
        margin-top: 15px;
    }
    .nav-links li {
        margin: 0 10px;
    }
}