:root {
    --primary: #2ecc71;
    --primary-dark: #27ae60;
    --dark: #2c3e50;
    --light: #f8f9fa;
    --gray: #bdc3c7;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f0f3f4;
    color: var(--dark);
}

header {
    background-color: var(--dark);
    color: white;
    text-align: center;
    padding: 2rem 1rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.container {
    max-width: 600px;
    margin: 2rem auto;
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.05);
}

.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--light);
    padding-bottom: 10px;
}

.tab-btn {
    flex: 1;
    padding: 10px;
    border: none;
    background: #e5e8e8;
    color: var(--dark);
    font-size: 1rem;
    font-weight: bold;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-btn.active {
    background-color: var(--primary);
    color: white;
}

.tab-content {
    display: none;
}

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

h2 {
    margin-bottom: 1.5rem;
    font-size: 1.3rem;
    color: #34495e;
}

.input-group {
    margin-bottom: 1.2rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

input, select {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--gray);
    border-radius: 8px;
    font-size: 1rem;
    outline: none;
    transition: border 0.3s;
}

input:focus, select:focus {
    border-color: var(--primary);
}

.calc-btn {
    width: 100%;
    padding: 14px;
    background-color: var(--primary);
    color: white;
    border: none;
    font-size: 1.1rem;
    font-weight: bold;
    border-radius: 8px;
    cursor: pointer;
    margin-top: 1rem;
    transition: background 0.2s;
}

.calc-btn:hover {
    background-color: var(--primary-dark);
}

.result-box {
    margin-top: 2rem;
    background-color: #ebf5fb;
    padding: 1.5rem;
    border-radius: 8px;
    border-right: 5px solid #3498db;
}

.result-box h3 {
    margin-bottom: 1rem;
    color: #2980b9;
}

.result-box p {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.total-line {
    font-size: 1.4rem !important;
    font-weight: bold;
    color: var(--primary-dark);
    margin: 10px 0;
}

.hidden {
    display: none;
}

.disclaimer {
    display: block;
    margin-top: 1rem;
    color: #7f8c8d;
}

.progress-bar-container {
    width: 100%;
    background-color: #d5dbdb;
    height: 15px;
    border-radius: 10px;
    margin: 15px 0;
    overflow: hidden;
}

.progress-bar-fill {
    width: 0%;
    height: 100%;
    background-color: var(--primary);
    transition: width 1s ease-out;
}

.tip-text {
    font-style: italic;
    color: #7f8c8d;
    margin-top: 10px;
}

footer {
    text-align: center;
    padding: 2rem;
    color: #7f8c8d;
    font-size: 0.9rem;
}