:root {
    --massa-blue: #0000FF;
    --massa-dark-bg: #0c0c0e;
    --massa-text-primary: #ffffff;
    --massa-text-secondary: #a0a0a0;
    --massa-card-bg: #1a1a1f;
    --massa-border-color: #333333;
}

body {
    font-family: 'Poppins', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    background-color: var(--massa-dark-bg);
    color: var(--massa-text-primary);
    -webkit-font-smoothing: antialiased;
}

.app-container {
    max-width: 700px;
    margin: 0 auto;
    padding: 20px;
}

.logo-area {
    text-align: center;
    padding: 20px 0;
}
.massa-logo {
    height: 40px;
    width: auto;
}

/* Sections Styling */
.calculator, .result-section, .details-section {
    background: var(--massa-card-bg);
    border: 1px solid var(--massa-border-color);
    border-radius: 8px;
    padding: 2.5em;
    margin-bottom: 30px;
}

.calculator h2 { text-align: center; margin-top: 0; color: var(--massa-text-primary); }
.calculator .tagline { text-align: center; margin-bottom: 25px; color: var(--massa-text-secondary); }
.calculator label { display: block; text-align: left; margin-top: 20px; font-weight: 600; font-size: 0.9em; }

/* Input, Select & Button Styles */
input, select { 
    width: 100%; box-sizing: border-box; padding: 12px; margin-top: 8px; 
    border-radius: 4px; border: 1px solid var(--massa-border-color);
    background-color: var(--massa-dark-bg);
    color: var(--massa-text-primary);
    font-size: 1em;
    font-family: 'Poppins', sans-serif;
}
select {
    appearance: none;
    background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%22292.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%23a0a0a0%22%20d%3D%22M287%2069.4a17.6%2017.6%200%200%200-13-5.4H18.4c-5%200-9.3%201.8-12.9%205.4A17.6%2017.6%200%200%200%200%2082.2c0%205%201.8%209.3%205.4%2012.9l128%20127.9c3.6%203.6%207.8%205.4%2012.8%205.4s9.2-1.8%2012.8-5.4L287%2095c3.5-3.5%205.4-7.8%205.4-12.8%200-5-1.9-9.2-5.5-12.8z%22%2F%3E%3C%2Fsvg%3E');
    background-repeat: no-repeat;
    background-position: right 1rem center;
    background-size: .65em auto;
}
button { 
    background-color: var(--massa-blue); color: white; padding: 12px 20px; 
    border: none; border-radius: 6px; cursor: pointer; margin-top: 25px; 
    width: 100%; font-size: 1em; font-weight: 600;
    transition: transform 0.2s;
}
button:hover { transform: scale(1.02); }

/* Result Box Styles */
.result-section p { margin: 10px 0; display: flex; justify-content: space-between; }
.result-section .info-box { 
    background-color: rgba(0, 0, 255, 0.1); border-left: 4px solid var(--massa-blue); 
    padding: 10px; margin: 15px 0 20px 0; font-size: 0.9em; 
}
.result-section .total { border-top: 1px solid var(--massa-border-color); padding-top: 10px; font-size: 1.15em; font-weight: 600; }
.refund-section { margin-top: 20px; padding-top: 15px; border-top: 2px dashed var(--massa-border-color); }
.refund-section h4 { margin-top: 0; color: #28a745; }
.refund-section .highlight { 
    font-size: 1.1em; background-color: rgba(40, 167, 69, 0.1); padding: 8px; border-radius: 4px; 
}
.disclaimer { font-size: 0.8em; color: var(--massa-text-secondary); margin-top: 15px; text-align: center; }

/* Breakdown & Details Styles */
.details-section h3, .details-section h4 {
    margin-top: 0;
    border-bottom: 2px solid var(--massa-blue);
    padding-bottom: 10px;
    font-weight: 600;
}
.details-section hr { border: none; border-top: 1px solid var(--massa-border-color); margin: 25px 0; }
.details-section .assumption-box {
    background-color: rgba(0, 0, 255, 0.1);
    border: 1px solid var(--massa-blue);
    padding: 15px;
    border-radius: 4px;
    font-size: 0.9em;
}

#calculationBreakdown .step {
    background-color: var(--massa-dark-bg);
    border: 1px solid var(--massa-border-color);
    border-radius: 6px;
    padding: 15px;
    margin-bottom: 15px;
}
#calculationBreakdown h5 { margin-top: 0; margin-bottom: 10px; font-size: 1.1em; color: var(--massa-text-primary); }
#calculationBreakdown p { font-family: 'Roboto Mono', monospace; font-size: 0.9em; line-height: 1.6; margin: 5px 0; word-break: break-all; }
#calculationBreakdown .value { color: var(--massa-blue); font-weight: 600; }
#calculationBreakdown .final-cost {
    display: block; margin-top: 10px; padding: 8px;
    background-color: rgba(0, 0, 255, 0.1); border-radius: 4px;
    font-size: 1.1em; text-align: center;
}
.step-placeholder {
    text-align: center; padding: 40px 20px;
    background-color: var(--massa-dark-bg); border: 1px dashed var(--massa-border-color);
    border-radius: 6px; color: var(--massa-text-secondary);
}