:root {
    --primary-color: #2563eb;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --success-bg: #1e293b; /* Dark slate for result */
    --success-text: #ffffff;
    --error-bg: #fef2f2;
    --error-text: #991b1b;
    --error-border: #fecaca;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.5;
    display: flex;
    justify-content: center;
    min-height: 100vh;
    padding: 20px;
}

.tool-container {
    width: 100%;
    max-width: 480px;
    background: transparent;
}

header {
    text-align: center;
    margin-bottom: 24px;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 8px;
}

header p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Input Sections */
.input-group {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px;
    margin-bottom: 16px;
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

.input-group h2 {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 12px;
}

/* Radio Button Styling */
.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.options-grid.three-col {
    grid-template-columns: 1fr 1fr 1fr;
}

.options-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* Hidden Radio Input */
input[type="radio"] {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

/* Clickable Label */
.option-card, .option-row {
    display: flex;
    align-items: center;
    justify-content: center; /* Center text in cards */
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.95rem;
    transition: all 0.2s ease;
    background: #fff;
}

.option-row {
    justify-content: flex-start; /* Left align for list items */
    padding-left: 16px;
}

.option-card:hover, .option-row:hover {
    background-color: #f1f5f9;
}

/* Checked State */
input[type="radio"]:checked + .label-text {
    font-weight: 600;
    color: var(--primary-color);
}

.option-card:has(input:checked), .option-row:has(input:checked) {
    border-color: var(--primary-color);
    background-color: #eff6ff; /* Light blue tint */
    box-shadow: 0 0 0 1px var(--primary-color);
}

/* Result Area */
.result-container {
    margin-top: 24px;
    min-height: 200px;
}

.placeholder {
    text-align: center;
    color: var(--text-muted);
    padding: 40px 20px;
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    font-size: 0.9rem;
}

/* Success Card */
.result-card {
    background: var(--success-bg);
    color: var(--success-text);
    border-radius: 12px;
    padding: 24px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.result-header {
    margin-bottom: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.badge {
    background: rgba(34, 197, 94, 0.2);
    color: #86efac;
    font-size: 0.75rem;
    padding: 4px 8px;
    border-radius: 999px;
    border: 1px solid rgba(34, 197, 94, 0.3);
}

.field-group label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: rgba(255,255,255,0.6);
    margin-bottom: 4px;
}

.value {
    font-weight: 500;
    font-size: 1rem;
}

.value.large {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.result-details {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 16px;
    padding-top: 16px;
    border-top: 1px solid rgba(255,255,255,0.2);
}

.result-notes {
    background: rgba(255, 255, 0, 0.1);
    color: #fef08a;
    padding: 12px;
    border-radius: 8px;
    font-size: 0.85rem;
    margin-top: 16px;
}

/* Error Card */
.error-card {
    background: var(--error-bg);
    border: 1px solid var(--error-border);
    color: var(--error-text);
    padding: 20px;
    border-radius: 12px;
}

.error-card h3 {
    font-size: 1rem;
    margin-bottom: 8px;
}

.error-card p {
    font-size: 0.9rem;
}

/* Utilities */
.hidden {
    display: none !important;
}