:root {
    --bg-dark: #0a0f1d;
    --panel-bg: #141f35;
    --text-main: #f1f5f9;
    --text-muted: #cbd5e1;
    --accent-blue: #3b82f6;
    --accent-blue-hover: #1d4ed8;
    --accent-yellow: #eab308;
    --border: #1e293b;
    --input-bg: #0f172a;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    font-size: 15px; /* 🎯 Scaled down to standard readable baseline */
}

.app-container {
    max-width: 950px; /* Snugged the container back down */
    width: 100%;
}

header h1 {
    font-size: 2rem; /* 🎯 Cleaner header title size */
    color: var(--text-main);
    margin-bottom: 5px;
    letter-spacing: -0.5px;
}

.subtitle {
    color: var(--text-muted);
    margin-top: 0;
    margin-bottom: 25px;
    font-size: 0.95rem; /* 🎯 Balanced subtitle size */
    line-height: 1.5;
}

.grid-layout {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 25px; /* Balanced gap between panels */
}

@media (max-width: 768px) {
    .grid-layout {
        grid-template-columns: 1fr;
    }
}

.panel {
    background-color: var(--panel-bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 22px; /* Tightened internal box padding */
}

h2 {
    font-size: 1.25rem; /* 🎯 Standard panel section headers */
    margin-top: 0;
    margin-bottom: 20px;
    border-bottom: 2px solid var(--border);
    padding-bottom: 10px;
}

.input-group {
    display: flex;
    flex-direction: column;
    margin-bottom: 16px; /* Closer group spacing */
}

label {
    font-size: 0.9rem; /* 🎯 Clean form label text */
    font-weight: 600;
    color: var(--text-main);
    margin-bottom: 6px;
}

input, select {
    background-color: var(--input-bg);
    color: white;
    border: 1px solid var(--border);
    padding: 10px; /* Snugger input targets */
    border-radius: 6px;
    font-size: 0.95rem; /* 🎯 Clean input font size */
}

input:focus, select:focus {
    outline: none;
    border-color: var(--accent-blue);
}

small {
    color: var(--text-muted);
    margin-top: 6px;
    font-size: 0.8rem; /* 🎯 Clean helper details under input boxes */
    line-height: 1.4;
}

button {
    background-color: var(--accent-blue);
    color: white;
    border: none;
    padding: 14px;
    width: 100%;
    border-radius: 6px;
    font-size: 1.1rem; /* 🎯 Sharp calculate button text */
    font-weight: 700;
    cursor: pointer;
    transition: background 0.15s;
    margin-top: 5px;
}

button:hover {
    background-color: var(--accent-blue-hover);
}

.metric-box {
    background-color: var(--input-bg);
    padding: 16px;
    border-radius: 8px;
    margin-bottom: 15px;
    border-left: 4px solid var(--border);
}

.metric-label {
    font-size: 0.85rem; /* 🎯 Standard output labels */
    color: var(--text-muted);
    margin-bottom: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.metric-value {
    font-size: 1.6rem; /* 🎯 Perfectly balanced output values */
    font-weight: 800;
}

.highlight {
    color: var(--accent-blue);
}

.highlight-yellow {
    color: var(--accent-yellow);
}

.system-box {
    border-left-color: #475569;
}

.system-highlight {
    color: #cbd5e1;
}

.affiliate-section {
    margin-top: 40px;
    border-top: 1px solid var(--border);
    padding-top: 30px;
}

.affiliate-section h3 {
    margin-top: 0;
    margin-bottom: 20px;
    font-size: 1.2rem; /* 🎯 Standard recommendation area header */
}

.affiliate-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}

.affiliate-card {
    background-color: var(--panel-bg);
    padding: 20px;
    border-radius: 8px;
    border: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.affiliate-card h4 {
    margin-top: 0;
    color: var(--text-main);
    font-size: 1.05rem; /* 🎯 Balanced product card title */
    margin-bottom: 8px;
}

.affiliate-card p {
    font-size: 0.85rem; /* 🎯 Balanced product text description */
    color: var(--text-muted);
    line-height: 1.45;
    margin-bottom: 15px;
}

.placeholder-btn {
    display: block;
    text-align: center;
    background-color: var(--input-bg);
    color: white;
    padding: 10px;
    border-radius: 4px;
    font-size: 0.85rem; /* 🎯 Clean shopping link text */
    font-weight: 700;
    text-decoration: none;
    border: 1px solid var(--border);
    transition: background 0.15s, color 0.15s;
}

.placeholder-btn:hover {
    background-color: var(--accent-yellow);
    color: #000;
}

.legal-disclaimer-section {
    margin-top: 40px;
    border-top: 1px solid var(--border);
    padding-top: 20px;
    font-size: 0.78rem; /* 🎯 Clean footer disclaimer text */
    color: var(--text-muted);
    line-height: 1.5;
}

.legal-disclaimer-section p {
    margin-bottom: 10px;
}

.hidden {
    display: none;
}