:root {
    --primary: #4b6cb7;
    --primary-dark: #1f2937;
    --accent: #f59e0b;
    --bg: #f7f8fa;
    --card: #ffffff;
    --ink: #1a1f2c;
    --muted: #6b7280;
    --shadow: 0 4px 10px rgba(0,0,0,.08);
    --up: #16a34a;
    --down: #dc2626;
    --you: #dc2626;
    --median: #2563eb;
}

* { box-sizing: border-box; }

body.sim-body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    background: var(--bg);
    color: var(--ink);
    line-height: 1.55;
}

.sim-header {
    background: var(--primary-dark);
    color: #fff;
    padding: 22px 15px;
    text-align: center;
    box-shadow: var(--shadow);
}
.sim-header h1 { margin: 0; font-size: 1.7em; }
.sim-subtitle { margin: 6px 0 0; color: #cbd5e1; font-weight: 500; }

.sim-main {
    max-width: 960px;
    margin: 0 auto;
    padding: 15px;
    display: grid;
    gap: 15px;
}

.panel {
    background: var(--card);
    border-radius: 12px;
    padding: 15px 18px;
    box-shadow: var(--shadow);
    border-left: 6px solid var(--primary);
}
.panel h2 {
    color: var(--primary-dark);
    margin: 0 0 12px;
    font-size: 1.15em;
    border-bottom: 1px dashed #ddd;
    padding-bottom: 8px;
}

.ctrl-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 10px 14px;
}
.ctrl-grid label {
    display: flex;
    flex-direction: column;
    font-size: .85em;
    color: var(--muted);
    gap: 4px;
}
.ctrl-grid input, .ctrl-grid select {
    padding: 7px 8px;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    font-size: 1em;
    background: #f9fafb;
    color: var(--ink);
}
.ctrl-grid input:focus, .ctrl-grid select:focus { outline: 2px solid var(--primary); outline-offset: 1px; }

.btn-row { margin-top: 12px; display: flex; flex-wrap: wrap; gap: 8px; }
.btn-row button {
    padding: 8px 14px;
    border: none;
    border-radius: 8px;
    background: var(--primary);
    color: #fff;
    font-size: .95em;
    cursor: pointer;
    transition: background .15s;
}
.btn-row button:hover:not(:disabled) { background: #3b5896; }
.btn-row button:disabled { background: #cbd5e1; cursor: not-allowed; }
#btn-reset { background: #6b7280; }
#btn-reset:hover { background: #4b5563; }
#btn-run-monte { background: #7c3aed; }
#btn-run-monte:hover { background: #6d28d9; }
#btn-run-random { background: var(--accent); }
#btn-run-random:hover { background: #d97706; }

.hint { color: var(--muted); font-size: .85em; margin: 10px 0 0; line-height: 1.5; }
.hint b { color: var(--ink); }

.stat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 8px 12px;
}
.stat {
    background: #f1f5f9;
    border-radius: 8px;
    padding: 8px 10px;
    display: flex;
    flex-direction: column;
}
.stat .lbl { font-size: .75em; color: var(--muted); }
.stat .val {
    font-size: 1.25em;
    font-weight: 600;
    color: var(--primary-dark);
    margin-top: 2px;
}

.chart-panel canvas {
    width: 100%;
    height: auto;
    display: block;
    background: #fafcff;
    border-radius: 8px;
    border: 1px solid #e5e7eb;
}

.insight-panel { border-left-color: var(--accent); }
.insight-item {
    background: #fff7ed;
    border: 1px solid #fed7aa;
    border-radius: 8px;
    padding: 10px 12px;
    margin: 8px 0;
    font-size: .95em;
    color: var(--ink);
    line-height: 1.55;
}
.insight-item b { color: #b45309; }

.log-panel { border-left-color: var(--down); }
.log {
    max-height: 240px;
    overflow-y: auto;
    background: #f9fafb;
    border-radius: 8px;
    padding: 10px 12px;
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: .82em;
    line-height: 1.5;
}
.log .entry { border-bottom: 1px dotted #e5e7eb; padding: 4px 0; }
.log .entry:last-child { border-bottom: none; }
.log .entry.muted { color: var(--muted); font-style: italic; }
.log .age { color: var(--primary-dark); font-weight: 600; }
.log .event { color: var(--down); font-weight: 700; }
.log .event.crash-major { color: #7c2d12; }
.log .event.crash-bear { color: #b91c1c; }

.sim-footer {
    text-align: center;
    color: var(--muted);
    padding: 10px 5px 30px;
    font-size: .85em;
}
.sim-footer a { color: var(--primary); }

@media (min-width: 700px) {
    .sim-main { padding: 20px; gap: 18px; }
}