:root {
  color-scheme: light dark;
  --bg:           #0d1117;
  --panel:        #13191f;
  --surface:      #161b22;
  --surface-2:    #1f252d;
  --surface-3:    #2a3038;
  --border:       #21262d;
  --border-bright:#30363d;
  --text:         #f0ede6;
  --text-muted:   #9ca3af;
  --text-dim:     #7a7468;
  --accent:       #f0b429;
  --accent-dim:   #78460d;
  --accent-glow:  rgba(240,180,41,0.2);
  --danger:       #f87171;
  --radius:       8px;
  --font:         ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
}

[data-theme="light"] {
  --bg:           #f8f7f4;
  --panel:        #f0ede8;
  --surface:      #ffffff;
  --surface-2:    #f0ede8;
  --surface-3:    #e8e5e0;
  --border:       #d6cfc8;
  --border-bright:#bfb8b0;
  --text:         #1c1917;
  --text-muted:   #57534e;
  --text-dim:     #78716c;
  --accent:       #d97706;
  --accent-dim:   #fef3c7;
  --accent-glow:  rgba(217,119,6,0.15);
  --danger:       #dc2626;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg:           #f8f7f4;
    --panel:        #f0ede8;
    --surface:      #ffffff;
    --surface-2:    #f0ede8;
    --surface-3:    #e8e5e0;
    --border:       #d6cfc8;
    --border-bright:#bfb8b0;
    --text:         #1c1917;
    --text-muted:   #57534e;
    --text-dim:     #78716c;
    --accent:       #d97706;
    --accent-dim:   #fef3c7;
    --accent-glow:  rgba(217,119,6,0.15);
    --danger:       #dc2626;
  }
}

* { box-sizing: border-box; }
html, body { min-height: 100vh; }
body {
  margin: 0; padding: 80px 16px 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.5;
  display: flex;
  flex-direction: column;
}
.container { max-width: 720px; margin: 0 auto; width: 100%; flex: 1; }
h1 { margin: 0 0 8px; font-size: 1.6rem; }
.subtitle { color: var(--text-muted); margin-bottom: 24px; font-size: 0.95rem; }
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 16px;
}
.card h2 { margin: 0; font-size: 1.15rem; color: var(--accent); }
label { display: block; margin-bottom: 4px; font-size: 0.9rem; color: var(--text-muted); }
input, select {
  width: 100%;
  padding: 10px 12px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-size: 1rem;
  margin-bottom: 12px;
}
input:focus, select:focus { outline: none; border-color: var(--accent); }
.row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
@media (max-width: 560px) { .row { grid-template-columns: 1fr; } }
button, .btn {
  display: inline-block;
  padding: 12px 16px;
  background: var(--accent);
  color: var(--bg);
  border: none;
  border-radius: var(--radius);
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  text-decoration: none;
}
button:hover, .btn:hover { opacity: 0.92; }
.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.result-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; margin-top: 12px; }
.kpi {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px;
  text-align: center;
}
.kpi .value { font-size: 1.1rem; font-weight: 700; color: var(--accent); }
.kpi .label { font-size: 0.75rem; color: var(--text-muted); margin-top: 2px; }
.tmi-badge {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 999px;
  background: var(--accent);
  color: var(--bg);
  font-weight: 800;
  font-size: 0.95rem;
}
.muted { color: var(--text-muted); font-size: 0.85rem; }
.hidden { display: none !important; }

/* Collapsible main block */
.result-toggle {
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
}
.result-toggle .chevron {
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: transform .2s ease;
}
.main-card.collapsed .chevron { transform: rotate(-90deg); }
.main-body {
  overflow: hidden;
  transition: max-height .35s ease, opacity .25s ease, margin-top .2s ease;
  max-height: 1200px;
  opacity: 1;
  margin-top: 16px;
}
.main-card.collapsed .main-body {
  max-height: 0;
  opacity: 0;
  margin-top: 0;
}
.tmi-inline {
  font-weight: 700;
  color: var(--accent);
  font-size: 1rem;
  white-space: nowrap;
}

/* Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s ease;
}
.modal-overlay.open { opacity: 1; pointer-events: auto; }
.modal-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  max-width: 620px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  padding: 20px;
}
.modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
.modal-header h3 { margin: 0; font-size: 1.1rem; color: var(--accent); }
.modal-close { background: none; border: none; color: var(--text-muted); font-size: 1.4rem; cursor: pointer; padding: 0 4px; }

table { width: 100%; border-collapse: collapse; margin-top: 10px; font-size: 0.9rem; }
th, td { padding: 8px; text-align: left; border-bottom: 1px solid var(--border); }
th { color: var(--text-muted); font-weight: 500; }
.detail-step {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 12px;
  margin-bottom: 8px;
  font-size: 0.9rem;
}
.detail-step .expr { color: var(--text-muted); font-size: 0.8rem; }
.detail-step .res { color: var(--accent); font-weight: 700; }

/* Simulation bar */
.sim-bar {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 12px;
  margin-bottom: 14px;
}
.sim-bar-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}
.sim-bar-actions {
  display: flex;
  gap: 8px;
  align-items: center;
}
.sim-select {
  width: auto;
  padding: 8px 10px;
  font-size: 0.85rem;
  margin-bottom: 0;
  min-width: 160px;
}
.btn-small {
  padding: 8px 12px;
  font-size: 0.85rem;
}
.sim-name-wrap {
  flex: 1;
  min-width: 140px;
}
.sim-name-input {
  width: 100%;
  padding: 8px 10px;
  font-size: 0.9rem;
  margin-bottom: 0;
  background: var(--surface-3);
}
.btn-danger {
  border-color: var(--danger);
  color: var(--danger);
}
.btn-danger:hover {
  background: var(--danger);
  color: var(--bg);
}

/* Topbar */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 200;
  height: 56px;
  background: rgba(13,17,23,0.92);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; padding: 0 20px; gap: 12px;
}
[data-theme="light"] .topbar { background: rgba(248,247,244,0.92); }
.topbar-logo {
  font-size: 0.875rem; font-weight: 700;
  color: var(--accent); margin-right: auto; white-space: nowrap;
  display: flex; align-items: center; gap: 8px;
  text-decoration: none;
}
.topbar-logo:hover { opacity: 0.85; }
.topbar-logo svg { color: var(--accent); }
#theme-toggle {
  display: flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: 8px; border: 1px solid var(--border);
  background: var(--surface); color: var(--text); cursor: pointer;
  transition: all 0.2s; flex-shrink: 0;
  padding: 0;
  position: static;
}
#theme-toggle:hover { border-color: var(--accent); background: var(--accent-dim); }

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 16px 20px;
  margin-top: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}
.footer-brand {
  font-size: 0.85rem; font-weight: 600;
  color: var(--text-dim);
  display: flex; align-items: center; gap: 6px;
}
.footer-brand svg { color: var(--accent); }
.footer-links { display: flex; align-items: center; gap: 6px; }
.footer-links a { color: var(--accent); text-decoration: none; font-size: 0.8rem; }
.footer-links a:hover { text-decoration: underline; }
.footer-sep { color: var(--text-dim); }