:root,
[data-theme="light"] {
  --sim-bg: #f0f4f8;
  --sim-surface: #ffffff;
  --sim-surface-hover: #f8fafc;
  --sim-text: #0f213c;
  --sim-text-soft: #3a4a66;
  --sim-text-muted: #6b7a92;
  --sim-border: #e2e8f0;
  --sim-brand: #0b5ed7;
  --sim-brand-light: #e6efff;
  --sim-brand-dark: #08458f;
  --sim-shadow: 0 1px 3px rgba(15, 33, 60, 0.06);
  --sim-shadow-lg: 0 8px 24px rgba(15, 33, 60, 0.1);
  --sim-input-bg: #ffffff;
  --sim-input-border: #cfd7e3;
  --sim-header-bg: rgba(255, 255, 255, 0.92);
  --sim-ok: #047857;
  --sim-ok-bg: #ecfdf5;
  --sim-warn: #b45309;
  --sim-danger: #dc2626;
  --sim-slider-track: #e2e8f0;
  --sim-slider-thumb: #0b5ed7;
  --sim-chart-bg: #ffffff;
  --sim-chart-grid: #f0f4f8;
  --sim-chart-text: #6b7a92;
  --sim-chart-solar: #f59e0b;
  --sim-chart-consumption: #ef4444;
  --sim-chart-battery: #10b981;
  --sim-chart-import: #6366f1;
  --sim-chart-export: #8b5cf6;
  --sim-chart-soc: #3b82f6;
  --sim-metric-bg: #ffffff;
}

[data-theme="dark"] {
  --sim-bg: #0c1222;
  --sim-surface: #162032;
  --sim-surface-hover: #1e293b;
  --sim-text: #e2e8f0;
  --sim-text-soft: #94a3b8;
  --sim-text-muted: #64748b;
  --sim-border: #1e3050;
  --sim-brand: #3b82f6;
  --sim-brand-light: #1e3050;
  --sim-brand-dark: #60a5fa;
  --sim-shadow: 0 1px 3px rgba(0, 0, 0, 0.25);
  --sim-shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.35);
  --sim-input-bg: #1a2744;
  --sim-input-border: #2d3f5e;
  --sim-header-bg: rgba(12, 18, 34, 0.92);
  --sim-ok: #34d399;
  --sim-ok-bg: #064e3b;
  --sim-warn: #fbbf24;
  --sim-danger: #f87171;
  --sim-slider-track: #1e3050;
  --sim-slider-thumb: #3b82f6;
  --sim-chart-bg: #162032;
  --sim-chart-grid: #1e293b;
  --sim-chart-text: #64748b;
  --sim-chart-solar: #fbbf24;
  --sim-chart-consumption: #f87171;
  --sim-chart-battery: #34d399;
  --sim-chart-import: #818cf8;
  --sim-chart-export: #a78bfa;
  --sim-chart-soc: #60a5fa;
  --sim-metric-bg: #162032;
}

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

html {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Ubuntu, Cantarell, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  color: var(--sim-text);
  background: var(--sim-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img { max-width: 100%; display: block; }
a { color: var(--sim-brand); text-decoration: none; }
a:hover { text-decoration: underline; }

.sim-wrap {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

h1, h2, h3 {
  color: var(--sim-text);
  line-height: 1.2;
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(24px, 3.5vw, 36px); margin-bottom: 8px; }
h2 { font-size: clamp(20px, 2.5vw, 28px); margin-bottom: 16px; }
h3 { font-size: 16px; margin-bottom: 8px; }

/* Header */
.sim-header {
  position: sticky;
  top: 0;
  background: var(--sim-header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--sim-border);
  z-index: 50;
}

.sim-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.sim-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 16px;
  color: var(--sim-text);
  text-decoration: none;
}
.sim-brand:hover { text-decoration: none; }

.sim-header-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.sim-page-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--sim-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.sim-theme-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--sim-border);
  border-radius: 10px;
  background: var(--sim-surface);
  color: var(--sim-text-soft);
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.sim-theme-btn:hover {
  background: var(--sim-surface-hover);
  color: var(--sim-text);
  border-color: var(--sim-brand);
}

[data-theme="light"] .sim-icon-sun { display: none; }
[data-theme="light"] .sim-icon-moon { display: block; }
[data-theme="dark"] .sim-icon-sun { display: block; }
[data-theme="dark"] .sim-icon-moon { display: none; }

/* Main */
.sim-main {
  flex: 1;
  padding: 32px 0 48px;
}

/* Intro */
.sim-intro {
  margin-bottom: 28px;
}
.sim-intro p {
  color: var(--sim-text-soft);
  font-size: 16px;
  max-width: 720px;
}

/* Panel */
.sim-panel {
  background: var(--sim-surface);
  border: 1px solid var(--sim-border);
  border-radius: 14px;
  padding: 24px;
  margin-bottom: 24px;
  box-shadow: var(--sim-shadow);
}

.sim-panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.sim-panel-header h2 { margin-bottom: 0; font-size: 18px; }

.sim-panel-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--sim-border);
  border-radius: 8px;
  background: var(--sim-surface);
  color: var(--sim-text-soft);
  cursor: pointer;
  transition: transform 0.2s;
}
.sim-panel-toggle[aria-expanded="false"] svg {
  transform: rotate(-90deg);
}

.sim-inputs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  margin-top: 20px;
  overflow: hidden;
  transition: max-height 0.3s ease, opacity 0.2s ease;
}
.sim-inputs-grid.collapsed {
  max-height: 0;
  opacity: 0;
  margin-top: 0;
  overflow: hidden;
}

.sim-input-section h3 {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--sim-brand);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--sim-border);
}

.sim-input-group {
  margin-bottom: 14px;
}
.sim-input-group:last-child { margin-bottom: 0; }

.sim-input-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--sim-text-soft);
  margin-bottom: 6px;
}

.sim-input-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.sim-input-row input[type="range"] {
  flex: 1;
  -webkit-appearance: none;
  appearance: none;
  height: 6px;
  background: var(--sim-slider-track);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}
.sim-input-row input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--sim-slider-thumb);
  border: 2px solid var(--sim-surface);
  box-shadow: 0 1px 4px rgba(0,0,0,0.2);
  cursor: grab;
  transition: transform 0.1s;
}
.sim-input-row input[type="range"]::-webkit-slider-thumb:active {
  transform: scale(1.15);
  cursor: grabbing;
}
.sim-input-row input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--sim-slider-thumb);
  border: 2px solid var(--sim-surface);
  box-shadow: 0 1px 4px rgba(0,0,0,0.2);
  cursor: grab;
}

.sim-input-val {
  display: flex;
  align-items: center;
  gap: 4px;
  min-width: 100px;
}

.sim-input-val input[type="number"] {
  width: 64px;
  padding: 6px 8px;
  border: 1px solid var(--sim-input-border);
  border-radius: 8px;
  background: var(--sim-input-bg);
  color: var(--sim-text);
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  text-align: right;
  -moz-appearance: textfield;
}
.sim-input-val input[type="number"]::-webkit-outer-spin-button,
.sim-input-val input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
.sim-input-val input[type="number"]:focus {
  outline: none;
  border-color: var(--sim-brand);
  box-shadow: 0 0 0 3px rgba(11, 94, 215, 0.12);
}

.sim-unit {
  font-size: 13px;
  color: var(--sim-text-muted);
  font-weight: 500;
  white-space: nowrap;
}

/* Season buttons */
.sim-input-section-inline {
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
}

.sim-season-btns {
  display: flex;
  gap: 6px;
}

.sim-season-btn {
  flex: 1;
  padding: 8px 12px;
  border: 1px solid var(--sim-border);
  border-radius: 8px;
  background: var(--sim-surface);
  color: var(--sim-text-soft);
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.sim-season-btn:hover {
  background: var(--sim-surface-hover);
  color: var(--sim-text);
}
.sim-season-btn.active {
  background: var(--sim-brand);
  color: #ffffff;
  border-color: var(--sim-brand);
}

/* Metrics */
.sim-metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.sim-metric-card {
  background: var(--sim-metric-bg);
  border: 1px solid var(--sim-border);
  border-radius: 12px;
  padding: 18px 20px;
  box-shadow: var(--sim-shadow);
  display: flex;
  flex-direction: column;
  gap: 2px;
  transition: transform 0.12s, box-shadow 0.2s;
}
.sim-metric-card:hover {
  transform: translateY(-1px);
  box-shadow: var(--sim-shadow-lg);
}

.sim-metric-highlight {
  border-color: var(--sim-brand);
  background: var(--sim-brand-light);
}

.sim-metric-label {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--sim-text-muted);
}

.sim-metric-value {
  font-size: 28px;
  font-weight: 700;
  color: var(--sim-text);
  line-height: 1.1;
}

.sim-metric-unit {
  font-size: 13px;
  color: var(--sim-text-muted);
  font-weight: 500;
}

/* Charts */
.sim-charts-section { margin-bottom: 32px; }

.sim-charts-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.sim-chart-card {
  background: var(--sim-surface);
  border: 1px solid var(--sim-border);
  border-radius: 14px;
  padding: 20px;
  box-shadow: var(--sim-shadow);
}
.sim-chart-card h3 {
  font-size: 15px;
  color: var(--sim-text-soft);
  margin-bottom: 12px;
}

.sim-chart-wide { grid-column: 1 / -1; }

.sim-chart {
  width: 100%;
  height: 300px;
}

/* Economics */
.sim-economics {
  margin-bottom: 24px;
}
.sim-economics h2 { margin-bottom: 20px; }

.sim-econ-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
  margin-bottom: 20px;
}

.sim-econ-card {
  background: var(--sim-surface);
  border: 1px solid var(--sim-border);
  border-radius: 14px;
  padding: 24px;
  box-shadow: var(--sim-shadow);
}
.sim-econ-card h3 {
  font-size: 14px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--sim-brand);
  margin-bottom: 16px;
}

.sim-econ-highlight {
  border-color: var(--sim-brand);
}

.sim-econ-table {
  width: 100%;
  border-collapse: collapse;
}
.sim-econ-table td {
  padding: 8px 0;
  font-size: 14px;
  color: var(--sim-text-soft);
  border-bottom: 1px solid var(--sim-border);
}
.sim-econ-table tr:last-child td {
  border-bottom: none;
}
.sim-econ-val {
  text-align: right;
  font-weight: 600;
  color: var(--sim-text);
  font-variant-numeric: tabular-nums;
}
.sim-econ-total td {
  font-weight: 700;
  color: var(--sim-text);
  padding-top: 12px;
  border-top: 2px solid var(--sim-border);
  border-bottom: none;
}

.sim-roi {
  text-align: center;
  padding: 20px 0;
}
.sim-roi-value {
  display: block;
  font-size: 42px;
  font-weight: 800;
  color: var(--sim-brand);
  line-height: 1;
  margin-bottom: 6px;
}
.sim-roi-label {
  display: block;
  font-size: 13px;
  color: var(--sim-text-muted);
}

.sim-econ-note {
  font-size: 12px;
  color: var(--sim-text-muted);
  margin-top: 12px;
  line-height: 1.5;
  padding-top: 12px;
  border-top: 1px solid var(--sim-border);
}

/* SVR / flexibility scenario switch */
.sim-svr-scenario {
  margin-bottom: 14px;
}
.sim-svr-scenario-label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  color: var(--sim-text-muted);
  margin-bottom: 8px;
}
.sim-svr-btns {
  display: flex;
  gap: 6px;
}
.sim-svr-btn {
  flex: 1;
  padding: 8px 10px;
  border: 1px solid var(--sim-border);
  border-radius: 8px;
  background: var(--sim-surface);
  color: var(--sim-text-soft);
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.sim-svr-btn:hover {
  background: var(--sim-surface-hover);
  color: var(--sim-text);
}
.sim-svr-btn.active {
  background: var(--sim-brand);
  color: #ffffff;
  border-color: var(--sim-brand);
}

.sim-roi-recommendation {
  font-size: 13px;
  font-weight: 600;
  color: var(--sim-text);
  margin-top: 12px;
  line-height: 1.5;
  padding-top: 12px;
  border-top: 1px solid var(--sim-border);
}

/* UPS Info */
.sim-ups-info {
  background: var(--sim-surface);
  border: 1px solid var(--sim-border);
  border-radius: 14px;
  padding: 24px;
  box-shadow: var(--sim-shadow);
}
.sim-ups-info h3 {
  font-size: 14px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--sim-brand);
  margin-bottom: 16px;
}

.sim-ups-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 16px;
}
.sim-ups-stat {
  text-align: center;
}
.sim-ups-val {
  display: block;
  font-size: 28px;
  font-weight: 700;
  color: var(--sim-text);
  line-height: 1.1;
}
.sim-ups-label {
  display: block;
  font-size: 12px;
  color: var(--sim-text-muted);
  margin-top: 4px;
}

.sim-ups-bar-wrap {
  height: 8px;
  background: var(--sim-slider-track);
  border-radius: 4px;
  overflow: hidden;
}
.sim-ups-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--sim-chart-battery), var(--sim-brand));
  border-radius: 4px;
  transition: width 0.5s ease;
}

/* API Note */
.sim-api-note {
  background: var(--sim-brand-light);
  border: 1px solid var(--sim-border);
  border-left: 4px solid var(--sim-brand);
  border-radius: 10px;
  padding: 16px 20px;
  margin-bottom: 24px;
}
.sim-api-note p {
  font-size: 13px;
  color: var(--sim-text-soft);
  margin: 0;
}

/* Footer */
.sim-footer {
  padding: 24px 0;
  border-top: 1px solid var(--sim-border);
  background: var(--sim-surface);
}
.sim-footer p {
  font-size: 14px;
  color: var(--sim-text-muted);
  text-align: center;
}
.sim-footer a {
  color: var(--sim-brand);
}

/* Responsive */
@media (max-width: 960px) {
  .sim-charts-grid {
    grid-template-columns: 1fr;
  }
  .sim-chart-wide { grid-column: auto; }

  .sim-metrics {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 720px) {
  .sim-wrap { padding: 0 16px; }
  .sim-main { padding: 20px 0 32px; }

  .sim-panel-toggle { display: flex; }

  .sim-inputs-grid {
    grid-template-columns: 1fr;
  }

  .sim-metrics {
    grid-template-columns: repeat(2, 1fr);
  }

  .sim-metric-value { font-size: 22px; }

  .sim-chart { height: 240px; }

  .sim-econ-grid {
    grid-template-columns: 1fr;
  }

  .sim-ups-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
  }
  .sim-ups-val { font-size: 22px; }

  .sim-page-title { display: none; }

  .sim-roi-value { font-size: 32px; }
}

@media (max-width: 480px) {
  .sim-metrics {
    grid-template-columns: 1fr 1fr;
    gap: 10px;
  }
  .sim-metric-card { padding: 14px 16px; }
  .sim-metric-value { font-size: 20px; }
  .sim-panel { padding: 16px; }
}

/* Transitions for theme switch */
html {
  transition: background 0.3s ease;
}
.sim-header,
.sim-panel,
.sim-metric-card,
.sim-chart-card,
.sim-econ-card,
.sim-ups-info,
.sim-footer,
.sim-theme-btn,
.sim-season-btn,
.sim-api-note {
  transition: background 0.3s ease, border-color 0.3s ease, color 0.3s ease, box-shadow 0.3s ease;
}