:root {
  --ubam-blue: #29abe2;
  --ubam-blue-dark: #1e8fc4;
  --ubam-green: #7ac143;
  --ubam-green-dark: #5fa032;
  --ink: #2c3e50;
  --text: #58595b;
  --text-light: #74777a;
  --orange: #ff6b35;
  --yellow: #ffd93d;
  --purple: #9b59b6;
  --paper: #fff;
  --shadow: rgba(41, 171, 226, .2);
  --radius: 16px;
  --radius-sm: 10px;
}

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

body {
  min-height: 100vh;
  overflow-x: hidden;
  background: linear-gradient(180deg, #29abe2 0%, #7dd3f0 60%, #7ac143 60%, #5fa032 100%);
  color: var(--text);
  font-family: 'Fredoka', sans-serif;
}

.sky-bg { position: fixed; inset: 0; z-index: 0; overflow: hidden; pointer-events: none; }

.sun {
  position: absolute;
  top: 42px;
  right: 7vw;
  width: 88px;
  height: 88px;
  background: var(--yellow);
  border: 4px solid #f39c12;
  border-radius: 50%;
  box-shadow: 0 0 40px rgba(255, 217, 61, .6);
  animation: pulse 3s ease-in-out infinite;
}

@keyframes pulse { 50% { transform: scale(1.06); } }

.cloud { position: absolute; height: 38px; background: rgba(255,255,255,.9); border: 3px solid #d5dbdb; border-radius: 50px; }
.cloud::before, .cloud::after { position: absolute; content: ''; background: inherit; border: inherit; border-radius: 50%; }
.cloud-1 { top: 84px; left: 10%; width: 100px; animation: drift 20s linear infinite; }
.cloud-1::before { top: -27px; left: 13px; width: 50px; height: 50px; }
.cloud-1::after { top: -16px; right: 9px; width: 58px; height: 40px; }
.cloud-2 { top: 180px; left: 54%; width: 78px; animation: drift 26s linear infinite reverse; }
.cloud-2::before { top: -20px; left: 9px; width: 40px; height: 40px; }
.cloud-2::after { top: -13px; right: 8px; width: 44px; height: 33px; }
.cloud-3 { top: 36px; left: 70%; width: 66px; animation: drift 18s linear infinite; }
.cloud-3::before { top: -18px; left: 7px; width: 35px; height: 35px; }
.cloud-3::after { top: -11px; right: 4px; width: 39px; height: 29px; }
@keyframes drift { to { transform: translateX(32px); } }

.site-header, .layout, .footer { position: relative; z-index: 1; max-width: 1400px; margin-inline: auto; }

.site-header { padding: 14px 20px 8px; }
.back-link { display: inline-block; margin-bottom: 10px; color: rgba(255,255,255,.92); font-size: .85rem; font-weight: 600; text-decoration: none; }
.back-link:hover { text-decoration: underline; }
.site-header-inner { display: flex; align-items: center; gap: 14px; }
.site-header-logo { width: 72px; height: auto; opacity: .92; filter: drop-shadow(0 1px 3px rgba(0,0,0,.14)); }
.site-header-kicker { margin-bottom: 2px; color: rgba(255,255,255,.85); font-size: .75rem; font-weight: 600; letter-spacing: .04em; text-shadow: 0 1px 2px rgba(0,0,0,.15); text-transform: uppercase; }
h1 { color: #fff; font-size: 1.65rem; letter-spacing: -.3px; line-height: 1.15; text-shadow: 0 2px 4px rgba(0,0,0,.18); }
.subtitle { margin-top: 2px; color: rgba(255,255,255,.9); font-family: 'Patrick Hand', cursive; font-size: 1rem; text-shadow: 0 1px 2px rgba(0,0,0,.12); }

.layout { display: grid; grid-template-columns: minmax(0, 1fr) 320px; grid-template-rows: auto auto auto auto; gap: 20px; padding: 0 20px 40px; }
.canvas-section { grid-column: 1; grid-row: 1; }
.controls-panel { grid-column: 2; grid-row: 1 / 3; }
.stats-panel { grid-column: 1; grid-row: 2; }
.formulas-panel { grid-column: 1 / -1; grid-row: 3; }
.graph-panel { grid-column: 1 / -1; grid-row: 4; }

.canvas-section, .controls-panel, .stats-panel, .formulas-panel, .graph-panel { padding: 20px; background: var(--paper); border: 3px solid var(--ubam-blue); border-radius: var(--radius); box-shadow: 6px 6px 0 var(--shadow); }
h2 { display: flex; align-items: center; gap: 8px; margin-bottom: 16px; color: var(--ink); font-size: 1.3rem; }

.canvas-toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-bottom: 12px; }
#sim-canvas { display: block; width: 100%; height: auto; background: #eef6fb; border: 3px solid var(--ink); border-radius: var(--radius-sm); cursor: grab; touch-action: none; }
#sim-canvas.dragging { cursor: grabbing; }
.canvas-hint { margin-top: 8px; color: var(--text-light); font-family: 'Patrick Hand', cursive; font-size: .95rem; }
.canvas-legend { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 8px; color: var(--text-light); font-size: .85rem; }
.canvas-legend span { display: flex; align-items: center; gap: 6px; }
.dot { display: inline-block; width: 12px; height: 12px; border: 2px solid var(--ink); border-radius: 50%; }
.dot-incident { background: var(--yellow); }
.dot-reflected { background: var(--purple); }
.dot-image { background: var(--orange); }
.dot-normal { background: #fff; }

.btn-mode { border-color: var(--ink); background: #fff; color: var(--ink); }
.btn-mode.is-active { border-color: var(--ubam-blue-dark); background: var(--ubam-blue); color: #fff; }
.toggle-label.hidden { display: none; }

.btn { padding: 10px 18px; border: 3px solid var(--ubam-blue-dark); border-radius: var(--radius-sm); box-shadow: 3px 3px 0 var(--shadow); cursor: pointer; font-family: inherit; font-size: .95rem; font-weight: 600; transition: transform .1s, box-shadow .1s; }
.btn:hover:not(:disabled) { transform: translate(-1px, -1px); box-shadow: 4px 4px 0 var(--shadow); }
.btn:active:not(:disabled) { transform: translate(2px, 2px); box-shadow: 1px 1px 0 var(--shadow); }
.btn:disabled { cursor: not-allowed; opacity: .5; }
.btn-primary { border-color: var(--ubam-blue-dark); background: var(--ubam-blue); color: #fff; }
.btn-primary:hover:not(:disabled) { background: var(--ubam-blue-dark); }
.btn-secondary { border-color: var(--ubam-green-dark); background: var(--ubam-green); color: #fff; }
.toggle-label { display: flex; align-items: center; gap: 6px; cursor: pointer; font-size: .85rem; user-select: none; }
.toggle-label input { width: 18px; height: 18px; accent-color: var(--ubam-green); }

.control-group { margin-bottom: 20px; }
.control-group.hidden { display: none; }
.control-group label { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-bottom: 8px; color: var(--ink); font-size: .93rem; font-weight: 600; }
.value-display { min-width: 80px; padding: 2px 8px; border: 2px solid var(--ubam-blue); border-radius: 8px; background: rgba(41,171,226,.14); color: var(--ubam-blue-dark); font-size: .83rem; text-align: center; }
input[type="range"] { width: 100%; height: 10px; appearance: none; outline: none; border: 2px solid var(--ink); border-radius: 6px; background: #e8e8e8; }
input[type="range"]::-webkit-slider-thumb { width: 24px; height: 24px; appearance: none; border: 3px solid var(--ubam-green-dark); border-radius: 50%; background: var(--ubam-green); cursor: grab; }
input[type="range"]::-moz-range-thumb { width: 18px; height: 18px; border: 3px solid var(--ubam-green-dark); border-radius: 50%; background: var(--ubam-green); cursor: grab; }

.select-input {
  width: 100%;
  padding: 8px 10px;
  border: 2px solid var(--ink);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--ink);
  font-family: inherit;
  font-size: .9rem;
  font-weight: 600;
  cursor: pointer;
}

.tip-box { padding: 12px; border: 2px solid #f39c12; border-radius: var(--radius-sm); background: #fff3cd; color: var(--ink); font-size: .85rem; line-height: 1.4; }

.stats-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(155px, 1fr)); gap: 12px; }
.stat-card { padding: 14px; border: 2px solid var(--ink); border-radius: var(--radius-sm); background: #f8f9fa; text-align: center; transition: transform .15s; }
.stat-card:hover { transform: scale(1.02); }
.stat-card.highlight { border-color: var(--ubam-green); background: linear-gradient(135deg, rgba(41,171,226,.12), rgba(122,193,67,.18)); }
.stat-card.alert { border-color: var(--orange); background: linear-gradient(135deg, rgba(255,107,53,.16), rgba(255,217,61,.22)); }
.stat-icon { margin-bottom: 4px; font-size: 1.5rem; }
.stat-label { margin-bottom: 4px; color: var(--text-light); font-size: .74rem; line-height: 1.2; }
.stat-value { color: var(--ink); font-size: 1.05rem; font-weight: 700; font-variant-numeric: tabular-nums; }

.formulas-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 16px; }
.formula-card { padding: 16px; border: 2px solid var(--ubam-blue); border-radius: var(--radius-sm); background: rgba(41,171,226,.06); }
.formula-card h3 { margin-bottom: 8px; color: var(--ubam-blue-dark); font-size: 1rem; }
.formula { margin-bottom: 8px; padding: 10px; border: 2px dashed var(--ubam-blue); border-radius: 8px; background: #fff; color: var(--ink); font-family: 'Patrick Hand', cursive; font-size: 1.1rem; text-align: center; }
.formula-calc { margin-bottom: 8px; color: var(--ubam-green-dark); font-size: .95rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.formula-desc { color: var(--text-light); font-size: .8rem; line-height: 1.4; }

.graphs-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.graph-box { padding: 12px; border: 2px solid var(--ink); border-radius: var(--radius-sm); background: #fafafa; }
.graph-box h3 { margin-bottom: 8px; color: var(--ink); font-size: .9rem; text-align: center; }
.graph-box canvas { display: block; width: 100%; height: auto; border-radius: 6px; }

.footer { margin-top: 8px; padding: 18px 16px 24px; border-top: 4px solid var(--ubam-green); background: #fff; color: var(--text-light); font-size: .85rem; text-align: center; }
.footer-logo { display: block; max-width: 96px; height: auto; margin: 0 auto 10px; opacity: .9; }
.footer-school { margin-top: 4px; color: var(--text); font-size: .86rem; font-weight: 600; }

@media (max-width: 1100px) {
  .layout { grid-template-columns: 1fr; grid-template-rows: auto; }
  .canvas-section, .controls-panel, .stats-panel, .formulas-panel, .graph-panel { grid-column: 1; grid-row: auto; }
  .graphs-row { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  .site-header { padding-inline: 14px; }
  .layout { padding-inline: 14px; }
  .site-header-logo { width: 62px; }
  h1 { font-size: 1.3rem; }
  .subtitle { font-size: .9rem; }
  .canvas-toolbar { justify-content: center; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .formulas-grid { grid-template-columns: 1fr; }
  .footer-logo { max-width: 88px; }
}