@import url('https://fonts.googleapis.com/css2?family=Lora:ital,wght@0,400;0,600;0,700;1,400&family=Source+Sans+3:wght@300;400;500;600;700&display=swap');

:root {
  --bg:       #faf9f5;
  --bg2:      #f3f1eb;
  --card:     #ffffff;
  --border:   #ddd8cc;
  --grid:     #e8e4dc;
  --orange:   #e05c00;
  --orange2:  #f07a20;
  --blue:     #1a5fa8;
  --blue2:    #3b82c4;
  --teal:     #0d7c6e;
  --red:      #c0392b;
  --text:     #1c1a16;
  --text2:    #5a5548;
  --text3:    #8a8278;
  --muted:    #ccc8c0;
}

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

body {
  font-family: 'Source Sans 3', sans-serif;
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
}

/* ── GRID BACKGROUND ─────────────── */
.ca-grid-bg {
  position: fixed; inset: 0; pointer-events: none; z-index: 0;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 28px 28px;
  opacity: 0.55;
}

/* ── HEADER ──────────────────────── */
.ca-header {
  position: relative; z-index: 1;
  background: linear-gradient(135deg, #1a3a6a 0%, #1a5fa8 60%, #2e7dc9 100%);
  padding: 0; overflow: hidden; min-height: 320px;
  display: flex; align-items: center;
}

#caHeaderCanvas {
  position: absolute; inset: 0; width: 100%; height: 100%;
  opacity: 0.22; pointer-events: none;
}

.ca-header-inner {
  position: relative; z-index: 2;
  max-width: 960px; margin: 0 auto; padding: 60px 32px 48px;
}

.ca-dept { font-size: 0.7rem; letter-spacing: 0.2em; text-transform: uppercase; color: rgba(255,255,255,.6); margin-bottom: 18px; font-weight: 600; }

.ca-title {
  font-family: 'Lora', serif;
  font-size: clamp(2.8rem, 8vw, 5.5rem);
  font-weight: 700; line-height: 0.9;
  color: #fff;
}
.ca-title-sub { color: var(--orange2); font-size: 0.55em; display: block; margin-top: 6px; font-style: italic; }

.ca-tagline { margin-top: 16px; color: rgba(255,255,255,.7); font-size: 0.95rem; }

.ca-founders { display: flex; align-items: center; gap: 16px; margin-top: 24px; }
.ca-founder { display: flex; flex-direction: column; gap: 2px; }
.ca-f-date { font-size: 0.72rem; color: rgba(255,255,255,.5); }
.ca-f-name { font-family: 'Lora', serif; font-size: 1.1rem; font-weight: 700; color: #fff; }
.ca-founder-sep { font-family: 'Lora', serif; font-size: 1.5rem; color: var(--orange2); }

/* ── NAV ─────────────────────────── */
.ca-nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(250,249,245,.95); backdrop-filter: blur(8px);
  border-bottom: 2px solid var(--border);
  display: flex; flex-wrap: wrap; justify-content: center;
}
.ca-nav-a {
  padding: 11px 15px; font-size: 0.82rem; font-weight: 500;
  text-decoration: none; color: var(--text2);
  border-bottom: 2px solid transparent; transition: all .2s; white-space: nowrap;
}
.ca-nav-a:hover { color: var(--orange); border-color: var(--orange); }
.ca-nav-a.active { color: var(--orange); border-color: var(--orange); }

/* ── MAIN ────────────────────────── */
.ca-main {
  position: relative; z-index: 1;
  max-width: 960px; margin: 0 auto; padding: 48px 24px 80px;
  display: flex; flex-direction: column; gap: 52px;
}

/* ── SECTION ─────────────────────── */
.ca-section { opacity: 0; transform: translateY(24px); transition: opacity .5s, transform .5s; }
.ca-section.visible { opacity: 1; transform: translateY(0); }

.ca-sec-head {
  display: flex; align-items: center; gap: 12px;
  padding: 13px 20px; border-radius: 8px 8px 0 0; border-left: 5px solid transparent;
}
.ca-sec-head.orange { background: rgba(224,92,0,.07); border-color: var(--orange); }
.ca-sec-head.blue   { background: rgba(26,95,168,.07); border-color: var(--blue); }
.ca-sec-icon { font-size: 1.2rem; }
.ca-sec-head h2 { font-family: 'Lora', serif; font-size: 1.25rem; font-weight: 700; color: var(--text); }

.ca-sec-body {
  background: var(--card); border: 1px solid var(--border);
  border-top: none; border-radius: 0 0 8px 8px; padding: 26px;
  box-shadow: 0 2px 8px rgba(0,0,0,.04);
}
.ca-sec-body p { color: var(--text2); line-height: 1.85; font-size: 0.95rem; margin-bottom: 16px; }
.ca-sec-body p:last-child { margin-bottom: 0; }
.ca-sec-body strong { color: var(--text); }

/* ── TIMELINE ────────────────────── */
.ca-timeline { display: flex; flex-direction: column; gap: 10px; }
.ca-tl { display: flex; gap: 16px; }
.ca-tl-y { font-size: 0.75rem; font-weight: 700; color: var(--orange); width: 80px; flex-shrink: 0; text-align: right; padding-top: 3px; }
.ca-tl-c { flex: 1; background: var(--bg2); border: 1px solid var(--border); border-radius: 6px; padding: 10px 14px; font-size: 0.87rem; color: var(--text2); line-height: 1.7; }
.ca-tl-c strong { color: var(--text); }
.ca-tl-c em { color: var(--blue); font-style: italic; }

/* ── FORMULA BOX ─────────────────── */
.ca-formula-box {
  border-radius: 8px; padding: 16px 20px; margin: 14px 0; text-align: center;
}
.ca-formula-box.orange { background: rgba(224,92,0,.05); border: 1px solid rgba(224,92,0,.2); }
.ca-formula-box.blue   { background: rgba(26,95,168,.05); border: 1px solid rgba(26,95,168,.2); }
.ca-fb-label { font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: var(--text3); margin-bottom: 8px; }
.ca-fb-eq { font-family: 'Lora', serif; font-size: 1.05rem; color: var(--text); }
.ca-formula-box.orange .ca-fb-eq { color: var(--orange); }
.ca-formula-box.blue   .ca-fb-eq { color: var(--blue); }

/* ── LIMITS GRID ─────────────────── */
.ca-limits-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 14px; margin-top: 14px; }
.ca-lim-card { background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; padding: 16px; }
.ca-lim-card h4 { font-family: 'Lora', serif; font-size: 0.9rem; font-weight: 700; color: var(--blue); margin-bottom: 10px; }

/* ── FML LIST ────────────────────── */
.ca-fml-list { list-style: none; display: flex; flex-direction: column; gap: 6px; }
.ca-fml-list li { font-size: 0.84rem; color: var(--text2); font-family: Georgia, 'Times New Roman', serif; line-height: 1.6; padding-left: 14px; position: relative; }
.ca-fml-list li::before { content: '›'; position: absolute; left: 0; color: var(--orange); font-weight: 700; }
.ca-fml-list strong { color: var(--text); font-family: 'Source Sans 3', sans-serif; }

/* ── CANVAS WRAP ─────────────────── */
.ca-canvas-wrap { margin: 18px 0; text-align: center; }
#derivCanvas, #integCanvas {
  display: block; width: 100%; max-width: 560px; height: auto;
  border: 1px solid var(--border); border-radius: 8px;
  background: #fff; cursor: pointer; margin: 0 auto;
}
.ca-canvas-caption { font-size: 0.78rem; color: var(--text3); margin-top: 6px; font-style: italic; }

/* ── TABLES ──────────────────────── */
.ca-deriv-table, .ca-integ-table, .ca-taylor-table {
  border: 1px solid var(--border); border-radius: 8px; overflow: hidden; margin: 18px 0;
}
.ca-dt-head {
  display: grid; grid-template-columns: 2fr 2fr 1.2fr;
  padding: 9px 14px; background: var(--bg2);
  font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text3);
}
.ca-dt-row {
  display: grid; grid-template-columns: 2fr 2fr 1.2fr;
  padding: 8px 14px; border-top: 1px solid var(--border);
  font-size: 0.87rem; color: var(--text2); font-family: Georgia, serif;
  transition: background .15s;
}
.ca-dt-row:hover { background: rgba(26,95,168,.03); }
.ca-dt-row span:first-child { color: var(--orange); font-weight: 600; }
.ca-dt-row span:nth-child(2) { color: var(--blue); }

/* ── RULES GRID ──────────────────── */
.ca-rules-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 14px; }
.ca-rule-card { background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; padding: 16px; }
.ca-rule-card h4 { font-family: 'Lora', serif; font-size: 0.9rem; color: var(--orange); margin-bottom: 10px; }

/* ── TFA ─────────────────────────── */
.ca-tfa-parts { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 18px; }
.ca-tfa-part { background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; padding: 18px; }
.ca-tfa-n { font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: var(--orange); margin-bottom: 8px; }
.ca-tfa-part p { font-size: 0.87rem; color: var(--text2); margin: 0; }

.ca-tfa-example { background: rgba(26,95,168,.04); border: 1px solid rgba(26,95,168,.15); border-radius: 8px; padding: 18px 22px; }
.ca-tfa-example h4 { font-family: 'Lora', serif; font-size: 0.92rem; color: var(--blue); margin-bottom: 14px; }
.ca-tfa-steps { display: flex; flex-direction: column; gap: 10px; }
.ca-step { display: flex; align-items: center; gap: 12px; }
.ca-step-n { width: 26px; height: 26px; flex-shrink: 0; background: var(--blue); color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 0.75rem; font-weight: 700; }
.ca-step code { font-family: Georgia, serif; font-size: 0.95rem; color: var(--blue); flex: 1; }
.ca-step span { font-size: 0.82rem; color: var(--text3); }

/* ── TECHNIQUES ──────────────────── */
.ca-tech-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 14px; }
.ca-tech-card { background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; padding: 16px; }
.ca-tech-card h4 { font-family: 'Lora', serif; font-size: 0.87rem; font-weight: 700; color: var(--blue); margin-bottom: 8px; }
.ca-tech-formula { font-family: Georgia, serif; font-size: 0.87rem; color: var(--orange); background: rgba(224,92,0,.05); border: 1px solid rgba(224,92,0,.15); border-radius: 5px; padding: 8px 12px; margin-bottom: 8px; line-height: 1.6; }
.ca-tech-card p { font-size: 0.82rem; color: var(--text2); margin-bottom: 6px; line-height: 1.65; }

/* ── SERIES ──────────────────────── */
.ca-series-row { display: grid; grid-template-columns: repeat(3,1fr); gap: 14px; margin-bottom: 18px; }
.ca-serie-card { background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; padding: 16px; }
.ca-serie-card h4 { font-family: 'Lora', serif; font-size: 0.87rem; color: var(--orange); margin-bottom: 8px; font-weight: 700; }
.ca-se-fml { font-family: Georgia, serif; font-size: 0.88rem; color: var(--blue); margin-bottom: 8px; padding: 6px 10px; background: rgba(26,95,168,.05); border-radius: 4px; }
.ca-serie-card p { font-size: 0.82rem; color: var(--text2); margin: 0; line-height: 1.65; }

/* ── EDO ─────────────────────────── */
.ca-edo-types { display: grid; grid-template-columns: repeat(2,1fr); gap: 14px; }
.ca-edo-card { background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; padding: 18px; }
.ca-edo-card h4 { font-family: 'Lora', serif; font-size: 0.9rem; color: var(--blue); margin-bottom: 8px; font-weight: 700; }
.ca-edo-card p { font-size: 0.85rem; color: var(--text2); margin: 0; line-height: 1.7; }

/* ── FOOTER ──────────────────────── */
.ca-footer { position: relative; z-index: 1; border-top: 2px solid var(--border); background: var(--bg2); padding: 20px 32px; }
.ca-footer-inner { max-width: 960px; margin: 0 auto; display: flex; align-items: center; gap: 14px; font-size: 0.82rem; color: var(--text3); }
.ca-footer-int { font-family: 'Lora', serif; font-size: 1.6rem; color: var(--orange); }

/* ── RESPONSIVE ──────────────────── */
@media (max-width: 768px) {
  .ca-limits-grid, .ca-tech-grid, .ca-series-row, .ca-edo-types { grid-template-columns: 1fr; }
  .ca-rules-grid, .ca-tfa-parts { grid-template-columns: 1fr; }
  .ca-dt-head, .ca-dt-row { grid-template-columns: 2fr 2fr; }
  .ca-dt-row span:last-child, .ca-dt-head span:last-child { display: none; }
}