/* =============================================
   DESIGN TOKENS — exact match to sgoley.github.io / design.md
   ============================================= */
:root {
  color-scheme: dark;
  --font-sans: "Avenir Next", Avenir, "Segoe UI", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --bg:             #09090b;
  --bg-glow:        #161630;
  --panel:          #131317;
  --panel-soft:     #141418;
  --surface:        #0f0f12;
  --surface-raised: #1a1a20;
  --surface-muted:  #101015;

  --ink:            #f5f5f7;
  --prose-ink:      #d8d8de;
  --muted:          #a3a3ad;

  --line:           rgba(255, 255, 255, 0.10);
  --line-strong:    rgba(79, 143, 251, 0.45);

  --header-bg:      rgba(9, 9, 11, 0.84);
  --hero-bg:        linear-gradient(150deg, #181824 0%, #101015 100%);

  --accent:         #4f8ffb;
  --accent-2:       #55c4ff;
  --accent-bg:      rgba(79, 143, 251, 0.16);

  --code-bg:        #202026;
  --error:          #ffb4b4;
  --shadow-lg:      0 16px 36px rgba(0, 0, 0, 0.45);

  /* App-specific heatmap color aliases */
  --heatmap-neg-deep: #8c3f3f;
  --heatmap-neg:      #b85a5a;
  --heatmap-neutral:  #ebdcd0;
  --heatmap-pos-soft: #d5e2c1;
  --heatmap-pos:      #8d9f63;
  --heatmap-pos-deep: #315f32;
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg:             #f6f7fb;
  --bg-glow:        #e7ecff;
  --panel:          #ffffff;
  --panel-soft:     #ffffff;
  --surface:        #f5f6fb;
  --surface-raised: #ffffff;
  --surface-muted:  #ffffff;

  --ink:            #171923;
  --prose-ink:      #2c3140;
  --muted:          #4d566d;

  --line:           rgba(23, 25, 35, 0.12);
  --line-strong:    rgba(47, 111, 223, 0.45);

  --header-bg:      rgba(246, 247, 251, 0.90);
  --hero-bg:        linear-gradient(150deg, #ffffff 0%, #eef2ff 100%);

  --accent:         #2f6fdf;
  --accent-2:       #1f8fd8;
  --accent-bg:      rgba(47, 111, 223, 0.14);

  --code-bg:        #e7ebf8;
  --error:          #9c2525;
  --shadow-lg:      0 16px 36px rgba(17, 26, 46, 0.15);
}

/* =============================================
   RESET & BASE
   ============================================= */
*, *::before, *::after {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-sans);
  background: radial-gradient(circle at 0% 0%, var(--bg-glow), transparent 32%), var(--bg);
  color: var(--ink);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  padding-top: 60px; /* space for sticky header */
}

button {
  font: inherit;
}

/* =============================================
   STICKY HEADER / NAV
   ============================================= */
.app-navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.nav-wrap {
  width: min(1480px, calc(100% - 2.4rem));
  margin: 0 auto;
  display: flex;
  align-items: center;
  min-height: 60px;
  gap: 1rem;
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.logo-icon {
  font-size: 18px;
}

.logo-text {
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.01em;
}

/* Tab navigation as pill links (right-aligned) */
.nav-tabs {
  display: flex;
  gap: 0.4rem;
  margin-left: auto;
  flex-wrap: wrap;
}

.nav-tab {
  background: none;
  border: 1px solid transparent;
  border-radius: 999px;
  color: var(--muted);
  padding: 0.35rem 0.8rem;
  font-family: var(--font-sans);
  font-size: 13.5px;
  font-weight: 500;
  cursor: pointer;
  transition: 120ms ease;
  white-space: nowrap;
}

.nav-tab:hover {
  color: var(--ink);
  border-color: var(--line);
}

.nav-tab.active {
  color: var(--ink);
  border-color: var(--line-strong);
  background: var(--accent-bg);
}

/* Theme toggle button */
.theme-toggle {
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
  width: 2.2rem;
  height: 2.2rem;
  padding: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.05rem;
  line-height: 1;
  cursor: pointer;
  transition: 120ms ease;
  flex-shrink: 0;
}

.theme-toggle:hover {
  border-color: var(--line-strong);
  background: var(--accent-bg);
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--line-strong);
  outline-offset: 2px;
}

.theme-toggle-icon {
  display: inline-block;
  transform: translateY(-1px);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* =============================================
   LAYOUT SHELL
   ============================================= */
.layout {
  width: min(1480px, calc(100% - 2.4rem));
  margin: 0 auto;
  padding: 1.5rem 0 2rem;
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 1.5rem;
}

/* =============================================
   SIDEBAR / COPY PANEL
   ============================================= */
.copy {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 1.5rem 1.25rem;
  align-self: start;
}

.header-group {
  margin-bottom: 1rem;
}

/* =============================================
   TYPOGRAPHY
   ============================================= */
.eyebrow {
  display: block;
  font-size: 0.76rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.13em;
  color: var(--accent-2);
  margin: 0 0 0.4rem;
}

h1 {
  margin: 0;
  font-family: var(--font-sans);
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  line-height: 1.2;
  font-weight: 700;
  color: var(--ink);
}

h2 {
  font-family: var(--font-sans);
  font-size: clamp(1.1rem, 2vw, 1.4rem);
  margin: 0 0 0.75rem;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.2;
}

h3 {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.2;
}

.intro {
  margin: 0 0 1.25rem;
  font-size: 0.95rem;
  line-height: 1.65;
  color: var(--prose-ink);
}

.body-text {
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--prose-ink);
  margin-bottom: 1rem;
}

.note {
  margin-top: 0.75rem;
  color: var(--muted);
  font-size: 0.8rem;
  line-height: 1.5;
}

/* =============================================
   LEGEND
   ============================================= */
.legend {
  margin-bottom: 1.5rem;
  border-top: 1px solid var(--line);
  padding-top: 1rem;
}

.legend h2 {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 0.5rem;
}

.bar {
  height: 12px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: linear-gradient(
    90deg,
    var(--heatmap-neg-deep) 0%,
    var(--heatmap-neg) 25%,
    var(--heatmap-neutral) 50%,
    var(--heatmap-pos-soft) 65%,
    var(--heatmap-pos) 80%,
    var(--heatmap-pos-deep) 100%
  );
}

.ticks {
  display: flex;
  justify-content: space-between;
  margin-top: 0.38rem;
  font-size: 0.72rem;
  font-weight: 500;
  font-family: var(--font-mono);
  color: var(--muted);
}

/* =============================================
   STATS CARDS
   ============================================= */
.stats {
  border-top: 1px solid var(--line);
  padding-top: 1rem;
  margin-bottom: 1rem;
  display: grid;
  gap: 0.5rem;
}

.stats h2 {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 0.25rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.card {
  background: var(--surface-raised);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.62rem 0.875rem;
}

.card h3 {
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.card p {
  margin: 0.25rem 0 0;
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent-2);
}

/* =============================================
   CHART CANVAS WRAP
   ============================================= */
.chart-wrap {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 20px;
  overflow: hidden;
  padding: 8px;
}

.axis-title {
  position: absolute;
  z-index: 2;
  background: var(--accent-bg);
  border: 1px solid var(--line-strong);
  color: var(--accent-2);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  text-transform: uppercase;
}

.axis-title.top {
  top: 12px;
  left: 84px;
}

.axis-title.left {
  transform: rotate(-90deg);
  transform-origin: left top;
  top: 840px;
  left: 16px;
}

canvas {
  width: 100%;
  height: auto;
  display: block;
}

/* =============================================
   TOOLTIP
   ============================================= */
.tooltip {
  position: absolute;
  pointer-events: none;
  z-index: 130;
  background: var(--panel);
  color: var(--ink);
  border-radius: 12px;
  padding: 0.62rem 0.875rem;
  font-size: 0.82rem;
  line-height: 1.45;
  min-width: 200px;
  border: 1px solid var(--line-strong);
  box-shadow: var(--shadow-lg);
  transition: opacity 120ms ease;
}

.tooltip strong {
  font-family: var(--font-sans);
  font-size: 0.88rem;
  font-weight: 700;
  display: block;
  margin-bottom: 0.25rem;
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.25rem;
  color: var(--ink);
}

.tooltip .return-val {
  font-size: 0.88rem;
  font-weight: 700;
  font-family: var(--font-mono);
}

.tooltip .return-val.positive {
  color: #6db87d;
}

.tooltip .return-val.negative {
  color: #e38888;
}

/* =============================================
   RESPONSIVENESS
   ============================================= */
@media (max-width: 1180px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .axis-title.left {
    top: 750px;
  }
}

@media (max-width: 640px) {
  body {
    padding-top: 100px;
  }

  .app-navbar {
    height: auto;
  }

  .nav-wrap {
    flex-direction: column;
    align-items: stretch;
    padding: 0.6rem 1rem;
    gap: 0.5rem;
    min-height: auto;
  }

  .navbar-brand {
    justify-content: space-between;
  }

  .nav-tabs {
    margin-left: 0;
    justify-content: center;
  }

  .nav-tab {
    padding: 0.35rem 0.6rem;
    font-size: 12px;
  }
}