/* MarginArc Theme — Dark (default) + Light mode */

:root {
  --bg: #050d1a;
  --bg-secondary: #0a1628;
  --bg-card: rgba(10,22,40,0.6);
  --bg-card-solid: #0a1628;
  --bg-card-hover: rgba(10,22,40,0.8);
  --bg-input: rgba(255,255,255,0.04);
  --nav-bg: rgba(5,13,26,0.92);
  --nav-border: rgba(255,255,255,0.06);
  --text: #b0bec5;
  --text-heading: #ffffff;
  --text-emphasis: #e2e8f0;
  --text-muted: #64748b;
  --text-faint: #475569;
  --accent: #0ea5a5;
  --accent-light: #14d4d4;
  --accent-bg: rgba(14,165,165,0.08);
  --accent-border: rgba(14,165,165,0.15);
  --border: rgba(255,255,255,0.06);
  --border-strong: rgba(255,255,255,0.12);
  --shadow-card: 0 4px 20px rgba(0,0,0,0.3);
  --glow: rgba(14,165,165,0.06);
  --grid-line: rgba(14,165,165,0.03);
  --code-bg: rgba(10,22,40,0.8);
  --success: #34d399;
  --success-bg: rgba(52,211,153,0.08);
  --error: #ef4444;
  --error-bg: rgba(239,68,68,0.08);
  --warning: #fbbf24;
  --warning-bg: rgba(251,191,36,0.08);
  --btn-primary-text: #050d1a;
  --btn-secondary-bg: rgba(255,255,255,0.06);
  --btn-secondary-text: #e2e8f0;
  --btn-secondary-border: rgba(255,255,255,0.12);
  --gradient-accent: linear-gradient(135deg, #0ea5a5, #0fbeac);
  --invert-logo: 0;
}

[data-theme="light"] {
  --bg: #ffffff;
  --bg-secondary: #f4f6f8;
  --bg-card: #f8fafc;
  --bg-card-solid: #f8fafc;
  --bg-card-hover: #eef2f7;
  --bg-input: #ffffff;
  --nav-bg: rgba(255,255,255,0.95);
  --nav-border: rgba(0,0,0,0.1);
  --text: #334155;
  --text-heading: #0f172a;
  --text-emphasis: #1e293b;
  --text-muted: #64748b;
  --text-faint: #94a3b8;
  --accent: #0d9494;
  --accent-light: #0ea5a5;
  --accent-bg: rgba(14,165,165,0.07);
  --accent-border: rgba(14,165,165,0.25);
  --border: rgba(0,0,0,0.12);
  --border-strong: rgba(0,0,0,0.18);
  --shadow-card: 0 2px 12px rgba(0,0,0,0.08);
  --glow: rgba(14,165,165,0.05);
  --grid-line: rgba(14,165,165,0.06);
  --code-bg: #f1f5f9;
  --success: #059669;
  --success-bg: rgba(5,150,105,0.08);
  --error: #dc2626;
  --error-bg: rgba(220,38,38,0.08);
  --warning: #d97706;
  --warning-bg: rgba(217,119,6,0.08);
  --btn-primary-text: #ffffff;
  --btn-secondary-bg: rgba(0,0,0,0.05);
  --btn-secondary-text: #1e293b;
  --btn-secondary-border: rgba(0,0,0,0.15);
  --gradient-accent: linear-gradient(135deg, #0d9494, #0ea89e);
  --invert-logo: 1;
}

/* Logo swap: hide dark-mode logos in light mode and vice versa */
[data-theme="light"] img.logo-dark { display: none !important; }
[data-theme="light"] img.logo-light { display: initial !important; }
img.logo-light { display: none !important; }

/* Academy logo still uses invert (no dark asset) */
[data-theme="light"] img[src*="academy-logo"] {
  filter: invert(1) brightness(0.15);
}

/* SVG color overrides for light mode diagrams */
[data-theme="light"] svg text[fill="#e2e8f0"],
[data-theme="light"] svg tspan[fill="#e2e8f0"] { fill: #1e293b; }
[data-theme="light"] svg text[fill="#b0bec5"],
[data-theme="light"] svg tspan[fill="#b0bec5"] { fill: #475569; }
[data-theme="light"] svg text[fill="#fff"],
[data-theme="light"] svg text[fill="#ffffff"],
[data-theme="light"] svg tspan[fill="#fff"],
[data-theme="light"] svg tspan[fill="#ffffff"] { fill: #0f172a; }
[data-theme="light"] svg rect[fill="#050d1a"] { fill: #ffffff; }
[data-theme="light"] svg rect[fill="#0a1628"] { fill: #f8fafc; }
[data-theme="light"] svg line[stroke="#1a2a44"] { stroke: #e2e8f0; }
[data-theme="light"] svg line[stroke="rgba(255,255,255,0.06)"] { stroke: rgba(0,0,0,0.08); }
[data-theme="light"] svg [stroke="#475569"] { stroke: #94a3b8; }
[data-theme="light"] svg [stroke="#64748b"] { stroke: #94a3b8; }
[data-theme="light"] svg [fill="#64748b"] { fill: #94a3b8; }
[data-theme="light"] svg [fill="#475569"] { fill: #64748b; }
[data-theme="light"] svg [fill="#0a1628"] { fill: #f8fafc; }
[data-theme="light"] svg [fill="#050d1a"] { fill: #ffffff; }

/* ── SVG chart contrast fixes for light mode ── */
/* Node/box backgrounds: --bg-secondary/--bg-card/--bg-input are near-white in light mode */
[data-theme="light"] svg [fill="var(--bg-secondary)"] { fill: #dde3ec; }
[data-theme="light"] svg [fill="var(--bg-card)"] { fill: #dde3ec; }
[data-theme="light"] svg [fill="var(--bg-input)"] { fill: #e8ecf2; }
/* Area/bar fills: the -bg variants are <10% opacity in light mode — boost them */
[data-theme="light"] svg [fill="var(--accent-bg)"] { fill: rgba(13,148,148,0.16); }
[data-theme="light"] svg [fill="var(--accent-bg-subtle)"],
[data-theme="light"] svg [fill*="accent-bg-subtle"] { fill: rgba(13,148,148,0.10); }
[data-theme="light"] svg [fill="var(--error-bg)"] { fill: rgba(220,38,38,0.13); }
[data-theme="light"] svg [fill="var(--success-bg)"] { fill: rgba(5,150,105,0.13); }
[data-theme="light"] svg [fill="var(--warning-bg)"] { fill: rgba(217,119,6,0.13); }
/* Grid lines & connectors: --border is rgba(0,0,0,0.12), too faint for chart lines */
[data-theme="light"] svg [stroke="var(--border)"] { stroke: rgba(0,0,0,0.22); }
[data-theme="light"] svg [stroke="var(--bg-input)"] { stroke: rgba(0,0,0,0.15); }
/* Accent borders used as fills */
[data-theme="light"] svg [fill="var(--accent-border)"] { fill: rgba(13,148,148,0.30); }
[data-theme="light"] svg [fill="var(--border)"] { fill: rgba(0,0,0,0.18); }
[data-theme="light"] svg [fill="var(--border-strong)"] { fill: rgba(0,0,0,0.22); }
/* Gradient stops that wash out */
[data-theme="light"] svg [stop-color="var(--border)"] { stop-color: rgba(0,0,0,0.18); }
[data-theme="light"] svg [stop-color="var(--bg-input)"] { stop-color: #e8ecf2; }

/* Theme toggle button */
.theme-toggle {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border-strong);
  background: var(--bg-card-solid);
  color: var(--text-emphasis);
  cursor: pointer;
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-card);
  transition: background 0.2s, border-color 0.2s, transform 0.15s;
  padding: 0;
}
.theme-toggle:hover {
  transform: scale(1.08);
  border-color: var(--accent);
}
.theme-toggle svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: block; }
[data-theme="light"] .theme-toggle .icon-sun { display: block; }
[data-theme="light"] .theme-toggle .icon-moon { display: none; }