/* ============================================================
   theme.css — Shared paper/ink theme for CS demo suite
   Fonts: IBM Plex Mono + Epilogue (loaded by each page)
   ============================================================ */

/* ── Variables — Light mode (default) ── */
:root {
  --bg:        #f5f0e8;
  --paper:     #faf7f2;
  --ink:       #1a1208;
  --muted:     #8a7a60;
  --border:    #d4c9b0;
  --accent:    #e85d04;
  --accent2:   #2563eb;
  --accent3:   #16a34a;
  --accent4:   #9333ea;
  --accent5:   #dc2626;
  --accent6:   #0891b2;
  --accent7:   #ca8a04;
  --warn:      #dc2626;
  --slot-empty: #ede9df;
  --slot-fill:  #fff8ee;
  --mono:      'IBM Plex Mono', monospace;
  --display:   'Epilogue', sans-serif;
  --shadow:    0 2px 8px rgba(26,18,8,0.10);
  --shadow-lg: 0 6px 24px rgba(26,18,8,0.14);
  /* nav-specific tokens */
  --nav-bg:      #1a1208;
  --nav-border:  #3a2e1a;
  --nav-divider: #2a1e10;
  --nav-muted:   #8a7a60;
  --nav-active:  #3a2e1a;
  --nav-text:    #f5f0e8;
}

/* ── Variables — Dark mode ── */
html.dark {
  --bg:        #0f1117;
  --paper:     #1a1d27;
  --ink:       #e8eaf0;
  --muted:     #8892a4;
  --border:    #2e3347;
  --accent:    #ff7a35;
  --accent2:   #4d8ef8;
  --accent3:   #34c76e;
  --accent4:   #b06af5;
  --accent5:   #f05252;
  --accent6:   #22b8d4;
  --accent7:   #e8a020;
  --warn:      #f05252;
  --slot-empty: #1e2230;
  --slot-fill:  #22242e;
  --shadow:    0 2px 8px rgba(0,0,0,0.40);
  --shadow-lg: 0 6px 24px rgba(0,0,0,0.55);
  /* nav tokens stay dark in both modes — nav is always dark */
  --nav-bg:      #0a0c12;
  --nav-border:  #1e2230;
  --nav-divider: #141720;
  --nav-muted:   #5a6480;
  --nav-active:  #1e2230;
  --nav-text:    #c8d0e0;
}

/* ── Dark mode: invert canvas backgrounds ── */
html.dark canvas { filter: brightness(0.92); }
html.dark .java-snippet { background: #0a0c12; }
html.dark input[type="text"],
html.dark input[type="number"],
html.dark select { background: #0f1117; color: var(--ink); border-color: var(--border); }
html.dark .code-block { background: #0a0c12; }
html.dark .log-box,
html.dark .output-log,
html.dark .sim-output,
html.dark .trace-log { background: #0a0c12; }
html.dark .viz-canvas-wrap,
html.dark .chart-wrap { background: #13151e; }
/* Fix hardcoded white canvas backgrounds in demos */
html.dark .canvas-wrap { background: #13151e; }

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

/* ── Base ── */
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--display);
  min-height: 100vh;
  transition: background 0.25s, color 0.25s;
}

/* Ruled-paper texture */
body::before {
  content: '';
  position: fixed; inset: 0;
  background-image: repeating-linear-gradient(
    0deg, transparent, transparent 28px,
    rgba(180,160,120,0.07) 28px, rgba(180,160,120,0.07) 29px
  );
  pointer-events: none;
  z-index: 0;
}
html.dark::before {
  background-image: repeating-linear-gradient(
    0deg, transparent, transparent 28px,
    rgba(255,255,255,0.02) 28px, rgba(255,255,255,0.02) 29px
  );
}

/* ── Site navigation ── */
.site-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  background: var(--nav-bg);
  border-bottom: 2px solid var(--nav-border);
  display: flex;
  align-items: stretch;
  height: 42px;
  overflow-x: auto;
  scrollbar-width: none;
}
.site-nav::-webkit-scrollbar { display: none; }

.site-nav a {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 0 14px;
  font-family: var(--mono);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--nav-muted);
  text-decoration: none;
  white-space: nowrap;
  border-right: 1px solid var(--nav-divider);
  transition: background 0.12s, color 0.12s;
  flex-shrink: 0;
}
.site-nav a:hover  { background: var(--nav-divider); color: var(--nav-text); }
.site-nav a.active { background: var(--nav-active); color: var(--nav-text); border-bottom: 2px solid var(--accent); }
.site-nav .nav-icon { font-size: 0.9rem; }
.site-nav .nav-home {
  padding: 0 16px;
  border-right: 2px solid var(--nav-border);
  color: var(--accent);
  letter-spacing: 0.1em;
}
.site-nav .nav-home:hover { background: var(--nav-divider); }

/* lang-toggle inside nav */
.site-nav .lang-toggle {
  position: static;
  margin: auto 0 auto auto;
  border-radius: 0;
  box-shadow: none;
  height: 100%;
  border: none;
  border-left: 1px solid var(--nav-divider);
}
.site-nav .lang-btn {
  height: 100%;
  border-radius: 0;
  border: none;
  border-right: 1px solid var(--nav-divider);
  background: transparent;
  color: var(--nav-muted);
  font-family: var(--mono);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 0 13px;
  cursor: pointer;
  transition: all 0.15s;
}
.site-nav .lang-btn:last-child { border-right: none; }
.site-nav .lang-btn.active     { background: var(--nav-active); color: var(--nav-text); }
.site-nav .lang-btn:not(.active):hover { background: var(--nav-divider); color: var(--nav-text); }

/* dark-mode toggle button in nav */
.dark-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 100%;
  background: transparent;
  border: none;
  border-left: 1px solid var(--nav-divider);
  color: var(--nav-muted);
  cursor: pointer;
  font-size: 1rem;
  transition: background 0.12s, color 0.12s;
  flex-shrink: 0;
}
.dark-btn:hover { background: var(--nav-divider); color: var(--nav-text); }

/* ── Page wrapper ── */
.app {
  position: relative; z-index: 1;
  max-width: 1300px;
  margin: 0 auto;
  padding: 70px 24px 60px;
}

/* ── Header ── */
header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 28px;
  flex-wrap: wrap; gap: 12px;
  border-bottom: 2px solid var(--ink);
  padding-bottom: 18px;
}

.title-block h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1;
  color: var(--ink);
}

.title-block h1 span { color: var(--accent); }

.subtitle {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--muted);
  margin-top: 5px;
  letter-spacing: 0.06em;
}

.tag {
  font-family: var(--mono);
  font-size: 0.65rem;
  border: 1.5px solid var(--ink);
  padding: 3px 10px;
  letter-spacing: 0.08em;
  font-weight: 700;
}

/* ── Two-column layout ── */
.layout {
  display: grid;
  grid-template-columns: 290px 1fr;
  gap: 20px;
  align-items: start;
}

@media (max-width: 860px) {
  .layout { grid-template-columns: 1fr; }
}

.right-col { display: flex; flex-direction: column; gap: 16px; }

/* ── Panel ── */
.panel {
  background: var(--paper);
  border: 1.5px solid var(--border);
  border-radius: 4px;
  padding: 20px;
  box-shadow: var(--shadow);
}

.panel-title {
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
}

.panel-title::after {
  content: ''; flex: 1; height: 1px; background: var(--border);
}

.divider { height: 1.5px; background: var(--border); margin: 16px 0; }

/* ── Form elements ── */
label {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--muted);
  display: block;
  margin-bottom: 5px;
  letter-spacing: 0.04em;
}

.input-group  { margin-bottom: 14px; }
.input-row    { display: flex; gap: 8px; margin-bottom: 10px; }

input[type="text"],
input[type="number"],
select {
  background: #fff;
  border: 1.5px solid var(--border);
  border-radius: 3px;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.85rem;
  padding: 8px 11px;
  width: 100%;
  outline: none;
  transition: border-color 0.15s;
}

input:focus, select:focus { border-color: var(--accent); }
input[type="number"]::-webkit-inner-spin-button { -webkit-appearance: none; }

input[type="range"] {
  -webkit-appearance: none;
  width: 100%; height: 4px;
  border-radius: 2px;
  background: var(--border);
  outline: none;
  margin-top: 4px;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--ink);
  cursor: pointer;
  border: 2px solid var(--bg);
  box-shadow: 0 1px 4px rgba(26,18,8,0.2);
}

/* ── Buttons ── */
.btn {
  border: none;
  border-radius: 3px;
  cursor: pointer;
  font-family: var(--display);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 8px 14px;
  transition: all 0.12s;
  white-space: nowrap;
  letter-spacing: 0.01em;
}

.btn-primary   { background: var(--accent);  color: #fff; }
.btn-primary:hover   { background: #c44d03; }

.btn-secondary { background: var(--ink);     color: #fff; }
.btn-secondary:hover { background: #3a2e1a; }

.btn-danger    { background: var(--warn);    color: #fff; }
.btn-danger:hover    { background: #b91c1c; }

.btn-success   { background: var(--accent3); color: #fff; }
.btn-success:hover   { background: #15803d; }

.btn-purple    { background: var(--accent4); color: #fff; }
.btn-purple:hover    { background: #7e22ce; }

.btn-ghost {
  background: transparent;
  border: 1.5px solid var(--border);
  color: var(--ink);
}
.btn-ghost:hover { border-color: var(--ink); }

.btn-full  { width: 100%; margin-bottom: 8px; }
.btn-group { display: flex; gap: 8px; flex-wrap: wrap; }

/* ── Mode / segment tabs ── */
.mode-tabs { display: flex; margin-bottom: 14px; }

.mode-tab {
  flex: 1;
  padding: 8px 10px;
  border: 1.5px solid var(--border);
  background: transparent;
  font-family: var(--display);
  font-size: 0.75rem;
  font-weight: 700;
  cursor: pointer;
  color: var(--muted);
  transition: all 0.15s;
  margin-right: -1px;
}

.mode-tab:first-child { border-radius: 3px 0 0 3px; }
.mode-tab:last-child  { border-radius: 0 3px 3px 0; margin-right: 0; }
.mode-tab.active { background: var(--ink); color: var(--bg); border-color: var(--ink); z-index: 1; }

/* ── Stats cards ── */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.stat-card {
  background: var(--paper);
  border: 1.5px solid var(--border);
  border-radius: 4px;
  padding: 10px 12px;
  text-align: center;
}

.stat-val {
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--ink);
  line-height: 1;
  letter-spacing: -0.03em;
}

.stat-label {
  font-family: var(--mono);
  font-size: 0.58rem;
  color: var(--muted);
  margin-top: 3px;
  letter-spacing: 0.06em;
}

/* ── Log / output boxes ── */
.log-box,
.output-log {
  background: var(--ink);
  color: #f5f0e8;
  border-radius: 3px;
  font-family: var(--mono);
  font-size: 0.75rem;
  padding: 10px 14px;
  min-height: 46px;
  line-height: 1.7;
  word-break: break-all;
}

.log-box .log-ok,   .log-ok   { color: #86efac; }
.log-box .log-warn, .log-warn { color: #fbbf24; }
.log-box .log-err,  .log-err  { color: #f87171; }
.log-box .log-info, .log-info { color: #93c5fd; }

/* ── Concept cards ── */
.concept-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 10px;
}

.concept-card {
  border: 1.5px solid var(--border);
  border-radius: 4px;
  padding: 14px;
  background: var(--paper);
  transition: border-color 0.15s;
}

.concept-card:hover  { border-color: var(--ink); }
.concept-card .icon  { font-size: 1.3rem; margin-bottom: 7px; }
.concept-card h3     { font-size: 0.83rem; font-weight: 700; margin-bottom: 4px; }
.concept-card p      { font-family: var(--mono); font-size: 0.68rem; color: var(--muted); line-height: 1.55; }

/* ── Toast ── */
#toast {
  position: fixed;
  bottom: 22px; right: 22px;
  background: var(--ink);
  color: var(--bg);
  border-radius: 4px;
  padding: 11px 18px;
  font-family: var(--mono);
  font-size: 0.78rem;
  opacity: 0;
  transform: translateY(8px);
  transition: all 0.25s;
  pointer-events: none;
  z-index: 999;
  max-width: 280px;
}
#toast.show { opacity: 1; transform: translateY(0); }