/*
  Line Algorithm Comparator
  style.css

  Fonts (loaded in index.html via Google Fonts):
    Platypi      — page headings
    DM Sans      — UI labels, buttons, body text
    JetBrains Mono — code, formulas, table data
*/

/* ─────────────────────────────────────────
   DESIGN TOKENS  (matches cpu-scheduling sim)
───────────────────────────────────────── */
:root {
  --bg:       #0a0a0f;
  --surface:  #111118;
  --surface2: #18181f;
  --border:   #2a2a38;
  --accent:   #7c6aff;   /* purple — Bresenham */
  --accent2:  #ff6a6a;   /* red    — endpoints */
  --accent3:  #6affb8;   /* green  — DDA */
  --accent4:  #ffb86a;   /* orange — current step */
  --text:     #e8e8f0;
  --muted:    #7878a0;
}

/* ─────────────────────────────────────────
   RESET / BASE
───────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-bottom: 80px;
}

h1, h2, h3 {
  font-family: 'Platypi', serif;
  font-weight: 700;
  letter-spacing: -0.5px;
}

code, .mono {
  font-family: 'JetBrains Mono', monospace;
}

sub { font-size: 0.7em; }

::-webkit-scrollbar { width: 4px; height: 4px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

/* noise texture */
body::before {
  content: '';
  position: fixed; inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 0;
  opacity: 0.4;
}

/* ─────────────────────────────────────────
   TOP BAR
───────────────────────────────────────── */
#top-bar {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 200;
  background: rgba(10,10,15,0.92);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  padding: 0 24px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.top-bar-left {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
}

.top-bar-tag {
  color: var(--muted);
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  font-size: 10px;
}

.top-bar-sep { color: var(--border); }

.top-bar-title {
  color: var(--text);
  font-weight: 600;
  font-size: 13px;
}

.top-bar-right { display: flex; gap: 8px; }

.top-bar-badge {
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  padding: 2px 10px;
  border-radius: 100px;
  border: 1px solid;
}

.dda-badge {
  color: var(--accent3);
  border-color: rgba(106,255,184,0.3);
  background: rgba(106,255,184,0.06);
}

.bres-badge {
  color: var(--accent);
  border-color: rgba(124,106,255,0.3);
  background: rgba(124,106,255,0.06);
}

/* ─────────────────────────────────────────
   HERO
───────────────────────────────────────── */
.hero {
  position: relative;
  width: 100%;
  padding: 120px 24px 80px;
  text-align: center;
  z-index: 1;
  overflow: hidden;
}

.hero-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 60px 60px;
  opacity: 0.2;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.1;
  pointer-events: none;
}
.orb-purple { width: 400px; height: 400px; background: var(--accent); top: -100px; left: 20%; }
.orb-green  { width: 300px; height: 300px; background: var(--accent3); bottom: -50px; right: 20%; }

.hero-inner {
  position: relative;
  z-index: 2;
  max-width: 720px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #1a1a28;
  border: 1px solid var(--border);
  padding: 4px 14px;
  border-radius: 100px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 24px;
}

.badge-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 20px;
  background: linear-gradient(135deg, var(--text) 40%, var(--muted));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 16px;
  line-height: 1.7;
  color: var(--muted);
  max-width: 560px;
  margin: 0 auto;
}

.hero-sub .mono { color: var(--accent4); font-size: 14px; }

/* ─────────────────────────────────────────
   LAYOUT WRAPPER
───────────────────────────────────────── */
.section-wrap {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1120px;
  padding: 0 24px;
  margin-bottom: 28px;
}

/* ─────────────────────────────────────────
   THEORY CARDS
───────────────────────────────────────── */
.theory-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 700px) { .theory-row { grid-template-columns: 1fr; } }

.theory-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px 28px;
  position: relative;
  overflow: hidden;
}

.theory-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 2px;
}
.theory-card.accent-purple::before { background: linear-gradient(90deg, var(--accent), transparent); }
.theory-card.accent-green::before  { background: linear-gradient(90deg, var(--accent3), transparent); }

.tc-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 12px;
}

.tc-desc {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
  margin-bottom: 12px;
}

.formula-block {
  background: #0f0f18;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 16px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--accent3);
  line-height: 1.8;
  margin-bottom: 12px;
}

.accent-purple .formula-block { color: var(--accent); }

.tc-note {
  font-size: 12px;
  color: var(--muted);
  line-height: 1.6;
}

.tc-note code {
  background: rgba(255,255,255,0.05);
  padding: 1px 5px;
  border-radius: 4px;
  font-size: 11px;
}

/* ─────────────────────────────────────────
   VIZ BOX
───────────────────────────────────────── */
.viz-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
}

.viz-header {
  padding: 14px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--surface2);
}

.viz-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--muted);
}

.viz-hint {
  font-size: 12px;
  color: var(--muted);
}

/* ─────────────────────────────────────────
   CONTROLS BOX
───────────────────────────────────────── */
.controls-body {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  padding: 16px 20px;
}

.endpoint-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.ep-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
}

.ep-label-0 { color: var(--accent2); border-color: rgba(255,106,106,0.3); background: rgba(255,106,106,0.07); }
.ep-label-1 { color: var(--accent4); border-color: rgba(255,184,106,0.3); background: rgba(255,184,106,0.07); }

.ep-inputs {
  display: flex;
  gap: 8px;
}

.ep-inputs label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--muted);
  font-family: 'JetBrains Mono', monospace;
}

.ep-inputs input[type="number"] {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 10px;
  border-radius: 8px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  width: 60px;
  text-align: center;
  outline: none;
  transition: border-color 0.2s;
  -moz-appearance: textfield;
}
.ep-inputs input[type="number"]::-webkit-inner-spin-button,
.ep-inputs input[type="number"]::-webkit-outer-spin-button { -webkit-appearance: none; }
.ep-inputs input[type="number"]:focus { border-color: var(--accent); }

.ep-arrow {
  color: var(--muted);
  font-size: 18px;
}

.ctrl-divider {
  width: 1px;
  height: 36px;
  background: var(--border);
  flex-shrink: 0;
}

.ctrl-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.step-group .step-counter {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--muted);
  min-width: 60px;
  text-align: center;
}

.step-counter #step-cur { color: var(--accent4); font-weight: 700; }

/* ─────────────────────────────────────────
   SPEED / ZOOM SLIDERS
───────────────────────────────────────── */
.speed-ctrl, .zoom-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.speed-label, .zoom-group .speed-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--muted);
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 90px;
  height: 4px;
  border-radius: 99px;
  background: var(--border);
  outline: none;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  box-shadow: 0 0 6px rgba(124,106,255,0.5);
  transition: transform 0.15s;
}

input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.2); }

.speed-val {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  font-weight: 700;
  color: var(--accent);
  min-width: 28px;
}

/* ─────────────────────────────────────────
   BUTTONS
───────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  border: none;
  transition: all 0.18s;
  font-family: 'DM Sans', sans-serif;
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: #9080ff; transform: translateY(-1px); }

.btn-ghost {
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-ghost:hover { background: var(--border); }

/* ─────────────────────────────────────────
   CANVAS PANELS
───────────────────────────────────────── */
.canvas-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 840px) { .canvas-row { grid-template-columns: 1fr; } }

.canvas-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.panel-header {
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
  background: var(--surface2);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.panel-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 700;
  color: var(--text);
}

.panel-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}
.dda-dot  { background: var(--accent3); box-shadow: 0 0 6px var(--accent3); }
.bres-dot { background: var(--accent);  box-shadow: 0 0 6px var(--accent); }

.panel-meta {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--muted);
}

.canvas-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: auto;
  padding: 16px;
  background: var(--bg);
  min-height: 300px;
}

canvas {
  display: block;
  cursor: crosshair;
  image-rendering: pixelated;
}

.panel-footer {
  padding: 10px 18px;
  border-top: 1px solid var(--border);
  background: var(--surface2);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 11px;
  color: var(--muted);
}

.pixel-count .mono {
  color: var(--accent4);
  font-weight: 700;
}

/* ─────────────────────────────────────────
   BRESENHAM TABLE
───────────────────────────────────────── */
.table-scroll {
  overflow-x: auto;
  overflow-y: auto;
  max-height: 320px;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
}

.data-table th {
  font-size: 10px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--muted);
  padding: 10px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-family: 'JetBrains Mono', monospace;
  position: sticky; top: 0;
  background: var(--surface2);
  z-index: 10;
}

.data-table td {
  padding: 9px 16px;
  font-size: 12px;
  font-family: 'JetBrains Mono', monospace;
  border-bottom: 1px solid #1a1a24;
  transition: background 0.15s;
}

.data-table tr.row-active td {
  background: rgba(255,184,106,0.08);
  border-left: 2px solid var(--accent4);
}

.data-table tr.row-active td:first-child {
  color: var(--accent4);
}

.decision-yes { color: var(--accent3); }
.decision-no  { color: var(--accent2); }
.decision-init { color: var(--muted); }

/* pk positive/negative colouring */
.pk-pos { color: var(--accent3); }
.pk-neg { color: var(--accent2); }

/* ─────────────────────────────────────────
   METRICS ROW
───────────────────────────────────────── */
.metrics-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

@media (max-width: 600px) {
  .metrics-row { grid-template-columns: repeat(2, 1fr); }
}

.metric-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  text-align: center;
}

.metric-val {
  font-family: 'JetBrains Mono', monospace;
  font-size: 24px;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 6px;
}

.metric-lbl {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--muted);
}

/* ─────────────────────────────────────────
   STATUS BAR
───────────────────────────────────────── */
#status-bar {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  z-index: 200;
  background: rgba(10,10,15,0.95);
  border-top: 1px solid var(--border);
  backdrop-filter: blur(12px);
  padding: 10px 24px;
  display: flex;
  align-items: center;
}

#status-text {
  font-size: 12px;
  color: var(--muted);
  font-family: 'JetBrains Mono', monospace;
}

/* ─────────────────────────────────────────
   ANIMATIONS
───────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

.canvas-panel { animation: fadeUp 0.5s ease forwards; }
.theory-card  { animation: fadeUp 0.4s ease forwards; }

@keyframes pixelPop {
  0%   { transform: scale(0); opacity: 0; }
  60%  { transform: scale(1.15); }
  100% { transform: scale(1); opacity: 1; }
}