/* ══════════════════════════════════════════════════════════════
   style.css  —  TechVault Tutorial Hub  v2.0
   Theme: Futuristic / Video-game HUD  |  Blue · Black · White
   ══════════════════════════════════════════════════════════════ */

/* ── CSS CUSTOM PROPERTIES ──────────────────────────────────── */
:root {
  --clr-bg:          #030810;
  --clr-surface:     #060f1e;
  --clr-surface-2:   #0a1a2f;
  --clr-border:      rgba(0, 140, 255, 0.18);

  --clr-blue:        #008cff;
  --clr-blue-bright: #00c3ff;
  --clr-blue-dim:    rgba(0,140,255,0.08);

  --clr-text:        #c8e0ff;
  --clr-text-dim:    rgba(200,224,255,0.45);
  --clr-white:       #ffffff;

  --glow-sm:         0 0 8px rgba(0,140,255,0.55);
  --glow-md:         0 0 20px rgba(0,140,255,0.45), 0 0 60px rgba(0,140,255,0.15);
  --glow-lg:         0 0 40px rgba(0,195,255,0.55), 0 0 100px rgba(0,140,255,0.25);

  --font-display:    'Orbitron', sans-serif;
  --font-mono:       'Share Tech Mono', monospace;
  --font-body:       'Rajdhani', sans-serif;

  --radius:          6px;
  --card-radius:     10px;
  --transition:      0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── RESET & BASE ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background: var(--clr-bg);
  color: var(--clr-text);
  font-family: var(--font-body);
  font-size: 16px;
  min-height: 100vh;
  overflow-x: hidden;
  background-image: radial-gradient(
    ellipse 80% 60% at 50% 30%,
    rgba(0, 60, 120, 0.18) 0%, transparent 70%
  );
}

/* ── THREE.JS CANVAS ────────────────────────────────────────── */
#bg-canvas {
  position: fixed; inset: 0; width: 100%; height: 100%;
  z-index: 0; pointer-events: none;
}

/* ── SCAN-LINE OVERLAY ──────────────────────────────────────── */
.scanlines {
  position: fixed; inset: 0; z-index: 1; pointer-events: none;
  background: repeating-linear-gradient(
    to bottom, transparent 0px, transparent 3px,
    rgba(0, 0, 0, 0.12) 3px, rgba(0, 0, 0, 0.12) 4px
  );
  animation: scanMove 12s linear infinite;
}
@keyframes scanMove {
  from { background-position: 0 0; }
  to   { background-position: 0 80px; }
}

/* ── CORNER DECORATIONS ─────────────────────────────────────── */
.corner { position: fixed; width: 36px; height: 36px; z-index: 10; pointer-events: none; opacity: 0.6; }
.corner--tl { top: 12px;    left: 12px;  border-top:   2px solid var(--clr-blue); border-left:  2px solid var(--clr-blue); }
.corner--tr { top: 12px;    right: 12px; border-top:   2px solid var(--clr-blue); border-right: 2px solid var(--clr-blue); }
.corner--bl { bottom: 12px; left: 12px;  border-bottom:2px solid var(--clr-blue); border-left:  2px solid var(--clr-blue); }
.corner--br { bottom: 12px; right: 12px; border-bottom:2px solid var(--clr-blue); border-right: 2px solid var(--clr-blue); }

/* ── PAGES ──────────────────────────────────────────────────── */
.page {
  position: fixed; inset: 0; z-index: 5;
  display: flex; flex-direction: column;
  pointer-events: none; opacity: 0; visibility: hidden;
  transition: opacity 0.5s ease; overflow-y: auto;
}
.page.active { pointer-events: all; opacity: 1; visibility: visible; }

/* ── HUD TOP BAR ────────────────────────────────────────────── */
.hud-bar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 28px; border-bottom: 1px solid var(--clr-border);
  background: rgba(3, 8, 16, 0.75); backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: sticky; top: 0; z-index: 20; flex-shrink: 0;
}
.hud-left, .hud-right { display: flex; align-items: center; gap: 8px; min-width: 160px; }
.hud-right { justify-content: flex-end; }
.hud-center { flex: 1; text-align: center; }
.hud-label { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.12em; color: var(--clr-blue-bright); text-transform: uppercase; }
.hud-ip    { font-family: var(--font-mono); font-size: 12px; color: var(--clr-text); letter-spacing: 0.05em; color:lime; }

.hud-dot { width: 7px; height: 7px; border-radius: 50%; background: #00ff88; box-shadow: 0 0 6px #00ff88; }
.hud-dot.pulse { animation: dotPulse 2s ease-in-out infinite; }
@keyframes dotPulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 6px #00ff88; }
  50%       { opacity: 0.4; box-shadow: 0 0 2px #00ff88; }
}

.hud-clock { font-family: var(--font-mono); font-size: 18px; color: var(--clr-blue-bright); text-shadow: var(--glow-sm); letter-spacing: 0.1em; }
.hud-clock.small { font-size: 13px; }

/* ════════════════════════════════════════════════════════════
   SEARCH BAR
   ════════════════════════════════════════════════════════════ */
.search-zone {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 16px 24px 0;
  z-index: 15;
  position: relative;
  opacity: 0;
  transform: translateY(-8px);
  flex-shrink: 0;

}

.search-wrapper {
  width: 100%;
  max-width: 600px;
  position: relative;
}

.search-input-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(6, 15, 30, 0.92);
  border: 1px solid var(--clr-border);
  border-radius: 8px;
  padding: 0 16px;
  transition: border-color var(--transition), box-shadow var(--transition);
  backdrop-filter: blur(12px);
}

.search-input-wrap:focus-within {
  border-color: rgba(0, 195, 255, 0.55);
  box-shadow: var(--glow-sm), inset 0 0 20px rgba(0,140,255,0.04);
}

.search-icon-svg {
  color: var(--clr-blue-bright);
  flex-shrink: 0;
  opacity: 0.7;
}

.search-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--clr-white);
  padding: 13px 0;
  caret-color: var(--clr-blue-bright);
}

.search-input::placeholder {
  color: var(--clr-text-dim);
  letter-spacing: 0.12em;
}

.search-clear {
  color: var(--clr-text-dim);
  font-size: 14px;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.2s, color 0.2s;
  user-select: none;
  flex-shrink: 0;
  line-height: 1;
}
.search-clear:hover { color: var(--clr-blue-bright); }

/* Results dropdown */
.search-results {
  position: absolute;
  top: calc(100% + 6px);
  left: 0; right: 0;
  background: rgba(4, 11, 22, 0.98);
  border: 1px solid rgba(0, 140, 255, 0.28);
  border-radius: 8px;
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  pointer-events: none;
  transition: max-height 0.3s cubic-bezier(0.4,0,0.2,1), opacity 0.25s ease;
  z-index: 100;
  backdrop-filter: blur(16px);
  box-shadow: 0 16px 60px rgba(0,0,0,0.7), var(--glow-sm);
}
.search-results.open {
  max-height: 360px;
  opacity: 1;
  pointer-events: all;
  overflow-y: auto;
}

/* Custom scrollbar in results */
.search-results::-webkit-scrollbar { width: 3px; }
.search-results::-webkit-scrollbar-track { background: transparent; }
.search-results::-webkit-scrollbar-thumb { background: var(--clr-blue); border-radius: 50px; }

.sr-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 18px;
  cursor: pointer;
  border-bottom: 1px solid rgba(0,140,255,0.07);
  transition: background 0.15s;
}
.sr-item:last-child { border-bottom: none; }
.sr-item:hover, .sr-item.active {
  background: rgba(0, 140, 255, 0.1);
}

.sr-item-left {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 0;
}

.sr-cat-badge {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.14em;
  opacity: 0.85;
}

.sr-title {
  font-family: var(--font-body);
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--clr-white);
  letter-spacing: 0.03em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sr-title mark {
  background: none;
  color: var(--clr-blue-bright);
  text-shadow: 0 0 8px rgba(0,195,255,0.6);
}

.sr-item-right {
  display: flex;
  align-items: center;
  gap: 5px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--clr-text-dim);
  flex-shrink: 0;
}

.sr-empty {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 20px 18px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--clr-text-dim);
}

/* Keyboard hint row */
.search-hint {
  margin-top: 7px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--clr-text-dim);
  opacity: 0.6;
  display: flex;
  align-items: center;
  gap: 4px;
}
.search-hint-key {
  display: inline-block;
  border: 1px solid rgba(0,140,255,0.3);
  border-radius: 3px;
  padding: 1px 5px;
  font-size: 9px;
  color: var(--clr-blue-bright);
  letter-spacing: 0.05em;
  background: rgba(0,140,255,0.06);
}

/* ── HERO SECTION ───────────────────────────────────────────── */
.hero {
  flex: 1; display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  padding: 24px 24px 80px; text-align: center; position: relative;
}

.badge {
  font-family: var(--font-mono); font-size: 11px;
  color: var(--clr-blue-bright); letter-spacing: 0.18em;
  border: 1px solid var(--clr-border); padding: 6px 18px;
  border-radius: 50px; margin-bottom: 28px;
  background: rgba(0,140,255,0.06); box-shadow: var(--glow-sm);
  opacity: 0; transform: translateY(-10px);
}

.hero-title {
  font-family: var(--font-display); font-weight: 900;
  font-size: clamp(4rem, 12vw, 11rem); line-height: 0.9;
  letter-spacing: -0.02em; display: flex; flex-direction: column;
  gap: 0; margin-bottom: 28px; opacity: 0;
}
.hero-title .line { display: block; }
.hero-title .line-1 { color: var(--clr-white); text-shadow: 0 0 60px rgba(0,140,255,0.4); animation: glitchFlicker 8s infinite; }
.hero-title .line-2 {
  background: linear-gradient(90deg, var(--clr-blue) 0%, var(--clr-blue-bright) 60%, #80e8ff 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text; filter: drop-shadow(0 0 18px rgba(0,195,255,0.5));
}

@keyframes glitchFlicker {
  0%, 94%, 96%, 98%, 100% { opacity: 1; transform: none; }
  95%  { opacity: 0.85; transform: skewX(-0.5deg) translateX(2px); }
  97%  { opacity: 0.9;  transform: skewX(0.3deg) translateX(-1px); }
}

.hero-sub {
  font-family: var(--font-body); font-size: 1.1rem; font-weight: 400;
  color: whitesmoke; letter-spacing: 0.12em; text-transform: uppercase;
  margin-bottom: 48px; opacity: 0;
}

/* ── CATEGORY CARDS ─────────────────────────────────────────── */
.cards-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px; width: 100%; max-width: 1000px; margin: 0 auto;
}

.card {
  border-radius: var(--card-radius); cursor: pointer;
  opacity: 0; transform: translateY(40px);
  position: relative; transform-style: preserve-3d;
}

.card-inner {
  background: linear-gradient(145deg, var(--clr-surface) 0%, var(--clr-surface-2) 100%);
  border: 1px solid var(--clr-border); border-radius: var(--card-radius);
  padding: 36px 28px 32px; display: flex; flex-direction: column;
  align-items: flex-start; gap: 14px; position: relative; overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition);
  transform: translateZ(0);
}

.card--featured .card-inner { border-color: rgba(0,195,255,0.35); background: linear-gradient(145deg,#060f1e 0%,#0b1d36 100%); }
.card:hover .card-inner { border-color: rgba(0,195,255,0.6); box-shadow: var(--glow-md); }

.card-glow {
  position: absolute; width: 180px; height: 180px; border-radius: 50%;
  background: radial-gradient(circle,rgba(0,140,255,0.18) 0%,transparent 70%);
  bottom: -60px; right: -40px; pointer-events: none;
  transition: opacity var(--transition); opacity: 0;
}
.card:hover .card-glow { opacity: 1; }

.card-icon {
  width: 52px; height: 52px; color: var(--clr-blue-bright); padding: 10px;
  border: 1px solid var(--clr-border); border-radius: var(--radius);
  background: rgba(0,140,255,0.07); display: flex; align-items: center;
  justify-content: center; transition: box-shadow var(--transition), border-color var(--transition);
}
.card-icon svg { width: 100%; height: 100%; }
.card:hover .card-icon { box-shadow: var(--glow-sm); border-color: var(--clr-blue-bright); }

.card-title { font-family: var(--font-display); font-size: 1.2rem; font-weight: 700; color: var(--clr-white); letter-spacing: 0.04em; }
.card-desc  { font-family: var(--font-body); font-size: 0.85rem; color: var(--clr-text-dim); line-height: 1.6; letter-spacing: 0.04em; }

.card-cta {
  display: flex; align-items: center; gap: 8px; margin-top: 8px;
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.14em;
  color: var(--clr-blue); transition: color var(--transition), gap var(--transition);
}
.card:hover .card-cta { color: var(--clr-blue-bright); gap: 12px; }

.card--featured .card-inner::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg,transparent,var(--clr-blue-bright),transparent);
  box-shadow: 0 0 12px var(--clr-blue-bright);
}

/* ── HUD FOOTER ─────────────────────────────────────────────── */
.hud-footer {
  padding: 10px 28px; border-top: 1px solid var(--clr-border);
  background: rgba(3,8,16,0.75); backdrop-filter: blur(12px);
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.1em;
  color: var(--clr-text-dim); text-align: center;
  display: flex; align-items: center; justify-content: center; gap: 16px; flex-shrink: 0;
}
.hud-sep { color: var(--clr-border); }

/* ════════════════════════════════════════════════════════════
   TUTORIALS PAGE
   ════════════════════════════════════════════════════════════ */
.btn-back {
  display: flex; align-items: center; gap: 8px; background: none;
  border: 1px solid var(--clr-border); color: var(--clr-blue-bright);
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.14em;
  padding: 8px 16px; border-radius: var(--radius); cursor: pointer;
  transition: background var(--transition), border-color var(--transition), box-shadow var(--transition);
}
.btn-back:hover { background: rgba(0,140,255,0.1); border-color: var(--clr-blue); box-shadow: var(--glow-sm); }

.tutorials-section { flex: 1; padding: 40px 32px 80px; max-width: 1100px; margin: 0 auto; width: 100%; }
.tut-intro { margin-bottom: 32px; }
.tut-intro p { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.12em; color: var(--clr-text-dim); text-transform: uppercase; }

.tut-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 20px; }

.tut-card {
  background: linear-gradient(145deg, var(--clr-surface) 0%, var(--clr-surface-2) 100%);
  border: 1px solid var(--clr-border); border-radius: var(--card-radius);
  padding: 28px 24px; display: flex; flex-direction: column; gap: 16px;
  position: relative; overflow: hidden;
  opacity: 0; transform: translateY(24px);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.tut-card::before {
  content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  background: linear-gradient(to bottom, var(--clr-blue), var(--clr-blue-bright));
  box-shadow: var(--glow-sm);
}
.tut-card:hover { border-color: rgba(0,195,255,0.4); box-shadow: var(--glow-md); }

.tut-num   { font-family: var(--font-mono); font-size: 10px; color: var(--clr-blue); letter-spacing: 0.12em; }
.tut-title { font-family: var(--font-display); font-size: 0.9rem; font-weight: 600; color: var(--clr-white); letter-spacing: 0.04em; line-height: 1.4; flex: 1; }

.btn-pdf {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(0,140,255,0.08); border: 1px solid rgba(0,140,255,0.3);
  color: var(--clr-blue-bright); font-family: var(--font-mono); font-size: 11px;
  letter-spacing: 0.12em; padding: 9px 18px; border-radius: var(--radius);
  cursor: pointer; text-decoration: none; width: fit-content;
  transition: background var(--transition), border-color var(--transition), box-shadow var(--transition), color var(--transition);
}
.btn-pdf:hover { background: rgba(0,195,255,0.15); border-color: var(--clr-blue-bright); box-shadow: var(--glow-sm); color: var(--clr-white); }
.btn-pdf svg { flex-shrink: 0; }

/* ════════════════════════════════════════════════════════════
   NUCLEAR LAUNCH ANIMATION OVERLAY
   ════════════════════════════════════════════════════════════ */
.launch-overlay {
  position: fixed; inset: 0; z-index: 1000;
  background: rgba(1, 5, 14, 0.97);
  backdrop-filter: blur(20px);
  display: none;
  align-items: center;
  justify-content: center;
  pointer-events: all;
}
.launch-overlay.active { display: flex; }

.launch-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  padding: 40px;
  position: relative;
  width: 100%;
  max-width: 520px;
}

/* ── RING ─────────────────────────────────────────────────── */
.launch-ring {
  position: relative;
  width: 200px; height: 200px;
  flex-shrink: 0;
}

.launch-ring-svg {
  width: 200px; height: 200px;
  animation: ringRotate 4s linear infinite;
}

@keyframes ringRotate {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

.ring-track {
  fill: none; stroke: rgba(0,140,255,0.12); stroke-width: 3;
}

.ring-progress {
  fill: none;
  stroke: var(--clr-blue-bright);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-dasharray: 553;
  stroke-dashoffset: 553;
  filter: drop-shadow(0 0 6px var(--clr-blue-bright));
  transition: stroke-dashoffset 0.05s linear;
  transform-origin: center;
  transform: rotate(-90deg);
}

.ring-inner {
  fill: none; stroke: rgba(0,140,255,0.08); stroke-width: 1.5;
}
.ring-inner-2 {
  fill: none; stroke: rgba(0,140,255,0.05); stroke-width: 1;
}

.ring-tick { stroke: rgba(0,195,255,0.5); stroke-width: 2; stroke-linecap: round; }
.ring-tick-sm { stroke: rgba(0,140,255,0.35); stroke-width: 1.5; stroke-linecap: round; }

/* Center icon */
.launch-icon {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  color: var(--clr-blue-bright);
  width: 48px; height: 48px;
  display: flex; align-items: center; justify-content: center;
  animation: iconPulse 1.2s ease-in-out infinite;
  filter: drop-shadow(0 0 8px var(--clr-blue-bright));
}
@keyframes iconPulse {
  0%, 100% { opacity: 1; transform: translate(-50%,-50%) scale(1); }
  50%       { opacity: 0.7; transform: translate(-50%,-50%) scale(0.9); }
}

/* ── STATUS LINES ─────────────────────────────────────────── */
.launch-lines-top {
  display: flex; flex-direction: column; gap: 4px;
  width: 100%; max-width: 380px;
}

.launch-line {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--clr-text-dim);
  opacity: 0;
  transform: translateX(-10px);
  transition: opacity 0.3s ease, transform 0.3s ease, color 0.3s ease;
  padding-left: 12px;
  position: relative;
}
.launch-line::before {
  content: '▸';
  position: absolute; left: 0;
  color: var(--clr-blue); opacity: 0;
  transition: opacity 0.2s;
}
.launch-line.ll-visible {
  opacity: 0.9;
  transform: translateX(0);
  color: var(--clr-blue-bright);
}
.launch-line.ll-visible::before { opacity: 1; }
.launch-line.ll-done {
  color: rgba(0, 255, 136, 0.7);
}
.launch-line.ll-done::before { content: '✓'; color: #00ff88; }

/* ── HEX CODE STREAM ──────────────────────────────────────── */
.launch-code-stream {
  width: 100%; max-width: 380px;
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.06em;
  color: rgba(0,140,255,0.35);
  line-height: 1.6;
  overflow: hidden;
  height: 108px;
  position: relative;
  mask-image: linear-gradient(to bottom, transparent 0%, black 30%, black 70%, transparent 100%);
  -webkit-mask-image: linear-gradient(to bottom, transparent 0%, black 30%, black 70%, transparent 100%);
}

.cs-line {
  animation: csLineFade 0.15s ease-out;
}
@keyframes csLineFade {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ── BIG STATUS TEXT ──────────────────────────────────────── */
.launch-status {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--clr-blue-bright);
  letter-spacing: 0.2em;
  text-shadow: var(--glow-md);
  animation: statusFlicker 0.6s infinite;
}
@keyframes statusFlicker {
  0%, 85%, 100% { opacity: 1; }
  88%            { opacity: 0.7; }
}

.launch-pct {
  font-family: var(--font-mono);
  font-size: 2.5rem;
  color: var(--clr-white);
  letter-spacing: 0.05em;
  text-shadow: 0 0 30px rgba(0,195,255,0.8);
  min-width: 80px;
  text-align: center;
}

/* ── READY STATE ──────────────────────────────────────────── */
.launch-ready {
  position: absolute;
  inset: 0;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 12px;
  opacity: 0; pointer-events: none;
  transition: opacity 0.4s;
}
.launch-ready.ready-visible {
  opacity: 1;
  pointer-events: all;
}

.launch-ready-icon {
  font-size: 3rem;
  color: #00ff88;
  text-shadow: 0 0 30px #00ff88, 0 0 60px #00ff88;
  animation: readyPop 0.5s cubic-bezier(0.34,1.56,0.64,1) both;
}
@keyframes readyPop {
  from { transform: scale(0); opacity: 0; }
  to   { transform: scale(1); opacity: 1; }
}

.launch-ready-text {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 800;
  color: #00ff88;
  letter-spacing: 0.3em;
  text-shadow: 0 0 20px #00ff88;
}

.launch-ready-sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: rgba(0,255,136,0.6);
  animation: blink 0.8s step-end infinite;
}
@keyframes blink {
  50% { opacity: 0; }
}

/* ── SCROLLBAR ───────────────────────────────────────────── */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: var(--clr-bg); }
::-webkit-scrollbar-thumb { background: var(--clr-blue); border-radius: 50px; }

/* ── SHIMMER ─────────────────────────────────────────────── */
.shimmer {
  background: linear-gradient(90deg, var(--clr-surface) 25%, var(--clr-surface-2) 50%, var(--clr-surface) 75%);
  background-size: 200% 100%;
  animation: shimmerAnim 1.5s infinite;
}
@keyframes shimmerAnim {
  from { background-position: 200% 0; }
  to   { background-position: -200% 0; }
}

/* ── RESPONSIVE ──────────────────────────────────────────── */
@media (max-width: 600px) {
  .hero-title           { font-size: clamp(3rem, 20vw, 5rem); }
  .hud-bar              { padding: 10px 14px; }
  .tutorials-section    { padding: 24px 16px 60px; }
  .tut-grid             { grid-template-columns: 1fr; }
  .cards-grid           { grid-template-columns: 1fr; }
  .launch-inner         { padding: 24px 16px; gap: 14px; }
  .launch-ring          { width: 160px; height: 160px; }
  .launch-ring-svg      { width: 160px; height: 160px; }
  .launch-pct           { font-size: 2rem; }
  .search-hint          { display: none; }
}

/* ── UTILITY ─────────────────────────────────────────────── */
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
[data-tilt] { transform-style: preserve-3d; }

/* ════════════════════════════════════════════════════════════
   LEFT SIDEBAR
   ════════════════════════════════════════════════════════════ */
.sidebar {
  position: fixed;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 200;
  opacity: 0;
}

.sidebar-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 14px 10px;
  background: rgba(6,15,30,0.55);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border: 1px solid rgba(0,140,255,0.2);
  border-radius: 14px;
  box-shadow: 0 0 0 1px rgba(0,195,255,0.06) inset, 0 8px 32px rgba(0,0,0,0.5), 0 0 20px rgba(0,140,255,0.08);
}

.sidebar-divider {
  width: 24px; height: 1px;
  background: rgba(0,140,255,0.25);
  margin: 4px 0; border-radius: 2px;
}

.sidebar-btn {
  position: relative;
  display: flex; align-items: center; justify-content: center;
  width: 40px; height: 40px;
  border-radius: 10px;
  border: 1px solid rgba(0,140,255,0.12);
  background: rgba(0,140,255,0.04);
  color: rgba(200,224,255,0.55);
  cursor: pointer; text-decoration: none;
  transition: background var(--transition), border-color var(--transition),
              color var(--transition), box-shadow var(--transition),
              transform 0.2s cubic-bezier(0.34,1.56,0.64,1);
  outline: none;
}
.sidebar-btn:hover {
  background: rgba(0,140,255,0.18);
  border-color: rgba(0,195,255,0.5);
  color: var(--clr-blue-bright);
  box-shadow: 0 0 14px rgba(0,195,255,0.3), 0 0 30px rgba(0,140,255,0.12);
  transform: scale(1.13);
}
.sidebar-btn:active { transform: scale(0.96); }

.sidebar-tooltip {
  position: absolute;
  left: calc(100% + 14px);
  top: 50%; transform: translateY(-50%) translateX(-6px);
  background: rgba(4,11,22,0.97);
  border: 1px solid rgba(0,140,255,0.35);
  color: var(--clr-blue-bright);
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.12em;
  padding: 5px 10px; border-radius: 6px;
  white-space: nowrap; pointer-events: none; opacity: 0;
  transition: opacity 0.2s ease, transform 0.2s ease;
  box-shadow: 0 4px 16px rgba(0,0,0,0.5), var(--glow-sm);
}
.sidebar-tooltip::before {
  content: '';
  position: absolute; right: 100%; top: 50%; transform: translateY(-50%);
  border: 5px solid transparent;
  border-right-color: rgba(0,140,255,0.35);
}
.sidebar-btn:hover .sidebar-tooltip {
  opacity: 1; transform: translateY(-50%) translateX(0);
}

@media (max-width: 480px) { .sidebar { display: none; } }

/* ════════════════════════════════════════════════════════════
   ABOUT SECTION
   ════════════════════════════════════════════════════════════ */
.about-section {
  width: 100%; flex-shrink: 0;
  padding: 64px 24px 80px;
  border-top: 1px solid rgba(0,140,255,0.15);
  background: linear-gradient(to bottom, transparent 0%, rgba(0,30,70,0.25) 40%, rgba(0,20,50,0.45) 100%);
}
.about-inner {
  max-width: 680px; margin: 0 auto;
  display: flex; flex-direction: column; align-items: center;
  gap: 24px; text-align: center;
}
.about-badge {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em;
  color: var(--clr-blue-bright);
  border: 1px solid rgba(0,140,255,0.3); border-radius: 50px;
  padding: 5px 14px; background: rgba(0,140,255,0.07);
}
.about-badge-dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--clr-blue-bright);
  box-shadow: 0 0 8px var(--clr-blue-bright);
  animation: dotPulse 2s ease-in-out infinite;
}
.about-title {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 4vw, 2.2rem); font-weight: 800;
  color: var(--clr-white); letter-spacing: 0.12em;
  text-shadow: 0 0 30px rgba(0,195,255,0.35);
}
.about-desc {
  font-family: var(--font-body); font-size: 1.05rem;
  line-height: 1.75; color: var(--clr-text-dim); max-width: 560px;
}
.about-desc strong { color: var(--clr-blue-bright); font-weight: 600; }
.about-tags { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }
.about-tag {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.12em;
  color: var(--clr-blue);
  border: 1px solid rgba(0,140,255,0.25); border-radius: 4px;
  padding: 4px 10px; background: rgba(0,140,255,0.06);
  transition: background var(--transition), border-color var(--transition), color var(--transition);
}
.about-tag:hover {
  background: rgba(0,140,255,0.15);
  border-color: rgba(0,195,255,0.5);
  color: var(--clr-blue-bright);
}
.about-copy {
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.1em; color: rgba(200,224,255,0.25); margin-top: 12px;
}