/* ============================================================
   jack-low — Sci-Fi Portfolio
   Design system: neon-blue / magenta / violet on deep space navy
   ============================================================ */

:root {
  /* base space palette */
  --bg-0: #04060d;
  --bg-1: #060a16;
  --bg-2: #0a1124;
  --panel: rgba(12, 20, 40, 0.55);
  --panel-solid: #0a1020;
  --line: rgba(96, 165, 250, 0.16);
  --line-strong: rgba(96, 165, 250, 0.4);

  /* text */
  --ink: #e8f0ff;
  --ink-dim: #9fb2d4;
  --ink-faint: #5d6f93;

  /* neon accents */
  --cyan: #34e3ff;
  --blue: #3b82f6;
  --violet: #8b5cf6;
  --magenta: #f43bd0;
  --magenta-hot: #ff2bb5;
  --green: #2dd4a7;

  --glow-cyan: 0 0 18px rgba(52, 227, 255, 0.55);
  --glow-blue: 0 0 18px rgba(59, 130, 246, 0.55);
  --glow-magenta: 0 0 18px rgba(244, 59, 208, 0.5);

  --maxw: 1240px;
  --rail: 64px;

  --font-disp: 'Oxanium', system-ui, sans-serif;
  --font-jp: 'Noto Sans JP', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Roboto Mono', monospace;
}

/* ---------- light theme overrides ---------- */
html[data-theme="light"] {
  --bg-0: #eef2fb;
  --bg-1: #e6ecf8;
  --bg-2: #dfe7f6;
  --panel: rgba(255, 255, 255, 0.66);
  --panel-solid: #f4f7ff;
  --line: rgba(37, 99, 235, 0.18);
  --line-strong: rgba(37, 99, 235, 0.38);
  --ink: #0b1530;
  --ink-dim: #43557a;
  --ink-faint: #8294b6;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

/* ---------- accessibility: skip link + focus ---------- */
.skip-link {
  position: fixed;
  top: 8px; left: 8px;
  z-index: 200;
  transform: translateY(-150%);
  background: var(--cyan);
  color: #04101e;
  font-family: var(--font-jp);
  font-weight: 600;
  padding: 10px 16px;
  border-radius: 8px;
  text-decoration: none;
  transition: transform .2s;
}
.skip-link:focus { transform: none; outline: 2px solid #04101e; outline-offset: 2px; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 4px;
}
#main:focus { outline: none; }
@media (prefers-reduced-motion: reduce) { .skip-link { transition: none; } }

body {
  font-family: var(--font-jp);
  background: var(--bg-0);
  color: var(--ink);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  letter-spacing: 0.01em;
}

/* fixed background canvas + atmospheric layers */
#bg-canvas {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}
.atmosphere {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(120% 80% at 80% -10%, rgba(59, 130, 246, 0.18), transparent 55%),
    radial-gradient(90% 70% at 0% 30%, rgba(139, 92, 246, 0.14), transparent 55%),
    radial-gradient(70% 60% at 100% 80%, rgba(244, 59, 208, 0.10), transparent 55%);
  transition: opacity .4s;
}
html[data-theme="light"] .atmosphere { opacity: .5; }

/* grid overlay */
.grid-overlay {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(120% 100% at 50% 0%, #000 0%, transparent 80%);
          mask-image: radial-gradient(120% 100% at 50% 0%, #000 0%, transparent 80%);
  opacity: .5;
}

/* scanline + vignette */
.scanlines {
  position: fixed;
  inset: 0;
  z-index: 60;
  pointer-events: none;
  background: repeating-linear-gradient(
    to bottom, rgba(0,0,0,0) 0px, rgba(0,0,0,0) 2px,
    rgba(0, 10, 25, 0.14) 3px, rgba(0, 10, 25, 0.14) 4px);
  mix-blend-mode: multiply;
  opacity: .35;
}
.vignette {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  box-shadow: inset 0 0 240px 40px rgba(0,0,0,.65);
}
html[data-theme="light"] .scanlines { opacity: .12; }
html[data-theme="light"] .vignette { box-shadow: inset 0 0 240px 40px rgba(120,140,180,.3); }

/* ---------- layout shell ---------- */
.shell { position: relative; z-index: 2; }
.wrap {
  width: min(100% - 40px, var(--maxw));
  margin-inline: auto;
}
section {
  position: relative;
  padding-block: clamp(72px, 11vh, 130px);
}

/* section eyebrow / index */
.sec-eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .18em;
  color: var(--ink-faint);
  margin-bottom: 14px;
}
.sec-eyebrow .num {
  color: var(--cyan);
  text-shadow: var(--glow-cyan);
}
.sec-eyebrow .tag { color: var(--magenta); }
.sec-title {
  font-family: var(--font-jp);
  font-weight: 700;
  font-size: clamp(26px, 3.4vw, 40px);
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 8px;
}
.sec-title .ic {
  width: 34px; height: 34px;
  color: var(--cyan);
  filter: drop-shadow(var(--glow-cyan));
}
.sec-title .br { color: var(--magenta); font-family: var(--font-mono); font-weight: 600; }

/* ---------- nav ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px clamp(16px, 4vw, 40px);
  background: linear-gradient(to bottom, rgba(4,6,13,.9), rgba(4,6,13,.4) 70%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s, background .3s;
}
.nav.scrolled {
  border-bottom: 1px solid var(--line);
  background: rgba(4,6,13,.82);
}
html[data-theme="light"] .nav { background: linear-gradient(to bottom, rgba(238,242,251,.92), rgba(238,242,251,.4) 70%, transparent); }
html[data-theme="light"] .nav.scrolled { background: rgba(238,242,251,.85); }

.brand {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 17px;
  display: flex;
  align-items: center;
  gap: 9px;
  color: var(--ink);
}
.brand .chev { color: var(--cyan); text-shadow: var(--glow-cyan); }

.nav-links {
  display: flex;
  gap: clamp(14px, 2.2vw, 30px);
  align-items: center;
  list-style: none;
}
.nav-links a {
  font-size: 14px;
  color: var(--ink-dim);
  text-decoration: none;
  position: relative;
  padding: 4px 2px;
  transition: color .25s;
}
.nav-links a:hover, .nav-links a.active { color: var(--cyan); }
.nav-links a.active::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -3px;
  height: 2px;
  background: var(--cyan);
  box-shadow: var(--glow-cyan);
}

.nav-right { display: flex; align-items: center; gap: 16px; }

/* theme toggle */
.toggle {
  --w: 46px;
  width: var(--w); height: 24px;
  border-radius: 20px;
  border: 1px solid var(--line-strong);
  background: var(--panel);
  position: relative;
  cursor: pointer;
  flex: none;
}
.toggle .knob {
  position: absolute;
  top: 2px; left: 2px;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: var(--glow-cyan);
  transition: transform .3s cubic-bezier(.6,.1,.2,1.2), background .3s;
}
html[data-theme="light"] .toggle .knob { transform: translateX(22px); background: var(--violet); box-shadow: 0 0 14px rgba(139,92,246,.6); }

/* hamburger */
.burger { display: none; background: none; border: 0; cursor: pointer; width: 30px; height: 24px; position: relative; }
.burger span { position: absolute; left: 0; right: 0; height: 2px; background: var(--ink); transition: .3s; }
.burger span:nth-child(1) { top: 2px; }
.burger span:nth-child(2) { top: 11px; }
.burger span:nth-child(3) { top: 20px; }
body.menu-open .burger span:nth-child(1) { transform: translateY(9px) rotate(45deg); }
body.menu-open .burger span:nth-child(2) { opacity: 0; }
body.menu-open .burger span:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }

/* ---------- right section rail ---------- */
.rail {
  position: fixed;
  top: 50%; right: 22px;
  transform: translateY(-50%);
  z-index: 40;
  display: flex;
  flex-direction: column;
  gap: 26px;
}
.rail a {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-direction: row-reverse;
}
.rail .dot {
  width: 9px; height: 9px;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  background: transparent;
  transition: .3s;
  flex: none;
}
.rail .meta {
  text-align: right;
  font-family: var(--font-mono);
  font-size: 10px;
  line-height: 1.25;
  color: var(--ink-faint);
  opacity: 0;
  transform: translateX(6px);
  transition: .3s;
}
.rail .meta .rn { display: block; color: var(--ink-dim); }
.rail a:hover .meta, .rail a.active .meta { opacity: 1; transform: none; }
.rail a.active .dot {
  background: var(--cyan);
  box-shadow: var(--glow-cyan);
  border-color: var(--cyan);
  transform: scale(1.25);
}

/* ---------- buttons ---------- */
.btn {
  font-family: var(--font-jp);
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 13px 22px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  position: relative;
  transition: transform .2s, box-shadow .3s, background .3s;
  clip-path: polygon(10px 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%, 0 10px);
}
.btn .mi { width: 17px; height: 17px; }
.btn-primary {
  background: linear-gradient(135deg, var(--blue), var(--cyan));
  color: #04101e;
  font-weight: 600;
  box-shadow: 0 0 22px rgba(52,227,255,.4);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 0 34px rgba(52,227,255,.7); }
.btn-ghost {
  background: var(--panel);
  border-color: var(--line-strong);
  color: var(--ink);
  backdrop-filter: blur(6px);
}
.btn-ghost:hover { transform: translateY(-2px); border-color: var(--cyan); box-shadow: 0 0 20px rgba(52,227,255,.3); }

/* ---------- panels ---------- */
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  backdrop-filter: blur(8px);
  position: relative;
}
.panel::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 12px;
  padding: 1px;
  background: linear-gradient(135deg, rgba(52,227,255,.4), transparent 40%, transparent 60%, rgba(244,59,208,.3));
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
          mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  opacity: .5;
  pointer-events: none;
}

/* corner brackets */
.bracket { position: relative; }
.bracket::before, .bracket::after {
  content: "";
  position: absolute;
  width: 14px; height: 14px;
  border: 1.5px solid var(--cyan);
  opacity: .7;
}
.bracket::before { top: -1px; left: -1px; border-right: 0; border-bottom: 0; }
.bracket::after  { bottom: -1px; right: -1px; border-left: 0; border-top: 0; }

/* ---------- reveal animations (keyframe-based: robust on-load) ---------- */
.reveal { opacity: 0; transform: translateY(34px); will-change: transform, opacity; }
.reveal-x { opacity: 0; transform: translateX(-40px); will-change: transform, opacity; }
.reveal-r { transform: translateX(40px); }

.reveal.in   { animation: revUp .85s cubic-bezier(.2,.7,.2,1) var(--d, 0ms) both; }
.reveal-x.in { animation: revX  .85s cubic-bezier(.2,.7,.2,1) var(--d, 0ms) both; }
.reveal-x.reveal-r.in { animation-name: revR; }

@keyframes revUp { from { opacity: 0; transform: translateY(34px); } to { opacity: 1; transform: none; } }
@keyframes revX  { from { opacity: 0; transform: translateX(-40px); } to { opacity: 1; transform: none; } }
@keyframes revR  { from { opacity: 0; transform: translateX(40px); }  to { opacity: 1; transform: none; } }

@media (prefers-reduced-motion: reduce) {
  .reveal, .reveal-x { opacity: 1 !important; transform: none !important; animation: none !important; }
}

/* scroll down chevron */
.scroll-cue {
  display: flex;
  justify-content: center;
  margin-top: 40px;
  color: var(--cyan);
}
.scroll-cue svg { width: 26px; height: 26px; animation: bob 1.8s ease-in-out infinite; filter: drop-shadow(var(--glow-cyan)); }
@keyframes bob { 0%,100% { transform: translateY(0); } 50% { transform: translateY(8px); } }
@media (prefers-reduced-motion: reduce) { .scroll-cue svg { animation: none; } }