/* ============================================================
   DESIGN TOKENS — Kim Chan-Hyuk Portfolio
   Theme: "Edge Defender" — Cloudflare orange + cyber-noir
   ============================================================ */

:root {
  /* ---- Color: noir base ---- */
  --bg-0: #07080c;
  --bg-1: #0d1017;
  --bg-2: #141823;
  --bg-3: #1c2230;
  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.16);

  /* ---- Color: text ---- */
  --text-1: #f4f5f8;
  --text-2: #b8bdc9;
  --text-3: #7a8194;
  --text-mute: #565d6e;

  /* ---- Color: brand ---- */
  --cf-orange: #f6821f;
  --cf-orange-soft: #ffb567;
  --cf-orange-glow: rgba(246, 130, 31, 0.35);
  --accent-cyan: #38bdf8;
  --accent-mint: #5eead4;
  --accent-violet: #a78bfa;
  --accent-red: #ef4444;
  --accent-green: #22c55e;

  /* ---- Gradients ---- */
  --grad-edge: linear-gradient(135deg, #f6821f 0%, #f43f5e 50%, #a78bfa 100%);
  --grad-glow: radial-gradient(circle at 30% 20%, rgba(246, 130, 31, 0.18), transparent 55%),
               radial-gradient(circle at 80% 60%, rgba(56, 189, 248, 0.12), transparent 60%);
  --grad-card: linear-gradient(180deg, rgba(255,255,255,0.04) 0%, rgba(255,255,255,0.01) 100%);

  /* ---- Type ---- */
  --font-sans: 'Pretendard', 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'D2Coding', ui-monospace, monospace;
  --font-display: 'Pretendard', 'Noto Sans KR', sans-serif;

  --fs-hero: clamp(2.6rem, 5.2vw, 4.6rem);
  --fs-h1: clamp(2.0rem, 3.4vw, 2.8rem);
  --fs-h2: clamp(1.5rem, 2.4vw, 2.0rem);
  --fs-h3: 1.25rem;
  --fs-body: 1.0rem;
  --fs-small: 0.875rem;
  --fs-xs: 0.75rem;

  --lh-tight: 1.15;
  --lh-base: 1.6;
  --lh-loose: 1.8;

  /* ---- Spacing ---- */
  --s-1: 4px;
  --s-2: 8px;
  --s-3: 12px;
  --s-4: 16px;
  --s-5: 24px;
  --s-6: 32px;
  --s-7: 48px;
  --s-8: 64px;
  --s-9: 96px;
  --s-10: 128px;

  /* ---- Radius ---- */
  --r-sm: 6px;
  --r-md: 12px;
  --r-lg: 18px;
  --r-xl: 28px;
  --r-full: 999px;

  /* ---- Shadows ---- */
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.25);
  --shadow-md: 0 8px 24px rgba(0,0,0,0.35);
  --shadow-lg: 0 20px 60px rgba(0,0,0,0.45);
  --shadow-glow: 0 0 40px var(--cf-orange-glow);

  /* ---- Motion ---- */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
  --dur-fast: 160ms;
  --dur: 280ms;
  --dur-slow: 520ms;

  /* ---- Layout ---- */
  --max-w: 1240px;
  --max-w-narrow: 920px;
  --nav-h: 68px;
}

/* ============================================================
   RESET + BASE
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 16px);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: var(--lh-base);
  color: var(--text-1);
  background: var(--bg-0);
  overflow-x: hidden;
  font-weight: 400;
  letter-spacing: -0.005em;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-weight: 700;
  line-height: var(--lh-tight);
  letter-spacing: -0.022em;
}

p { margin: 0; }
a { color: inherit; text-decoration: none; transition: color var(--dur) var(--ease-out); }
img { max-width: 100%; display: block; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }

::selection { background: var(--cf-orange); color: var(--bg-0); }

/* Section spacing */
.section {
  padding: var(--s-10) var(--s-5);
  position: relative;
}

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  width: 100%;
}

.container--narrow { max-width: var(--max-w-narrow); }

/* Section heading kit */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cf-orange);
  margin-bottom: var(--s-4);
}
.eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--cf-orange);
}

.section-title {
  font-size: var(--fs-h1);
  margin-bottom: var(--s-3);
  color: var(--text-1);
}
.section-lead {
  color: var(--text-2);
  max-width: 60ch;
  margin-bottom: var(--s-7);
}

/* Reusable card */
.card {
  background: var(--bg-1);
  background-image: var(--grad-card);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: var(--s-6);
  transition: border-color var(--dur) var(--ease-out), transform var(--dur) var(--ease-out);
}
.card:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

/* Chip / pill */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: var(--r-full);
  font-size: var(--fs-xs);
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  background: rgba(246,130,31,0.08);
  color: var(--cf-orange-soft);
  border: 1px solid rgba(246,130,31,0.25);
}
.chip--mute {
  background: rgba(255,255,255,0.04);
  color: var(--text-2);
  border-color: var(--line);
}
.chip--cyan {
  background: rgba(56,189,248,0.08);
  color: var(--accent-cyan);
  border-color: rgba(56,189,248,0.25);
}
.chip--mint {
  background: rgba(94,234,212,0.08);
  color: var(--accent-mint);
  border-color: rgba(94,234,212,0.25);
}
.chip--violet {
  background: rgba(167,139,250,0.08);
  color: var(--accent-violet);
  border-color: rgba(167,139,250,0.25);
}

/* Subtle scanline / grid bg helper */
.grid-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse at center, rgba(0,0,0,0.9), transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse at center, rgba(0,0,0,0.9), transparent 75%);
}

/* Section divider */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line-strong), transparent);
  border: 0;
  margin: 0;
}

/* Reveal animation hook (JS toggles .is-in) */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 700ms var(--ease-out), transform 700ms var(--ease-out);
  will-change: opacity, transform;
}
.reveal.is-in { opacity: 1; transform: none; }

/* Focus */
:focus-visible {
  outline: 2px solid var(--cf-orange);
  outline-offset: 3px;
  border-radius: 4px;
}

@media (max-width: 768px) {
  .section { padding: var(--s-8) var(--s-4); }
}