/* PithClaw · 揽萃云 — Design Tokens */
:root{
  /* Color — 黛紫夜青 + 霓虹青瓷 */
  --void: oklch(13% 0.035 285);
  --void-2: oklch(16% 0.045 282);
  --ink: oklch(21% 0.055 278);
  --ink-2: oklch(26% 0.06 274);
  --mist: oklch(42% 0.045 265);
  --line: oklch(35% 0.04 268 / 0.55);
  --line-soft: oklch(35% 0.04 268 / 0.22);

  --celadon: oklch(82% 0.13 182);         /* 霓虹青瓷 · 主色 */
  --celadon-2: oklch(72% 0.14 186);
  --celadon-deep: oklch(55% 0.12 190);
  --celadon-glow: oklch(82% 0.18 182 / 0.55);

  --zhusha: oklch(66% 0.19 28);           /* 朱砂印 */
  --jin: oklch(84% 0.13 85);              /* 金箔 */
  --lilac: oklch(70% 0.14 310);           /* 黛紫点缀 */

  --bone: oklch(94% 0.01 90);
  --bone-dim: oklch(78% 0.015 90 / 0.75);
  --bone-mute: oklch(68% 0.02 90 / 0.55);

  /* Type */
  --ff-serif: "Noto Serif SC", "Songti SC", "SimSun", serif;
  --ff-sans: "Space Grotesk", "Inter", "HarmonyOS Sans SC", system-ui, sans-serif;
  --ff-mono: "JetBrains Mono", "SF Mono", ui-monospace, monospace;

  /* Rhythm */
  --radius-s: 4px;
  --radius-m: 8px;
  --radius-l: 14px;

  --grid: 8px;
  --gutter: clamp(16px, 2vw, 32px);

  /* Motion */
  --ease: cubic-bezier(.2,.7,.2,1);
  --ease-out: cubic-bezier(.16,.84,.3,1);
}

*,*::before,*::after{ box-sizing: border-box; }
html,body{ margin:0; padding:0; }
html{ background: var(--void); color: var(--bone); -webkit-font-smoothing: antialiased; }
body{
  font-family: var(--ff-sans);
  font-size: 15px;
  line-height: 1.55;
  color: var(--bone);
  background:
    radial-gradient(1200px 800px at 80% -10%, oklch(30% 0.1 282 / 0.35), transparent 60%),
    radial-gradient(900px 700px at -10% 60%, oklch(30% 0.12 190 / 0.22), transparent 60%),
    var(--void);
  min-height: 100vh;
  overflow-x: hidden;
}
a{ color: inherit; text-decoration: none; }
button{ font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
img{ display:block; max-width: 100%; }
::selection{ background: var(--celadon-glow); color: var(--void); }

/* Grain + grid overlays (global, optional) */
.grid-overlay{
  position: fixed; inset: 0; pointer-events: none; z-index: 1;
  background-image:
    linear-gradient(var(--line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px);
  background-size: 80px 80px, 80px 80px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, black 30%, transparent 80%);
  opacity: .35;
}
.grain-overlay{
  position: fixed; inset: 0; pointer-events: none; z-index: 2; mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' seed='3'/><feColorMatrix values='0 0 0 0 0.9  0 0 0 0 0.9  0 0 0 0 0.9  0 0 0 0.6 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
  opacity: var(--grain-opacity, .08);
}

/* Chrome scrollbars */
::-webkit-scrollbar{ width: 10px; height: 10px; }
::-webkit-scrollbar-track{ background: var(--void); }
::-webkit-scrollbar-thumb{ background: var(--ink-2); border-radius: 10px; }
::-webkit-scrollbar-thumb:hover{ background: var(--celadon-deep); }

/* Utility */
.mono{ font-family: var(--ff-mono); font-size: 11px; letter-spacing: .08em; text-transform: uppercase; color: var(--bone-mute); }
.serif{ font-family: var(--ff-serif); font-weight: 500; letter-spacing: .02em; }
.hairline{ height: 1px; background: linear-gradient(90deg, transparent, var(--line), transparent); }
.dot{ width: 6px; height: 6px; border-radius: 50%; background: var(--celadon); box-shadow: 0 0 12px var(--celadon-glow); display:inline-block; }

/* Focus */
:focus-visible{ outline: 1px solid var(--celadon); outline-offset: 2px; }

/* Button base */
.btn{
  display: inline-flex; align-items: center; gap: 10px;
  padding: 10px 16px; border: 1px solid var(--line);
  border-radius: 999px; font-family: var(--ff-mono); font-size: 11px;
  letter-spacing: .12em; text-transform: uppercase; color: var(--bone);
  background: oklch(22% 0.05 278 / 0.35);
  backdrop-filter: blur(8px);
  transition: all .35s var(--ease);
}
.btn:hover{ border-color: var(--celadon); color: var(--celadon); box-shadow: 0 0 28px var(--celadon-glow); }
.btn--solid{ background: var(--celadon); color: var(--void); border-color: var(--celadon); }
.btn--solid:hover{ background: var(--bone); border-color: var(--bone); color: var(--void); }

/* Panel */
.panel{
  border: 1px solid var(--line);
  background: linear-gradient(180deg, oklch(20% 0.05 278 / 0.55), oklch(15% 0.04 282 / 0.55));
  backdrop-filter: blur(10px);
  border-radius: var(--radius-m);
}

/* Scroll-shown */
.reveal{ opacity: 0; transform: translateY(18px); transition: opacity .8s var(--ease), transform .8s var(--ease); }
.reveal.in{ opacity: 1; transform: none; }