/* SEPIA — Tinted Gray system tokens (mirrors RESEARCH/0.소스코드/ai_native_web globals.css). */
:root {
  --color-white: #FFFFFF;
  --color-snow: #FAFAFA;
  --color-pearl: #F5F5F5;
  --color-silk: #EEEEEE;
  --color-graphite: #1A1A2E;
  --color-charcoal: #2D2D44;
  --color-slate: #6B7280;
  --color-mist: #9CA3AF;
  --color-line: #E0E0E0;
  --color-line-light: #F0F0F0;
  --color-accent: #3B5998;
  --color-accent-light: #4A6BA8;

  --color-badge-blue-bg: #EFF1F5;
  --color-badge-blue-fg: #3B4157;
  --color-badge-blue-border: #D8DCE6;
  --color-badge-rose-bg: #F5F0F1;
  --color-badge-rose-fg: #8C7A7E;
  --color-badge-sage-solid: #3D5247;
  --color-badge-sage-text: #F0F5F2;

  --font-sans: "Pretendard Variable", "Pretendard", -apple-system, BlinkMacSystemFont, system-ui, Roboto, "Helvetica Neue", sans-serif;
  --font-mono: "SF Mono", "Fira Code", monospace;
}

* { box-sizing: border-box; }
html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
body {
  margin: 0; padding: 0;
  font-family: var(--font-sans);
  color: var(--color-graphite);
  background: var(--color-snow);
  line-height: 1.55;
}
::selection { background: var(--color-accent); color: white; }

.container { max-width: 720px; margin: 0 auto; padding: 0 20px; }

header { background: var(--color-white); border-bottom: 1px solid var(--color-line); }
.nav { display: flex; align-items: baseline; justify-content: space-between; padding: 18px 20px; }
.brand { font-weight: 700; font-size: 1.05rem; letter-spacing: 0.04em; color: var(--color-graphite); }
.brand-tag { color: var(--color-slate); font-size: 0.78rem; letter-spacing: 0.02em; }

.hero { padding: 56px 0 32px; text-align: center; }
.hero h1 { font-size: 2rem; font-weight: 700; margin: 0 0 12px; color: var(--color-graphite); }
.hero .sub { color: var(--color-slate); font-size: 1.02rem; margin: 0; }

.stepper { list-style: none; display: flex; gap: 8px; padding: 0; margin: 8px 0 24px; counter-reset: step; flex-wrap: wrap; }
.stepper li {
  flex: 1; min-width: 110px; text-align: center;
  padding: 10px 8px; font-size: 0.82rem; font-weight: 500;
  background: var(--color-pearl); color: var(--color-slate);
  border-radius: 6px; border: 1px solid var(--color-line);
}
.stepper li.active { background: var(--color-badge-blue-bg); color: var(--color-badge-blue-fg); border-color: var(--color-badge-blue-border); }
.stepper li.done { background: var(--color-badge-sage-solid); color: var(--color-badge-sage-text); border-color: var(--color-badge-sage-solid); }

.card {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: 8px;
  padding: 28px;
  margin: 16px 0;
}
.card.hidden { display: none; }
.card h2 { font-size: 1.1rem; font-weight: 600; margin: 0 0 14px; color: var(--color-charcoal); }
.muted { color: var(--color-slate); font-size: 0.92rem; margin: 0 0 18px; }
.fail { color: var(--color-badge-rose-fg); background: var(--color-badge-rose-bg); padding: 12px 14px; border-radius: 6px; font-size: 0.93rem; }

label { display: block; margin: 0 0 14px; font-size: 0.85rem; color: var(--color-slate); font-weight: 500; }
input[type="text"], input[type="email"], input[type="url"] {
  display: block; width: 100%; margin-top: 6px;
  padding: 10px 12px; font-family: var(--font-sans); font-size: 0.95rem;
  background: var(--color-snow); border: 1px solid var(--color-line); border-radius: 6px;
  color: var(--color-graphite); transition: border-color 120ms;
}
input:focus { outline: none; border-color: var(--color-accent); }

button {
  font-family: var(--font-sans); font-size: 0.92rem; font-weight: 500;
  padding: 10px 18px; border-radius: 6px; cursor: pointer; transition: background 120ms;
}
button.primary { background: var(--color-graphite); color: var(--color-white); border: 1px solid var(--color-graphite); }
button.primary:hover { background: var(--color-charcoal); }
button.primary:disabled { opacity: 0.55; cursor: progress; }
button.secondary { background: var(--color-white); color: var(--color-graphite); border: 1px solid var(--color-line); }
button.secondary:hover { background: var(--color-snow); }
button.copy { background: var(--color-pearl); color: var(--color-slate); border: 1px solid var(--color-line); padding: 4px 10px; font-size: 0.78rem; margin-left: 8px; border-radius: 4px; }

.kv { display: flex; align-items: center; gap: 10px; margin: 8px 0; flex-wrap: wrap; }
.kv .k { color: var(--color-slate); font-size: 0.82rem; min-width: 110px; }
.kv .v {
  font-family: var(--font-mono); font-size: 0.84rem;
  background: var(--color-pearl); padding: 6px 10px; border-radius: 4px;
  color: var(--color-graphite); flex: 1; min-width: 0; word-break: break-all;
}
.cert { background: var(--color-snow); border: 1px solid var(--color-line-light); border-radius: 6px; padding: 18px; }

.error { color: var(--color-badge-rose-fg); font-size: 0.88rem; margin-top: 10px; min-height: 1em; }

.foot { color: var(--color-mist); font-size: 0.78rem; text-align: center; padding: 32px 0; }

.hidden { display: none !important; }