/* ===== Design tokens (OLED dark, green accent) ===== */
:root {
  --color-background: #0f172a;
  --color-surface: #1e293b;
  --color-surface-deep: #111a2e;
  --color-muted: #272f42;
  --color-border: #334155;
  --color-foreground: #f8fafc;
  --color-dim: #94a3b8;
  --color-accent: #22c55e;
  --color-accent-hover: #4ade80;
  --color-on-accent: #052e16;
  --color-destructive: #ef4444;
  --color-warn: #d4a72c;
  --radius: 12px;
  --radius-sm: 8px;
  --max-w: 860px;
  --dur: 200ms;
  --ease: cubic-bezier(0.2, 0, 0, 1);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Inter", "Pretendard", "Noto Sans KR", "Malgun Gothic", system-ui, sans-serif;
  background: var(--color-background);
  color: var(--color-foreground);
  line-height: 1.65;
  font-size: 16px;
}

/* 접근성 유틸 */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: 8px; top: -48px;
  background: var(--color-accent);
  color: var(--color-on-accent);
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  text-decoration: none;
  z-index: 100;
  transition: top var(--dur) var(--ease);
}
.skip-link:focus { top: 8px; }

:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.icon {
  width: 1.1em;
  height: 1.1em;
  flex: none;
  vertical-align: -0.18em;
}

/* ===== Header ===== */
.site-header {
  text-align: center;
  padding: 48px 16px 8px;
}
.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px; height: 56px;
  border-radius: 16px;
  background: linear-gradient(145deg, var(--color-surface), var(--color-muted));
  border: 1px solid var(--color-border);
  color: var(--color-accent);
  margin-bottom: 14px;
}
.logo-mark .icon { width: 30px; height: 30px; }
.site-header h1 {
  margin: 0 0 8px;
  font-size: clamp(1.4rem, 4vw, 1.9rem);
  font-weight: 700;
  letter-spacing: -0.01em;
}
.tagline { margin: 0; color: var(--color-dim); font-size: 1rem; }

/* ===== Layout ===== */
main, .content, .ad-slot, .site-footer {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 16px;
}

.panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px;
  margin: 16px 0;
}

.panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 12px;
}
.panel-head h2 {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-size: 1.02rem;
  font-weight: 600;
}
.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px; height: 26px;
  flex: none;
  border-radius: 50%;
  background: var(--color-muted);
  border: 1px solid var(--color-border);
  color: var(--color-accent);
  font-size: 0.85rem;
  font-weight: 700;
}

textarea {
  width: 100%;
  min-height: 176px;
  resize: vertical;
  background: var(--color-surface-deep);
  color: var(--color-foreground);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 14px;
  font-family: Consolas, "D2Coding", ui-monospace, monospace;
  font-size: 0.88rem;
  line-height: 1.55;
  transition: border-color var(--dur) var(--ease);
}
textarea::placeholder { color: #64748b; }
textarea:hover { border-color: #475569; }
textarea:focus-visible { outline-offset: 0; }

/* ===== Buttons ===== */
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 18px;
  background: var(--color-muted);
  color: var(--color-foreground);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.92rem;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              transform 100ms var(--ease);
}
.btn:hover:not(:disabled) { background: #313c55; border-color: #475569; }
.btn:active:not(:disabled) { transform: scale(0.97); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }

.btn-primary {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-on-accent);
  font-weight: 700;
}
.btn-primary:hover:not(:disabled) {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
}

.btn-ghost { background: transparent; }
.btn-ghost:hover:not(:disabled) { background: var(--color-muted); }

.fix-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  margin: 6px 0;
  flex-wrap: wrap;
}
.fix-bar .btn-primary { font-size: 1.02rem; padding: 13px 30px; }

.toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  color: var(--color-dim);
  font-size: 0.9rem;
  user-select: none;
  cursor: pointer;
}
.toggle input { accent-color: var(--color-accent); width: 16px; height: 16px; cursor: pointer; }

/* ===== Status & fix list ===== */
.status {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  margin-bottom: 12px;
  font-size: 0.92rem;
  white-space: pre-wrap;
  word-break: break-all;
}
.status .icon { margin-top: 3px; }
.status.ok {
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.55);
}
.status.ok .icon { color: var(--color-accent); }
.status.err {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.55);
}
.status.err .icon { color: var(--color-destructive); }

.fix-list {
  margin: 0 0 12px;
  padding: 12px 16px 12px 34px;
  background: rgba(212, 167, 44, 0.07);
  border: 1px solid rgba(212, 167, 44, 0.35);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: #e8d9a8;
}
.fix-list li { margin: 3px 0; }

.ad-slot { margin: 20px auto; text-align: center; }

/* ===== Content ===== */
.content {
  margin-top: 44px;
  padding-bottom: 8px;
  color: #cbd5e1;
  font-size: 0.95rem;
}
.content h2 {
  font-size: 1.18rem;
  color: var(--color-foreground);
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 8px;
  margin-top: 36px;
  font-weight: 600;
}
.content code {
  background: var(--color-muted);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 0.85em;
}
.content kbd {
  background: var(--color-muted);
  border: 1px solid var(--color-border);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 0 6px;
  font-size: 0.85em;
}
.content details {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  margin: 10px 0;
  transition: border-color var(--dur) var(--ease);
}
.content details:hover { border-color: #475569; }
.content details[open] { border-color: var(--color-accent); }
.content summary { cursor: pointer; font-weight: 600; color: var(--color-foreground); }
.content summary:focus-visible { outline-offset: 4px; }

/* ===== Footer ===== */
.site-footer {
  margin-top: 48px;
  padding: 24px 16px 36px;
  text-align: center;
  color: var(--color-dim);
  font-size: 0.83rem;
  border-top: 1px solid var(--color-border);
}
.site-footer p { margin: 4px 0; }

/* ===== Responsive ===== */
@media (max-width: 600px) {
  .site-header { padding-top: 32px; }
  .panel { padding: 16px; }
  .panel-head { flex-direction: column; align-items: flex-start; }
  .btn-row { width: 100%; }
  .btn-row .btn { flex: 1; }
  .fix-bar { flex-direction: column; gap: 8px; }
  .fix-bar .btn-primary { width: 100%; }
}

/* ===== Reduced motion ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}