/* dl-guide: bilingual columns + step cards + progress */

/* ── Bilingual two-column row ── */
.bi-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--s-lg);
}
.bi-row [lang="zh"] {
  font-family: var(--f-serif);
  color: var(--c-text);
  font-size: 1em;
  line-height: 1.9;
}
.bi-row [lang="en"] {
  font-family: var(--f-sans);
  color: var(--c-text);
  font-size: 1em;
  font-weight: 400;
  font-style: normal;
  line-height: 1.8;
  border-left: 1px solid var(--c-border);
  padding-left: var(--s-lg);
}
/* title row: no border, just side by side */
.bi-title {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--s-lg);
  align-items: baseline;
}
.bi-title [lang="zh"] {
  font-family: var(--f-serif);
}
.bi-title [lang="en"] {
  font-family: var(--f-sans);
  font-style: normal;
  font-weight: 400;
  color: var(--c-muted);
  font-size: 0.9em;
}

/* ── Progress bar ── */
.progress-bar {
  position: sticky;
  top: 60px;
  z-index: 10;
  background: rgba(250, 249, 247, 0.92);
  backdrop-filter: blur(8px);
  padding: var(--s-md) 0;
  border-bottom: 1px solid var(--c-border);
}
.progress-track {
  height: 4px;
  background: var(--c-border);
  border-radius: 2px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--c-accent);
  border-radius: 2px;
  width: 20%;
  transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}
.progress-label {
  font-size: 0.8rem;
  color: var(--c-muted);
  margin-top: var(--s-xs);
  font-family: var(--f-sans);
}

/* ── Step cards ── */
.steps-container {
  display: flex;
  flex-direction: column;
  gap: var(--s-lg);
  padding: var(--s-xl) 0;
}
.step-card {
  background: var(--c-white);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-sm);
  /* hidden state */
  display: none;
}
.step-card.active {
  display: block;
  animation: stepIn 0.5s ease both;
}
@keyframes stepIn {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: none; }
}
.step-card:hover {
  box-shadow: var(--shadow-md);
}

/* card inner layout */
.step-header {
  padding: var(--s-lg) var(--s-lg) 0;
}
.step-body {
  padding: 0 var(--s-lg);
}
.step-body p { margin-bottom: var(--s-sm); }
.step-body strong { font-weight: 600; }
.step-body em { font-style: italic; }
.step-footer {
  padding: var(--s-md) var(--s-lg) var(--s-lg);
}

/* Step badge */
.step-badge {
  display: inline-block;
  font-size: 0.78rem;
  font-family: var(--f-sans);
  color: var(--c-accent);
  background: rgba(139, 115, 85, 0.08);
  padding: 0.2em 0.7em;
  border-radius: 999px;
  margin-bottom: var(--s-md);
  font-weight: 500;
  letter-spacing: 0.02em;
}

/* ── Continue button ── */
.btn-continue {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 0.55em 1.3em;
  font-family: var(--f-sans);
  font-size: 0.9rem;
  color: var(--c-white);
  background: var(--c-accent);
  border: none;
  border-radius: var(--r-md);
  cursor: pointer;
  transition: background var(--ease), transform 0.15s ease;
}
.btn-continue:hover {
  background: var(--c-accent-hover);
  transform: translateY(-1px);
}
.btn-continue:active { transform: translateY(0); }
.btn-continue .sep {
  opacity: 0.5;
  margin: 0 0.15em;
}

/* ── Download links ── */
.download-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-sm);
  margin-top: var(--s-md);
}

/* ── Note block ── */
.step-note {
  margin: var(--s-md) var(--s-lg) var(--s-lg);
  padding: var(--s-md);
  background: var(--c-bg-alt);
  border-radius: var(--r-md);
  font-size: 0.85rem;
  color: var(--c-muted);
  line-height: 1.7;
}
.step-note .bi-row [lang="zh"],
.step-note .bi-row [lang="en"] {
  color: inherit;
  font-size: inherit;
  line-height: inherit;
}

/* ── Responsive ── */
@media (max-width: 720px) {
  .bi-row {
    grid-template-columns: 1fr;
    gap: var(--s-sm);
  }
  .bi-row [lang="en"] {
    border-left: none;
    padding-left: 0;
    padding-top: var(--s-sm);
    border-top: 1px solid var(--c-border);
  }
  .bi-title {
    grid-template-columns: 1fr;
    gap: 0.2em;
  }
  .step-header, .step-body, .step-footer {
    padding-left: var(--s-md);
    padding-right: var(--s-md);
  }
  .step-note {
    margin-left: var(--s-md);
    margin-right: var(--s-md);
  }
  .progress-bar { top: 52px; }
}