/* 계단 계산기(Stair Calc) 전용 스타일
   테마: Square Check와 같은 CLAUDE.md 5-4 "전문가용 시공 도구" 카테고리라 절제된
   다크모드를 이어가되, 목재·계단을 연상시키는 앰버(amber) 포인트 컬러를 써서
   같은 다크모드 계열 안에서도 다른 도구(시안)와 확실히 구분되게 했습니다. */

:root {
  --stc-bg: #0f172a;
  --stc-card-bg: #1e293b;
  --stc-border: #334155;
  --stc-text: #e2e8f0;
  --stc-text-muted: #94a3b8;
  --stc-accent: #f59e0b;
  --stc-accent-dark: #d97706;
  --stc-warning: #fbbf24;
  --stc-radius: 12px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  background: var(--stc-bg);
  color: var(--stc-text);
  line-height: 1.6;
}

.top-bar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  height: 56px;
  padding: 0 16px;
  background: var(--stc-bg);
}

/* PC처럼 넓은 화면에서는 스크롤을 올렸을 때 상단바 전체가 화면을 가리지 않도록,
   막대(.top-bar) 자체를 폭 전체가 아니라 버튼 크기만큼만 남기고 배경도 지웁니다.
   .back-link 자체가 이미 불투명한 배경(pill 버튼)을 갖고 있어서 겹침 문제 없이
   버튼만 떠 있는 것처럼 보입니다. */
@media (min-width: 768px) {
  .top-bar {
    width: fit-content;
    height: auto;
    padding: 12px 16px 0;
    background: transparent;
  }
}

.back-link {
  display: inline-block;
  padding: 6px 14px;
  background: var(--stc-card-bg);
  border: 1px solid var(--stc-border);
  border-radius: 999px;
  color: var(--stc-text-muted);
  text-decoration: none;
  font-size: 0.85rem;
}

.back-link:hover {
  color: var(--stc-accent);
  border-color: var(--stc-accent);
}

.page-header {
  text-align: center;
  padding: 10px 16px 16px;
}

.page-header h1 {
  margin: 0 0 8px;
  font-family: "Encode Sans Expanded", -apple-system, BlinkMacSystemFont, sans-serif;
  font-weight: 800;
  font-size: 2.2rem;
  letter-spacing: -0.01em;
  color: var(--stc-accent);
}

.subtitle {
  margin: 0;
  color: var(--stc-text-muted);
  font-size: 1.1rem;
}

.tagline-extra {
  margin: 6px 0 0;
  color: var(--stc-text-muted);
  font-size: 0.9rem;
}

main {
  max-width: 560px;
  margin: 0 auto;
  padding: 0 16px 48px;
}

.stc-setup-section {
  margin-top: 24px;
  background: var(--stc-card-bg);
  border: 1px solid var(--stc-border);
  border-radius: var(--stc-radius);
  padding: 20px;
}

.stc-field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.stc-field label {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--stc-text-muted);
}

.stc-input-with-unit {
  display: flex;
  align-items: center;
  gap: 10px;
}

.stc-input-with-unit input {
  flex: 1;
  padding: 12px 14px;
  font-size: 1.1rem;
  border: 2px solid var(--stc-border);
  border-radius: 8px;
  outline: none;
  color: var(--stc-text);
  background: var(--stc-bg);
  font-family: inherit;
  transition: border-color 0.15s ease;
}

.stc-input-with-unit input:focus {
  border-color: var(--stc-accent);
}

.stc-unit {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--stc-text-muted);
}

.stc-error {
  margin: 10px 0 0;
  padding: 10px 14px;
  background: rgba(248, 113, 113, 0.12);
  border: 1px solid rgba(248, 113, 113, 0.4);
  border-radius: 8px;
  color: #f87171;
  font-size: 0.85rem;
}

.stc-result-section {
  margin-top: 20px;
  background: var(--stc-card-bg);
  border: 1px solid var(--stc-border);
  border-radius: var(--stc-radius);
  padding: 20px;
  text-align: center;
}

.stc-diagram {
  width: 100%;
  max-width: 462px;
  height: auto;
}

.stc-dim-line {
  stroke: var(--stc-text-muted);
  stroke-width: 1;
}

.stc-dim-label {
  font-size: 11px;
  fill: var(--stc-text-muted);
  font-weight: 600;
}

.stc-dim-leader {
  stroke: var(--stc-text-muted);
  stroke-width: 1;
  stroke-dasharray: 3 3;
  opacity: 0.7;
}

.stc-dim-line-detail {
  stroke: var(--stc-accent);
  stroke-width: 1.5;
}

.stc-dim-label-detail {
  font-size: 11px;
  fill: var(--stc-accent);
  font-weight: 700;
}

.stc-angle-arc {
  stroke: var(--stc-text-muted);
  stroke-width: 1.5;
}

.stc-angle-label {
  font-size: 12px;
  fill: var(--stc-accent);
  font-weight: 700;
}

.stc-result-grid {
  margin-top: 12px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}

.stc-result-card {
  background: var(--stc-bg);
  border: 1px solid var(--stc-border);
  border-radius: 10px;
  padding: 14px 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.stc-result-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--stc-text-muted);
}

.stc-result-value {
  font-family: "Encode Sans Expanded", -apple-system, BlinkMacSystemFont, sans-serif;
  font-weight: 800;
  font-size: 1.3rem;
  color: var(--stc-accent);
}

.stc-warning {
  margin: 14px 0 0;
  padding: 10px 14px;
  background: rgba(251, 191, 36, 0.12);
  border: 1px solid rgba(251, 191, 36, 0.4);
  border-radius: 8px;
  color: var(--stc-warning);
  font-size: 0.85rem;
  text-align: left;
}

.stc-disclaimer {
  margin: 16px 0 0;
  padding-top: 16px;
  border-top: 1px solid var(--stc-border);
  font-size: 0.78rem;
  color: var(--stc-text-muted);
  text-align: left;
}

.ads-container {
  margin: 40px 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--stc-card-bg);
  border: 1px solid var(--stc-border);
  border-radius: var(--stc-radius);
  color: var(--stc-text-muted);
  font-size: 0.85rem;
}

.ads-rail {
  position: fixed;
  top: 50%;
  transform: translateY(-50%);
  width: 160px;
  margin: 0;
  display: none;
  z-index: 5;
}

.ads-rail-left {
  left: 16px;
}

.ads-rail-right {
  right: 16px;
}

@media (min-width: 892px) {
  .ads-rail {
    display: flex;
  }
}

.info-section {
  margin-top: 24px;
}

.info-section h2 {
  color: var(--stc-accent);
  font-size: 1.35rem;
  margin-top: 32px;
}

.faq-list .faq-item {
  margin-bottom: 16px;
}

.faq-list dt {
  font-weight: 600;
  color: var(--stc-text);
  margin-bottom: 4px;
}

.faq-list dd {
  margin: 0;
  color: var(--stc-text-muted);
}

.footer-links {
  margin: 8px 0 0;
}

.footer-links a {
  color: var(--stc-text-muted);
  text-decoration: underline;
}

.footer-links a:hover {
  color: var(--stc-accent);
}

.page-footer {
  text-align: center;
  padding: 24px 16px 40px;
  color: var(--stc-text-muted);
  font-size: 0.85rem;
}

.scroll-top-btn {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 20;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: none;
  background: var(--stc-accent);
  color: #0f172a;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 2px 10px rgba(245, 158, 11, 0.3);
  transition: background 0.12s ease, transform 0.12s ease;
}

.scroll-top-btn:hover {
  background: var(--stc-accent-dark);
  transform: translateY(-2px);
}

.scroll-top-btn[hidden] {
  display: none;
}

@media (max-width: 480px) {
  .page-header h1 {
    font-size: 1.7rem;
  }

  .stc-result-value {
    font-size: 1.1rem;
  }
}