/* 템포 카운터 도구 전용 스타일
   테마: 운동 도구답게 에너지틱한 계열이지만 인터벌 타이머(오렌지)와는 구별되도록
   차분하면서도 리드미컬한 느낌의 에메랄드 그린을 기본색으로 씁니다. 하강 구간은
   진한 에메랄드, 상승 구간은 밝은 라임으로 살짝 색을 바꿔서 두 구간이 번갈아
   재생되고 있다는 걸 화면만 봐도 알 수 있게 합니다. */

:root {
  --tcounter-primary: #059669;
  --tcounter-primary-dark: #047857;
  --tcounter-up: #65a30d;
  --tcounter-up-dark: #4d7c0f;
  --tcounter-bg: #f7f7f7;
  --tcounter-card-bg: #ffffff;
  --tcounter-border: #e2e8f0;
  --tcounter-text: #212529;
  --tcounter-text-muted: #53575e;
  --tcounter-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(--tcounter-bg);
  color: var(--tcounter-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(--tcounter-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(--tcounter-card-bg);
  border: 1px solid var(--tcounter-border);
  border-radius: 999px;
  color: var(--tcounter-text-muted);
  text-decoration: none;
  font-size: 0.85rem;
  box-shadow: 0 1px 6px rgba(0, 0, 0, 0.08);
}

.back-link:hover {
  color: var(--tcounter-primary);
}

.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(--tcounter-primary-dark);
}

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

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

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

.tcounter-display-section {
  margin-top: 24px;
  text-align: center;
  background: var(--tcounter-card-bg);
  border: 2px solid var(--tcounter-border);
  border-radius: var(--tcounter-radius);
  padding: 52px 20px;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.tcounter-display-section.is-down {
  background: #ecfdf5;
  border-color: var(--tcounter-primary);
}

.tcounter-display-section.is-up {
  background: #f7fee7;
  border-color: var(--tcounter-up);
}

.tcounter-phase-label {
  margin: 0;
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--tcounter-text-muted);
}

.tcounter-display-section.is-down .tcounter-phase-label {
  color: var(--tcounter-primary-dark);
}

.tcounter-display-section.is-up .tcounter-phase-label {
  color: var(--tcounter-up-dark);
}

.tcounter-rep-count {
  margin: 14px 0 0;
  font-family: "Encode Sans Expanded", -apple-system, BlinkMacSystemFont, sans-serif;
  font-weight: 800;
  font-size: 7rem;
  letter-spacing: -0.02em;
  color: var(--tcounter-text);
}

.tcounter-rep-label {
  margin: 6px 0 0;
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--tcounter-text-muted);
}

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

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

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

.tcounter-field input,
.tcounter-field select {
  padding: 11px 12px;
  font-size: 1rem;
  border: 2px solid var(--tcounter-border);
  border-radius: 8px;
  outline: none;
  color: var(--tcounter-text);
  font-family: inherit;
  background: var(--tcounter-card-bg);
  transition: border-color 0.15s ease;
}

.tcounter-field input:focus,
.tcounter-field select:focus {
  border-color: var(--tcounter-primary);
}

.tcounter-field input:disabled,
.tcounter-field select:disabled {
  background: #f3f4f6;
  color: var(--tcounter-text-muted);
}

.tcounter-error {
  margin: 12px 0 0;
  padding: 10px 14px;
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: 8px;
  color: #b91c1c;
  font-size: 0.85rem;
}

.tcounter-controls {
  margin-top: 18px;
  display: flex;
  gap: 10px;
}

.tcounter-btn {
  flex: 1;
  padding: 13px 0;
  font-size: 1rem;
  font-weight: 700;
  border: 1px solid var(--tcounter-border);
  border-radius: 999px;
  background: var(--tcounter-card-bg);
  color: var(--tcounter-text-muted);
  cursor: pointer;
  transition: background 0.12s ease, transform 0.08s ease;
}

.tcounter-btn-primary {
  border: none;
  background: var(--tcounter-primary);
  color: #fff;
}

.tcounter-btn-primary:hover {
  background: var(--tcounter-primary-dark);
}

/* 정지 버튼은 다른 보조 버튼과 같은 흰 배경이면 테두리가 옅어서 잘 안 보인다는
   피드백이 있어, 빨간 계열 테두리·글자색을 줘서 "동작을 멈추는 버튼"임을
   시각적으로도 더 뚜렷하게 구분되게 했습니다. */
.tcounter-btn-stop {
  border-color: #dc2626;
  color: #dc2626;
}

.tcounter-btn-stop:hover {
  background: #fef2f2;
  color: #b91c1c;
}

.tcounter-btn:active {
  transform: scale(0.98);
}

.ads-container {
  margin: 40px 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--tcounter-card-bg);
  border: 1px solid var(--tcounter-border);
  border-radius: var(--tcounter-radius);
  color: var(--tcounter-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(--tcounter-primary-dark);
  font-size: 1.35rem;
  margin-top: 32px;
}

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

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

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

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

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

.footer-links a:hover {
  color: var(--tcounter-primary);
}

.page-footer {
  text-align: center;
  padding: 24px 16px 40px;
  color: var(--tcounter-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(--tcounter-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 2px 10px rgba(5, 150, 105, 0.3);
  transition: background 0.12s ease, transform 0.12s ease;
}

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

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

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

  .tcounter-rep-count {
    font-size: 4.5rem;
  }

  .tcounter-phase-label {
    font-size: 1.6rem;
  }
}