:root {
  --ink: #444;
  --ink-strong: #34343c;
  --text: #333;
  --muted: #606060;
  --accent: #f7931a;
  --red: #b73a3a;
  --soft-bg: #f7f8fa;
  --grey-bg: #eee;
  --dark: #444;
  --line: #e7eaf0;
  --shadow: 0 3px 5px rgba(0, 0, 0, .18);
  --container: 1240px;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 50px; }
body {
  margin: 0;
  font-family: "Play", Arial, sans-serif;
  font-size: 19px;
  line-height: 1.6;
  color: var(--text);
  background: #fff;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
h1, h2, h3, p, ul, ol, dl, dd { margin: 0; }
.container { width: 100%; max-width: calc(var(--container) + 30px); margin: 0 auto; padding: 0 15px; }

.section-title {
  font-size: 37px;
  font-weight: 700;
  font-style: italic;
  line-height: 1.2;
  color: var(--ink);
  text-align: center;
  margin-bottom: 40px;
}
.section-title-left { text-align: left; margin-bottom: 20px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .95);
  border-bottom: 5px solid var(--dark);
}
.header-inner { display: flex; align-items: center; justify-content: center; height: 50px; padding: 0 15px; }
.brand { display: none; }
.site-nav { display: flex; }
.site-nav a {
  display: block;
  padding: 0 18px;
  line-height: 50px;
  font-size: 15px;
  font-weight: 700;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--ink);
  transition: color .2s;
}
.site-nav a:hover { color: var(--accent); }
.nav-toggle { display: none; }

/* ---------- Hero ---------- */
.hero-section { background: #a1a1a1; padding: 50px 0; border-bottom: 5px solid var(--dark); }
.hero-slider { position: relative; overflow: hidden; }
.hero-track { display: flex; transition: transform .6s ease; }
.hero-slide { flex: 0 0 100%; display: block; }
.hero-slide img { width: 100%; }
.hero-mobile { display: none; }
.hero-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 30px;
  height: 50px;
  border: 0;
  background: rgba(68, 68, 68, .6);
  color: #fff;
  font-size: 30px;
  line-height: 1;
  cursor: pointer;
}
.hero-prev { left: 0; }
.hero-next { right: 0; }
.hero-arrow:hover { background: var(--dark); }

/* ---------- Intro（白色斜切面板疊在照片上） ---------- */
.intro-section {
  position: relative;
  background: #1b1c21 url("../images/intro-bg.jpg") no-repeat 100% 50% / contain;
  min-height: 489px;
}
.intro-panel {
  position: relative;
  width: 63%;
  min-height: 489px;
  padding: 60px 140px 60px 105px;
  background: #fff;
  clip-path: polygon(0 0, 100% 0, 91% 100%, 0 100%);
}
.intro-title { font-size: 36px; font-weight: 700; line-height: 1.4; color: var(--ink-strong); margin-bottom: 25px; }
.intro-panel p { color: var(--ink); margin-bottom: 20px; }
.intro-list { padding-left: 20px; color: var(--muted); }

/* ---------- About ---------- */
.about-section { background: var(--soft-bg); padding: 80px 0 60px; }
.about-grid { display: grid; grid-template-columns: 499px 1fr; gap: 70px; align-items: start; margin-top: -75px; }
.about-photo { width: 100%; }
.profile-table { margin: 0 0 15px; }
.profile-table > div { display: flex; justify-content: space-between; gap: 15px; padding: 7px 15px; }
.profile-table dt { flex: 0 1 auto; max-width: 45%; }
.profile-table dd { flex: 1 1 auto; }
.profile-table > div:nth-child(even) { background: var(--grey-bg); }
.profile-table dt, .profile-table dd { color: var(--ink-strong); }
.profile-table dd { text-align: right; }
.about-certificate { width: calc(100% - 30px); margin: 0 15px; box-shadow: var(--shadow); }

.about-timeline { position: relative; padding-top: 91px; }
.timeline-head { border-top: 1px solid var(--line); border-left: 1px solid var(--line); padding: 15px 0 40px 40px; margin-left: -40px; }
.timeline-head h3 { font-size: 26px; font-weight: 400; line-height: 1.4; color: var(--ink); }
.timeline-head p { color: var(--text); }
.timeline { list-style: none; padding: 0 0 0 40px; margin-left: -40px; border-left: 1px solid var(--line); }
.timeline li { position: relative; padding-bottom: 12px; }
.timeline li::before {
  content: "";
  position: absolute;
  left: -54px;
  top: 2px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: #fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='%23c9c9c9' stroke-width='1.2'%3E%3Cpath d='M4 14V2.5m0 0h7.5l-1.5 2.5 1.5 2.5H4'/%3E%3C/svg%3E") no-repeat center / 13px;
}
.timeline-year { display: block; font-size: 17px; color: var(--red); }

/* ---------- 「The lead of dental implant」深色塊＋右圖 ---------- */
.lead-section { padding: 80px 0; }
.lead-section-alt { background: var(--grey-bg); }
.lead-grid { display: grid; grid-template-columns: 1fr 1fr; max-width: 1270px; margin: 0 auto; padding: 0 15px; }
.lead-box {
  background: var(--dark);
  color: #fff;
  text-align: center;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 40px 35px;
}
.lead-box h3 { font-size: 25px; font-weight: 700; line-height: 1.6; margin-bottom: 5px; }
.lead-box p { font-size: 21px; }
.lead-image { width: 100%; height: 100%; object-fit: cover; }
.lead-section:not(.lead-section-alt) { padding-top: 40px; padding-bottom: 0; }

/* ---------- Cards ---------- */
.card { background: #fff; border-radius: 5px; box-shadow: var(--shadow); padding: 20px; }
.card-title { font-size: 23px; font-weight: 700; color: var(--ink); margin-bottom: 10px; }
.chevron-list { list-style: none; padding: 0; }
.chevron-list li { position: relative; padding-left: 25px; margin-bottom: 20px; }
.chevron-list li:last-child { margin-bottom: 0; }
.chevron-list li::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 10px;
  width: 7px;
  height: 7px;
  border-top: 1.5px solid #555;
  border-right: 1.5px solid #555;
  transform: rotate(45deg);
}

.pubs-section { padding: 40px 0 80px; }
.pubs-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; align-items: start; }
.pubs-col { display: grid; gap: 20px; }

/* ---------- Editorials ---------- */
.editorials-section { padding: 0 0 80px; }
.editorials-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; align-items: start; margin-bottom: 40px; }
.card-label { font-size: 19px; font-weight: 700; color: var(--ink); border-left: 4px solid var(--accent); padding-left: 10px; line-height: 1; margin-bottom: 15px; }
.editorials-grid p { padding-left: 15px; margin-bottom: 10px; }
.editorials-grid .card-small { font-size: 15px; color: var(--muted); line-height: 1.4; padding-left: 0; }
.book-covers { display: flex; gap: 30px; padding-left: 0; }
.book-covers img { width: 118px; }

/* Reference（可收合） */
.reference { background: #fff; box-shadow: 1px 2px 5px rgba(0, 0, 0, .07); }
.reference-toggle {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: 15px 15px 15px 15px;
  border: 0;
  background: #fff;
  font: italic 700 37px/1.4 "Play", Arial, sans-serif;
  color: var(--ink);
  text-align: left;
  cursor: pointer;
}
.reference-icon { position: relative; width: 16px; height: 16px; margin-right: 20px; }
.reference-icon::before, .reference-icon::after { content: ""; position: absolute; background: var(--accent); }
.reference-icon::before { left: 0; top: 7px; width: 16px; height: 3px; }
.reference-icon::after { left: 7px; top: 0; width: 3px; height: 16px; transition: transform .2s; }
.reference-toggle[aria-expanded="true"] .reference-icon::after { transform: scaleY(0); }
.reference-list { columns: 2; column-gap: 30px; padding: 30px 20px; }
.reference-item {
  display: block;
  break-inside: avoid;
  margin-bottom: 20px;
  background: #fff;
  box-shadow: var(--shadow);
  text-decoration: none;
  color: var(--ink);
}
.reference-item span { display: block; padding: 12px 15px; text-align: center; font-size: 17px; }
.reference-item:hover span { color: var(--accent); }

/* ---------- Case gallery ---------- */
.case-section { padding: 80px 0; }
.case-item { text-align: center; padding: 30px 0 25px; }
.case-item + .case-item { border-top: 0; }
.case-item::before {
  content: "";
  display: block;
  width: 370px;
  max-width: 60%;
  margin: 0 auto 30px;
  border-top: 1px dashed #aaa;
}
.case-item h3 { font-size: 25px; font-weight: 700; color: var(--ink); line-height: 1.4; margin-bottom: 15px; }
.case-image { margin: 0 auto; box-shadow: var(--shadow); }
.case-image-plain { box-shadow: none; }
.case-lead { font-size: 19px; font-weight: 700; color: var(--text); margin-bottom: 10px; }
.case-caption { color: var(--ink-strong); margin-top: 5px; }
.btn-dark {
  display: inline-block;
  margin-top: 30px;
  padding: 12px 25px;
  background: var(--dark);
  color: #fff;
  font-size: 16px;
  text-decoration: none;
  transition: background .2s;
}
.btn-dark:hover { background: var(--accent); }

/* ---------- Contact ---------- */
.contact-section { background: var(--soft-bg); padding: 80px 0 60px; }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; align-items: start; }
.contact-map { width: 100%; height: 450px; border: 0; }
.contact-info { padding-left: 0; }
.contact-info ul { padding-left: 20px; color: var(--muted); }
.contact-info a { text-decoration: none; }

/* ---------- Footer ---------- */
.site-footer { background: var(--dark); border-top: 2px solid var(--red); padding: 20px 15px 10px; }
.site-footer p { font-size: 15px; color: #f3f3f3; text-align: center; }

/* ---------- Lightbox ---------- */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px 15px;
  background: rgba(0, 0, 0, .85);
}
.lightbox[hidden] { display: none; }
.lightbox img { max-height: 100%; width: auto; }
.lightbox-close {
  position: absolute;
  top: 10px;
  right: 15px;
  border: 0;
  background: none;
  color: #fff;
  font-size: 44px;
  line-height: 1;
  cursor: pointer;
}

/* ---------- 平板 ---------- */
@media (max-width: 1199px) {
  .intro-panel { width: 70%; padding: 50px 90px 50px 40px; }
  .about-grid { grid-template-columns: 40% 1fr; gap: 50px; }
}

/* ---------- 手機 ---------- */
@media (max-width: 767px) {
  body { font-size: 19px; line-height: 1.4; }
  .section-title { font-size: 29px; margin-bottom: 25px; }

  .site-header { background: #fff; border-bottom-width: 1px; }
  .header-inner { justify-content: center; position: relative; }
  .brand { display: block; }
  .nav-toggle {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 4px;
    position: absolute;
    left: 15px;
    top: 9px;
    width: 34px;
    height: 32px;
    padding: 0 6px;
    border: 0;
    background: none;
    cursor: pointer;
  }
  .nav-toggle span { display: block; height: 2px; background: var(--ink); }
  .site-nav {
    display: none;
    position: absolute;
    top: 50px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: #fff;
    border-bottom: 1px solid var(--line);
    box-shadow: 0 4px 6px rgba(0, 0, 0, .08);
  }
  .site-nav.open { display: flex; }
  .site-nav a { padding: 0 20px; line-height: 44px; border-top: 1px solid var(--line); }

  .hero-section { padding: 0; border-bottom: 0; background: none; }
  .hero-desktop { display: none; }
  .hero-mobile { display: block; }

  .intro-section { background: #fff; min-height: 0; }
  .intro-panel { width: auto; min-height: 0; padding: 60px 20px; clip-path: none; }
  .intro-title { font-size: 25px; }

  .about-section { padding: 40px 0 60px; }
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .about-grid { margin-top: 0; }
  .profile-table > div { padding: 7px 8px; gap: 10px; }
  .about-timeline { padding-top: 0; }
  .timeline-head, .timeline { margin-left: 0; }
  .timeline-head { padding-left: 30px; }
  .timeline { padding-left: 30px; }
  .timeline li::before { left: -44px; }

  .lead-section, .lead-section:not(.lead-section-alt) { padding: 0; background: none; }
  .lead-grid { grid-template-columns: 1fr; padding: 0; }
  .lead-image { height: auto; }
  .lead-box { padding: 30px 15px; }
  .lead-box h3 { font-size: 22px; }
  .lead-box p { font-size: 19px; line-height: 1.5; }
  .pubs-section { padding: 40px 0; }
  .book-covers img { width: calc(50% - 15px); max-width: 150px; }

  .pubs-grid, .editorials-grid, .contact-grid { grid-template-columns: 1fr; gap: 20px; }
  .reference-toggle { font-size: 29px; }
  .reference-list { columns: 1; padding: 20px 10px; }

  .case-section { padding: 40px 0; }
  .case-item h3 { font-size: 19px; font-weight: 400; }
  .case-item::before { width: 140px; }

  .contact-section { padding: 40px 0; }
  .contact-map { height: 300px; order: 2; }
}