/* ============================================================
   精誠資訊實習期末報告
   元智大學資訊管理學系 · 1142 學期
   Design System — "Ink & Gold" Editorial
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+TC:wght@400;500;700;900&family=Noto+Sans+TC:wght@300;400;500;700&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* ─── Reset ─────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
img { display: block; max-width: 100%; }
a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }

/* ─── Variables ─────────────────────────────────────── */
:root {
  /* Palette */
  --ink:          #0A1628;
  --ink-mid:      #1E3050;
  --ink-light:    #2D4870;
  --gold:         #C9943A;
  --gold-lt:      #E8BB70;
  --gold-pale:    #F5E6C8;
  --cream:        #F8F3EB;
  --cream-dk:     #F0E8DC;
  --white:        #FFFFFF;
  --text:         #1A2035;
  --text-mid:     #4A5568;
  --text-lt:      #6B7990;
  --blue:         #2D6BB0;
  --border:       #E2D9CC;
  --border-lt:    #EDE6DC;

  /* Typography */
  --serif:  'Noto Serif TC', Georgia, serif;
  --sans:   'Noto Sans TC', 'PingFang TC', 'Microsoft JhengHei', sans-serif;
  --mono:   'JetBrains Mono', 'Courier New', monospace;

  /* Layout */
  --nav-h:  64px;
  --max-w:  1200px;
  --r:      8px;
  --r-lg:   16px;

  /* Shadows */
  --s1: 0 2px  8px rgba(10,22,40,.08);
  --s2: 0 4px 16px rgba(10,22,40,.12);
  --s3: 0 8px 32px rgba(10,22,40,.16);
  --s4: 0 16px 48px rgba(10,22,40,.22);

  /* Easing */
  --ease: cubic-bezier(.4,0,.2,1);
  --t:    .25s var(--ease);
  --ts:   .4s  var(--ease);
}

/* ─── Base ───────────────────────────────────────────── */
body {
  font-family: var(--sans);
  color: var(--text);
  background: var(--cream);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

.container {
  width: min(var(--max-w), 100% - 3rem);
  margin-inline: auto;
}

h1, h2, h3, h4 {
  font-family: var(--serif);
  line-height: 1.3;
}

/* ─── Navigation ─────────────────────────────────────── */
.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 200;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  transition: background var(--t), box-shadow var(--t);
}

.nav.scrolled {
  background: rgba(252,249,244,.95);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: var(--s1);
}

.nav .container {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-logo {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 1rem;
  color: #fff;
  white-space: nowrap;
  transition: color var(--t);
  letter-spacing: .03em;
}
.nav.scrolled .nav-logo { color: var(--ink); }

.nav-links {
  display: flex;
  align-items: center;
  margin-left: auto;
  gap: 0;
}

.nav-links li { position: relative; }

.nav-links a {
  display: block;
  padding: .4rem .9rem;
  font-size: .8rem;
  color: rgba(255,255,255,.8);
  transition: color var(--t);
  letter-spacing: .02em;
  white-space: nowrap;
}
.nav.scrolled .nav-links a { color: var(--text-mid); }
.nav-links a:hover { color: var(--gold) !important; }

/* Dropdown */
.nav-drop-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: #fff;
  border-radius: var(--r);
  box-shadow: var(--s3);
  border: 1px solid var(--border);
  min-width: 160px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--t);
  overflow: hidden;
}
.nav-links li:hover .nav-drop-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.nav-drop-menu a {
  display: block !important;
  padding: .6rem 1.1rem !important;
  font-size: .78rem !important;
  color: var(--text-mid) !important;
  border-bottom: 1px solid var(--border-lt);
}
.nav-drop-menu a:last-child { border-bottom: none; }
.nav-drop-menu a:hover { background: var(--cream); color: var(--gold) !important; }

/* ─── Hero ───────────────────────────────────────────── */
.hero {
  height: 100vh;
  min-height: 600px;
  background: var(--ink);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Animated grid bg */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg, transparent, transparent 59px, rgba(255,255,255,.028) 59px, rgba(255,255,255,.028) 60px),
    repeating-linear-gradient(90deg, transparent, transparent 59px, rgba(255,255,255,.028) 59px, rgba(255,255,255,.028) 60px);
  animation: gridDrift 25s linear infinite;
}

@keyframes gridDrift {
  to { transform: translate(60px, 60px); }
}

.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 70% 30%, rgba(201,148,58,.08), transparent),
    radial-gradient(ellipse 40% 60% at 20% 70%, rgba(45,107,176,.07), transparent),
    linear-gradient(to top, rgba(10,22,40,.55), transparent 50%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 2rem;
  animation: riseIn .9s var(--ease) both;
}

@keyframes riseIn {
  from { opacity: 0; transform: translateY(28px); }
  to   { opacity: 1; transform: translateY(0); }
}

.hero-eyebrow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: .75rem;
  margin-bottom: 1.75rem;
  animation: riseIn .9s var(--ease) .15s both;
}

.hero-eyebrow-line {
  width: 36px;
  height: 1px;
  background: rgba(201,148,58,.45);
}

.hero-tag {
  font-family: var(--serif);
  font-size: .68rem;
  letter-spacing: .2em;
  color: var(--gold);
  text-transform: uppercase;
}

.hero-title {
  font-family: var(--serif);
  font-size: clamp(2.6rem, 6vw, 5rem);
  font-weight: 900;
  color: #fff;
  line-height: 1.15;
  margin-bottom: 1rem;
  animation: riseIn .9s var(--ease) .25s both;
}

.hero-subtitle {
  font-size: clamp(.85rem, 1.8vw, 1.05rem);
  color: rgba(255,255,255,.45);
  letter-spacing: .06em;
  margin-bottom: 1.75rem;
  animation: riseIn .9s var(--ease) .35s both;
}

.hero-rule {
  width: 56px;
  height: 2px;
  background: var(--gold);
  margin: 0 auto 2rem;
  animation: riseIn .9s var(--ease) .45s both;
}

.hero-members {
  display: flex;
  justify-content: center;
  gap: 3rem;
  animation: riseIn .9s var(--ease) .55s both;
}

.hero-member-name {
  font-family: var(--serif);
  font-size: 1.05rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: .05em;
}

.hero-member-id {
  font-family: var(--mono);
  font-size: .68rem;
  color: rgba(255,255,255,.35);
  margin-top: .2rem;
  letter-spacing: .12em;
}

@keyframes riseInCenter {
  from { opacity: 0; transform: translateX(-50%) translateY(28px); }
  to   { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* Scroll cue */
.hero-scroll {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .5rem;
  animation: riseInCenter .9s var(--ease) .8s both;
}

.hero-scroll-label {
  font-size: .58rem;
  letter-spacing: .22em;
  color: rgba(255,255,255,.25);
  text-transform: uppercase;
}

.hero-scroll-bar {
  width: 1px;
  height: 44px;
  background: linear-gradient(to bottom, rgba(201,148,58,.7), transparent);
  animation: barPulse 2.2s ease-in-out infinite;
}

@keyframes barPulse {
  0%, 100% { opacity: .35; transform: scaleY(1); }
  50%       { opacity: 1;   transform: scaleY(1.15); }
}

/* ─── Stats Band ─────────────────────────────────────── */
.stats-band {
  background: var(--ink);
  border-top: 1px solid rgba(201,148,58,.15);
  padding: 3.5rem 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

.stat-item {
  text-align: center;
  padding: 1rem;
  position: relative;
}

.stat-item + .stat-item::before {
  content: '';
  position: absolute;
  left: 0; top: 20%; bottom: 20%;
  width: 1px;
  background: rgba(255,255,255,.08);
}

.stat-num {
  font-family: var(--mono);
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 600;
  color: var(--gold);
  line-height: 1;
  margin-bottom: .5rem;
  letter-spacing: -.02em;
}

.stat-label {
  font-size: .75rem;
  color: rgba(255,255,255,.4);
  letter-spacing: .06em;
}

/* ─── Generic Section ────────────────────────────────── */
.section {
  padding: 5rem 0;
}

.section-hd {
  margin-bottom: 3.5rem;
}

.section-eyebrow {
  display: flex;
  align-items: center;
  gap: .6rem;
  margin-bottom: .75rem;
}

.section-eyebrow-text {
  font-family: var(--serif);
  font-size: .68rem;
  letter-spacing: .22em;
  color: var(--gold);
  text-transform: uppercase;
}

.section-eyebrow-line {
  width: 28px;
  height: 1px;
  background: var(--gold);
  opacity: .5;
}

.section-title {
  font-family: var(--serif);
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  font-weight: 900;
  color: var(--ink);
  line-height: 1.25;
}

.section-lead {
  font-size: .95rem;
  color: var(--text-mid);
  line-height: 1.85;
  margin-top: .85rem;
  max-width: 640px;
}

/* ─── Chapter Cards ──────────────────────────────────── */
.chapters-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.ch-card {
  background: #fff;
  border-radius: var(--r-lg);
  padding: 2.5rem;
  border: 1px solid var(--border);
  transition: transform var(--t), box-shadow var(--t), border-color var(--t);
  position: relative;
  overflow: hidden;
  cursor: pointer;
  display: block;
}

.ch-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(201,148,58,.06), transparent 60%);
  opacity: 0;
  transition: opacity var(--t);
}

.ch-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--s3);
  border-color: rgba(201,148,58,.3);
}

.ch-card:hover::before { opacity: 1; }

.ch-card-num {
  font-family: var(--serif);
  font-size: 3.2rem;
  font-weight: 900;
  color: var(--gold-pale);
  line-height: 1;
  margin-bottom: 1.25rem;
}

.ch-card-title {
  font-family: var(--serif);
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--text);
  margin-bottom: .4rem;
}

.ch-card-sub {
  font-size: .8rem;
  color: var(--text-lt);
  line-height: 1.6;
}

.ch-card-arrow {
  position: absolute;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--cream);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .85rem;
  transition: all var(--t);
}

.ch-card:hover .ch-card-arrow {
  background: var(--gold);
  color: #fff;
  transform: translate(2px, -2px);
}

/* ─── Team Cards ─────────────────────────────────────── */
.team-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.team-card {
  background: #fff;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--border);
  transition: transform var(--t), box-shadow var(--t);
  display: flex;
  flex-direction: column;
}

.team-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--s4);
}

.team-card-top {
  background: var(--ink);
  padding: 1.75rem 1.75rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.1rem;
}

.team-avatar {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: rgba(201,148,58,.12);
  border: 2px solid rgba(201,148,58,.3);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  flex-shrink: 0;
}

.team-name {
  font-family: var(--serif);
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: .02em;
}

.team-id {
  font-family: var(--mono);
  font-size: .68rem;
  color: var(--gold);
  margin-top: .15rem;
  letter-spacing: .1em;
}

.team-card-body {
  padding: 1.5rem;
  flex: 1;
}

.team-role {
  font-size: .7rem;
  color: var(--gold);
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  margin-bottom: .75rem;
}

.team-desc {
  font-size: .84rem;
  color: var(--text-mid);
  line-height: 1.75;
}

.team-tags {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem;
  margin-top: 1rem;
}

.tag {
  font-size: .66rem;
  padding: .18rem .55rem;
  background: var(--cream);
  border-radius: 20px;
  color: var(--text-mid);
  border: 1px solid var(--border);
  font-family: var(--mono);
}

.team-card-foot {
  padding: .9rem 1.5rem;
  border-top: 1px solid var(--border);
  background: var(--cream);
}

.team-card-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: .78rem;
  color: var(--blue);
  font-weight: 600;
  transition: color var(--t);
}
.team-card-link:hover { color: var(--gold); }

/* ─── Page Header (inner pages) ─────────────────────── */
.page-hd {
  background: var(--ink);
  padding: calc(var(--nav-h) + 3.5rem) 0 3.5rem;
  position: relative;
  overflow: hidden;
}

.page-hd::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg, transparent, transparent 39px, rgba(255,255,255,.02) 39px, rgba(255,255,255,.02) 40px),
    repeating-linear-gradient(90deg, transparent, transparent 39px, rgba(255,255,255,.02) 39px, rgba(255,255,255,.02) 40px);
}

.page-hd::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 50% 70% at 80% 50%, rgba(201,148,58,.07), transparent);
}

.page-hd .container { position: relative; z-index: 1; }

.page-hd-eyebrow {
  font-family: var(--serif);
  font-size: .68rem;
  color: var(--gold);
  letter-spacing: .2em;
  text-transform: uppercase;
  margin-bottom: .75rem;
}

.page-hd-title {
  font-family: var(--serif);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 900;
  color: #fff;
  line-height: 1.2;
}

.page-hd-lead {
  font-size: .9rem;
  color: rgba(255,255,255,.45);
  margin-top: .75rem;
  max-width: 560px;
  line-height: 1.8;
}

/* ─── Intern Hub ─────────────────────────────────────── */
.intern-hd {
  background: var(--ink);
  padding: calc(var(--nav-h) + 3rem) 0 3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.intern-hd::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg, transparent, transparent 39px, rgba(255,255,255,.02) 39px, rgba(255,255,255,.02) 40px),
    repeating-linear-gradient(90deg, transparent, transparent 39px, rgba(255,255,255,.02) 39px, rgba(255,255,255,.02) 40px);
}

.intern-hd .container { position: relative; z-index: 1; }

.intern-hd-id {
  font-family: var(--mono);
  font-size: .72rem;
  color: var(--gold);
  letter-spacing: .2em;
  margin-bottom: .5rem;
}

.intern-hd-name {
  font-family: var(--serif);
  font-size: clamp(2.2rem, 4.5vw, 3.5rem);
  font-weight: 900;
  color: #fff;
  margin-bottom: .75rem;
}

.intern-hd-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  row-gap: .3rem;
  gap: .75rem;
  font-size: .78rem;
  color: rgba(255,255,255,.4);
}

.intern-hd-meta .dot {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--gold);
  opacity: .6;
}

/* ─── Tile Cards (Intern Hub) ────────────────────────── */
.tiles-wrap {
  padding: 4rem 0 5rem;
  background: var(--cream);
}

.tile-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.tile {
  background: #fff;
  border-radius: var(--r-lg);
  padding: 2.5rem 2rem 2.5rem;
  text-align: center;
  border: 1px solid var(--border);
  transition: transform var(--t), box-shadow var(--t), border-color var(--t);
  cursor: pointer;
  display: block;
  position: relative;
  overflow: hidden;
}

.tile::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gold);
  transform: scaleX(0);
  transition: transform var(--t);
  transform-origin: left;
}

.tile:hover {
  transform: translateY(-8px);
  box-shadow: var(--s4);
  border-color: rgba(201,148,58,.2);
}

.tile:hover::after { transform: scaleX(1); }

.tile-icon {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: var(--cream);
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  font-size: 2rem;
  transition: background var(--t), border-color var(--t);
}

.tile:hover .tile-icon {
  background: var(--ink);
  border-color: var(--ink);
}

.tile-label {
  font-family: var(--serif);
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.4;
}

/* ─── Content Page Body ──────────────────────────────── */
.content-wrap {
  padding: 4rem 0 6rem;
  background: #fff;
}

.content-block {
  max-width: 800px;
  margin: 0 auto;
}

.content-block h2 {
  font-family: var(--serif);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--ink);
  margin-bottom: 1.25rem;
  margin-top: 3rem;
  display: flex;
  align-items: flex-start;
  gap: .75rem;
}

.content-block h2:first-child { margin-top: 0; }

.content-block h2::before {
  content: '';
  display: block;
  width: 4px;
  height: 1.4em;
  background: var(--gold);
  border-radius: 2px;
  flex-shrink: 0;
  margin-top: .15rem;
}

.content-block h3 {
  font-family: var(--serif);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--ink-mid);
  margin-top: 2rem;
  margin-bottom: .65rem;
}

.content-block p {
  font-size: .92rem;
  line-height: 1.95;
  color: var(--text-mid);
  margin-bottom: 1rem;
}

.content-block ul, .content-block ol {
  margin-left: 1.5rem;
  margin-bottom: 1rem;
}

.content-block li {
  font-size: .9rem;
  line-height: 1.85;
  color: var(--text-mid);
  margin-bottom: .3rem;
}

.content-block ul li::marker { color: var(--gold); }

/* Callout box */
.callout {
  background: var(--cream);
  border-left: 4px solid var(--gold);
  border-radius: 0 var(--r) var(--r) 0;
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
}

.callout p { margin: 0; font-size: .88rem; }

/* Code / tech tags */
.tech-tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: .7rem;
  padding: .18rem .55rem;
  background: var(--ink);
  color: var(--gold-lt);
  border-radius: 4px;
  margin: .12rem;
}

/* ─── Timeline ───────────────────────────────────────── */
.timeline {
  position: relative;
  padding-left: 2.25rem;
  margin-top: 1.5rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: .5rem;
  top: .5rem;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--gold), rgba(201,148,58,.1));
}

.tl-item {
  position: relative;
  padding-bottom: 2.5rem;
}

.tl-item:last-child { padding-bottom: 0; }

.tl-dot {
  position: absolute;
  left: -1.875rem;
  top: .3rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--gold);
  border: 2px solid #fff;
  box-shadow: 0 0 0 2px var(--gold);
}

.tl-date {
  font-family: var(--mono);
  font-size: .7rem;
  color: var(--gold);
  font-weight: 600;
  letter-spacing: .08em;
  margin-bottom: .3rem;
}

.tl-title {
  font-family: var(--serif);
  font-size: .98rem;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: .5rem;
}

.tl-body {
  font-size: .87rem;
  color: var(--text-mid);
  line-height: 1.85;
}

/* ─── Info Cards ─────────────────────────────────────── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.info-card {
  background: var(--cream);
  border-radius: var(--r);
  padding: 1.5rem;
  border: 1px solid var(--border);
}

.info-card h4 {
  font-family: var(--serif);
  font-size: .95rem;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: .6rem;
  display: flex;
  align-items: center;
  gap: .5rem;
}

.info-card p {
  font-size: .84rem;
  color: var(--text-mid);
  line-height: 1.75;
  margin: 0;
}

/* ─── Company Section Image ──────────────────────────── */
.img-caption {
  font-size: .75rem;
  color: var(--text-lt);
  text-align: center;
  margin-top: .5rem;
  font-style: italic;
}

.img-placeholder {
  background: var(--cream-dk);
  border-radius: var(--r);
  border: 1px dashed var(--border);
  padding: 3rem 2rem;
  text-align: center;
  color: var(--text-lt);
  font-size: .85rem;
}

/* ─── Tech Stack Grid ────────────────────────────────── */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.tech-card {
  background: #fff;
  border-radius: var(--r);
  padding: 1.5rem;
  border: 1px solid var(--border);
  border-top: 3px solid var(--gold);
}

.tech-card h4 {
  font-family: var(--serif);
  font-size: .95rem;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: .5rem;
}

.tech-card p {
  font-size: .82rem;
  color: var(--text-mid);
  line-height: 1.7;
  margin: 0;
}

/* ─── Breadcrumb ─────────────────────────────────────── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: .5rem;
  font-size: .75rem;
  color: rgba(255,255,255,.4);
  margin-bottom: .75rem;
}

.breadcrumb a { color: rgba(255,255,255,.4); transition: color var(--t); }
.breadcrumb a:hover { color: var(--gold); }
.breadcrumb-sep { opacity: .4; }

/* ─── Back Link ──────────────────────────────────────── */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  font-size: .8rem;
  color: var(--blue);
  font-weight: 600;
  transition: color var(--t), gap var(--t);
  margin-bottom: 2rem;
}

.back-link:hover { color: var(--gold); gap: .6rem; }

/* ─── Section divider ────────────────────────────────── */
.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 3rem 0;
}

/* ─── Footer ─────────────────────────────────────────── */
.footer {
  background: var(--ink);
  padding: 3rem 0;
  border-top: 1px solid rgba(201,148,58,.15);
}

.footer-inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-brand {
  font-family: var(--serif);
  font-size: 1.05rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: .5rem;
}

.footer-rule {
  width: 36px;
  height: 2px;
  background: var(--gold);
  border-radius: 1px;
  margin-top: .5rem;
}

.footer-info {
  font-size: .78rem;
  color: rgba(255,255,255,.32);
  line-height: 1.9;
  text-align: right;
}

/* ─── Fade-Up Animation ──────────────────────────────── */
.fu {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}

.fu.vis { opacity: 1; transform: translateY(0); }

/* ─── Intern Sticky Tab Bar ─────────────────────────── */
.intern-tabs {
  position: sticky;
  top: var(--nav-h);
  z-index: 150;
  background: rgba(252,249,244,.96);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 2px 12px rgba(10,22,40,.07);
}

.intern-tabs-inner {
  display: flex;
  align-items: stretch;
  width: min(var(--max-w), 100% - 3rem);
  margin-inline: auto;
}

.intern-tab {
  padding: 1rem 1.75rem;
  font-family: var(--serif);
  font-size: .85rem;
  font-weight: 700;
  color: var(--text-lt);
  cursor: pointer;
  border-bottom: 3px solid transparent;
  transition: color var(--t), border-color var(--t);
  white-space: nowrap;
  letter-spacing: .02em;
  user-select: none;
}

.intern-tab:hover { color: var(--ink); }

.intern-tab.active {
  color: var(--ink);
  border-bottom-color: var(--gold);
}

/* Intern sections */
.intern-section {
  padding: 4.5rem 0;
  border-bottom: 1px solid var(--border);
}

.intern-section:last-child { border-bottom: none; }

.intern-section-hd {
  margin-bottom: 2.5rem;
}

.intern-section-num {
  font-family: var(--mono);
  font-size: .68rem;
  color: var(--gold);
  letter-spacing: .2em;
  text-transform: uppercase;
  margin-bottom: .4rem;
}

.intern-section-title {
  font-family: var(--serif);
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--ink);
}

/* Project card */
.project-card {
  background: #fff;
  border-radius: var(--r-lg);
  padding: 2rem;
  border: 1px solid var(--border);
  margin-bottom: 1.5rem;
  position: relative;
  overflow: hidden;
}

.project-card::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 4px;
  background: var(--gold);
}

.project-card h3 {
  font-family: var(--serif);
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--ink);
  margin-bottom: .75rem;
  padding-left: .75rem;
}

.project-card p {
  font-size: .88rem;
  line-height: 1.85;
  color: var(--text-mid);
  margin-bottom: .75rem;
  padding-left: .75rem;
}

.project-card p:last-child { margin-bottom: 0; }

.project-card ul {
  margin-left: 2.25rem;
  margin-bottom: .75rem;
}

.project-card li {
  font-size: .87rem;
  line-height: 1.8;
  color: var(--text-mid);
  margin-bottom: .25rem;
}

.project-card li::marker { color: var(--gold); }

/* Growth items */
.growth-item {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 1rem;
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border-lt);
  align-items: start;
}

.growth-item:last-child { border-bottom: none; }

.growth-num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--ink);
  color: var(--gold);
  font-family: var(--serif);
  font-size: .85rem;
  font-weight: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.growth-content h4 {
  font-family: var(--serif);
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: .5rem;
}

.growth-content p {
  font-size: .87rem;
  line-height: 1.85;
  color: var(--text-mid);
}

/* ─── Hamburger Button ───────────────────────────────── */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  cursor: pointer;
  margin-left: auto;
  flex-shrink: 0;
  background: none;
  border: none;
  padding: 0;
}

.nav-hamburger span {
  display: block;
  height: 2px;
  background: rgba(255,255,255,.85);
  border-radius: 2px;
  transition: all var(--t);
  transform-origin: center;
}

.nav.scrolled .nav-hamburger span { background: var(--ink); }

.nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ─── Responsive ─────────────────────────────────────── */

/* Tablet */
@media (max-width: 960px) {
  .chapters-grid { grid-template-columns: 1fr; }
  .team-grid { grid-template-columns: 1fr 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .tile-grid { grid-template-columns: 1fr; max-width: 400px; margin: 0 auto; }
}

/* Mobile nav — 768px breakpoint */
@media (max-width: 768px) {
  .nav-hamburger { display: flex; }

  /*
   * Fix: backdrop-filter on .nav.scrolled creates a new fixed-position
   * containing block on iOS Safari, causing .nav-links (position:fixed,
   * top: --nav-h, bottom: 0) to be sized relative to the 64px nav instead
   * of the viewport — making the panel effectively zero-height when scrolled.
   * Removing backdrop-filter on mobile restores correct viewport positioning.
   */
  .nav.scrolled {
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
    background: rgba(252, 249, 244, 0.98);
  }

  .nav-links {
    display: none;
    position: fixed;
    top: var(--nav-h);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--ink);
    flex-direction: column;
    align-items: stretch;
    padding: .5rem 0 2rem;
    overflow-y: auto;
    z-index: 199;
  }

  .nav-links.mobile-open { display: flex; }

  .nav-links > li > a {
    font-size: 1rem !important;
    padding: .9rem 1.75rem !important;
    color: rgba(255,255,255,.75) !important;
    border-bottom: 1px solid rgba(255,255,255,.07);
    white-space: normal;
  }

  .nav-links > li > a:hover { color: var(--gold) !important; }

  /* Dropdown becomes an inline block on mobile */
  .nav-drop-menu {
    position: static !important;
    opacity: 1 !important;
    visibility: visible !important;
    transform: none !important;
    box-shadow: none !important;
    border: none !important;
    border-radius: 0 !important;
    background: rgba(255,255,255,.05) !important;
    min-width: unset;
    display: none;
  }

  .nav-links li.drop-open .nav-drop-menu { display: block !important; }

  .nav-drop-menu a {
    padding: .65rem 2.5rem !important;
    font-size: .88rem !important;
    color: rgba(255,255,255,.5) !important;
    border-bottom: 1px solid rgba(255,255,255,.05) !important;
  }

  .nav-drop-menu a:hover { color: var(--gold) !important; background: transparent !important; }
}

/* Mobile — 640px */
@media (max-width: 640px) {
  /* Grid adjustments */
  .team-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .stat-item + .stat-item::before { display: none; }
  .footer-info { text-align: left; }

  /* Hero */
  .hero-members { 
    flex-direction: column; 
    gap: 0.8rem; 
    margin-bottom: 3rem;
    align-items: center;
  }
  .hero-inner { padding: 1.25rem; }
  .hero-scroll { bottom: 1.2rem; }
  .hero-scroll-bar { height: 32px; }

  /* Sections */
  .section { padding: 3.5rem 0; }
  .intern-section { padding: 3rem 0; }

  /* Intern tabs — horizontally scrollable */
  .intern-tabs-inner {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    width: 100%;
  }
  .intern-tabs-inner::-webkit-scrollbar { display: none; }
  .intern-tab {
    padding: .8rem 1rem;
    font-size: .78rem;
    flex-shrink: 0;
  }

  /* Project cards */
  .project-card { padding: 1.5rem 1.25rem; }
  .project-card h3 { font-size: .95rem; }

  /* Growth items */
  .growth-item { gap: .75rem; }

  /* Card grids */
  .card-grid { grid-template-columns: 1fr; }

  /* Chapter cards */
  .ch-card { padding: 1.75rem 1.5rem; }
  .ch-card-num { font-size: 2.4rem; }

  /* Footer */
  .footer { padding: 2rem 0; }
  .footer-inner { flex-direction: column; gap: 1rem; }

  /* 企業願景 — collapse two-column layouts on mobile */
  .vision-grid { grid-template-columns: 1fr !important; gap: 2rem !important; }
  .service-cards-grid { grid-template-columns: 1fr !important; }
}
column layouts on mobile */
  .vision-grid { grid-template-columns: 1fr !important; gap: 2rem !important; }
  .service-cards-grid { grid-template-columns: 1fr !important; }
}