/* ── Reset & base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:       #f6f8fa;
  --surface:  #ffffff;
  --border:   #d0d7de;
  --text:     #1f2328;
  --muted:    #59636e;
  --accent:   #0969da;
  --accent2:  #1a7f37;
  --danger:   #cf222e;
  --radius:   10px;
  --shadow:   0 6px 24px rgba(140,149,159,.25);
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  line-height: 1.7;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Layout ── */
.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

/* ── Nav ── */
nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 60px;
}
.nav-brand { font-size: 1.1rem; font-weight: 700; color: var(--text); }
.nav-links { display: flex; gap: 20px; align-items: center; }
.nav-links a { font-size: .9rem; color: var(--muted); transition: color .2s; }
.nav-links a:hover { color: var(--text); text-decoration: none; }
.lang-btn {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 4px 12px;
  border-radius: 6px;
  font-size: .85rem;
  cursor: pointer;
  transition: border-color .2s;
}
.lang-btn:hover { border-color: var(--accent); }

/* ── Hero ── */
.hero {
  padding: 80px 0 60px;
  text-align: center;
}
.hero-avatar {
  width: 80px; height: 80px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  display: flex; align-items: center; justify-content: center;
  font-size: 2rem; margin: 0 auto 20px;
}
.hero h1 { font-size: 2.4rem; font-weight: 800; margin-bottom: 10px; }
.hero h1 span { color: var(--accent); }
.hero p { font-size: 1.1rem; color: var(--muted); max-width: 540px; margin: 0 auto 28px; }
.hero-tags { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.hero-tag {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 4px 14px; border-radius: 999px;
  font-size: .82rem; color: var(--muted);
}

/* ── Section ── */
.section { padding: 48px 0; }
.section-title {
  font-size: 1.4rem; font-weight: 700; margin-bottom: 32px;
  display: flex; align-items: center; gap: 10px;
}
.section-title::after {
  content: ''; flex: 1; height: 1px; background: var(--border);
}

/* ── Project grid ── */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex; flex-direction: column;
  transition: transform .2s, border-color .2s, box-shadow .2s;
}
.card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: var(--shadow);
}
.card-cover {
  width: 100%; height: 180px; object-fit: cover;
  background: linear-gradient(135deg, #eef1f5 0%, #e2e7ee 100%);
  display: flex; align-items: center; justify-content: center;
  font-size: 3rem; color: var(--border);
}
.card-cover img { width: 100%; height: 100%; object-fit: cover; }
.card-body { padding: 20px; flex: 1; display: flex; flex-direction: column; }
.card-title { font-size: 1.05rem; font-weight: 700; margin-bottom: 6px; }
.card-desc { font-size: .88rem; color: var(--muted); margin-bottom: 14px; flex: 1; }
.tag-list { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 16px; }
.tag {
  background: rgba(88,166,255,.1);
  border: 1px solid rgba(88,166,255,.25);
  color: var(--accent);
  font-size: .75rem; padding: 2px 10px; border-radius: 999px;
}
.tag.green {
  background: rgba(63,185,80,.1);
  border-color: rgba(63,185,80,.25);
  color: var(--accent2);
}
.btn {
  display: inline-block;
  background: var(--accent);
  color: #ffffff;
  padding: 8px 18px; border-radius: 6px;
  font-size: .875rem; font-weight: 600;
  transition: opacity .2s;
  align-self: flex-start;
}
.btn:hover { opacity: .85; text-decoration: none; }
.btn-outline {
  background: transparent;
  border: 1px solid var(--accent);
  color: var(--accent);
}
.btn-outline:hover { background: rgba(88,166,255,.1); }

/* ── Project detail page ── */
.detail-hero {
  padding: 60px 0 40px;
  border-bottom: 1px solid var(--border);
}
.back-link { font-size: .875rem; color: var(--muted); margin-bottom: 16px; display: inline-block; }
.back-link:hover { color: var(--text); }
.detail-hero h1 { font-size: 2rem; font-weight: 800; margin-bottom: 10px; }
.detail-hero .sub { color: var(--muted); font-size: 1rem; }

.detail-content { padding: 48px 0; }
.detail-content h2 {
  font-size: 1.2rem; font-weight: 700; margin: 36px 0 14px;
  padding-bottom: 8px; border-bottom: 1px solid var(--border);
  color: var(--accent);
}
.detail-content h2:first-child { margin-top: 0; }
.detail-content p { margin-bottom: 14px; color: var(--text); }
.detail-content ul, .detail-content ol { padding-left: 22px; margin-bottom: 14px; }
.detail-content li { margin-bottom: 6px; }
.detail-content code {
  background: rgba(27,31,36,.06);
  color: #cf222e;
  padding: 1px 6px; border-radius: 4px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: .875em;
}
.detail-content pre {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px; overflow-x: auto;
  margin-bottom: 18px;
}
.detail-content pre code { background: none; padding: 0; }

.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px; margin-bottom: 24px;
}
.screenshot-item {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--surface);
}
.screenshot-item img { width: 100%; display: block; }
.screenshot-caption {
  padding: 8px 12px; font-size: .78rem; color: var(--muted); text-align: center;
}
.placeholder-img {
  width: 100%; height: 160px;
  background: linear-gradient(135deg, #eef1f5 0%, #e2e7ee 100%);
  display: flex; align-items: center; justify-content: center;
  color: var(--border); font-size: .8rem; flex-direction: column; gap: 8px;
}
.placeholder-img svg { width: 36px; height: 36px; opacity: .4; }

.info-box {
  background: rgba(88,166,255,.07);
  border: 1px solid rgba(88,166,255,.2);
  border-radius: var(--radius);
  padding: 16px 20px; margin-bottom: 20px;
}
.info-box.green {
  background: rgba(63,185,80,.07);
  border-color: rgba(63,185,80,.2);
}

/* ── Arch diagram ── */
.arch-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px; font-family: monospace;
  font-size: .82rem; line-height: 1.8; white-space: pre;
  overflow-x: auto; margin-bottom: 20px; color: var(--text);
}

/* ── Footer ── */
footer {
  border-top: 1px solid var(--border);
  padding: 32px 0; text-align: center;
  color: var(--muted); font-size: .85rem;
}
footer a { color: var(--muted); }
footer a:hover { color: var(--accent); }

/* ── Lightbox ── */
.lb-trigger {
  cursor: zoom-in;
  transition: opacity .2s, transform .2s;
  display: block; width: 100%;
}
.lb-trigger:hover { opacity: .9; transform: scale(1.01); }

#lightbox {
  display: none;
  position: fixed; inset: 0; z-index: 9999;
  background: rgba(0,0,0,.88);
  align-items: center; justify-content: center;
  padding: 24px;
}
#lightbox.open { display: flex; }
#lightbox img {
  max-width: min(92vw, 1200px);
  max-height: 88vh;
  border-radius: 8px;
  box-shadow: 0 8px 48px rgba(0,0,0,.7);
  object-fit: contain;
}
#lb-close {
  position: fixed; top: 16px; right: 20px;
  background: rgba(255,255,255,.15); border: none;
  color: #fff; font-size: 1.6rem; line-height: 1;
  width: 40px; height: 40px; border-radius: 50%;
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  transition: background .2s; z-index: 10001;
}
#lb-close:hover { background: rgba(255,255,255,.3); }
#lb-prev, #lb-next {
  position: fixed; top: 50%; transform: translateY(-50%);
  background: rgba(255,255,255,.15); border: none;
  color: #fff; font-size: 2.8rem; line-height: 1;
  width: 52px; height: 52px; border-radius: 50%;
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  transition: background .2s; z-index: 10001;
  user-select: none;
}
#lb-prev:hover, #lb-next:hover { background: rgba(255,255,255,.3); }
#lb-prev { left: 20px; }
#lb-next { right: 20px; }
#lb-caption {
  position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%);
  color: rgba(255,255,255,.75); font-size: .85rem;
  background: rgba(0,0,0,.45); padding: 4px 16px; border-radius: 20px;
  pointer-events: none; white-space: nowrap; max-width: 80vw;
  overflow: hidden; text-overflow: ellipsis;
}

/* ── Callout boxes ── */
.callout {
  border-left: 3px solid var(--accent);
  background: rgba(88,166,255,.06);
  padding: 12px 16px; border-radius: 0 8px 8px 0;
  margin-bottom: 18px; font-size: .9rem;
}
.callout.green { border-color: var(--accent2); background: rgba(63,185,80,.06); }
.callout.orange { border-color: #e3b341; background: rgba(227,179,65,.06); }
.callout strong { display: block; margin-bottom: 4px; }

/* ── Pipeline steps ── */
.pipeline {
  display: flex; flex-wrap: wrap; gap: 0; margin-bottom: 20px;
  border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden;
}
.pipeline-step {
  flex: 1; min-width: 100px;
  padding: 12px 10px; text-align: center;
  background: var(--surface); font-size: .8rem;
  border-right: 1px solid var(--border); position: relative;
}
.pipeline-step:last-child { border-right: none; }
.pipeline-step .step-num {
  display: block; font-size: .7rem; color: var(--muted); margin-bottom: 4px;
}
.pipeline-step .step-name { font-weight: 600; color: var(--text); }
.pipeline-step .step-desc { color: var(--muted); font-size: .75rem; margin-top: 4px; }
.pipeline-step::after {
  content: '→';
  position: absolute; right: -10px; top: 50%; transform: translateY(-50%);
  color: var(--muted); font-size: .9rem; z-index: 1;
}
.pipeline-step:last-child::after { display: none; }

/* ── Feature list ── */
.feature-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px; margin-bottom: 20px;
}
.feature-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px;
}
.feature-card .fc-icon { font-size: 1.4rem; margin-bottom: 8px; }
.feature-card .fc-title { font-weight: 700; font-size: .9rem; margin-bottom: 6px; }
.feature-card .fc-desc { font-size: .82rem; color: var(--muted); }

/* ── CV-style entries (used by homepage sections) ── */
.entry { margin-bottom: 18px; }
.entry-head { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 4px 12px; font-weight: 700; font-size: .98rem; }
.entry-head .when { color: var(--muted); font-weight: 500; font-size: .84rem; white-space: nowrap; }
.tagline { color: var(--accent2); font-size: .82rem; margin: 2px 0 8px; font-weight: 600; }
.entry ul { padding-left: 20px; margin: 4px 0; }
.entry li { margin-bottom: 5px; font-size: .9rem; color: var(--text); }
.edu-row {
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 4px 12px;
  padding: 9px 0; border-bottom: 1px dashed var(--border); font-size: .9rem;
}
.edu-row .when { color: var(--muted); font-size: .84rem; white-space: nowrap; }
.pub-list { padding-left: 20px; margin: 0; }
.pub-list li { margin-bottom: 8px; font-size: .9rem; }
.skill-list { padding-left: 20px; margin: 0; }
.skill-list li { margin-bottom: 7px; font-size: .9rem; color: var(--text); }

/* ── Personal homepage: sidebar + content ── */
.layout {
  display: flex; gap: 52px;
  max-width: 1120px; margin: 0 auto; padding: 0 24px;
  align-items: flex-start;
}
.sidebar {
  position: sticky; top: 0; align-self: flex-start;
  width: 290px; flex-shrink: 0; height: 100vh;
  padding: 52px 8px 28px 0;
  display: flex; flex-direction: column; gap: 16px;
  overflow-y: auto;
}
.sidebar .avatar {
  width: 156px; height: 156px; border-radius: 50%;
  object-fit: cover; object-position: top center;
  border: 4px solid var(--surface); box-shadow: var(--shadow);
}
.s-name { font-size: 1.55rem; font-weight: 800; line-height: 1.25; }
.s-name .en { display: block; font-size: .95rem; color: var(--muted); font-weight: 500; margin-top: 3px; }
.s-title { font-size: .9rem; color: var(--text); font-weight: 600; }
.s-affil { font-size: .84rem; color: var(--muted); }
.s-bio { font-size: .82rem; color: var(--muted); line-height: 1.65; }
.side-nav { display: flex; flex-direction: column; gap: 1px; margin: 4px 0; border-left: 2px solid var(--border); }
.side-nav a { padding: 5px 14px; font-size: .9rem; color: var(--muted); border-left: 2px solid transparent; margin-left: -2px; }
.side-nav a:hover { color: var(--text); text-decoration: none; }
.side-nav a.active { color: var(--accent); border-left-color: var(--accent); font-weight: 600; }
.side-links { display: flex; flex-wrap: wrap; gap: 10px 16px; align-items: center; margin-top: auto; padding-top: 14px; border-top: 1px solid var(--border); }
.side-links a { font-size: .85rem; color: var(--muted); }
.side-links a:hover { color: var(--accent); }

.content { flex: 1; min-width: 0; max-width: 740px; padding: 52px 0 72px; }
.intro-hi { font-size: 1.7rem; font-weight: 800; margin-bottom: 10px; }
.home-section { margin-bottom: 40px; scroll-margin-top: 20px; }
.home-section > h2 {
  font-size: 1.18rem; font-weight: 700; color: var(--text);
  margin: 0 0 16px; padding-bottom: 8px;
  border-bottom: 2px solid var(--accent); display: inline-block;
}
.home-section p { color: var(--text); margin-bottom: 12px; }

.proj-list { display: flex; flex-direction: column; gap: 14px; }
.proj-item {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px 18px;
  transition: border-color .2s, box-shadow .2s, transform .2s;
}
.proj-item:hover { border-color: var(--accent); box-shadow: var(--shadow); transform: translateY(-2px); }
.proj-item .p-head { display: flex; justify-content: space-between; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.proj-item .p-title { font-weight: 700; font-size: 1rem; }
.proj-item .p-link { font-size: .85rem; white-space: nowrap; font-weight: 600; }
.proj-item .p-desc { font-size: .88rem; color: var(--muted); margin: 6px 0 10px; }
.proj-item .tag-list { margin-bottom: 0; }
.proj-item .p-note {
  font-size: .82rem; margin: 0 0 10px;
  background: rgba(63,185,80,.08); border-left: 3px solid var(--accent2);
  padding: 7px 12px; border-radius: 0 6px 6px 0; color: var(--text);
}
.proj-item.featured-bench { border-color: rgba(126,87,194,.4); }
.proj-more { margin-top: 6px; }

@media (max-width: 900px) {
  .layout { flex-direction: column; gap: 0; }
  .sidebar {
    position: static; width: 100%; height: auto;
    flex-direction: row; flex-wrap: wrap; align-items: center;
    gap: 6px 16px; padding: 28px 0 18px; border-bottom: 1px solid var(--border);
  }
  .sidebar .avatar { width: 88px; height: 88px; }
  .s-bio { width: 100%; order: 5; }
  .side-nav { flex-direction: row; flex-wrap: wrap; border-left: none; width: 100%; order: 6; gap: 2px 4px; }
  .side-nav a { border-left: none; border-bottom: 2px solid transparent; margin-left: 0; padding: 4px 10px; }
  .side-nav a.active { border-left: none; border-bottom-color: var(--accent); }
  .side-links { margin-top: 0; width: 100%; order: 7; border-top: none; padding-top: 4px; }
  .content { padding: 28px 0 52px; max-width: 100%; }
}

/* ── Responsive ── */
@media (max-width: 640px) {
  .hero h1 { font-size: 1.7rem; }
  .grid { grid-template-columns: 1fr; }
  .nav-links .hide-sm { display: none; }
  .pipeline { flex-direction: column; }
  .pipeline-step::after { content: '↓'; right: auto; left: 50%; top: auto; bottom: -14px; transform: translateX(-50%); }
}