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

/* ── Fonts ───────────────────────────────────────────────── */
:root {
  /* UI / body: Inter for English, 宋体 fallback for Chinese */
  --font-ui:      'Inter', ui-sans-serif, -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-body:    'Inter', ui-sans-serif, -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui,
                  'STSong', 'Songti SC', 'Noto Serif CJK SC', 'SimSun', '宋体', serif;
  /* Display serif: Playfair Display for English titles, 宋体 for Chinese */
  --font-display: 'Playfair Display', 'STSong', 'Songti SC', 'Noto Serif CJK SC', 'SimSun', Georgia, serif;
  --font-mono:    ui-monospace, 'SFMono-Regular', 'SF Mono', Menlo, Consolas, monospace;

  /* Palette — near-monochrome */
  --bg:       #fafaf8;
  --surface:  #ffffff;
  --text:     #181816;
  --text-2:   #6b6b67;
  --text-3:   #aaa9a4;
  --border:   #e8e7e2;
  --border-2: #d4d3cd;

  --max-w:    680px;
  --transition: 0.15s ease;
}

html { font-size: 16px; }

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  min-height: 100dvh;
}

a { color: inherit; text-decoration: none; }

/* ── Shared page wrapper ─────────────────────────────────── */
.page {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

/* ── LOGIN ───────────────────────────────────────────────── */
.login-page {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 32px;
}

.login-brand {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 400;
  font-style: italic;
  color: var(--text-3);
}

.login-form {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  width: 220px;
}

.login-input {
  width: 100%;
  padding: 11px 16px;
  font-family: var(--font-ui);
  font-size: 15px;
  letter-spacing: .2em;
  text-align: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  outline: none;
  transition: border-color var(--transition);
}

.login-input:focus { border-color: var(--border-2); }
.login-input::placeholder { letter-spacing: .05em; color: var(--text-3); }

.login-btn {
  width: 100%;
  padding: 10px;
  font-family: var(--font-ui);
  font-size: 13.5px;
  font-weight: 500;
  background: var(--text);
  color: var(--bg);
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: opacity var(--transition);
}

.login-btn:hover { opacity: .82; }

.login-error {
  font-family: var(--font-ui);
  font-size: 12px;
  color: #b04040;
  min-height: 16px;
}

/* ── HOME ────────────────────────────────────────────────── */
.home {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
}

.home-brand {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 400;
  font-style: italic;
  letter-spacing: .01em;
  color: var(--text-3);
  margin-bottom: 56px;
}

.home-list {
  width: 100%;
  max-width: 360px;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.home-project {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: color var(--transition);
}

.home-project:first-child { border-top: 1px solid var(--border); }

.home-project-name {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 400;
  color: var(--text);
  transition: color var(--transition);
}

.home-project:hover .home-project-name { color: var(--text-2); }

.home-project-count {
  font-family: var(--font-ui);
  font-size: 12px;
  color: var(--text-3);
}

.home-empty {
  font-size: 14px;
  color: var(--text-3);
  text-align: center;
  padding: 40px 0;
}

/* ── PROJECT page ────────────────────────────────────────── */
.project-header {
  padding: 32px 24px 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.back-link {
  align-self: flex-start;
  font-family: var(--font-ui);
  font-size: 13px;
  color: var(--text-3);
  display: flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  transition: color var(--transition);
}

.back-link:hover { color: var(--text-2); }

.search-wrap {
  width: 100%;
  max-width: var(--max-w);
  position: relative;
}

.search-input {
  width: 100%;
  padding: 10px 16px 10px 38px;
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  outline: none;
  transition: border-color var(--transition);
}

.search-input:focus { border-color: var(--border-2); }
.search-input::placeholder { color: var(--text-3); }

.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-3);
  pointer-events: none;
}

.project-title {
  font-family: var(--font-display);
  font-size: 30px;
  font-weight: 400;
  letter-spacing: -.2px;
  color: var(--text);
  align-self: flex-start;
  max-width: var(--max-w);
  width: 100%;
}

.project-desc {
  font-size: 14px;
  color: var(--text-3);
  align-self: flex-start;
  max-width: var(--max-w);
  width: 100%;
  margin-top: -8px;
}

/* ── Timeline ────────────────────────────────────────────── */
.timeline {
  width: 100%;
  max-width: var(--max-w);
  margin: 40px auto;
  padding: 0 24px 80px;
}

.tl-entry {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 0 28px;
  padding: 22px 0;
  border-top: 1px solid var(--border);
  cursor: pointer;
  transition: opacity var(--transition);
}

.tl-entry:last-child { border-bottom: 1px solid var(--border); }
.tl-entry:hover { opacity: .72; }

.tl-date {
  font-family: var(--font-ui);
  font-size: 11.5px;
  color: var(--text-3);
  padding-top: 4px;
  line-height: 1.4;
  text-align: right;
  flex-shrink: 0;
}

.tl-body {}

.tl-title {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 400;
  color: var(--text);
  line-height: 1.4;
  margin-bottom: 5px;
}

.tl-excerpt {
  font-size: 13.5px;
  color: var(--text-2);
  line-height: 1.65;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.tl-empty {
  padding: 60px 0;
  text-align: center;
  font-size: 14px;
  color: var(--text-3);
  border-top: 1px solid var(--border);
}

/* ── POST page ───────────────────────────────────────────── */
.post-page {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 40px 24px 120px;
}

.post-back {
  font-family: var(--font-ui);
  font-size: 13px;
  color: var(--text-3);
  display: flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  transition: color var(--transition);
  margin-bottom: 40px;
}

.post-back:hover { color: var(--text-2); }

.post-title {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 400;
  line-height: 1.3;
  letter-spacing: -.1px;
  margin-bottom: 14px;
}

.post-meta {
  font-family: var(--font-ui);
  font-size: 12.5px;
  color: var(--text-3);
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 36px;
  padding-bottom: 36px;
  border-bottom: 1px solid var(--border);
}

.post-meta-sep { color: var(--border-2); }

/* ── Markdown content ────────────────────────────────────── */
.md {
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--text);
}

.md h1, .md h2, .md h3, .md h4 {
  font-family: var(--font-display);
  font-weight: 500;
  line-height: 1.3;
  margin: 2em 0 .6em;
  letter-spacing: -.1px;
}

.md h1 { font-size: 22px; }
.md h2 { font-size: 19px; border-bottom: 1px solid var(--border); padding-bottom: .4em; }
.md h3 { font-size: 16px; }
.md h4 { font-size: 14.5px; color: var(--text-2); }

.md p  { margin: .9em 0; }

.md a  { color: var(--text); text-decoration: underline; text-underline-offset: 3px;
         text-decoration-color: var(--border-2); }
.md a:hover { text-decoration-color: var(--text-2); }

.md ul, .md ol { padding-left: 1.5em; margin: .8em 0; }
.md li { margin: .3em 0; }
.md li > ul, .md li > ol { margin: .2em 0; }

.md blockquote {
  border-left: 2px solid var(--border-2);
  padding: .1em 0 .1em 1.2em;
  margin: 1.2em 0;
  color: var(--text-2);
  font-style: italic;
}

.md code {
  font-family: var(--font-mono);
  font-size: .88em;
  background: #f2f1ec;
  padding: .15em .4em;
  border-radius: 3px;
  color: var(--text);
}

.md pre {
  background: #f2f1ec;
  border-radius: 6px;
  padding: 16px 20px;
  overflow-x: auto;
  margin: 1.2em 0;
}

.md pre code {
  background: none;
  padding: 0;
  font-size: .85em;
  line-height: 1.6;
}

.md table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  margin: 1.2em 0;
}

.md th, .md td {
  border: 1px solid var(--border);
  padding: 8px 12px;
  text-align: left;
}

.md th { background: #f5f4ef; font-weight: 600; }
.md tr:hover td { background: #fafaf8; }

.md hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2em 0;
}

.md img { max-width: 100%; border-radius: 4px; margin: .8em 0; }

/* ── Scrollbar ───────────────────────────────────────────── */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* ── Loading / Error ─────────────────────────────────────── */
.status-msg {
  padding: 80px 24px;
  text-align: center;
  font-family: var(--font-ui);
  font-size: 13px;
  color: var(--text-3);
}