/* ============================================================
   HÀNH TRÌNH TỶ ĐÔ — phong cách trắng đen · bí ẩn · khởi nghiệp
   ============================================================ */

:root {
  --bg:        #0a0a0a;
  --bg-soft:   #111111;
  --bg-card:   #0e0e0e;
  --ink:       #ededed;
  --ink-soft:  #b7b7b7;
  --ink-muted: #7a7a7a;
  --line:      #262626;
  --line-soft: #1a1a1a;
  --accent:    #f5f5f5;
  --serif: 'Cormorant Garamond', Georgia, 'Times New Roman', serif;
  --sans:  'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --maxw: 720px;
}

* { box-sizing: border-box; }

html { -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility; }

body {
  margin: 0;
  overflow-x: hidden;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-weight: 300;
  line-height: 1.75;
  font-size: 17px;
  /* nền tối bí ẩn với chút chiều sâu */
  background-image:
    radial-gradient(1200px 600px at 50% -10%, #161616 0%, transparent 70%);
  background-attachment: fixed;
}

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

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Header ---------- */
.site-header {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 34px 24px 26px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line-soft);
}

.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  font-size: 22px;
  color: var(--ink);
  border: 1px solid var(--line);
  width: 40px; height: 40px;
  display: grid; place-items: center;
  border-radius: 50%;
  transition: border-color .3s ease;
}
.brand:hover .brand-mark { border-color: var(--ink-soft); }
.brand-name {
  font-family: var(--serif);
  font-size: 20px;
  letter-spacing: .06em;
  text-transform: uppercase;
  font-weight: 500;
}

.site-nav { display: flex; gap: 26px; }
.site-nav a {
  font-size: 13px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--ink-muted);
  padding-bottom: 3px;
  border-bottom: 1px solid transparent;
  transition: color .25s ease, border-color .25s ease;
}
.site-nav a:hover,
.site-nav a.active { color: var(--ink); border-color: var(--ink); }

/* ---------- Hero (ảnh nền bầu trời sao, tràn viền) ---------- */
.hero {
  position: relative;
  text-align: center;
  width: 100vw;
  margin-left: calc(-50vw + 50%);
  padding: 130px 24px 96px;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--line-soft);
  background-image:
    linear-gradient(180deg, rgba(10,10,10,.62) 0%, rgba(10,10,10,.42) 42%, rgba(10,10,10,.94) 100%),
    url('/assets/hero.jpg');
  background-size: cover;
  background-position: center 40%;
  background-repeat: no-repeat;
}
.hero > * { position: relative; z-index: 1; }
.hero-mark {
  color: rgba(255,255,255,.85);
  margin-bottom: 24px;
  line-height: 0;
}
.hero-mark .mark { filter: drop-shadow(0 2px 14px rgba(0,0,0,.75)); }
.hero-title {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(44px, 9vw, 76px);
  line-height: 1.02;
  margin: 0 0 20px;
  letter-spacing: .02em;
  color: #fff;
  text-shadow: 0 2px 34px rgba(0,0,0,.85), 0 1px 4px rgba(0,0,0,.6);
}
.hero-tagline {
  color: rgba(240,240,240,.92);
  font-family: var(--serif);
  font-style: italic;
  font-size: 22px;
  margin: 0 auto;
  max-width: 520px;
  text-shadow: 0 2px 24px rgba(0,0,0,.8);
}

/* ---------- Danh sách bài viết ---------- */
.post-list { padding: 30px 0 60px; }
.post-card {
  display: block;
  padding: 34px 0;
  border-bottom: 1px solid var(--line-soft);
  transition: padding-left .35s cubic-bezier(.2,.7,.3,1);
}
.post-card:hover { padding-left: 14px; }
.post-card-meta {
  font-size: 12px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 12px;
}
.post-card-title {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 32px;
  line-height: 1.15;
  margin: 0 0 12px;
}
.post-card-excerpt {
  color: var(--ink-soft);
  margin: 0 0 16px;
  font-weight: 300;
}
.read-more {
  font-size: 13px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--ink-muted);
  transition: color .25s ease;
}
.post-card:hover .read-more { color: var(--ink); }

/* ---------- Bài viết ---------- */
.post { padding: 60px 0 40px; }
.post-meta {
  text-align: center;
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 20px;
}
.post-title {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(34px, 6vw, 52px);
  line-height: 1.12;
  text-align: center;
  margin: 0 auto 44px;
  max-width: 620px;
  letter-spacing: .01em;
}
.post-body { font-size: 18px; }
.post-body p { margin: 0 0 26px; color: var(--ink); }
.post-body h2 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 30px;
  margin: 52px 0 18px;
  letter-spacing: .01em;
}
.post-body h3 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 23px;
  margin: 40px 0 14px;
}
.post-body a {
  color: var(--ink);
  border-bottom: 1px solid var(--ink-muted);
  transition: border-color .2s ease;
}
.post-body a:hover { border-color: var(--ink); }
.post-body strong { font-weight: 500; color: #fff; }
.post-body em { color: var(--ink-soft); }
.post-body ul, .post-body ol { padding-left: 24px; margin: 0 0 26px; }
.post-body li { margin-bottom: 10px; }
.post-body blockquote {
  margin: 32px 0;
  padding: 4px 0 4px 26px;
  border-left: 2px solid var(--line);
  color: var(--ink-soft);
  font-family: var(--serif);
  font-style: italic;
  font-size: 21px;
}
.post-body blockquote p { margin-bottom: 12px; color: var(--ink-soft); }
.post-body hr {
  border: 0;
  text-align: center;
  margin: 48px 0;
}
.post-body hr::before {
  content: '∴';
  color: var(--ink-muted);
  letter-spacing: .3em;
  font-size: 18px;
}
.post-body code {
  background: var(--bg-soft);
  border: 1px solid var(--line-soft);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 14px;
  font-family: 'SF Mono', Menlo, Consolas, monospace;
}
.post-body pre {
  background: var(--bg-soft);
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  padding: 18px 20px;
  overflow-x: auto;
  margin: 0 0 26px;
}
.post-body pre code { background: none; border: 0; padding: 0; }
.post-body img { max-width: 100%; border-radius: 8px; margin: 12px 0; }

.post-foot {
  margin-top: 60px;
  padding-top: 28px;
  border-top: 1px solid var(--line-soft);
  text-align: center;
}
.back-link {
  font-size: 13px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--ink-muted);
  transition: color .25s ease;
}
.back-link:hover { color: var(--ink); }

.page .post-body { font-size: 17px; }

/* ---------- Footer ---------- */
.site-footer {
  text-align: center;
  padding: 70px 24px 60px;
  margin-top: 40px;
  border-top: 1px solid var(--line-soft);
  color: var(--ink-muted);
}
.footer-mark { color: var(--ink-muted); margin-bottom: 16px; line-height: 0; }
.mark { display: inline-block; vertical-align: middle; }
.site-footer p { margin: 4px 0; font-size: 14px; }
.muted { color: var(--ink-muted); }

/* ---------- Responsive ---------- */
@media (max-width: 600px) {
  body { font-size: 16px; }
  .site-header { flex-direction: column; gap: 18px; padding-top: 26px; }
  .hero { padding: 84px 20px 60px; background-position: center 45%; }
  .post-card-title { font-size: 27px; }
  .post-body { font-size: 17px; }
}

::selection { background: #e9e9e9; color: #0a0a0a; }