/* ============================================================
   Duy Tân concept — scoped under [data-site="duytan"]
   Direction 2026-2030: Circularity Loop
   Fingerprint: compact-link-rail · circular-loop-photo-frame · serif-craft-speckle ·
   phase-card-photo-fan · loop-pulse-breaks · real-plastics-photography ·
   recycle-arrows-ring · slow-rotation
   ============================================================ */

[data-site="duytan"] {
  --dt-canvas: #f5f2ea;
  --dt-surface: #ffffff;
  --dt-text: #23303a;
  --dt-muted: #5d6b74;
  --dt-green: #0a5c48;
  --dt-green-mid: #0e7a5f;
  --dt-sand: #e9e2d2;
  --dt-speck: #8d9aa3;
  --dt-clay: #c96f4a;
  --dt-border: #ddd5c3;
  --dt-serif: Georgia, "Times New Roman", "Noto Serif", serif;
  --dt-container: 74rem;
  --dt-t-fast: 150ms;
  --dt-t-base: 260ms;

  font-family: system-ui, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  background: var(--dt-canvas);
  color: var(--dt-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  margin: 0;
}

[data-site="duytan"] *,
[data-site="duytan"] *::before,
[data-site="duytan"] *::after { box-sizing: border-box; }
[data-site="duytan"] img { display: block; max-width: 100%; height: auto; }

[data-site="duytan"] h1,
[data-site="duytan"] h2,
[data-site="duytan"] h3 {
  font-family: var(--dt-serif);
  font-weight: 600;
  line-height: 1.15;
  margin: 0 0 0.6em;
}

[data-site="duytan"] p { margin: 0 0 1em; }
[data-site="duytan"] ul, [data-site="duytan"] ol { margin: 0; padding: 0; list-style: none; }
[data-site="duytan"] a { color: var(--dt-green); }
[data-site="duytan"] svg { max-width: 100%; }
[data-site="duytan"] .loop-ring { max-width: none; }

[data-site="duytan"] :focus-visible {
  outline: 3px solid var(--dt-green-mid);
  outline-offset: 3px;
  border-radius: 8px;
}

[data-site="duytan"] .visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

[data-site="duytan"] .skip {
  position: absolute;
  left: 1rem; top: -4rem;
  background: var(--dt-green);
  color: #fff;
  font-weight: 700;
  padding: 0.7rem 1.2rem;
  z-index: 100;
  text-decoration: none;
  transition: top var(--dt-t-fast) ease;
}
[data-site="duytan"] .skip:focus { top: 1rem; }

[data-site="duytan"] .container {
  width: min(100% - 2.5rem, var(--dt-container));
  margin-inline: auto;
}

/* ---------- concept strip ---------- */
[data-site="duytan"] .concept-strip {
  background: var(--dt-green);
  color: #d7ead9;
  font-size: 0.8rem;
  padding: 0.55rem 1rem;
  text-align: center;
}
[data-site="duytan"] .concept-tag {
  display: inline-block;
  background: var(--dt-sand);
  color: #4a3d22;
  font-weight: 800;
  font-size: 0.66rem;
  letter-spacing: 0.12em;
  padding: 0.12rem 0.6rem;
  margin-right: 0.5rem;
  vertical-align: 1px;
}

/* ---------- header ---------- */
[data-site="duytan"] .site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(245, 242, 234, 0.96);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--dt-border);
}
[data-site="duytan"] .header-inner {
  display: flex;
  align-items: center;
  gap: 1.4rem;
  padding: 0.65rem 0;
}
[data-site="duytan"] .brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--dt-green);
}
[data-site="duytan"] .brand-glyph {
  display: grid;
  place-items: center;
  width: 42px; height: 42px;
  background: var(--dt-green);
  border-radius: 50%;
  color: #fff;
}
[data-site="duytan"] .brand-text { display: flex; flex-direction: column; line-height: 1.15; }
[data-site="duytan"] .brand-name {
  font-family: var(--dt-serif);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--dt-green);
}
[data-site="duytan"] .brand-sub {
  font-size: 0.6rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  color: #93481f;
  text-transform: uppercase;
}
[data-site="duytan"] .main-nav { margin-left: auto; }
[data-site="duytan"] .main-nav ul { display: flex; gap: 0.15rem; flex-wrap: wrap; }
[data-site="duytan"] .main-nav a {
  display: block;
  text-decoration: none;
  color: var(--dt-text);
  font-weight: 700;
  font-size: 0.9rem;
  padding: 0.55rem 0.95rem;
  border-radius: 999px;
  transition: background var(--dt-t-fast) ease, color var(--dt-t-fast) ease;
}
[data-site="duytan"] .main-nav a:hover { background: var(--dt-green); color: #fff; }
[data-site="duytan"] .header-cta {
  text-decoration: none;
  font-weight: 800;
  font-size: 0.85rem;
  color: #fff;
  background: var(--dt-green-mid);
  padding: 0.6rem 1.05rem;
  border-radius: 999px;
  white-space: nowrap;
  transition: background var(--dt-t-fast) ease;
}
[data-site="duytan"] .header-cta:hover { background: var(--dt-green); }

[data-site="duytan"] .nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  padding: 0.5rem;
  cursor: pointer;
  margin-left: auto;
}
[data-site="duytan"] .nav-toggle span {
  width: 24px; height: 3px;
  background: var(--dt-green);
}

/* ---------- hero ---------- */
[data-site="duytan"] .hero {
  background:
    radial-gradient(46rem 26rem at -8% 0%, var(--dt-sand) 0%, transparent 60%),
    var(--dt-canvas);
  padding: 3.75rem 0;
}
[data-site="duytan"] .hero-grid {
  display: grid;
  grid-template-columns: 1.02fr 0.98fr;
  gap: 2.75rem;
  align-items: center;
}
[data-site="duytan"] .eyebrow {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
  color: var(--dt-green);
  font-weight: 800;
  font-size: 0.82rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin: 0 0 1rem;
}
[data-site="duytan"] .eyebrow-dark { color: #566b5f; }
[data-site="duytan"] .eyebrow-inline { display: inline; }
[data-site="duytan"] .chip {
  background: var(--dt-green);
  color: #fff;
  padding: 0.18rem 0.7rem;
  font-size: 0.76rem;
  letter-spacing: 0.08em;
}
[data-site="duytan"] .hero h1 {
  font-size: clamp(2.4rem, 5.2vw, 4rem);
  margin-bottom: 0.35em;
  color: var(--dt-text);
}
[data-site="duytan"] .hero h1 em { font-style: italic; color: var(--dt-green-mid); }
[data-site="duytan"] .lede { color: var(--dt-muted); max-width: 40rem; }
[data-site="duytan"] .hero-actions { display: flex; gap: 0.8rem; flex-wrap: wrap; margin-top: 1.5rem; }

[data-site="duytan"] .btn {
  display: inline-block;
  text-decoration: none;
  font-weight: 800;
  border-radius: 999px;
  padding: 0.85rem 1.6rem;
  transition: transform var(--dt-t-fast) ease, background var(--dt-t-fast) ease, border-color var(--dt-t-fast) ease;
}
[data-site="duytan"] .btn-green { background: var(--dt-green-mid); color: #fff; }
[data-site="duytan"] .btn-green:hover { background: var(--dt-green); transform: translateY(-2px); }
[data-site="duytan"] .btn-outline { color: var(--dt-green); border: 2px solid var(--dt-green-mid); }
[data-site="duytan"] .btn-outline:hover { border-color: var(--dt-clay); color: var(--dt-clay); }
[data-site="duytan"] .btn-lg { padding: 1rem 1.9rem; font-size: 1rem; }

[data-site="duytan"] .hero-loop { margin: 0; }
[data-site="duytan"] .loop-frame {
  position: relative;
  width: min(100%, 24rem);
  aspect-ratio: 1;
  margin-inline: auto;
}
[data-site="duytan"] .loop-frame > img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 50%;
  border: 6px solid var(--dt-surface);
  box-shadow: 0 26px 54px rgba(23, 48, 58, 0.18);
}
[data-site="duytan"] .loop-ring {
  position: absolute;
  inset: -9%;
  width: 118%;
  height: 118%;
  max-width: none;
  pointer-events: none;
}
[data-site="duytan"] .hero-loop figcaption {
  margin-top: 0.8rem;
  text-align: center;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.7rem;
  color: var(--dt-muted);
}
[data-site="duytan"] .hero-loop a,
[data-site="duytan"] .phase-credit a,
[data-site="duytan"] .loop-pulse a { color: inherit; text-decoration: underline; text-underline-offset: 2px; }
[data-site="duytan"] .loop-spin {
  transform-origin: 260px 260px;
  animation: dt-spin 42s linear infinite;
}
@keyframes dt-spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* ---------- sections ---------- */
[data-site="duytan"] .section { padding: 4rem 0; }
[data-site="duytan"] .section-head { max-width: 44rem; margin-bottom: 2.25rem; }
[data-site="duytan"] .section-head h2 { font-size: clamp(1.85rem, 3.5vw, 2.6rem); }
[data-site="duytan"] .section-note { color: var(--dt-muted); }

/* phase fan */
[data-site="duytan"] .phase-fan {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.2rem;
}
[data-site="duytan"] .phase {
  background: var(--dt-surface);
  border: 1px solid var(--dt-border);
  border-radius: 22px;
  padding: 1.8rem 1.65rem 1.6rem;
  position: relative;
  overflow: hidden;
}
[data-site="duytan"] .phase::after {
  content: "";
  position: absolute;
  right: -46px; top: -46px;
  width: 130px; height: 130px;
  border-radius: 50%;
  border: 18px solid var(--dt-sand);
  opacity: .8;
}
[data-site="duytan"] .phase-b::after { border-color: #d6e7dc; }
[data-site="duytan"] .phase-c::after { border-color: #efd9cb; }
[data-site="duytan"] .phase-no {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--dt-clay);
}
[data-site="duytan"] .phase h3 { font-size: 1.35rem; margin: 0.35em 0 0.35em; }
[data-site="duytan"] .phase p { margin: 0 0 0.9rem; color: var(--dt-muted); font-size: 0.94rem; }
[data-site="duytan"] .chip-row { display: flex; flex-wrap: wrap; gap: 0.45rem; }
[data-site="duytan"] .chip-row li {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--dt-green);
  background: #edf3ee;
  border-radius: 999px;
  padding: 0.3rem 0.8rem;
}
[data-site="duytan"] .phase-b .chip-row li { background: #e7efe9; }
[data-site="duytan"] .phase-c .chip-row li { background: #f5e9e0; color: #8f4218; }

/* metrics */
[data-site="duytan"] .metrics { padding: 2.75rem 0; }
[data-site="duytan"] .metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}
[data-site="duytan"] .metric {
  border-radius: 20px;
  padding: 1.5rem 1.35rem;
}
[data-site="duytan"] .metric-green { background: var(--dt-green); color: #fff; }
[data-site="duytan"] .metric-sand { background: var(--dt-sand); color: var(--dt-text); }
[data-site="duytan"] .metric-value {
  display: block;
  font-family: var(--dt-serif);
  font-size: 2.3rem;
  font-weight: 700;
  line-height: 1;
  margin-bottom: 0.4rem;
}
[data-site="duytan"] .metric-label { font-size: 0.86rem; }

/* sustain */
[data-site="duytan"] .sustain { background: var(--dt-surface); }
[data-site="duytan"] .sus-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 3rem;
  align-items: center;
}
[data-site="duytan"] .sus-grid h2 { font-size: clamp(1.85rem, 3.5vw, 2.6rem); }
[data-site="duytan"] .sus-list { display: grid; gap: 0.6rem; margin-top: 1.1rem; }
[data-site="duytan"] .sus-list li {
  display: flex;
  gap: 0.65rem;
  align-items: baseline;
  font-weight: 600;
}
[data-site="duytan"] .sus-list li::before {
  content: "";
  flex: none;
  width: 0.85rem; height: 0.85rem;
  border-radius: 50%;
  border: 3px solid var(--dt-green-mid);
  border-top-color: transparent;
  transform: translateY(1px);
}
[data-site="duytan"] .loop-pulse { margin: 0; }
[data-site="duytan"] .loop-pulse img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 24px;
  border: 1px solid var(--dt-border);
}
[data-site="duytan"] .loop-pulse figcaption {
  margin-top: 0.7rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.7rem;
  color: var(--dt-muted);
}
[data-site="duytan"] .phase,
[data-site="duytan"] .sus-grid > div:first-child {
  background-image:
    radial-gradient(circle, rgba(141, 154, 163, 0.16) 0 1.4px, transparent 1.6px);
  background-size: 22px 22px;
}
[data-site="duytan"] .phase-photo {
  display: block;
  width: 100%;
  height: clamp(140px, 15vw, 180px);
  object-fit: cover;
  border-radius: 14px;
  border: 1px solid var(--dt-border);
  margin: 0.7rem 0 0.9rem;
}
[data-site="duytan"] .phase-credit {
  display: block;
  margin-top: 0.8rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.66rem;
  color: var(--dt-muted);
}

/* loop band */
[data-site="duytan"] .loop-band {
  background: var(--dt-green);
  padding: 1.6rem 0;
  text-align: center;
}
[data-site="duytan"] .loop-band-text {
  margin: 0;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: clamp(0.95rem, 2.4vw, 1.3rem);
  font-weight: 700;
  letter-spacing: 0.22em;
  color: #eef6ef;
}
[data-site="duytan"] .loop-band-text span { color: #a9d3b8; margin: 0 0.5rem; }

/* cta */
[data-site="duytan"] .cta { padding: 4rem 0; text-align: center; }
[data-site="duytan"] .cta-inner h2 { font-size: clamp(1.85rem, 3.5vw, 2.5rem); }

/* footer */
[data-site="duytan"] .site-footer {
  background: #1d2b26;
  color: #c3d2c8;
  padding: 3.25rem 0 2rem;
}
[data-site="duytan"] .footer-brand { display: flex; align-items: baseline; gap: 0.9rem; margin-bottom: 1.4rem; flex-wrap: wrap; }
[data-site="duytan"] .f-name { font-family: var(--dt-serif); color: #fff; font-size: 1.4rem; font-weight: 700; }
[data-site="duytan"] .f-sub { font-size: 0.8rem; color: #96c4a6; }
[data-site="duytan"] .footer-nav ul { display: flex; flex-wrap: wrap; gap: 0.5rem 1.5rem; margin-bottom: 1.6rem; }
[data-site="duytan"] .footer-nav a { color: #e2ece4; text-decoration: none; font-size: 0.9rem; font-weight: 600; }
[data-site="duytan"] .footer-nav a:hover { color: #96c4a6; }
[data-site="duytan"] .disclaimer {
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  padding-top: 1.4rem;
  font-size: 0.82rem;
  color: #a3b5a9;
  max-width: 60rem;
}
[data-site="duytan"] .colophon { font-size: 0.75rem; color: #82988a; }

/* ---------- responsive ---------- */
@media (max-width: 1020px) {
  [data-site="duytan"] .hero-grid { grid-template-columns: 1fr; }
  [data-site="duytan"] .metrics-grid { grid-template-columns: repeat(2, 1fr); }
  [data-site="duytan"] .phase-fan { grid-template-columns: 1fr; }
  [data-site="duytan"] .sus-grid { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  [data-site="duytan"] .nav-toggle { display: flex; }
  [data-site="duytan"] .main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0; right: 0;
    background: var(--dt-canvas);
    border-bottom: 1px solid var(--dt-border);
    padding: 0.75rem 1.25rem 1.25rem;
  }
  [data-site="duytan"] .main-nav.is-open { display: block; }
  [data-site="duytan"] .main-nav ul { flex-direction: column; gap: 0.25rem; }
  [data-site="duytan"] .header-cta { display: none; }
}

@media (max-width: 560px) {
  [data-site="duytan"] .loop-frame { width: min(100%, 15rem); }
  [data-site="duytan"] .loop-ring { inset: -8%; width: 116%; height: 116%; }
}

@media (max-width: 520px) {
  [data-site="duytan"] .metrics-grid { grid-template-columns: 1fr; }
  [data-site="duytan"] .section { padding: 3rem 0; }
}

/* ---------- motion ---------- */
@media (prefers-reduced-motion: reduce) {
  [data-site="duytan"] * {
    animation: none !important;
    transition: none !important;
  }
}

/* ---------- polish: motion layer 2 ---------- */
[data-site="duytan"] .phase::after {
  transition: transform 0.7s var(--dt-t-base, 260ms) ease;
}
[data-site="duytan"] .phase:hover::after {
  transform: rotate(90deg) scale(1.12);
}
[data-site="duytan"] .loop-band-text span {
  display: inline-block;
  animation: dt-tick 2.4s ease-in-out infinite;
}
[data-site="duytan"] .loop-band-text span:nth-child(2) { animation-delay: 0.3s; }
[data-site="duytan"] .loop-band-text span:nth-child(3) { animation-delay: 0.6s; }
@keyframes dt-tick {
  30% { transform: translateY(-4px); }
}
[data-site="duytan"] .chip-row li:hover {
  background: var(--dt-green);
  color: #fff;
  transition: background 0.2s ease, color 0.2s ease;
}