:root {
  --indigo-950: #1e1b4b;
  --indigo-900: #312e81;
  --indigo-700: #4338ca;
  --indigo-600: #4f46e5;
  --indigo-500: #6366f1;
  --indigo-400: #818cf8;
  --indigo-100: #eef2ff;
  --indigo-50: #f5f7ff;
  --slate-900: #0f172a;
  --slate-700: #334155;
  --slate-600: #475569;
  --slate-500: #64748b;
  --slate-200: #e2e8f0;
  --slate-100: #f1f5f9;
  --white: #ffffff;
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.08);
  --shadow-md: 0 8px 30px rgba(49, 46, 129, 0.12);
  --shadow-lg: 0 20px 50px rgba(49, 46, 129, 0.18);
  --radius: 14px;
  --radius-lg: 20px;
  --nav-width: 260px;
  --header-h: 64px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 24px);
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  color: var(--slate-700);
  background: var(--slate-100);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--indigo-600);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ── Header ── */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--slate-200);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  color: var(--indigo-900);
  font-size: 0.95rem;
}

.brand-mark {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--indigo-600), var(--indigo-400));
  display: grid;
  place-items: center;
  color: white;
  font-size: 1rem;
}

.header-actions {
  display: flex;
  gap: 0.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.45rem 0.9rem;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  font-family: inherit;
  transition: all 0.2s;
}

.btn-ghost {
  background: transparent;
  color: var(--slate-600);
  border-color: var(--slate-200);
}

.btn-ghost:hover {
  background: var(--indigo-50);
  border-color: var(--indigo-400);
  color: var(--indigo-700);
  text-decoration: none;
}

.btn-primary {
  background: var(--indigo-600);
  color: white;
}

.btn-primary:hover {
  background: var(--indigo-700);
}

/* ── Layout ── */
.layout {
  display: flex;
  padding-top: var(--header-h);
}

.sidebar {
  position: fixed;
  top: var(--header-h);
  left: 0;
  width: var(--nav-width);
  height: calc(100vh - var(--header-h));
  overflow-y: auto;
  padding: 1.25rem 1rem;
  background: var(--white);
  border-right: 1px solid var(--slate-200);
  z-index: 50;
}

.sidebar-label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--slate-500);
  margin: 0 0 0.75rem 0.5rem;
}

.nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  display: block;
  padding: 0.45rem 0.65rem;
  border-radius: 8px;
  font-size: 0.82rem;
  color: var(--slate-600);
  text-decoration: none;
  border-left: 3px solid transparent;
  margin-bottom: 2px;
}

.nav-list a:hover {
  background: var(--indigo-50);
  color: var(--indigo-700);
}

.nav-list a.active {
  background: var(--indigo-100);
  color: var(--indigo-900);
  border-left-color: var(--indigo-500);
  font-weight: 600;
}

.nav-part {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--indigo-500);
  padding: 0.75rem 0.65rem 0.25rem;
  margin-top: 0.5rem;
}

.main {
  flex: 1;
  margin-left: var(--nav-width);
  min-width: 0;
}

/* ── Hero ── */
.hero {
  position: relative;
  padding: 5rem 3rem 4rem;
  background: linear-gradient(145deg, var(--indigo-950) 0%, var(--indigo-900) 40%, var(--indigo-600) 100%);
  color: white;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 80%, rgba(129, 140, 248, 0.35) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(99, 102, 241, 0.25) 0%, transparent 45%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  max-width: 900px;
}

.hero-badge {
  display: inline-block;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.2);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  margin-bottom: 1.25rem;
}

.hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.hero-sub {
  margin: 0 0 1.5rem;
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  opacity: 0.92;
  font-weight: 400;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  font-size: 0.88rem;
  opacity: 0.85;
}

.hero-meta span {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* ── Sections ── */
.section {
  padding: 3.5rem 3rem;
  max-width: 1100px;
}

.section-wide {
  max-width: none;
  padding-left: 3rem;
  padding-right: 3rem;
}

.section-alt {
  background: var(--white);
}

.section-part {
  background: linear-gradient(90deg, var(--indigo-900), var(--indigo-600));
  color: white;
  padding: 2.5rem 3rem;
  max-width: none;
}

.section-part h2 {
  margin: 0;
  font-size: 1.5rem;
  color: white;
}

.section-part p {
  margin: 0.5rem 0 0;
  opacity: 0.88;
  font-size: 1rem;
}

.section-header {
  margin-bottom: 2rem;
}

.section-header h2 {
  margin: 0 0 0.5rem;
  font-size: 1.75rem;
  color: var(--indigo-900);
  letter-spacing: -0.02em;
}

.section-header p {
  margin: 0;
  color: var(--slate-500);
  font-size: 1.05rem;
  max-width: 640px;
}

.section-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--indigo-600);
  background: var(--indigo-100);
  padding: 0.25rem 0.6rem;
  border-radius: 6px;
  margin-bottom: 0.6rem;
}

/* ── Cards & grids ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
}

.card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 1.35rem;
  border: 1px solid var(--slate-200);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.card-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--indigo-100);
  color: var(--indigo-600);
  display: grid;
  place-items: center;
  font-size: 1.2rem;
  margin-bottom: 0.85rem;
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1rem;
  color: var(--indigo-900);
}

.card p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--slate-600);
}

.card .impact {
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px dashed var(--slate-200);
  font-size: 0.82rem;
  color: var(--slate-500);
}

/* ── Quote block ── */
.quote-block {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 2rem 2.25rem;
  border: 1px solid var(--indigo-100);
  box-shadow: var(--shadow-md);
  position: relative;
}

.quote-block::before {
  content: "\201C";
  position: absolute;
  top: -0.2rem;
  left: 1.5rem;
  font-size: 4rem;
  line-height: 1;
  color: var(--indigo-200);
  font-family: Georgia, serif;
}

.quote-block p {
  margin: 0 0 1rem;
  font-size: 1.15rem;
  color: var(--indigo-900);
  font-weight: 600;
  line-height: 1.5;
}

.quote-block ul {
  margin: 0;
  padding-left: 1.25rem;
  color: var(--slate-600);
}

/* ── Pipeline (6 phases) ── */
.pipeline {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 0.5rem;
  margin-bottom: 2rem;
}

@media (max-width: 900px) {
  .pipeline {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 520px) {
  .pipeline {
    grid-template-columns: repeat(2, 1fr);
  }
}

.pipeline-step {
  text-align: center;
  padding: 1rem 0.5rem;
  background: var(--white);
  border-radius: var(--radius);
  border: 1px solid var(--slate-200);
  position: relative;
}

.pipeline-step:not(:last-child)::after {
  content: "→";
  position: absolute;
  right: -0.55rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--indigo-400);
  font-weight: 700;
  z-index: 1;
}

@media (max-width: 900px) {
  .pipeline-step:nth-child(3)::after,
  .pipeline-step:nth-child(6)::after {
    display: none;
  }
}

.pipeline-num {
  width: 28px;
  height: 28px;
  margin: 0 auto 0.5rem;
  border-radius: 50%;
  background: var(--indigo-600);
  color: white;
  font-size: 0.75rem;
  font-weight: 700;
  display: grid;
  place-items: center;
}

.pipeline-step h4 {
  margin: 0 0 0.25rem;
  font-size: 0.85rem;
  color: var(--indigo-900);
}

.pipeline-step p {
  margin: 0;
  font-size: 0.72rem;
  color: var(--slate-500);
  line-height: 1.4;
}

/* ── Tables ── */
.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius);
  border: 1px solid var(--slate-200);
  background: var(--white);
  box-shadow: var(--shadow-sm);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

th {
  background: var(--indigo-600);
  color: white;
  text-align: left;
  padding: 0.75rem 1rem;
  font-weight: 600;
  white-space: nowrap;
}

td {
  padding: 0.7rem 1rem;
  border-bottom: 1px solid var(--slate-200);
  vertical-align: top;
}

tr:last-child td {
  border-bottom: none;
}

tr:nth-child(even) td {
  background: var(--indigo-50);
}

td strong {
  color: var(--indigo-900);
}

/* ── Timeline (state machine) ── */
.timeline {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  position: relative;
  padding: 1rem 0;
}

.timeline-item {
  flex: 1 1 120px;
  min-width: 110px;
  text-align: center;
  padding: 0 0.5rem 1rem;
  position: relative;
}

.timeline-dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--indigo-500);
  border: 3px solid var(--indigo-100);
  margin: 0 auto 0.6rem;
  position: relative;
  z-index: 1;
}

.timeline-item:not(:last-child) .timeline-dot::after {
  content: "";
  position: absolute;
  top: 50%;
  left: calc(100% + 3px);
  width: calc(100vw / 9);
  max-width: 80px;
  height: 2px;
  background: var(--indigo-200);
  transform: translateY(-50%);
}

.timeline-item h4 {
  margin: 0 0 0.2rem;
  font-size: 0.78rem;
  color: var(--indigo-900);
}

.timeline-item .phase-en {
  font-size: 0.68rem;
  color: var(--indigo-500);
  font-family: ui-monospace, monospace;
  margin-bottom: 0.35rem;
}

.timeline-item p {
  margin: 0;
  font-size: 0.72rem;
  color: var(--slate-500);
  line-height: 1.35;
}

/* ── Split content + image ── */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  align-items: start;
}

@media (max-width: 860px) {
  .split {
    grid-template-columns: 1fr;
  }
}

.split-content h3 {
  margin: 0 0 1rem;
  color: var(--indigo-900);
}

.split-content ul {
  padding-left: 1.2rem;
  margin: 0 0 1rem;
}

.split-content li {
  margin-bottom: 0.4rem;
}

.steps-list {
  list-style: none;
  padding: 0;
  margin: 0;
  counter-reset: step;
}

.steps-list li {
  counter-increment: step;
  display: flex;
  gap: 0.85rem;
  margin-bottom: 0.85rem;
  align-items: flex-start;
}

.steps-list li::before {
  content: counter(step);
  flex-shrink: 0;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--indigo-600);
  color: white;
  font-size: 0.75rem;
  font-weight: 700;
  display: grid;
  place-items: center;
}

/* ── Image showcase ── */
.figure {
  margin: 0;
}

.figure-full {
  margin: 2rem 0;
}

.figure img {
  width: 100%;
  border-radius: var(--radius-lg);
  border: 1px solid var(--slate-200);
  box-shadow: var(--shadow-lg);
  cursor: zoom-in;
  transition: transform 0.25s, box-shadow 0.25s;
}

.figure img:hover {
  transform: scale(1.005);
  box-shadow: 0 24px 60px rgba(49, 46, 129, 0.22);
}

.figure figcaption {
  margin-top: 0.85rem;
  font-size: 0.85rem;
  color: var(--slate-500);
  text-align: center;
}

.figure-badge {
  display: inline-block;
  margin-bottom: 0.75rem;
  padding: 0.2rem 0.55rem;
  background: var(--indigo-100);
  color: var(--indigo-700);
  border-radius: 6px;
  font-size: 0.72rem;
  font-weight: 700;
}

/* ── Gates (3 checkpoints) ── */
.gates {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

@media (max-width: 720px) {
  .gates {
    grid-template-columns: 1fr;
  }
}

.gate {
  background: linear-gradient(160deg, var(--white) 0%, var(--indigo-50) 100%);
  border: 2px solid var(--indigo-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
}

.gate-num {
  font-size: 2rem;
  font-weight: 800;
  color: var(--indigo-400);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.gate h3 {
  margin: 0 0 0.5rem;
  color: var(--indigo-900);
  font-size: 1.05rem;
}

.gate p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--slate-600);
}

/* ── Flow diagram ── */
.flow-bar {
  background: var(--white);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  border: 1px solid var(--slate-200);
  font-family: ui-monospace, "Cascadia Code", monospace;
  font-size: 0.82rem;
  color: var(--indigo-800);
  overflow-x: auto;
  white-space: nowrap;
  margin-bottom: 1.5rem;
}

.flow-bar span {
  color: var(--indigo-500);
}

/* ── Compare table highlight ── */
.compare-plan td:last-child {
  background: rgba(99, 102, 241, 0.08);
  font-weight: 500;
}

/* ── Value cards ── */
.value-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

@media (max-width: 640px) {
  .value-grid {
    grid-template-columns: 1fr;
  }
}

.value-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 1.5rem;
  border-left: 4px solid var(--indigo-500);
  box-shadow: var(--shadow-sm);
}

.value-card h3 {
  margin: 0 0 0.5rem;
  color: var(--indigo-900);
}

.value-card p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--slate-600);
}

/* ── Footer CTA ── */
.footer-cta {
  background: var(--indigo-950);
  color: white;
  padding: 4rem 3rem;
  text-align: center;
}

.footer-cta h2 {
  margin: 0 0 0.5rem;
  font-size: 2rem;
  color: white;
}

.footer-cta p {
  margin: 0 0 2rem;
  opacity: 0.8;
}

.link-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
}

.link-grid a {
  padding: 0.65rem 1.25rem;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 10px;
  color: white;
  font-size: 0.9rem;
  text-decoration: none;
  transition: background 0.2s;
}

.link-grid a:hover {
  background: rgba(255, 255, 255, 0.18);
  text-decoration: none;
}

/* ── Lightbox ── */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(15, 23, 42, 0.92);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  cursor: zoom-out;
}

.lightbox.open {
  display: flex;
}

.lightbox img {
  max-width: min(95vw, 1400px);
  max-height: 90vh;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
}

.lightbox-close {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  background: rgba(255, 255, 255, 0.15);
  border: none;
  color: white;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  font-size: 1.5rem;
  cursor: pointer;
  display: grid;
  place-items: center;
}

/* ── Present mode ── */
body.present-mode .sidebar {
  display: none;
}

body.present-mode .main {
  margin-left: 0;
}

body.present-mode .site-header .nav-toggle-label {
  display: none;
}

body.present-mode .section,
body.present-mode .section-wide,
body.present-mode .section-part {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

/* ── Mobile ── */
.nav-toggle {
  display: none;
}

@media (max-width: 960px) {
  .sidebar {
    transform: translateX(-100%);
    transition: transform 0.25s;
    box-shadow: var(--shadow-lg);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .main {
    margin-left: 0;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .section,
  .section-wide,
  .section-part,
  .hero {
    padding-left: 1.25rem;
    padding-right: 1.25rem;
  }

  .hero {
    padding-top: 3rem;
  }
}