/* ============================================
   Design Tokens
   ============================================ */
:root {
  /* Greens — agricultural palette */
  --green-950: #143d27;
  --green-900: #1a4d30;
  --green-850: #1f5a37;
  --green-700: #2d7547;
  --green-600: #3a8f57;
  --green-200: #cfe8d6;
  --green-100: #e8f4e8;
  --green-50: #f2faf4;

  /* Warm neutrals */
  --cream: #fbf7eb;
  --cream-strong: #f3ead4;

  /* Accent — wheat gold */
  --wheat: #c9962f;
  --wheat-soft: #f2d58b;
  --wheat-light: #faf0d8;

  /* Text */
  --ink: #1a1a1a;
  --ink-secondary: #3a3a3c;
  --muted: #6b7280;
  --muted-light: #9ca3af;

  /* Surfaces & borders */
  --surface: #f7f7f7;
  --surface-elevated: #ffffff;
  --card: #ffffff;
  --line: #e5e5e5;
  --line-soft: #f0f0f0;

  /* Shadows — multi-layer depth system */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 4px 12px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 2px 4px rgba(0, 0, 0, 0.04), 0 8px 24px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 4px 8px rgba(0, 0, 0, 0.04), 0 16px 48px rgba(0, 0, 0, 0.08);
  --shadow-card: 0 0 0 1px rgba(0, 0, 0, 0.04), 0 2px 4px rgba(0, 0, 0, 0.04), 0 8px 24px rgba(0, 0, 0, 0.06);

  /* Radii */
  --radius-xs: 6px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 9999px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
  --duration-fast: 150ms;
  --duration-normal: 250ms;
  --duration-slow: 400ms;
}

/* ============================================
   Reset & Base
   ============================================ */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  min-width: 320px;
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  background: var(--surface);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

button {
  font: inherit;
  cursor: pointer;
}

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

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, p {
  margin-top: 0;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--green-700);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

h1 {
  margin-bottom: 20px;
  font-size: clamp(2.5rem, 12vw, 4.5rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--green-950);
}

h2 {
  margin-bottom: 10px;
  font-size: clamp(1.65rem, 7vw, 2.75rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--green-950);
}

h3 {
  margin-bottom: 6px;
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--green-950);
}

.section__head p:not(.eyebrow) {
  margin-bottom: 0;
  color: var(--muted);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 24px;
  border: 0;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.01em;
  transition: transform var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-normal) var(--ease-out),
              background var(--duration-fast) var(--ease-out);
}

.btn:active {
  transform: translateY(1px) scale(0.98);
}

.btn--primary {
  color: #fffdf6;
  background: var(--green-950);
  box-shadow: 0 2px 8px rgba(20, 61, 39, 0.2);
}

.btn--primary:hover {
  background: var(--green-900);
  box-shadow: 0 4px 16px rgba(20, 61, 39, 0.25);
}

.btn--secondary {
  color: var(--green-950);
  background: var(--surface-elevated);
  border: 1px solid var(--line);
}

.btn--secondary:hover {
  background: var(--green-50);
  border-color: var(--green-200);
}

.btn--full {
  width: 100%;
  margin-top: 16px;
}

/* ============================================
   Hero
   ============================================ */
.hero {
  position: relative;
  min-height: 100vh;
  padding: 60px 20px 48px;
  display: flex;
  align-items: center;
  background: var(--surface-elevated);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 20% 80%, rgba(207, 232, 214, 0.3) 0%, transparent 70%),
    radial-gradient(ellipse 60% 50% at 80% 20%, rgba(242, 213, 139, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero__inner {
  position: relative;
  z-index: 1;
  width: min(100%, 1200px);
  margin: 0 auto;
  display: grid;
  gap: 40px;
  align-items: center;
}

.hero__lead {
  max-width: 36rem;
  margin-bottom: 24px;
  color: var(--ink-secondary);
  font-size: 1.05rem;
  line-height: 1.7;
}

.hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 28px;
}

.hero__tags span {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 6px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-full);
  background: var(--surface-elevated);
  color: var(--green-850);
  font-size: 0.85rem;
  font-weight: 600;
}

.hero__actions {
  display: grid;
  gap: 10px;
}

/* Hero product card */
.hero-card {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: var(--card);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-lg);
}

.hero-card__img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.hero-card__overlay {
  position: absolute;
  top: 14px;
  left: 14px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  color: var(--green-950);
  font-size: 0.78rem;
  font-weight: 600;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.hero-card__stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line-soft);
}

.hero-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 16px 8px;
  text-align: center;
}

.hero-stat:not(:last-child) {
  border-right: 1px solid var(--line-soft);
}

.hero-stat strong {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--green-950);
  line-height: 1.1;
}

.hero-stat span {
  margin-top: 2px;
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 500;
}

/* Status dot */
.status-dot {
  display: inline-block;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  flex-shrink: 0;
}

.status-dot--green {
  background: var(--green-700);
  box-shadow: 0 0 0 3px rgba(45, 117, 71, 0.15);
}

.status-dot--gold {
  background: var(--wheat);
  box-shadow: 0 0 0 3px rgba(201, 150, 47, 0.15);
}

/* ============================================
   Sections
   ============================================ */
.section {
  width: min(100% - 32px, 1120px);
  margin: 0 auto;
  padding: 64px 0 24px;
}

.section__head {
  margin-bottom: 28px;
}

/* ============================================
   Flow Cards (Process 01)
   ============================================ */
.flow-visual {
  position: relative;
  margin-bottom: 24px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.flow-visual__img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.flow-visual__badge {
  position: absolute;
  top: 12px;
  left: 12px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  color: var(--green-950);
  font-size: 0.78rem;
  font-weight: 600;
}

.flow-list {
  display: grid;
  gap: 14px;
}

.flow-card {
  position: relative;
  padding: 22px 18px 20px 72px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--card);
  box-shadow: var(--shadow-card);
  transition: box-shadow var(--duration-normal) var(--ease-out),
              transform var(--duration-normal) var(--ease-out);
}

.flow-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.flow-card:not(:last-child)::after {
  content: "\2193";
  position: absolute;
  left: 30px;
  bottom: -26px;
  z-index: 2;
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: var(--green-950);
  background: var(--green-100);
  font-weight: 700;
  font-size: 0.85rem;
}

.flow-card__num {
  position: absolute;
  left: 18px;
  top: 22px;
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-sm);
  color: #fffdf6;
  background: var(--green-850);
  font-weight: 700;
  font-size: 0.9rem;
}

.flow-card p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

/* ============================================
   Traceability (Process 02)
   ============================================ */
.trace-panel {
  display: grid;
  gap: 16px;
}

.qr-card,
.batch-card,
.sample-card,
.report-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--card);
  box-shadow: var(--shadow-card);
}

.qr-card {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.qr-visual {
  position: relative;
  width: 100%;
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: 16px;
}

.qr-visual__img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.qr-visual__badge {
  position: absolute;
  top: 10px;
  left: 10px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  color: var(--green-950);
  font-size: 0.75rem;
  font-weight: 600;
}

.qr-visual__mock {
  text-align: center;
  margin-bottom: 4px;
}

.mock-qr {
  width: 130px;
  height: 130px;
  margin: 0 auto 10px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
  padding: 10px;
  border: 1.5px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface-elevated);
}

.mock-qr span {
  border-radius: 4px;
  background: var(--green-850);
}

.mock-qr span:nth-child(2n),
.mock-qr span:nth-child(7),
.mock-qr span:nth-child(11) {
  background: var(--wheat);
}

.qr-visual__label {
  color: var(--green-950);
  font-weight: 600;
  font-size: 0.9rem;
}

/* Card shared elements */
.card-title-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 16px;
}

.status-pill {
  flex: 0 0 auto;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  color: var(--green-950);
  background: var(--green-100);
  font-size: 0.8rem;
  font-weight: 700;
  white-space: nowrap;
}

.status-pill--gold {
  background: var(--wheat-light);
  color: var(--wheat);
}

.info-grid {
  display: grid;
  gap: 8px;
  margin: 0;
}

.info-grid div {
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  background: var(--surface);
}

.info-grid dt {
  color: var(--muted);
  font-size: 0.82rem;
}

.info-grid dd {
  margin: 2px 0 0;
  color: var(--green-950);
  font-weight: 600;
}

.recommendation {
  margin: 14px 0 0;
  padding: 12px 14px;
  border-left: 4px solid var(--wheat);
  border-radius: var(--radius-sm);
  background: var(--cream);
}

/* ============================================
   Detection Report (Process 03)
   ============================================ */
.section--report {
  width: 100%;
  padding: 64px 16px 24px;
  background: var(--surface);
  border-top: 1px solid var(--line);
}

.section--report .section__head,
.section--report .detect-panel {
  width: min(100%, 1120px);
  margin-inline: auto;
}

.detect-panel {
  display: grid;
  gap: 16px;
}

.sample-card {
  text-align: center;
}

.sample-visual {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: 16px;
}

.sample-visual__img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.sample-visual__badge {
  position: absolute;
  top: 10px;
  left: 10px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  color: var(--green-950);
  font-size: 0.75rem;
  font-weight: 600;
}

.grain-sample {
  min-height: 120px;
  margin-bottom: 14px;
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 8px;
  padding: 18px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #d4a843, #c69030);
}

.grain-sample i {
  display: block;
  height: 28px;
  border-radius: 50% 45% 48% 52%;
  background: linear-gradient(135deg, #e8c56a, #c68925 58%, #8b5b1c);
  transform: rotate(-18deg);
}

.grain-sample i:nth-child(3n) {
  transform: rotate(14deg);
}

.score-block {
  margin-bottom: 14px;
  padding: 20px;
  border-radius: var(--radius-md);
  color: #fffdf6;
  background: var(--green-950);
}

.score-block span {
  display: block;
  margin-bottom: 4px;
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.85rem;
  font-weight: 500;
}

.score-block strong {
  font-size: 2.25rem;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.02em;
}

/* ============================================
   Resource Cycle (Process 04)
   ============================================ */
.cycle-visual {
  position: relative;
  margin-bottom: 24px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.cycle-visual__img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.cycle-visual__badge {
  position: absolute;
  top: 12px;
  left: 12px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  color: var(--green-950);
  font-size: 0.78rem;
  font-weight: 600;
}

.cycle-grid {
  display: grid;
  gap: 14px;
}

.feature-card {
  padding: 22px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--card);
  box-shadow: var(--shadow-card);
  transition: box-shadow var(--duration-normal) var(--ease-out),
              transform var(--duration-normal) var(--ease-out);
}

.feature-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.feature-card__icon {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  margin-bottom: 12px;
  border-radius: 50%;
  color: #fffdf6;
  background: var(--green-850);
  font-weight: 700;
  font-size: 0.9rem;
}

.feature-card p {
  margin-bottom: 10px;
  color: var(--muted);
  font-size: 0.92rem;
}

.feature-card__tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: var(--green-50);
  color: var(--green-700);
  font-size: 0.75rem;
  font-weight: 600;
}

/* ============================================
   Application Scenes
   ============================================ */
.section--scenes {
  padding-bottom: 40px;
}

.scene-grid {
  display: grid;
  gap: 14px;
}

.scene-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--card);
  box-shadow: var(--shadow-card);
  transition: box-shadow var(--duration-normal) var(--ease-out),
              transform var(--duration-normal) var(--ease-out);
}

.scene-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.scene-card__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.scene-card__icon {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-sm);
  background: var(--green-50);
  color: var(--green-700);
}

.scene-card__status {
  padding: 3px 8px;
  border-radius: var(--radius-full);
  background: var(--green-50);
  color: var(--green-700);
  font-size: 0.72rem;
  font-weight: 600;
}

.scene-card h3 {
  font-size: 1rem;
  margin-bottom: 6px;
}

.scene-card p {
  margin-bottom: 12px;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.6;
}

.scene-card__data {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.scene-card__data span {
  padding: 3px 8px;
  border-radius: var(--radius-full);
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink-secondary);
  font-size: 0.72rem;
  font-weight: 600;
}

/* ============================================
   Summary
   ============================================ */
.summary {
  margin: 24px auto 40px;
  width: min(100% - 32px, 900px);
  padding: 36px 28px;
  border-radius: var(--radius-lg);
  background: var(--card);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-card);
}

.summary h2 {
  margin-bottom: 12px;
}

.summary p {
  color: var(--muted);
  line-height: 1.7;
}

.summary__badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 20px;
}

.summary__badges span {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 5px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-full);
  background: var(--surface-elevated);
  color: var(--green-850);
  font-size: 0.85rem;
  font-weight: 600;
}

/* ============================================
   Back to Top
   ============================================ */
.back-top {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 5;
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  color: var(--green-950);
  background: var(--surface-elevated);
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity var(--duration-normal) var(--ease-out),
              transform var(--duration-normal) var(--ease-out),
              background var(--duration-fast) var(--ease-out);
}

.back-top.is-visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-top:hover {
  background: var(--green-50);
}

/* ============================================
   Footer
   ============================================ */
.site-footer {
  width: min(100% - 32px, 1120px);
  margin: 0 auto;
  padding: 20px 0 36px;
  text-align: center;
}

.site-footer p {
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.6;
}

/* ============================================
   Animation: hidden attribute
   ============================================ */
[hidden] {
  display: none !important;
}

/* ============================================
   Animation: panel flash (batch/report reveal)
   ============================================ */
.panel-flash {
  animation: panel-flash 0.4s var(--ease-out);
}

@keyframes panel-flash {
  0% {
    transform: translateY(8px);
    opacity: 0.5;
  }
  100% {
    transform: translateY(0);
    opacity: 1;
  }
}

/* ============================================
   Scroll Animations
   ============================================ */
[data-animate] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s var(--ease-out),
              transform 0.6s var(--ease-out);
}

[data-animate].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
[data-animate="stagger"] {
  transition-delay: calc(var(--stagger-index, 0) * 80ms);
}

/* ============================================
   Responsive: Tablet (≥720px)
   ============================================ */
@media (min-width: 720px) {
  .hero {
    min-height: 720px;
    padding-inline: 40px;
  }

  .hero__inner {
    grid-template-columns: 1fr 1fr;
    gap: 48px;
  }

  .hero__actions {
    grid-template-columns: repeat(2, max-content);
    gap: 12px;
  }

  .flow-list {
    grid-template-columns: repeat(3, 1fr);
  }

  .flow-card {
    padding: 72px 20px 22px;
  }

  .flow-card__num {
    left: 20px;
  }

  .flow-card:not(:last-child)::after {
    content: "\2192";
    left: auto;
    right: -22px;
    top: 36px;
    bottom: auto;
  }

  .trace-panel,
  .detect-panel {
    grid-template-columns: 0.85fr 1.15fr;
    align-items: start;
  }

  .cycle-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .scene-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .scene-grid .scene-card:last-child {
    grid-column: 1 / -1;
    max-width: calc(33.333% - 10px);
  }
}

/* ============================================
   Responsive: Desktop (≥1024px)
   ============================================ */
@media (min-width: 1024px) {
  .scene-grid {
    grid-template-columns: repeat(5, 1fr);
  }

  .scene-grid .scene-card:last-child {
    grid-column: auto;
    max-width: none;
  }

  .scene-card__data span {
    font-size: 0.7rem;
  }
}

/* ============================================
   Reduced Motion
   ============================================ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }

  [data-animate] {
    opacity: 1;
    transform: none;
  }

  .back-top {
    transition: none;
  }
}