/* ═══════════════════════════════════════════════════
   Plant Disease Identifier — Standalone Stylesheet
   Matches LivePlant homepage design system
   Prefix: pd- (plant disease)
   ═══════════════════════════════════════════════════ */

/* ─── Design Tokens ─── */
:root {
  --pd-ink: #0f172a;
  --pd-ink-soft: #334155;
  --pd-muted: #475569;
  --pd-emerald: #16a34a;
  --pd-emerald-dark: #15803d;
  --pd-emerald-soft: #dcfce7;
  --pd-border: #e2e8f0;
  --pd-surface: #ffffff;
  --pd-surface-soft: #f6fff9;
  --pd-hero-a: #5ec29e;
  --pd-hero-b: #43a882;
  --pd-hero-c: #2d7a5d;
  --pd-coral: #dc2626;
  --pd-coral-soft: #fee2e2;
  --pd-coral-deep: #b91c1c;
  --pd-radius: 1.5rem;
  --pd-radius-sm: 1rem;
  --pd-transition: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --pd-shell: 72rem;
  --pd-shell-narrow: 48rem;
  --pd-shell-prose: 42rem;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Plus Jakarta Sans", system-ui, sans-serif;
  background: var(--pd-surface);
  color: var(--pd-ink);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.6;
}

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

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

button {
  font: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}

/* ─── Layout ─── */
.pd-shell {
  width: min(calc(100% - 3rem), var(--pd-shell));
  margin-inline: auto;
}

.pd-shell--narrow {
  width: min(calc(100% - 3rem), var(--pd-shell-narrow));
  margin-inline: auto;
}

.pd-shell--prose {
  width: min(calc(100% - 3rem), var(--pd-shell-prose));
  margin-inline: auto;
}

.pd-section {
  padding-block: 4rem;
}

.pd-section--lg {
  padding-block: 5rem;
}

.pd-section--alt {
  background: var(--pd-surface-soft);
  border-block: 1px solid var(--pd-border);
}

/* ─── Typography ─── */
.pd-eyebrow {
  display: inline-block;
  color: var(--pd-emerald-dark);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.pd-eyebrow--coral {
  color: var(--pd-coral-deep);
}

.pd-title {
  color: var(--pd-ink);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.pd-title--hero {
  font-size: clamp(2.25rem, 5vw, 3.75rem);
  margin-top: 0.75rem;
  margin-bottom: 1.25rem;
}

.pd-title--hero-accent {
  color: var(--pd-coral-deep);
}

.pd-title--section {
  font-size: clamp(1.875rem, 3.5vw, 2.5rem);
  margin-top: 0.75rem;
}

.pd-copy {
  color: var(--pd-muted);
  line-height: 1.7;
}

.pd-copy--lg {
  font-size: 1.125rem;
}

.pd-max-w-prose {
  max-width: 40rem;
  margin-inline: auto;
}

/* ─── Buttons ─── */
.pd-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.625rem;
  border-radius: 999px;
  font-weight: 700;
  transition:
    transform 0.15s ease,
    box-shadow 0.15s ease;
}

.pd-button:hover {
  transform: translateY(-2px);
}

.pd-button--primary {
  padding: 0.875rem 1.75rem;
  background: linear-gradient(135deg, var(--pd-hero-a), var(--pd-hero-b), var(--pd-hero-c));
  color: #ffffff;
  box-shadow: 0 8px 24px rgba(67, 168, 130, 0.3);
}

.pd-button--primary:hover {
  box-shadow: 0 12px 32px rgba(67, 168, 130, 0.45);
}

.pd-button--sm {
  padding: 0.625rem 1.25rem;
  font-size: 0.875rem;
}

/* ─── Hero Section ─── */
.pd-hero-section {
  padding-top: 0.5rem;
  padding-bottom: 0rem;
}

.pd-hero-header {
  text-align: center;
  margin-bottom: 0.5rem;
}

/* ─── Trust Strip ─── */
.pd-trust {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 2rem 2.5rem;
  font-size: 0.875rem;
  color: var(--pd-muted);
}

.pd-trust strong {
  color: var(--pd-ink);
}

/* ─── Symptom Chips ─── */
.pd-symptoms {
  margin-top: 2.5rem;
  padding-top: 2.5rem;
  border-top: 1px solid var(--pd-border);
}

.pd-symptoms__label {
  text-align: center;
  font-size: 0.875rem;
  color: var(--pd-muted);
  margin-bottom: 1.25rem;
}

.pd-symptoms__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
}

.pd-symptom-chip {
  background: var(--pd-surface);
  border: 1px solid var(--pd-border);
  padding: 0.5rem 1rem;
  border-radius: 999px;
  font-size: 0.875rem;
  font-weight: 600;
  transition:
    background var(--pd-transition),
    border-color var(--pd-transition);
}

.pd-symptom-chip:hover {
  background: var(--pd-emerald-soft);
  border-color: var(--pd-emerald);
}

/* ─── Prose / Educational Content ─── */
.pd-prose p {
  color: var(--pd-muted);
  line-height: 1.75;
  margin-bottom: 1.25rem;
}

.pd-prose h3 {
  color: var(--pd-ink);
  font-weight: 800;
  font-size: 1.5rem;
  letter-spacing: -0.01em;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
}

.pd-prose ul {
  color: var(--pd-muted);
  line-height: 1.75;
  margin-bottom: 1.25rem;
  padding-left: 1.25rem;
}

.pd-prose ul li {
  margin-bottom: 0.5rem;
  list-style: disc;
}

.pd-prose strong {
  color: var(--pd-ink);
  font-weight: 700;
}

.pd-prose em {
  font-style: italic;
}

.pd-prose a {
  color: var(--pd-hero-b);
  font-weight: 600;
  text-decoration: underline;
}

.pd-prose a:hover {
  color: var(--pd-emerald-dark);
}

.pd-prose .pd-copy--lg {
  font-size: 1.125rem;
}

/* ─── Diseases Grid ─── */
.pd-diseases-header {
  margin-bottom: 2.5rem;
}

.pd-diseases-header .pd-copy {
  margin-top: 0.75rem;
  max-width: 36rem;
}

.pd-diseases-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 1rem;
}

.pd-disease-card {
  transition: transform var(--pd-transition);
}

.pd-disease-card:hover {
  transform: translateY(-3px);
}

.pd-disease-card__icon {
  aspect-ratio: 1 / 1;
  border-radius: var(--pd-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  font-size: 3rem;
  margin-bottom: 0.5rem;
  border: 1px solid rgba(255, 255, 255, 0.5);
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.05);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
  transition: transform var(--pd-transition);
}

.pd-disease-card:hover .pd-disease-card__icon {
  transform: scale(1.05);
}

.pd-disease-card__icon--red {
  background: rgba(254, 226, 226, 0.5);
}

.pd-disease-card__icon--green {
  background: rgba(223, 247, 236, 0.5);
}

.pd-disease-card__name {
  font-size: 0.875rem;
  font-weight: 700;
  margin: 0;
}

.pd-disease-card__tag {
  font-size: 0.75rem;
  color: var(--pd-muted);
  font-style: italic;
  margin: 0;
}

/* ─── How It Works / Step Cards ─── */
.pd-steps-header {
  text-align: center;
  margin-bottom: 3rem;
}

.pd-steps-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem;
}

.pd-step-card {
  padding: 1.5rem;
  border-radius: var(--pd-radius-sm);
  border: 1px solid var(--pd-border);
  background: var(--pd-surface);
}

.pd-step-card__number {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.125rem;
  font-weight: 800;
  color: #ffffff;
  background: linear-gradient(135deg, var(--pd-hero-a), var(--pd-hero-b));
  margin-bottom: 1rem;
}

.pd-step-card__title {
  font-weight: 800;
  font-size: 1.125rem;
  margin-bottom: 0.5rem;
}

.pd-step-card__copy {
  color: var(--pd-muted);
  font-size: 0.875rem;
  line-height: 1.6;
}

/* ─── FAQ ─── */
.pd-faq-header {
  text-align: center;
  margin-bottom: 3rem;
}

.pd-faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.pd-faq-item {
  border: 1px solid var(--pd-border);
  border-radius: var(--pd-radius-sm);
  background: var(--pd-surface);
  padding: 1.5rem;
}

.pd-faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  font-size: 1.125rem;
  font-weight: 800;
  list-style: none;
  cursor: pointer;
}

.pd-faq-question::-webkit-details-marker {
  display: none;
}

.pd-faq-icon {
  color: var(--pd-emerald);
  font-size: 2rem;
  line-height: 1;
  transition: transform var(--pd-transition);
  flex-shrink: 0;
}

.pd-faq-item[open] .pd-faq-icon {
  transform: rotate(45deg);
}

.pd-faq-answer {
  margin-top: 1rem;
  color: var(--pd-muted);
  line-height: 1.625;
}

/* ─── Utility ─── */
.pd-mt-3 {
  margin-top: 0.75rem;
}

/* ─── Responsive ─── */

/* Tablet */
@media (max-width: 64rem) {
  .pd-diseases-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* Small tablet / large phone */
@media (max-width: 48rem) {
  .pd-section {
    padding-block: 3rem;
  }

  .pd-section--lg {
    padding-block: 3.5rem;
  }

  .pd-steps-grid {
    grid-template-columns: 1fr;
  }

  .pd-diseases-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .pd-trust {
    gap: 1rem 1.5rem;
  }

  .pd-faq-question {
    font-size: 1rem;
  }
}

/* Mobile */
@media (max-width: 36rem) {
  .pd-title--hero {
    font-size: 2rem;
  }

  .pd-title--section {
    font-size: 1.625rem;
  }

  .pd-diseases-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .pd-symptom-chip {
    font-size: 0.8125rem;
    padding: 0.375rem 0.75rem;
  }
}

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