/* ============================================================
   Derek Marketing — Warm Minimal PE/VC Theme
   Cream #fffef2 / Dark #191918 / Gold #FFB923
   Near-square corners, 4px baseline spacing
   ============================================================ */

/* ── Navigation ── */
.dk-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--df-nav-height);
  z-index: var(--df-z-sticky);
  display: flex;
  align-items: center;
  padding: 0 var(--df-space-8);
  background: transparent;
  transition: background var(--df-duration-slow) var(--df-ease),
              backdrop-filter var(--df-duration-slow) var(--df-ease),
              box-shadow var(--df-duration-slow) var(--df-ease);
}

.dk-nav--scrolled {
  background: rgba(255, 254, 242, 0.92);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  box-shadow: 0 1px 0 var(--df-border);
}

.dk-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: var(--df-container-lg);
  margin: 0 auto;
}

.dk-nav__logo {
  display: flex;
  align-items: center;
  gap: var(--df-space-3);
  font-family: var(--df-font-body);
  font-weight: var(--df-weight-bold);
  font-size: 1.125rem;
  color: var(--df-text-primary);
  letter-spacing: -0.02em;
  text-decoration: none;
}

.dk-nav__logo-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--df-radius-md);
}

.dk-nav__logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.dk-nav__logo-brand {
  font-weight: var(--df-weight-bold);
}

.dk-nav__logo-sub {
  font-size: var(--df-text-nano);
  font-weight: var(--df-weight-normal);
  color: var(--df-text-muted);
  letter-spacing: 0.02em;
}

.dk-nav__links {
  display: flex;
  align-items: center;
  gap: var(--df-space-8);
}

.dk-nav__link {
  font-size: var(--df-text-micro);
  font-weight: var(--df-weight-medium);
  color: var(--df-text-tertiary);
  text-transform: uppercase;
  letter-spacing: var(--df-tracking-wide);
  text-decoration: none;
  /* Wenli 巧思: underline wipes in from the left on hover */
  background-image: linear-gradient(currentColor, currentColor);
  background-position: 0 100%;
  background-repeat: no-repeat;
  background-size: 0% 1.5px;
  transition: color var(--df-duration) var(--df-ease),
              background-size var(--df-duration) var(--df-ease);
}

.dk-nav__link:hover,
.dk-nav__link:focus-visible {
  color: var(--df-text-primary);
  background-size: 100% 1.5px;
}

.dk-nav__link--active {
  color: var(--df-text-primary);
  font-weight: var(--df-weight-semibold);
}

.dk-nav__cta {
  display: inline-flex;
  align-items: center;
  gap: var(--df-space-2);
  padding: var(--df-space-2) var(--df-space-5);
  background: var(--df-accent);
  border: 1px solid var(--df-accent);
  color: var(--dk-dark-1);
  font-size: var(--df-text-micro);
  font-weight: var(--df-weight-semibold);
  border-radius: var(--df-radius);
  text-transform: uppercase;
  letter-spacing: var(--df-tracking-wide);
  text-decoration: none;
  transition: all var(--df-duration) var(--df-ease);
}

.dk-nav__cta:hover {
  background: var(--df-accent-bright);
  border-color: var(--df-accent-bright);
}

.dk-nav__mobile-toggle {
  display: none;
  padding: var(--df-space-2);
  background: none;
  border: none;
  color: var(--df-text-primary);
  font-size: 1.25rem;
  cursor: pointer;
}

/* ── Hero Section ── */
.dk-hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--df-bg-base);
  padding: calc(var(--df-nav-height) + var(--df-space-16)) var(--df-space-8) var(--df-space-16);
}

.dk-hero__bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 20% 40%, rgba(255, 185, 35, 0.04), transparent),
    radial-gradient(ellipse 60% 50% at 80% 30%, rgba(217, 119, 6, 0.03), transparent),
    radial-gradient(ellipse 50% 40% at 50% 80%, rgba(255, 185, 35, 0.03), transparent);
  pointer-events: none;
}

.dk-hero__grid {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(25, 25, 24, 0.04) 1px, transparent 1px);
  background-size: 32px 32px;
  pointer-events: none;
}

.dk-hero__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--df-space-16);
  align-items: center;
  max-width: var(--df-container-lg);
  margin: 0 auto;
  width: 100%;
}

.dk-hero__content {
  max-width: 600px;
}

.dk-hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--df-space-2);
  padding: var(--df-space-1) var(--df-space-3);
  background: var(--df-accent-glow);
  border: 1px solid var(--df-accent-border);
  border-radius: var(--df-radius-full);
  font-size: var(--df-text-micro);
  font-weight: var(--df-weight-medium);
  color: var(--df-text-primary);
  margin-bottom: var(--df-space-6);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.dk-hero__badge-dot {
  width: 6px;
  height: 6px;
  background: var(--df-accent);
  border-radius: 50%;
  animation: dk-pulse 2s ease-in-out infinite;
}

@keyframes dk-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.dk-hero__headline {
  font-family: var(--df-font-headline);
  font-size: var(--df-text-display);
  font-weight: var(--df-weight-semibold);
  color: var(--df-text-primary);
  line-height: var(--df-leading-tight);
  letter-spacing: var(--df-tracking-tight);
  margin-bottom: var(--df-space-4);
}

.dk-hero__subheadline {
  font-family: var(--df-font-body);
  font-size: var(--df-text-display-2);
  font-weight: 400;
  color: var(--df-text-secondary);
  line-height: var(--df-leading-tight);
  margin-bottom: var(--df-space-6);
}

.dk-hero__body {
  font-size: 1.0625rem;
  color: var(--df-text-tertiary);
  line-height: var(--df-leading-relaxed);
  margin-bottom: var(--df-space-8);
  max-width: 520px;
}

.dk-hero__actions {
  display: flex;
  align-items: center;
  gap: var(--df-space-4);
  margin-bottom: var(--df-space-8);
}

/* ── Hero Visual Card ── */
.dk-hero-visual {
  position: relative;
  background: var(--dk-dark-1);
  border-radius: var(--df-radius-md);
  padding: var(--df-space-8);
  box-shadow: var(--df-shadow-lg);
  overflow: hidden;
}

.dk-hero-visual::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255, 185, 35, 0.08) 0%, transparent 50%);
  pointer-events: none;
}

.dk-hero-visual__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--df-space-6);
  padding-bottom: var(--df-space-4);
  border-bottom: 1px solid var(--dk-dark-3);
}

.dk-hero-visual__title {
  font-family: var(--df-font-body);
  font-size: var(--df-text-small);
  font-weight: var(--df-weight-semibold);
  color: var(--dk-text-on-dark);
  letter-spacing: 0.02em;
}

.dk-hero-visual__badge {
  font-size: var(--df-text-nano);
  font-weight: var(--df-weight-medium);
  color: var(--df-accent);
  text-transform: uppercase;
  letter-spacing: var(--df-tracking-wide);
}

.dk-hero-visual__metrics {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--df-space-4);
}

.dk-hero-visual__metric {
  padding: var(--df-space-4);
  background: var(--dk-dark-2);
  border-radius: var(--df-radius);
  border: 1px solid var(--dk-dark-3);
}

.dk-hero-visual__metric-label {
  font-size: var(--df-text-nano);
  font-weight: var(--df-weight-medium);
  color: var(--dk-text-on-dark-muted);
  text-transform: uppercase;
  letter-spacing: var(--df-tracking-wide);
  margin-bottom: var(--df-space-1);
}

.dk-hero-visual__metric-value {
  font-family: var(--df-font-mono);
  font-size: var(--df-text-h3);
  font-weight: var(--df-weight-medium);
  color: var(--dk-text-on-dark);
}

.dk-hero-visual__metric-value--gold {
  color: var(--df-accent);
}

.dk-hero-visual__metric-value--green {
  color: var(--dk-tier-top-border);
}

.dk-hero-visual__chart {
  margin-top: var(--df-space-6);
  padding-top: var(--df-space-4);
  border-top: 1px solid var(--dk-dark-3);
  height: 120px;
  display: flex;
  align-items: flex-end;
  gap: var(--df-space-2);
}

.dk-hero-visual__bar {
  flex: 1;
  background: linear-gradient(180deg, var(--df-accent), var(--df-accent-dim));
  border-radius: var(--df-radius-xs) var(--df-radius-xs) 0 0;
  opacity: 0;
  transform: scaleY(0);
  transform-origin: bottom;
  animation: dk-bar-grow 0.6s var(--df-ease-out) forwards;
}

.dk-hero-visual__bar:nth-child(1) { animation-delay: 0.1s; }
.dk-hero-visual__bar:nth-child(2) { animation-delay: 0.15s; }
.dk-hero-visual__bar:nth-child(3) { animation-delay: 0.2s; }
.dk-hero-visual__bar:nth-child(4) { animation-delay: 0.25s; }
.dk-hero-visual__bar:nth-child(5) { animation-delay: 0.3s; }
.dk-hero-visual__bar:nth-child(6) { animation-delay: 0.35s; }
.dk-hero-visual__bar:nth-child(7) { animation-delay: 0.4s; }
.dk-hero-visual__bar:nth-child(8) { animation-delay: 0.45s; }

@keyframes dk-bar-grow {
  to {
    opacity: 1;
    transform: scaleY(1);
  }
}

/* ── Sections ── */
.dk-section {
  padding: clamp(64px, 8vw, 96px) var(--df-space-8);
}

/* ── Section rhythm (Wenli 巧思 — break the uniform metronome) ──
   Vary vertical breathing so the page reads open → dense → open instead of
   every band getting identical air. Overrides only the block axis. */
.dk-section--spacious { padding-block: clamp(88px, 11vw, 144px); }
.dk-section--tight    { padding-block: clamp(44px, 5.5vw, 68px); }
.dk-section--flush-top { padding-top: 0; }

.dk-section--tint {
  background: var(--df-bg-cream);
}

.dk-section--dark {
  background: var(--dk-dark-1);
  color: var(--dk-text-on-dark);
}

.dk-section--dark .dk-section__title,
.dk-section--dark .dk-section__subtitle {
  color: var(--dk-text-on-dark);
}

.dk-section--dark .dk-section__subtitle {
  color: var(--dk-text-on-dark-muted);
}

.dk-section__inner {
  max-width: var(--df-container-lg);
  margin: 0 auto;
}

.dk-section__header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto var(--df-space-16);
}

.dk-section__header--left {
  text-align: left;
  margin-left: 0;
}

.dk-section__title {
  font-family: var(--df-font-headline);
  font-size: var(--df-text-h1);
  font-weight: var(--df-weight-semibold);
  line-height: var(--df-leading-tight);
  letter-spacing: var(--df-tracking-tight);
  margin-bottom: var(--df-space-4);
  color: var(--df-text-primary);
}

.dk-section__subtitle {
  font-size: 1.0625rem;
  line-height: var(--df-leading-relaxed);
  max-width: 600px;
  margin: 0 auto;
  color: var(--df-text-tertiary);
}

.dk-section__header--left .dk-section__subtitle {
  margin-left: 0;
}

/* ── Eyebrow Badge ── */
.dk-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--df-space-2);
  padding: var(--df-space-1) var(--df-space-3);
  background: var(--df-accent-glow);
  border: 1px solid var(--df-accent-border);
  border-radius: var(--df-radius-full);
  font-size: var(--df-text-micro);
  font-weight: var(--df-weight-semibold);
  color: var(--df-text-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--df-space-4);
}

.dk-section--dark .dk-eyebrow {
  background: rgba(255, 185, 35, 0.15);
  border-color: rgba(255, 185, 35, 0.3);
  color: var(--df-accent);
}

/* ── Grid Layouts ── */
.dk-grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--df-space-6);
}

.dk-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--df-space-6);
}

.dk-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--df-space-6);
}

/* ── Cards ── */
.dk-card {
  background: var(--df-bg-surface);
  border: 1px solid var(--df-border);
  border-radius: var(--df-radius-md);
  padding: var(--df-space-8);
  transition: border-color var(--df-duration) var(--df-ease),
              box-shadow var(--df-duration-slow) var(--df-ease),
              transform var(--df-duration) var(--df-ease);
}

.dk-card:hover {
  border-color: var(--df-border-3);
  box-shadow: var(--df-shadow-md);
  transform: translateY(-2px);
}

.dk-card:focus-visible {
  outline: 2px solid var(--df-accent);
  outline-offset: 2px;
}

.dk-card__icon {
  width: 56px;
  height: 56px;
  border-radius: var(--df-radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: var(--df-space-5);
  background: var(--df-accent-glow);
  color: var(--df-accent);
}

.dk-card__title {
  font-size: var(--df-text-h3);
  font-weight: var(--df-weight-bold);
  color: var(--df-text-primary);
  margin-bottom: var(--df-space-2);
}

.dk-card__desc {
  font-size: var(--df-text-body);
  color: var(--df-text-secondary);
  line-height: var(--df-leading-normal);
  margin-bottom: var(--df-space-5);
}

.dk-card__link {
  display: inline-flex;
  align-items: center;
  gap: var(--df-space-2);
  font-size: var(--df-text-small);
  font-weight: var(--df-weight-semibold);
  color: var(--df-accent);
  text-decoration: none;
  transition: gap var(--df-duration) var(--df-ease);
}

.dk-card__link:hover {
  gap: var(--df-space-3);
}

/* ── Buttons ── */
.dk-btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--df-space-2);
  padding: var(--df-space-3) var(--df-space-6);
  background: var(--df-accent);
  border: 1px solid var(--df-accent);
  color: var(--dk-dark-1);
  font-family: var(--df-font-body);
  font-size: var(--df-text-body);
  font-weight: var(--df-weight-semibold);
  border-radius: var(--df-radius);
  text-transform: uppercase;
  letter-spacing: var(--df-tracking-wide);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--df-duration) var(--df-ease);
}

.dk-btn-primary:hover {
  background: var(--df-accent-bright);
  border-color: var(--df-accent-bright);
  box-shadow: var(--df-shadow-blue);
  transform: translateY(-1px);
}

.dk-btn-primary:focus-visible,
.dk-btn-secondary:focus-visible,
.dk-nav__cta:focus-visible {
  outline: 2px solid var(--df-accent);
  outline-offset: 2px;
}

.dk-btn-primary--lg {
  padding: var(--df-space-4) var(--df-space-8);
  font-size: 1rem;
}

.dk-btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--df-space-2);
  padding: var(--df-space-3) var(--df-space-6);
  background: transparent;
  border: 1px solid var(--df-text-primary);
  color: var(--df-text-primary);
  font-family: var(--df-font-body);
  font-size: var(--df-text-body);
  font-weight: var(--df-weight-semibold);
  border-radius: var(--df-radius);
  text-transform: uppercase;
  letter-spacing: var(--df-tracking-wide);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--df-duration) var(--df-ease);
}

.dk-btn-secondary:hover {
  background: rgba(25, 25, 24, 0.05);
}

.dk-btn-secondary--lg {
  padding: var(--df-space-4) var(--df-space-8);
  font-size: 1rem;
}

.dk-section--dark .dk-btn-secondary {
  border-color: var(--dk-text-on-dark);
  color: var(--dk-text-on-dark);
}

.dk-section--dark .dk-btn-secondary:hover {
  background: rgba(255, 254, 242, 0.1);
}

/* ── Timeline (How It Works) ── */
.dk-timeline {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--df-space-8);
  position: relative;
  max-width: var(--df-container);
  margin: 0 auto;
}

.dk-timeline::before {
  content: '';
  position: absolute;
  top: 40px;
  left: calc(16.67% + 20px);
  right: calc(16.67% + 20px);
  height: 2px;
  background: var(--df-border);
}

.dk-timeline__step {
  position: relative;
  text-align: center;
  padding-top: var(--df-space-4);
}

.dk-timeline__number {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--df-bg-surface);
  border: 2px solid var(--df-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--df-font-mono);
  font-size: var(--df-text-h4);
  font-weight: var(--df-weight-bold);
  color: var(--df-accent);
  margin: 0 auto var(--df-space-5);
  position: relative;
  z-index: 1;
}

.dk-timeline__title {
  font-size: var(--df-text-h4);
  font-weight: var(--df-weight-bold);
  color: var(--df-text-primary);
  margin-bottom: var(--df-space-2);
}

.dk-timeline__desc {
  font-size: var(--df-text-small);
  color: var(--df-text-tertiary);
  line-height: var(--df-leading-normal);
  max-width: 280px;
  margin: 0 auto;
}

/* ── Stats ── */
.dk-stat {
  text-align: center;
  padding: var(--df-space-6);
}

.dk-stat__value {
  font-family: var(--df-font-headline);
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 400;
  color: var(--df-text-primary);
  line-height: 1;
  margin-bottom: var(--df-space-2);
}

.dk-stat__value--gold {
  color: var(--df-accent);
}

.dk-section--dark .dk-stat__value {
  color: var(--dk-text-on-dark);
}

.dk-stat__label {
  font-size: var(--df-text-small);
  font-weight: var(--df-weight-medium);
  color: var(--df-text-tertiary);
  text-transform: uppercase;
  letter-spacing: var(--df-tracking-wide);
}

.dk-section--dark .dk-stat__label {
  color: var(--dk-text-on-dark-muted);
}

/* ── Testimonials ── */
.dk-testimonial {
  background: var(--df-bg-surface);
  border: 1px solid var(--df-border);
  border-radius: var(--df-radius-md);
  padding: var(--df-space-8);
  position: relative;
  transition: border-color var(--df-duration) var(--df-ease),
              box-shadow var(--df-duration-slow) var(--df-ease);
}

.dk-testimonial:hover {
  border-color: var(--df-border-3);
  box-shadow: var(--df-shadow-sm);
}

.dk-testimonial:focus-visible {
  outline: 2px solid var(--df-accent);
  outline-offset: 2px;
}

.dk-testimonial::before {
  content: '\201C';
  position: absolute;
  top: var(--df-space-4);
  left: var(--df-space-6);
  font-family: var(--df-font-headline);
  font-size: 4rem;
  line-height: 1;
  color: var(--df-accent-glow);
  opacity: 0.5;
}

.dk-testimonial__quote {
  font-size: var(--df-text-body);
  font-style: italic;
  color: var(--df-text-secondary);
  line-height: var(--df-leading-relaxed);
  margin-bottom: var(--df-space-6);
  position: relative;
  z-index: 1;
}

.dk-testimonial__author {
  display: flex;
  align-items: center;
  gap: var(--df-space-3);
}

.dk-testimonial__avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--df-bg-cream);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--df-text-body);
  font-weight: var(--df-weight-bold);
  color: var(--df-text-muted);
}

.dk-testimonial__name {
  font-size: var(--df-text-small);
  font-weight: var(--df-weight-semibold);
  color: var(--df-text-primary);
}

.dk-testimonial__role {
  font-size: var(--df-text-micro);
  color: var(--df-text-muted);
}

/* ── CTA Section ── */
.dk-cta {
  background: var(--dk-dark-1);
  padding: var(--df-space-24) var(--df-space-8);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.dk-cta::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 30% 40%, rgba(255, 185, 35, 0.08), transparent),
    radial-gradient(ellipse 50% 40% at 70% 60%, rgba(255, 185, 35, 0.05), transparent);
  pointer-events: none;
}

.dk-cta__inner {
  position: relative;
  max-width: 720px;
  margin: 0 auto;
}

.dk-cta__title {
  font-family: var(--df-font-headline);
  font-size: var(--df-text-h1);
  font-weight: var(--df-weight-semibold);
  color: var(--dk-text-on-dark);
  margin-bottom: var(--df-space-4);
  line-height: var(--df-leading-tight);
}

.dk-cta__subtitle {
  font-size: 1.0625rem;
  color: var(--dk-text-on-dark-muted);
  margin-bottom: var(--df-space-8);
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
  line-height: var(--df-leading-relaxed);
}

.dk-cta__actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--df-space-4);
}

/* ── Integrations Strip ── */
.dk-integrations {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--df-space-10);
  flex-wrap: wrap;
  padding: var(--df-space-6) 0;
}

.dk-integrations__item {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  height: 48px;
  opacity: 0.5;
  filter: grayscale(100%);
  transition: opacity var(--df-duration) var(--df-ease),
              filter var(--df-duration) var(--df-ease);
}

.dk-integrations__item:hover {
  opacity: 1;
  filter: grayscale(0%);
}

.dk-integrations__item img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

/* ── Badge ── */
.dk-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--df-space-1);
  padding: 2px var(--df-space-2);
  background: var(--df-accent-glow);
  border: 1px solid var(--df-accent-border);
  border-radius: var(--df-radius-sm);
  font-size: var(--df-text-nano);
  font-weight: var(--df-weight-semibold);
  color: var(--df-text-primary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.dk-badge--dark {
  background: var(--dk-dark-2);
  border-color: var(--dk-dark-3);
  color: var(--df-accent);
}

/* ── Footer ── */
.dk-footer {
  background: var(--df-bg-cream);
  border-top: 1px solid var(--df-border);
  padding: var(--df-space-12) var(--df-space-8) var(--df-space-8);
}

.dk-footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  max-width: var(--df-container);
  margin: 0 auto;
  gap: var(--df-space-16);
}

.dk-footer__brand {
  max-width: 300px;
}

.dk-footer__logo {
  display: flex;
  align-items: center;
  gap: var(--df-space-3);
  font-size: 1.125rem;
  font-weight: var(--df-weight-bold);
  color: var(--df-text-primary);
  margin-bottom: var(--df-space-3);
  text-decoration: none;
}

.dk-footer__logo-icon {
  width: 28px;
  height: 28px;
  border-radius: var(--df-radius-sm);
}

.dk-footer__tagline {
  font-size: var(--df-text-small);
  color: var(--df-text-tertiary);
  line-height: var(--df-leading-normal);
  margin-bottom: var(--df-space-4);
}

.dk-footer__columns {
  display: flex;
  gap: var(--df-space-16);
}

.dk-footer__col-title {
  font-size: var(--df-text-micro);
  font-weight: var(--df-weight-semibold);
  color: var(--df-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--df-space-4);
}

.dk-footer__col-link {
  display: block;
  width: fit-content;
  font-size: var(--df-text-small);
  color: var(--df-text-tertiary);
  padding: var(--df-space-1) 0;
  text-decoration: none;
  /* Wenli 巧思: underline wipes in from the left (sits above the bottom padding) */
  background-image: linear-gradient(currentColor, currentColor);
  background-position: 0 calc(100% - var(--df-space-1));
  background-repeat: no-repeat;
  background-size: 0% 1px;
  transition: color var(--df-duration) var(--df-ease),
              background-size var(--df-duration) var(--df-ease);
}

.dk-footer__col-link:hover,
.dk-footer__col-link:focus-visible {
  color: var(--df-text-primary);
  background-size: 100% 1px;
}

.dk-footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: var(--df-container);
  margin: var(--df-space-8) auto 0;
  padding-top: var(--df-space-6);
  border-top: 1px solid var(--df-border);
  font-size: var(--df-text-micro);
  color: var(--df-text-muted);
}

.dk-footer__legal {
  display: flex;
  gap: var(--df-space-6);
}

.dk-footer__legal-link {
  color: var(--df-text-muted);
  text-decoration: none;
  transition: color var(--df-duration) var(--df-ease);
}

.dk-footer__legal-link:hover {
  color: var(--df-text-primary);
}

/* ── Container Utility ── */
.dk-container {
  max-width: var(--df-container);
  margin: 0 auto;
  padding: 0 var(--df-space-8);
}

.dk-container--lg {
  max-width: var(--df-container-lg);
}

.dk-container--sm {
  max-width: var(--df-container-sm);
}

/* ── Responsive: 1440px ── */
@media (max-width: 1440px) {
  .dk-grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ── Responsive: 1024px (Tablet Landscape) ── */
@media (max-width: 1024px) {
  .dk-hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--df-space-10);
  }

  .dk-hero__content {
    max-width: 640px;
    margin: 0 auto;
  }

  .dk-hero__body {
    margin-left: auto;
    margin-right: auto;
  }

  .dk-hero__actions {
    justify-content: center;
  }

  .dk-hero-visual {
    max-width: 500px;
    margin: 0 auto;
  }

  .dk-grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .dk-grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .dk-timeline {
    grid-template-columns: 1fr;
    gap: var(--df-space-6);
  }

  .dk-timeline::before {
    top: 0;
    bottom: 0;
    left: 23px;
    right: auto;
    width: 2px;
    height: auto;
  }

  .dk-timeline__step {
    text-align: left;
    padding-left: 72px;
    padding-top: 0;
    padding-bottom: var(--df-space-4);
  }

  .dk-timeline__number {
    position: absolute;
    left: 0;
    top: 0;
    margin: 0;
  }

  .dk-timeline__desc {
    margin: 0;
  }

  .dk-footer__inner {
    flex-direction: column;
    gap: var(--df-space-8);
  }

  .dk-footer__columns {
    flex-wrap: wrap;
    gap: var(--df-space-8);
  }
}

/* ── Responsive: 768px (Tablet Portrait) ── */
@media (max-width: 768px) {
  .dk-section {
    padding: var(--df-space-16) var(--df-space-5);
  }

  .dk-nav {
    padding: 0 var(--df-space-5);
  }

  .dk-nav__links {
    display: none;
  }

  .dk-nav__mobile-toggle {
    display: flex;
  }

  .dk-hero {
    padding-left: var(--df-space-5);
    padding-right: var(--df-space-5);
  }

  .dk-hero__actions {
    flex-direction: column;
    gap: var(--df-space-3);
  }

  .dk-hero__actions .dk-btn-primary,
  .dk-hero__actions .dk-btn-secondary {
    width: 100%;
  }

  .dk-grid-2,
  .dk-grid-3,
  .dk-grid-4 {
    grid-template-columns: 1fr;
  }

  .dk-footer__columns {
    flex-direction: column;
    gap: var(--df-space-6);
  }

  .dk-footer__bottom {
    flex-direction: column;
    gap: var(--df-space-4);
    text-align: center;
  }

  .dk-cta__actions {
    flex-direction: column;
    gap: var(--df-space-3);
  }

  .dk-cta__actions .dk-btn-primary,
  .dk-cta__actions .dk-btn-secondary {
    width: 100%;
    max-width: 320px;
  }

  .dk-integrations {
    gap: var(--df-space-6);
  }

  .dk-integrations__item {
    width: 60px;
    height: 36px;
  }
}

/* ── Scroll Reveal Animation ── */
.df-reveal,
.dk-reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.45s var(--df-ease-out), transform 0.45s var(--df-ease-out);
}

.df-reveal.is-visible,
.dk-reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Staggered reveal delays */
.df-reveal-delay-1 { transition-delay: 0.1s; }
.df-reveal-delay-2 { transition-delay: 0.2s; }
.df-reveal-delay-3 { transition-delay: 0.3s; }
.df-reveal-delay-4 { transition-delay: 0.4s; }
.df-reveal-delay-5 { transition-delay: 0.5s; }

/* Reduced motion preference (DESIGN-BAR section 7: blanket kill for all marketing animations) */
@media (prefers-reduced-motion: reduce) {
  .df-reveal,
  .dk-reveal,
  .dk-fade-in,
  .dk-slide-up,
  .dk-hero-visual__bar,
  .dk-hero__badge-dot,
  [class*='dk-delay-'] {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}

/* ── Animation Utilities ── */
.dk-fade-in {
  opacity: 0;
  animation: dk-fade-in 0.45s var(--df-ease-out) forwards;
}

@keyframes dk-fade-in {
  to { opacity: 1; }
}

.dk-slide-up {
  opacity: 0;
  transform: translateY(12px);
  animation: dk-slide-up 0.45s var(--df-ease-out) forwards;
}

@keyframes dk-slide-up {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Staggered animation delays */
.dk-delay-1 { animation-delay: 0.1s; }
.dk-delay-2 { animation-delay: 0.2s; }
.dk-delay-3 { animation-delay: 0.3s; }
.dk-delay-4 { animation-delay: 0.4s; }
.dk-delay-5 { animation-delay: 0.5s; }