/* ─────────────────────────────────────────────────────────────────────
   Kacha download site
   Design: Dieter Rams-influenced — function-first, no ornament.
   Palette: cream background, dark text, coral accent.
   Typography: system stack, deliberate weight + spacing.
───────────────────────────────────────────────────────────────────── */

:root {
  --bg:           #FAF7F2;
  --bg-elev:     #FFFFFF;
  --bg-sunken:   #F2EDE5;
  --ink:         #1E1B17;
  --ink-soft:    #4A453C;
  --ink-mute:    #8F8A82;
  --line:        #E3DDD3;
  --line-strong: #C8C0B6;

  --coral:       #FF5E5B;
  --coral-dark:  #E94B48;
  --coral-soft:  rgba(255, 94, 91, 0.10);

  --gold:        #E8A93B;

  --radius-sm:   6px;
  --radius:      10px;
  --radius-lg:   16px;

  --shadow-sm:   0 1px 3px rgba(40, 30, 20, 0.06), 0 1px 2px rgba(40, 30, 20, 0.04);
  --shadow:      0 4px 16px rgba(40, 30, 20, 0.08), 0 2px 4px rgba(40, 30, 20, 0.05);
  --shadow-lg:   0 20px 60px rgba(40, 30, 20, 0.12), 0 8px 20px rgba(40, 30, 20, 0.06);

  --font-sans:   -apple-system, BlinkMacSystemFont, "Inter", "PingFang TC",
                 "Noto Sans TC", "Microsoft JhengHei", sans-serif;
}

* { box-sizing: border-box; }

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-sans);
  font-weight: 400;
  line-height: 1.55;
  letter-spacing: -0.005em;
}

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

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

button, input, select {
  font-family: inherit;
  font-size: inherit;
}

/* ─── Nav ─────────────────────────────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 32px;
  background: rgba(250, 247, 242, 0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
}

.nav-brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
}
.nav-brand img {
  align-self: center;
  border-radius: 6px;
}
.nav-brand-name {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.nav-brand-romaji {
  font-size: 11px;
  color: var(--ink-mute);
  font-weight: 500;
  letter-spacing: 0.04em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 26px;
  font-size: 13.5px;
  font-weight: 500;
}
.nav-links a {
  color: var(--ink-soft);
  transition: color 0.15s;
}
.nav-links a:hover {
  color: var(--coral);
}
.nav-link-muted {
  color: var(--ink-mute) !important;
}

/* ─── Hero ────────────────────────────────────────────────────────── */
.hero {
  max-width: 920px;
  margin: 0 auto;
  padding: 100px 32px 56px;
  text-align: center;
}

.hero-title {
  font-size: clamp(48px, 7vw, 84px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.035em;
  margin: 0 0 20px;
  color: var(--ink);
}
.hero-accent {
  color: var(--coral);
  font-style: italic;
}

.hero-sub {
  font-size: 18px;
  line-height: 1.55;
  color: var(--ink-soft);
  margin: 0 auto 36px;
  max-width: 540px;
  font-weight: 450;
}

.hero-cta {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  margin-bottom: 28px;
}

.btn-primary {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 18px 40px;
  background: var(--coral);
  color: #FFFFFF;
  border-radius: var(--radius);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: -0.01em;
  box-shadow: var(--shadow);
  transition: transform 0.08s, box-shadow 0.2s, background 0.15s;
  cursor: pointer;
  border: none;
  min-width: 280px;
}
.btn-primary:hover {
  background: var(--coral-dark);
  box-shadow: var(--shadow-lg);
  transform: translateY(-1px);
}
.btn-primary:active {
  transform: translateY(0);
}
.btn-primary-label {
  font-size: 17px;
  font-weight: 700;
}
.btn-primary-meta {
  font-size: 11px;
  font-weight: 500;
  opacity: 0.85;
  letter-spacing: 0.02em;
}

.hero-alt-links {
  display: flex;
  gap: 18px;
  font-size: 13px;
  font-weight: 500;
}
.hero-alt-links a {
  color: var(--ink-mute);
  border-bottom: 1px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}
.hero-alt-links a:hover {
  color: var(--coral);
  border-bottom-color: var(--coral);
}

.hero-meta {
  font-size: 12.5px;
  color: var(--ink-mute);
  letter-spacing: 0.01em;
  display: flex;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
}
.hero-meta .dot,
.footer-row .dot {
  opacity: 0.5;
}

/* ─── Showcase ────────────────────────────────────────────────────── */
.showcase {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 32px 80px;
}

.showcase-frame {
  border-radius: var(--radius-lg);
  background: var(--bg-elev);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  aspect-ratio: 16 / 10;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ink-mute);
  font-size: 13px;
}
.showcase-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.showcase-frame img:not([src]),
.showcase-frame img[src=""] {
  display: none;
}

/* ─── Features ────────────────────────────────────────────────────── */
.features {
  max-width: 1080px;
  margin: 0 auto;
  padding: 40px 32px 100px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.feature {
  background: var(--bg-elev);
  padding: 32px 28px;
}
.feature-icon {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  background: var(--coral-soft);
  color: var(--coral);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
}
.feature h3 {
  margin: 0 0 8px;
  font-size: 15.5px;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.feature p {
  margin: 0;
  font-size: 13.5px;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* ─── Pricing ─────────────────────────────────────────────────────── */
.pricing {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 32px 100px;
}

.section-title {
  text-align: center;
  font-size: clamp(28px, 4vw, 38px);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin: 0 0 40px;
}

.pricing-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.plan {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
}
.plan-pro {
  border: 2px solid var(--coral);
  position: relative;
}

.plan-head {
  margin-bottom: 20px;
  position: relative;
}
.plan-badge {
  display: inline-block;
  padding: 3px 10px;
  font-size: 10px;
  font-weight: 900;
  letter-spacing: 0.12em;
  color: #FFFFFF;
  background: linear-gradient(135deg, var(--gold), var(--coral));
  border-radius: 99px;
  margin-bottom: 12px;
  text-transform: uppercase;
}
.plan-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--ink-mute);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0 0 6px;
}
.plan-price {
  font-size: 36px;
  font-weight: 800;
  letter-spacing: -0.025em;
  margin: 0;
  color: var(--ink);
}
.plan-price-unit {
  font-size: 16px;
  font-weight: 500;
  color: var(--ink-mute);
  letter-spacing: 0;
}
.plan-tagline {
  margin: 4px 0 0;
  font-size: 12.5px;
  color: var(--ink-mute);
}

.plan-features {
  list-style: none;
  margin: 0 0 28px;
  padding: 0;
  flex: 1;
}
.plan-features li {
  position: relative;
  padding: 8px 0 8px 22px;
  font-size: 13.5px;
  color: var(--ink-soft);
  border-bottom: 1px solid var(--line);
  line-height: 1.5;
}
.plan-features li:last-child {
  border-bottom: none;
}
.plan-features li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 14px;
  width: 12px;
  height: 6px;
  border-left: 2px solid var(--coral);
  border-bottom: 2px solid var(--coral);
  transform: rotate(-45deg);
  border-radius: 1px;
}

.plan-cta {
  display: block;
  text-align: center;
  padding: 13px 24px;
  border-radius: var(--radius);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: -0.005em;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  cursor: pointer;
}
.plan-cta-primary {
  background: var(--coral);
  color: #FFFFFF;
  border: 1px solid var(--coral);
}
.plan-cta-primary:hover {
  background: var(--coral-dark);
}
.plan-cta-secondary {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line-strong);
}
.plan-cta-secondary:hover {
  border-color: var(--ink);
}

/* ─── Download ────────────────────────────────────────────────────── */
.download {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 32px 100px;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 28px;
}

.dl-card {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 28px 24px;
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.15s, transform 0.08s, box-shadow 0.2s;
  cursor: pointer;
}
.dl-card:hover {
  border-color: var(--coral);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}
.dl-card-os {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--ink);
}
.dl-card-arch {
  font-size: 13px;
  font-weight: 600;
  color: var(--coral);
  letter-spacing: 0.005em;
}
.dl-card-size {
  margin-top: 4px;
  font-size: 12px;
  color: var(--ink-mute);
  letter-spacing: 0.02em;
}

.download-note {
  text-align: center;
  font-size: 13px;
  color: var(--ink-mute);
  margin: 0;
}
.download-note a {
  color: var(--ink-soft);
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 1px;
}
.download-note a:hover {
  color: var(--coral);
  border-bottom-color: var(--coral);
}

/* ─── Footer ──────────────────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--line);
  background: var(--bg-sunken);
  padding: 28px 32px;
  margin-top: 40px;
}
.footer-row {
  max-width: 1080px;
  margin: 0 auto;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 12.5px;
  color: var(--ink-mute);
}
.footer-row a {
  color: var(--ink-soft);
  transition: color 0.15s;
}
.footer-row a:hover {
  color: var(--coral);
}

/* ─── Responsive ──────────────────────────────────────────────────── */
@media (max-width: 720px) {
  .nav {
    padding: 12px 20px;
  }
  .nav-links {
    gap: 16px;
    font-size: 13px;
  }
  .hero {
    padding: 64px 24px 40px;
  }
  .hero-sub br { display: none; }
  .features {
    padding: 24px 20px 60px;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .pricing,
  .download,
  .showcase {
    padding-left: 20px;
    padding-right: 20px;
  }
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  .download-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .btn-primary {
    min-width: unset;
    width: 100%;
  }
  .hero-alt-links {
    flex-wrap: wrap;
    justify-content: center;
  }
}