/* =========================================================
   Z 视界官网 — 双主题静态长页
   ========================================================= */

:root {
  --font-display: "Outfit", "Noto Sans SC", sans-serif;
  --font-body: "Noto Sans SC", "Outfit", sans-serif;

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 22px;
  --radius-pill: 999px;

  --header-h: 72px;
  --container: 1160px;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --dur: 0.28s;

  --accent: #2f6bff;
  --accent-soft: rgba(47, 107, 255, 0.14);
  --windows: #2f6bff;
  --mac: #1c1c1e;
  --android: #3ddc84;
  --web: #7c5cff;

  --shadow-card: 0 10px 30px rgba(20, 40, 80, 0.08);
  --shadow-lift: 0 18px 40px rgba(20, 40, 80, 0.14);
}

html[data-theme="light"] {
  --bg: #f4f6fb;
  --bg-elevated: #ffffff;
  --bg-soft: #eef2f9;
  --text: #101828;
  --text-secondary: #5b6475;
  --text-muted: #8b93a7;
  --border: rgba(16, 24, 40, 0.08);
  --header-bg: rgba(244, 246, 251, 0.82);
  --glass: rgba(255, 255, 255, 0.72);
  --glow: rgba(47, 107, 255, 0.22);
  --pedestal: radial-gradient(circle at 50% 40%, #dbe7ff 0%, #b7c9f5 38%, #8ea6e0 70%, transparent 72%);
  --orb-bg: linear-gradient(145deg, rgba(255, 255, 255, 0.95), rgba(190, 214, 255, 0.55));
  --page-glow-1: rgba(120, 170, 255, 0.35);
  --page-glow-2: rgba(180, 210, 255, 0.28);
  --mac-btn: #1c1c1e;
  --mac-btn-text: #fff;
}

html[data-theme="dark"] {
  --bg: #070b14;
  --bg-elevated: rgba(18, 24, 38, 0.78);
  --bg-soft: rgba(28, 38, 58, 0.7);
  --text: #f3f6ff;
  --text-secondary: #a7b0c5;
  --text-muted: #7d879c;
  --border: rgba(255, 255, 255, 0.08);
  --header-bg: rgba(7, 11, 20, 0.78);
  --glass: rgba(16, 22, 36, 0.72);
  --glow: rgba(56, 189, 248, 0.28);
  --pedestal: radial-gradient(circle at 50% 40%, rgba(56, 189, 248, 0.55) 0%, rgba(37, 99, 235, 0.28) 40%, transparent 70%);
  --orb-bg: linear-gradient(145deg, rgba(120, 190, 255, 0.35), rgba(30, 60, 120, 0.55));
  --page-glow-1: rgba(37, 99, 235, 0.35);
  --page-glow-2: rgba(14, 165, 233, 0.22);
  --mac-btn: #f5f5f7;
  --mac-btn-text: #111;
  --shadow-card: 0 12px 36px rgba(0, 0, 0, 0.35);
  --shadow-lift: 0 20px 48px rgba(0, 0, 0, 0.45);
  --accent: #4d8dff;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 12px);
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.92em;
  padding: 0.1em 0.35em;
  border-radius: 6px;
  background: var(--bg-soft);
}

.page-bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(900px 520px at 12% -10%, var(--page-glow-1), transparent 60%),
    radial-gradient(800px 480px at 88% 8%, var(--page-glow-2), transparent 55%),
    radial-gradient(700px 420px at 70% 90%, var(--accent-soft), transparent 50%),
    var(--bg);
  transition: background var(--dur) var(--ease);
}

.container {
  width: min(100% - 2rem, var(--container));
  margin-inline: auto;
}

.section {
  padding: 96px 0;
}

.section-head {
  max-width: 640px;
  margin-bottom: 40px;
}

.section-head h2 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.section-desc {
  margin: 0;
  color: var(--text-secondary);
  font-size: 1.02rem;
}

.eyebrow {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: var(--header-bg);
  border-bottom: 1px solid var(--border);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.header-inner {
  height: 100%;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  transition: transform var(--dur) var(--ease);
}

.brand:hover {
  transform: translateY(-1px);
}

.brand-logo {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  box-shadow: 0 6px 16px var(--glow);
}

.nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.15rem;
}

.nav-link {
  position: relative;
  padding: 0.55rem 0.9rem;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 4px;
  width: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--accent);
  transform: translateX(-50%);
  transition: width var(--dur) var(--ease);
}

.nav-link:hover {
  color: var(--text);
  background: var(--accent-soft);
}

.nav-link.is-active {
  color: var(--text);
  font-weight: 600;
}

.nav-link.is-active::after {
  width: 18px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.theme-toggle {
  padding: 0;
}

.theme-toggle-track {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  width: 72px;
  height: 36px;
  padding: 0 8px;
  border-radius: var(--radius-pill);
  background: var(--bg-soft);
  border: 1px solid var(--border);
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.theme-toggle:hover .theme-toggle-track {
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.theme-icon {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  width: 100%;
  height: 100%;
  color: var(--text-muted);
}

.theme-icon svg {
  width: 15px;
  height: 15px;
}

.theme-knob {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--bg-elevated);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease);
}

html[data-theme="dark"] .theme-knob {
  transform: translateX(36px);
}

html[data-theme="light"] .theme-icon-sun {
  color: #f59e0b;
}

html[data-theme="dark"] .theme-icon-moon {
  color: #93c5fd;
}

.lang-switch {
  position: relative;
}

.lang-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  height: 36px;
  padding: 0 0.85rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-secondary);
  font-size: 0.88rem;
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.lang-btn svg {
  width: 15px;
  height: 15px;
  flex-shrink: 0;
}

.lang-btn .chevron {
  width: 14px;
  height: 14px;
  opacity: 0.7;
  transition: transform var(--dur) var(--ease);
}

.lang-switch.is-open .lang-btn .chevron {
  transform: rotate(180deg);
}

.lang-btn:hover {
  transform: translateY(-1px);
  border-color: var(--accent);
  box-shadow: 0 8px 18px var(--accent-soft);
}

.lang-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 60;
  min-width: 148px;
  margin: 0;
  padding: 6px;
  list-style: none;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  box-shadow: var(--shadow-lift);
  backdrop-filter: blur(12px);
}

.lang-menu[hidden] {
  display: none;
}

.lang-menu li {
  padding: 10px 12px;
  border-radius: 10px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}

.lang-menu li:hover {
  background: var(--accent-soft);
  color: var(--text);
}

.lang-menu li[aria-selected="true"] {
  color: var(--accent);
  font-weight: 700;
  background: var(--accent-soft);
}

.menu-toggle {
  display: none;
  width: 40px;
  height: 40px;
  padding: 0;
  margin: 0;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  line-height: 0;
}

.menu-toggle-lines {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 14px;
  gap: 4px;
}

.menu-toggle-lines span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 0;
  border-radius: 2px;
  background: var(--text);
  transform-origin: center;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

body.nav-open .menu-toggle-lines span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

body.nav-open .menu-toggle-lines span:nth-child(2) {
  opacity: 0;
}

body.nav-open .menu-toggle-lines span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* ---------- Hero ---------- */

.hero {
  padding-top: 48px;
  padding-bottom: 72px;
  min-height: calc(100vh - var(--header-h));
  display: flex;
  align-items: center;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2.5rem;
  align-items: center;
}

.hero-copy h1 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 4.6vw, 3.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
}

.hero-desc {
  margin: 0 0 28px;
  color: var(--text-secondary);
  font-size: 1.05rem;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
}

.dl-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 16px;
  border-radius: var(--radius-md);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  backdrop-filter: blur(10px);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.dl-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lift);
  border-color: color-mix(in srgb, var(--accent) 45%, transparent);
}

.dl-icon {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  display: grid;
  place-items: center;
}

.dl-icon svg {
  width: 22px;
  height: 22px;
}

.dl-icon.windows {
  color: #fff;
  background: linear-gradient(135deg, #4d8dff, #2f6bff);
}

.dl-icon.mac {
  color: #fff;
  background: linear-gradient(135deg, #3a3a3c, #1c1c1e);
}

html[data-theme="dark"] .dl-icon.mac {
  color: #111;
  background: linear-gradient(135deg, #f5f5f7, #d2d2d7);
}

.dl-icon.android {
  color: #063;
  background: linear-gradient(135deg, #86efac, #3ddc84);
}

.dl-icon.web {
  color: #fff;
  background: linear-gradient(135deg, #9b82ff, #7c5cff);
}

.dl-body h3 {
  margin: 0 0 4px;
  font-size: 0.92rem;
  font-weight: 700;
}

.dl-body p {
  margin: 0;
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.btn {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 36px;
  padding: 0 12px;
  border-radius: 10px;
  font-size: 0.82rem;
  font-weight: 700;
  color: #fff;
  transition: transform var(--dur) var(--ease), filter var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.btn svg {
  width: 14px;
  height: 14px;
}

.btn:hover {
  transform: translateY(-2px) scale(1.02);
  filter: brightness(1.06);
}

.btn:active,
.btn.is-pressed {
  transform: translateY(1px) scale(0.98);
}

.dl-card.is-pressed,
.feature-card.is-pressed {
  transform: translateY(-2px) scale(0.99);
}

.btn-windows {
  background: var(--windows);
  box-shadow: 0 8px 18px rgba(47, 107, 255, 0.28);
}

.btn-mac {
  background: var(--mac-btn);
  color: var(--mac-btn-text);
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.18);
}

.btn-android {
  background: #22c55e;
  box-shadow: 0 8px 18px rgba(34, 197, 94, 0.28);
}

.btn-web {
  background: var(--web);
  box-shadow: 0 8px 18px rgba(124, 92, 255, 0.28);
}

/* Hero visual */

.hero-visual {
  position: relative;
  min-height: 420px;
  display: grid;
  place-items: center;
}

.visual-stage {
  position: relative;
  width: min(100%, 420px);
  aspect-ratio: 1;
}

.orbit {
  position: absolute;
  inset: 8%;
  border-radius: 50%;
  border: 1px dashed color-mix(in srgb, var(--accent) 35%, transparent);
  animation: spin 28s linear infinite;
}

.orbit-b {
  inset: 18%;
  animation-duration: 18s;
  animation-direction: reverse;
  opacity: 0.7;
}

.pedestal {
  position: absolute;
  left: 50%;
  bottom: 8%;
  width: 72%;
  height: 28%;
  transform: translateX(-50%);
  background: var(--pedestal);
  filter: blur(2px);
  border-radius: 50%;
  opacity: 0.95;
}

.play-orb {
  position: absolute;
  inset: 22%;
  border-radius: 50%;
  background: var(--orb-bg);
  border: 1px solid color-mix(in srgb, #fff 35%, transparent);
  box-shadow:
    0 30px 60px var(--glow),
    inset 0 1px 0 rgba(255, 255, 255, 0.45);
  display: grid;
  place-items: center;
  animation: float 5.5s ease-in-out infinite;
  backdrop-filter: blur(8px);
}

.play-orb-inner {
  width: 72%;
  height: 72%;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: color-mix(in srgb, var(--bg-elevated) 35%, transparent);
}

.play-glyph {
  width: 58%;
  height: 58%;
}

.float-badge {
  position: absolute;
  display: grid;
  place-items: center;
  border-radius: 14px;
  background: var(--glass);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  backdrop-filter: blur(10px);
  animation: float 4.8s ease-in-out infinite;
}

.badge-1080 {
  top: 14%;
  right: 4%;
  width: 64px;
  height: 64px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 0.78rem;
  color: var(--accent);
  animation-delay: -1.2s;
}

.badge-wave {
  left: 2%;
  top: 42%;
  width: 56px;
  height: 56px;
  grid-auto-flow: column;
  gap: 3px;
  align-items: end;
  padding-bottom: 14px;
  animation-delay: -2s;
}

.badge-wave span {
  width: 4px;
  border-radius: 4px;
  background: var(--accent);
  animation: eq 1.2s ease-in-out infinite;
}

.badge-wave span:nth-child(1) { height: 10px; animation-delay: 0s; }
.badge-wave span:nth-child(2) { height: 18px; animation-delay: 0.15s; }
.badge-wave span:nth-child(3) { height: 14px; animation-delay: 0.3s; }
.badge-wave span:nth-child(4) { height: 22px; animation-delay: 0.45s; }

.badge-bag {
  right: 10%;
  bottom: 18%;
  width: 52px;
  height: 52px;
  color: var(--accent);
  animation-delay: -0.6s;
}

.badge-bag svg {
  width: 22px;
  height: 22px;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

@keyframes eq {
  0%, 100% { transform: scaleY(0.55); }
  50% { transform: scaleY(1); }
}

/* ---------- Features ---------- */

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.feature-card {
  padding: 24px;
  border-radius: var(--radius-lg);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lift);
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
}

.feature-icon {
  width: 44px;
  height: 44px;
  margin-bottom: 14px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: var(--accent-soft);
  color: var(--accent);
}

.feature-icon svg {
  width: 22px;
  height: 22px;
}

.feature-card h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  font-weight: 700;
}

.feature-card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ---------- Guide ---------- */

.guide {
  background: color-mix(in srgb, var(--bg-soft) 55%, transparent);
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.guide-card {
  padding: 24px;
  border-radius: var(--radius-lg);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.guide-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lift);
}

.guide-card h3 {
  margin: 0 0 14px;
  font-size: 1.05rem;
}

.guide-card ol {
  margin: 0;
  padding-left: 1.15rem;
  color: var(--text-secondary);
}

.guide-card li {
  margin-bottom: 0.55rem;
}

.guide-card li::marker {
  color: var(--accent);
  font-weight: 700;
}

/* ---------- FAQ ---------- */

.faq-list {
  max-width: 820px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.faq-item {
  border-radius: var(--radius-md);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.faq-item[open] {
  border-color: color-mix(in srgb, var(--accent) 45%, transparent);
  box-shadow: var(--shadow-lift);
}

.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 16px 48px 16px 18px;
  font-weight: 650;
  position: relative;
  transition: background var(--dur) var(--ease);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "";
  position: absolute;
  right: 18px;
  top: 50%;
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--text-muted);
  border-bottom: 2px solid var(--text-muted);
  transform: translateY(-70%) rotate(45deg);
  transition: transform var(--dur) var(--ease);
}

.faq-item[open] summary::after {
  transform: translateY(-20%) rotate(225deg);
}

.faq-item summary:hover {
  background: var(--accent-soft);
}

.faq-answer {
  padding: 0 18px 16px;
  color: var(--text-secondary);
}

.faq-answer p {
  margin: 0;
}

/* ---------- About ---------- */

.about-grid {
  display: grid;
  grid-template-columns: 1.4fr 0.6fr;
  gap: 24px;
  align-items: center;
}

.about-copy p {
  color: var(--text-secondary);
  max-width: 560px;
}

.about-meta {
  margin-top: 18px !important;
  font-size: 0.95rem;
}

.about-meta a {
  color: var(--accent);
  font-weight: 600;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease);
}

.about-meta a:hover {
  border-bottom-color: var(--accent);
}

.about-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 36px 24px;
  text-align: center;
  border-radius: var(--radius-lg);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.about-card:hover {
  transform: translateY(-4px) scale(1.01);
  box-shadow: var(--shadow-lift);
}

.about-card img {
  border-radius: 22px;
  box-shadow: 0 12px 28px var(--glow);
}

.about-card strong {
  font-family: var(--font-display);
  font-size: 1.25rem;
}

.about-card span {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 28px 0 36px;
  background: color-mix(in srgb, var(--bg-soft) 40%, transparent);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
}

.footer-brand img {
  border-radius: 8px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.92rem;
  transition: color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.footer-links a:hover {
  color: var(--accent);
  transform: translateY(-1px);
}

.footer-copy {
  margin: 0;
  width: 100%;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ---------- Reveal ---------- */

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- Responsive ---------- */

@media (max-width: 1100px) {
  .download-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero-grid {
    grid-template-columns: 1fr;
  }

  .hero-visual {
    order: -1;
    min-height: 320px;
  }

  .visual-stage {
    width: min(100%, 340px);
  }
}

@media (max-width: 900px) {
  .nav {
    position: fixed;
    inset: var(--header-h) 0 auto 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 12px;
    background: var(--header-bg);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(16px);
  }

  body.nav-open .nav {
    display: flex;
  }

  .nav-link {
    padding: 0.85rem 1rem;
  }

  .nav-link.is-active::after {
    left: 1rem;
    transform: none;
  }

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

  .lang-btn .lang-label,
  .lang-btn .chevron {
    display: none;
  }

  .lang-btn {
    width: 36px;
    padding: 0;
    justify-content: center;
  }

  .feature-grid,
  .guide-grid,
  .about-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .download-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 28px;
  }

  .section {
    padding: 72px 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
    scroll-behavior: auto !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}