:root {
  color-scheme: light dark;
  --background: #f3f7f4;
  --surface: #fbfdfc;
  --surface-raised: #f8fbf9;
  --surface-soft: #e6efe9;
  --text: #17241f;
  --muted: #52645b;
  --accent: #176b51;
  --accent-hover: #10533e;
  --accent-contrast: #f8fffb;
  --accent-soft: #dcebe3;
  --border: #cfddd5;
  --code: #e8efeb;
  --shadow: 0 24px 70px rgb(30 72 52 / 14%);
  --radius-panel: 24px;
  --radius-control: 12px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-synthesis: none;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #101713;
    --surface: #16201b;
    --surface-raised: #1b2721;
    --surface-soft: #20342a;
    --text: #edf5f0;
    --muted: #a7b8ae;
    --accent: #8ad7b5;
    --accent-hover: #a4e4c8;
    --accent-contrast: #10241b;
    --accent-soft: #203a2e;
    --border: #34473d;
    --code: #222f28;
    --shadow: 0 24px 70px rgb(2 10 6 / 38%);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

button,
input {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

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

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

h1,
h2,
h3,
p,
figure,
dl,
dd {
  margin: 0;
}

h1,
h2,
h3 {
  line-height: 1.15;
  letter-spacing: -0.035em;
}

h2 {
  font-size: clamp(2rem, 4vw, 3.25rem);
  font-weight: 720;
}

h3 {
  font-size: 1.25rem;
}

code,
kbd {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

.shell {
  width: min(1180px, calc(100% - 48px));
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 10;
  padding: 10px 16px;
  border-radius: var(--radius-control);
  background: var(--text);
  color: var(--background);
  transform: translateY(-150%);
}

.skip-link:focus {
  transform: translateY(0);
}

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 4px;
}

.site-header {
  position: relative;
  z-index: 2;
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--background) 92%, transparent);
}

.nav {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: none;
  font-size: 1.2rem;
  font-weight: 750;
  letter-spacing: -0.03em;
}

.brand img {
  border-radius: 9px;
}

.nav-links,
.footer-links {
  display: flex;
  align-items: center;
  gap: 30px;
  color: var(--muted);
  font-size: 0.92rem;
}

.nav-links {
  margin-left: auto;
}

.nav-links a,
.footer-links a,
.text-link {
  transition: color 180ms ease;
}

.nav-links a:hover,
.footer-links a:hover,
.text-link:hover {
  color: var(--accent);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 14px;
  flex: none;
}

.lang-toggle {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
}

.lang-toggle button {
  padding: 6px 12px;
  border: none;
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 0.82rem;
  font-weight: 650;
  line-height: 1;
  cursor: pointer;
  transition: background 180ms ease, color 180ms ease;
}

.lang-toggle button:hover {
  color: var(--text);
}

.lang-toggle button[aria-pressed="true"] {
  background: var(--accent);
  color: var(--accent-contrast);
}

.button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 22px;
  border: 1px solid var(--accent);
  border-radius: var(--radius-control);
  background: var(--accent);
  color: var(--accent-contrast);
  font-weight: 680;
  line-height: 1;
  white-space: nowrap;
  cursor: pointer;
  transition: background 180ms ease, border-color 180ms ease, transform 180ms ease;
}

.button:hover {
  border-color: var(--accent-hover);
  background: var(--accent-hover);
}

.button:active {
  transform: translateY(1px);
}

.button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.button-small {
  min-height: 40px;
  padding-inline: 17px;
  font-size: 0.9rem;
}

.button-secondary {
  border-color: var(--border);
  background: var(--surface);
  color: var(--text);
}

.button-secondary:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--text);
}

.button-quiet {
  border-color: transparent;
  background: transparent;
  color: var(--muted);
}

.button-quiet:hover {
  border-color: var(--border);
  background: var(--surface-soft);
  color: var(--text);
}

.hero {
  min-height: calc(100dvh - 73px);
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 0.85fr);
  align-items: center;
  gap: clamp(48px, 8vw, 110px);
  padding-block: 48px 64px;
}

.hero-copy {
  max-width: 580px;
}

.eyebrow {
  margin-bottom: 20px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 750;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.hero h1 {
  max-width: 580px;
  font-size: clamp(3.3rem, 6.3vw, 5.4rem);
  font-weight: 760;
  letter-spacing: -0.065em;
  line-height: 1.04;
}

.hero-intro {
  max-width: 440px;
  margin-top: 26px;
  color: var(--muted);
  font-size: clamp(1rem, 1.6vw, 1.18rem);
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.hero-visual {
  justify-self: center;
  width: min(100%, 420px);
}

.hero-visual picture {
  display: block;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius-panel);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.hero-visual img {
  width: 100%;
  height: auto;
}

.hero-visual figcaption,
.install-visual figcaption {
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.78rem;
  text-align: center;
}

.playground-section,
.install-section {
  padding-block: clamp(80px, 10vw, 128px);
  background: var(--surface-soft);
}

.section-heading {
  max-width: 700px;
  margin-bottom: 42px;
}

.section-heading p {
  max-width: 620px;
  margin-top: 18px;
  color: var(--muted);
  font-size: 1.04rem;
}

.converter-panel {
  padding: clamp(22px, 4vw, 42px);
  border: 1px solid var(--border);
  border-radius: var(--radius-panel);
  background: var(--surface);
  box-shadow: 0 18px 50px rgb(30 72 52 / 7%);
}

.converter-controls {
  display: flex;
  align-items: flex-end;
  gap: 16px;
}

.input-block {
  flex: 1;
  min-width: 0;
}

.input-block label {
  display: block;
  margin-bottom: 8px;
  font-size: 0.9rem;
  font-weight: 700;
}

.input-block input {
  width: 100%;
  min-height: 54px;
  padding: 0 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-control);
  background: var(--surface-raised);
  color: var(--text);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 1.08rem;
  transition: border-color 180ms ease, box-shadow 180ms ease;
}

.input-block input::placeholder {
  color: var(--muted);
  opacity: 0.8;
}

.input-block input:focus {
  border-color: var(--accent);
  outline: none;
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 20%, transparent);
}

.input-block p {
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.82rem;
}

.input-actions {
  display: flex;
  gap: 4px;
  padding-bottom: 27px;
}

.results-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-top: 30px;
  margin-bottom: 16px;
}

.results-heading h3 {
  font-size: 1rem;
  letter-spacing: 0;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.result-button {
  position: relative;
  min-width: 0;
  min-height: 100px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 6px 16px;
  padding: 16px 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius-control);
  background: var(--surface-raised);
  color: var(--text);
  text-align: left;
  cursor: pointer;
  transition: border-color 180ms ease, background 180ms ease, transform 180ms ease;
}

.result-button:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.result-button:active {
  transform: translateY(1px);
}

.result-button.is-copied {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.result-label {
  grid-column: 1;
  color: var(--muted);
  font-size: 0.76rem;
}

.result-value {
  grid-column: 1;
  overflow: hidden;
  font-size: clamp(1rem, 2vw, 1.18rem);
  font-weight: 650;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.result-action {
  grid-column: 2;
  grid-row: 1 / 3;
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 700;
}

.empty-state {
  padding: 54px 24px;
  border: 1px dashed var(--border);
  border-radius: var(--radius-control);
  text-align: center;
}

.empty-state p {
  margin-top: 8px;
  color: var(--muted);
}

.conversion-status {
  min-height: 24px;
  margin-top: 16px;
  color: var(--muted);
  font-size: 0.84rem;
}

.features-section {
  padding-block: clamp(80px, 10vw, 128px);
}

.feature-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
  gap: 20px;
}

.feature-stack {
  display: grid;
  gap: 20px;
}

.feature {
  padding: clamp(26px, 4vw, 42px);
  border: 1px solid var(--border);
  border-radius: var(--radius-panel);
  background: var(--surface);
}

.feature h3 {
  font-size: clamp(1.45rem, 2.5vw, 2rem);
}

.feature p {
  margin-top: 14px;
  color: var(--muted);
}

.feature-local {
  min-height: 530px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: var(--accent-soft);
}

.local-code {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
  margin-block: 40px;
  padding-block: 26px;
  border-block: 1px solid color-mix(in srgb, var(--accent) 28%, transparent);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

.local-code span {
  color: var(--muted);
  font-size: 0.85rem;
}

.local-code strong {
  color: var(--accent);
  font-size: clamp(4.5rem, 9vw, 7rem);
  font-weight: 500;
  letter-spacing: -0.08em;
  line-height: 0.8;
}

.text-link {
  width: fit-content;
  color: var(--accent);
  font-weight: 700;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 5px;
}

.feature-unicode {
  background: var(--surface-raised);
}

.feature-kicker {
  display: block;
  margin-bottom: 26px;
  color: var(--accent);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.8rem;
}

.format-sample {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 26px;
  padding: 16px 18px;
  border-radius: var(--radius-control);
  background: var(--code);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.9rem;
}

.format-sample span:last-child {
  color: var(--accent);
  font-weight: 700;
}

.shortcut-list {
  display: grid;
  gap: 18px;
  margin-top: 26px;
}

.shortcut-list > div {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.shortcut-list dt {
  color: var(--muted);
}

.shortcut-list dd {
  display: flex;
  align-items: center;
  gap: 7px;
}

kbd {
  padding: 5px 9px;
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 7px;
  background: var(--code);
  font-size: 0.76rem;
}

.install-layout {
  display: grid;
  grid-template-columns: minmax(320px, 0.8fr) minmax(0, 1.2fr);
  align-items: center;
  gap: clamp(40px, 7vw, 90px);
}

.install-steps {
  display: grid;
  gap: 36px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: install;
}

.install-steps li {
  position: relative;
  padding-left: 48px;
  counter-increment: install;
}

.install-steps li::before {
  content: counter(install);
  position: absolute;
  top: 0;
  left: 0;
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid var(--accent);
  border-radius: 50%;
  color: var(--accent);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.8rem;
}

.install-steps p {
  margin-top: 10px;
  color: var(--muted);
}

.install-steps .button {
  margin-top: 20px;
}

.chrome-address {
  display: block;
  width: fit-content;
  margin-top: 16px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 9px;
  background: var(--code);
  color: var(--text);
  font-size: 0.88rem;
  user-select: all;
}

.install-visual {
  min-width: 0;
}

.install-visual img {
  width: 100%;
  height: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-panel);
  box-shadow: var(--shadow);
}

.site-footer {
  border-top: 1px solid var(--border);
}

.footer-inner {
  min-height: 118px;
  display: flex;
  align-items: center;
  gap: 28px;
}

.footer-inner > p {
  color: var(--muted);
  font-size: 0.88rem;
}

.footer-links {
  margin-left: auto;
}

.privacy-shell {
  max-width: 880px;
  padding-block: clamp(56px, 8vw, 96px);
}

.privacy-content {
  padding: clamp(28px, 6vw, 68px);
  border: 1px solid var(--border);
  border-radius: var(--radius-panel);
  background: var(--surface);
}

.privacy-content h1 {
  font-size: clamp(2.6rem, 6vw, 4.5rem);
}

.privacy-date {
  margin-top: 18px;
  color: var(--muted);
  font-size: 0.9rem;
}

.privacy-lead {
  margin-top: 36px;
  color: var(--text);
  font-size: 1.1rem;
}

.privacy-content section {
  margin-top: 38px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}

.privacy-content section h2 {
  font-size: 1.3rem;
  letter-spacing: -0.02em;
}

.privacy-content section p {
  margin-top: 14px;
  color: var(--muted);
}

@media (prefers-reduced-motion: no-preference) {
  .hero-copy {
    animation: enter 600ms cubic-bezier(0.16, 1, 0.3, 1) both;
  }

  .hero-visual {
    animation: enter 700ms 100ms cubic-bezier(0.16, 1, 0.3, 1) both;
  }

  @keyframes enter {
    from {
      opacity: 0;
      transform: translateY(18px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
}

@media (max-width: 960px) {
  .hero {
    grid-template-columns: minmax(0, 1fr) minmax(300px, 0.75fr);
    gap: 40px;
  }

  .feature-grid,
  .install-layout {
    grid-template-columns: 1fr;
  }

  .feature-local {
    min-height: 430px;
  }

  .install-visual {
    grid-row: 1;
  }
}

@media (max-width: 767px) {
  .shell {
    width: min(100% - 32px, 620px);
  }

  .nav {
    min-height: 64px;
    gap: 12px;
  }

  .nav-links {
    display: none;
  }

  .nav-actions {
    margin-left: auto;
  }

  .hero {
    min-height: auto;
    grid-template-columns: 1fr;
    gap: 44px;
    padding-block: 48px 64px;
  }

  .hero-copy {
    max-width: none;
  }

  .hero h1 {
    font-size: clamp(3rem, 14vw, 4.4rem);
  }

  .hero-intro {
    margin-top: 22px;
  }

  .hero-visual {
    width: min(100%, 390px);
  }

  .converter-controls {
    align-items: stretch;
    flex-direction: column;
  }

  .input-actions {
    justify-content: flex-end;
    padding-bottom: 0;
  }

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

  .result-button {
    min-height: 88px;
  }

  .feature-local {
    min-height: 420px;
  }

  .install-visual {
    grid-row: auto;
  }

  .footer-inner {
    flex-wrap: wrap;
    gap: 16px 24px;
    padding-block: 28px;
  }

  .footer-inner > p {
    order: 3;
    width: 100%;
  }

  .footer-links {
    gap: 20px;
  }
}

@media (max-width: 420px) {
  .brand {
    font-size: 1.05rem;
  }

  .brand img {
    width: 32px;
    height: 32px;
  }

  .nav .button-small {
    padding-inline: 13px;
  }

  .hero-actions .button {
    flex: 1;
    padding-inline: 16px;
  }

  .converter-panel,
  .feature,
  .privacy-content {
    padding: 22px;
  }

  .local-code {
    align-items: flex-start;
    flex-direction: column;
  }

  .format-sample {
    align-items: flex-start;
    flex-direction: column;
  }

  .shortcut-list > div {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}