:root {
  --blue-950: #082b4f;
  --blue-900: #0b3b68;
  --blue-800: #145383;
  --blue-700: #17699f;
  --sky-200: #cce9f7;
  --sky-100: #eaf7fc;
  --sky-050: #f5fbfe;
  --paper: #ffffff;
  --text: #12293d;
  --muted: #4b6172;
  --border: #bed8e7;
  --sand: #d59a32;
  --sand-soft: #fff3d8;
  --warning: #713f12;
  --danger: #8d2d24;
  --danger-soft: #fff0ed;
  --success: #17583e;
  --success-soft: #e9f7f0;
  --shadow: 0 18px 50px rgba(8, 43, 79, 0.1);
  --shadow-soft: 0 8px 28px rgba(8, 43, 79, 0.07);
  --radius: 1.4rem;
  --content: 70rem;
  --transition: 180ms ease-out;
}

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

html {
  color-scheme: light;
  scroll-behavior: smooth;
  scroll-padding-top: 4.5rem;
}

body {
  margin: 0;
  overflow-x: hidden;
  color: var(--text);
  background: linear-gradient(180deg, #edf8fd 0, #f8fcfe 42rem, #fff 82rem);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
  font-size: 1rem;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
}

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

a { color: var(--blue-700); text-underline-offset: 0.2em; }
a:hover { color: var(--blue-950); }
:not(pre) > code { overflow-wrap: anywhere; color: var(--blue-900); }

button,
.button {
  min-height: 44px;
  border-radius: 0.75rem;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  touch-action: manipulation;
}

:focus-visible {
  outline: 3px solid #f4bd54;
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 0.5rem;
  left: 0.5rem;
  padding: 0.65rem 1rem;
  color: var(--paper);
  background: var(--blue-950);
  transform: translateY(-150%);
}
.skip-link:focus { transform: translateY(0); }

.reading-progress {
  position: fixed;
  z-index: 900;
  inset: 0 0 auto;
  width: 100%;
  height: 4px;
  border: 0;
  appearance: none;
}
.reading-progress::-webkit-progress-bar { background: rgba(255, 255, 255, 0.35); }
.reading-progress::-webkit-progress-value { background: var(--sand); }
.reading-progress::-moz-progress-bar { background: var(--sand); }

.site-header {
  position: absolute;
  z-index: 50;
  top: 4px;
  right: 0;
  left: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem clamp(1rem, 4vw, 3rem);
  color: var(--paper);
}
.brand { color: inherit; font-weight: 800; text-decoration: none; }
.header-actions { display: flex; align-items: center; gap: 0.5rem; }
.header-share {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  border: 1px solid rgba(255, 255, 255, 0.58);
  padding: 0.35rem 0.7rem;
  color: var(--paper);
  background: rgba(8, 43, 79, 0.36);
}
.header-share svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.header-share:hover { background: rgba(8, 43, 79, 0.6); }
.toc-button {
  border: 1px solid rgba(255, 255, 255, 0.55);
  padding: 0.45rem 1rem;
  color: var(--paper);
  background: rgba(8, 43, 79, 0.45);
  backdrop-filter: blur(8px);
}

.hero {
  position: relative;
  min-height: 78vh;
  min-height: 78dvh;
  display: grid;
  align-items: center;
  overflow: hidden;
  color: var(--paper);
  background: var(--blue-900);
}
.hero-media,
.hero-media img,
.hero-overlay { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero-media img { object-fit: cover; }
.hero-overlay {
  background:
    linear-gradient(90deg, rgba(3, 28, 53, 0.89) 0%, rgba(8, 43, 79, 0.66) 52%, rgba(8, 43, 79, 0.38) 100%),
    linear-gradient(180deg, rgba(8, 43, 79, 0.14) 65%, var(--sky-100) 100%);
}
.hero-content {
  position: relative;
  z-index: 2;
  width: min(52rem, calc(100% - 2rem));
  margin: 0 auto;
  padding: 7rem 0 5rem;
}
.eyebrow {
  display: inline-block;
  margin: 0 0 0.75rem;
  color: #f8d17f;
  font-size: 0.9rem;
  font-weight: 800;
  letter-spacing: 0.06em;
}
h1,
h2,
h3 { line-height: 1.25; text-wrap: balance; }
.hero h1 { max-width: 13ch; margin: 0; font-size: clamp(2.4rem, 6vw, 5rem); letter-spacing: -0.045em; }
.hero-lead { max-width: 38rem; margin: 1.25rem 0 0; font-size: clamp(1.08rem, 2.2vw, 1.35rem); }
.hero-outcome { max-width: 38rem; color: #e9f6ff; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 2rem; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.1rem;
  text-decoration: none;
  transition: transform var(--transition), background var(--transition);
}
.button:hover { transform: translateY(-1px); }
.button-primary { color: var(--blue-950); background: var(--paper); }
.button-secondary { border: 1px solid rgba(255, 255, 255, 0.7); color: var(--paper); background: rgba(8, 43, 79, 0.35); }
.hero-note { margin-top: 1.25rem; font-size: 0.9rem; color: #e9f6ff; }
.hero-credit { position: absolute; z-index: 3; right: 5.8rem; bottom: 1rem; border-radius: 999px; padding: 0.25rem 0.6rem; font-size: 0.72rem; background: rgba(8, 43, 79, 0.82); }
.hero-credit a { color: var(--paper); }

.toc-dialog {
  width: min(32rem, calc(100% - 2rem));
  max-height: min(80vh, 46rem);
  margin: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0;
  color: var(--text);
  background: var(--paper);
  box-shadow: var(--shadow);
}
.toc-dialog::backdrop { background: rgba(3, 28, 53, 0.65); }
.toc-head { position: sticky; top: 0; display: flex; justify-content: space-between; align-items: center; gap: 1rem; padding: 1rem 1.25rem; background: var(--paper); border-bottom: 1px solid var(--border); }
.toc-head h2 { margin: 0; font-size: 1.25rem; }
.icon-button { width: 44px; border: 0; color: var(--blue-950); background: var(--sky-100); }
.toc-dialog nav { padding: 0.75rem 1.25rem 1.25rem; }
.toc-dialog ol { margin: 0; padding-left: 1.4rem; }
.toc-dialog a { display: block; min-height: 44px; padding: 0.45rem 0.35rem; color: var(--text); text-decoration: none; }
.toc-dialog a[aria-current="location"] { color: var(--blue-800); font-weight: 800; background: var(--sky-100); }

.tutorial-wrap {
  width: min(var(--content), calc(100% - 2rem));
  margin-inline: auto;
}
.page-main { width: min(68ch, calc(100% - 2rem)); margin-inline: auto; }
.tutorial-wrap { padding: clamp(2.5rem, 6vw, 4.5rem) 0 4rem; }
.intro-card,
.tool-links,
.next-reading,
.page-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 10px 30px rgba(8, 43, 79, 0.07);
}
.intro-card { border-color: rgba(190, 216, 231, 0.72); border-radius: 2rem; padding: clamp(1.5rem, 4vw, 3rem); box-shadow: var(--shadow); }
.intro-card h2 { max-width: 18ch; margin: 0; color: var(--blue-950); font-size: clamp(2rem, 4vw, 3.2rem); letter-spacing: -0.035em; }
.section-kicker,
.pain-label {
  margin: 0 0 0.45rem;
  color: var(--blue-700);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.06em;
}
.pain-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); gap: 1rem; margin-top: 1.5rem; }
.pain-card { border: 0; border-radius: 1.15rem; padding: 1.25rem; background: #eef8fd; }
.pain-card:nth-child(2) { background: #fff6e5; }
.pain-card h3 { margin: 0; color: var(--blue-900); font-size: 1.35rem; }
.pain-card .text-link { display: inline-flex; min-height: 44px; align-items: center; margin-top: 0.3rem; font-weight: 800; }
.story-lead { max-width: 52rem; margin: 0.9rem 0 1.8rem; color: var(--muted); font-size: 1.08rem; }
.network-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 1.5rem;
  border: 1px solid rgba(23, 105, 159, 0.18);
  border-radius: 1.35rem;
  padding: clamp(1.25rem, 3vw, 2rem);
  background: linear-gradient(135deg, #e8f6fd, #f8fcff 68%);
}
.network-card h3 { margin: 0; color: var(--blue-900); font-size: 1.45rem; }
.network-card p { margin-bottom: 0; }
.service-label { margin: 0 0 0.35rem !important; color: var(--blue-700); font-size: 0.78rem; font-weight: 800; letter-spacing: 0.06em; }
.service-button { min-width: 13rem; color: #fff; background: var(--blue-800); box-shadow: 0 8px 20px rgba(20, 83, 131, 0.18); }
.service-button:hover { color: #fff; background: var(--blue-950); }
.account-steps { margin-top: 1.8rem; }
.account-steps h3 { margin-bottom: 0.85rem; color: var(--blue-900); }
.account-steps ol { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.8rem; margin: 0; padding: 0; counter-reset: account; list-style: none; }
.account-steps li { position: relative; min-height: 100%; border-top: 2px solid var(--sky-200); padding: 0.85rem 0.4rem 0 2.15rem; counter-increment: account; }
.account-steps li::before { content: counter(account); position: absolute; top: 0.7rem; left: 0; display: grid; width: 1.55rem; height: 1.55rem; place-items: center; border-radius: 50%; color: #fff; background: var(--blue-700); font-size: 0.75rem; font-weight: 800; }
.region-note { margin: 1.6rem 0 0; border-top: 1px solid var(--border); padding-top: 1rem; color: var(--muted); font-size: 0.82rem; line-height: 1.65; }
.core-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.25rem; margin-top: 1.25rem; }
.core-card { border: 1px solid var(--border); border-radius: 1.6rem; padding: clamp(1.35rem, 3vw, 2rem); box-shadow: var(--shadow-soft); }
.core-card h2 { max-width: 18ch; margin: 0; color: var(--blue-950); font-size: clamp(1.55rem, 3vw, 2.15rem); letter-spacing: -0.025em; }
.payment-card { background: linear-gradient(145deg, #fff8e9, #fffdf8); }
.host-card { background: linear-gradient(145deg, #edf8fd, #fbfdff); }
.text-cta { display: inline-flex; min-height: 44px; align-items: center; font-weight: 800; text-decoration-thickness: 2px; }
.small-note { color: var(--muted); font-size: 0.86rem; line-height: 1.65; }
.quick-start { margin-top: 1.25rem; border: 1px solid var(--border); border-radius: 1.35rem; padding: clamp(1.25rem, 3vw, 1.8rem); background: rgba(255, 255, 255, 0.78); }
.quick-start h2 { margin: 0; color: var(--blue-950); font-size: clamp(1.45rem, 3vw, 2rem); }
.finish-line { margin-bottom: 0; }
.compact-reading { margin-top: 1.25rem; border-top: 1px solid var(--border); padding: 1.8rem 0 0; }
.compact-reading h2 { margin: 0 0 1rem; color: var(--blue-950); font-size: 1.25rem; }
.compact-links { display: flex; flex-wrap: wrap; gap: 0.55rem; }
.compact-links a { display: inline-flex; min-height: 44px; align-items: center; border: 1px solid var(--border); border-radius: 999px; padding: 0.4rem 0.8rem; color: var(--blue-900); background: #fff; text-decoration: none; }
.compact-links a:hover { border-color: var(--blue-700); background: var(--sky-100); }
.other-tools { color: var(--muted); font-size: 0.9rem; }
.region-warning {
  margin-bottom: 1.5rem;
  border-left: 4px solid var(--sand);
  padding: 0.8rem 0 0.8rem 1rem;
  color: var(--warning);
  background: transparent;
}
.prep-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr)); gap: 0.65rem; padding: 0; list-style: none; }
.prep-list li { padding: 0.7rem 0.9rem; border-radius: 0.75rem; background: var(--sky-100); }

.step {
  position: relative;
  margin-top: 0;
  border-top: 1px solid rgba(190, 216, 231, 0.75);
  padding: clamp(2.5rem, 7vw, 4rem) clamp(0rem, 2vw, 0.5rem);
  background: transparent;
  scroll-margin-top: 5rem;
}
.intro-card + .step { margin-top: 3.5rem; }
.step h2 { max-width: 22ch; margin: 0; color: var(--blue-900); font-size: clamp(1.55rem, 4vw, 2.15rem); letter-spacing: -0.025em; }
.step-meta { display: flex; flex-wrap: wrap; gap: 0.55rem; margin: 0.75rem 0 1.25rem; color: var(--muted); font-size: 0.92rem; }
.step-meta span { position: relative; padding-right: 0.9rem; }
.step-meta span + span::before { content: '·'; position: absolute; left: -0.45rem; color: var(--sand); }
.action-list { padding-left: 1.25rem; }
.action-list li + li { margin-top: 0.55rem; }
.action-list li::marker { color: var(--blue-700); font-weight: 800; }
.success-check,
.warning-box,
.plain-note { margin-top: 1rem; border-radius: 0.8rem; padding: 0.9rem 1rem; }
.success-check { border-left: 3px solid var(--success); color: var(--success); background: rgba(233, 247, 240, 0.72); }
.warning-box { border-left: 4px solid var(--danger); color: var(--danger); background: var(--danger-soft); }
.plain-note { border-left: 4px solid var(--blue-700); background: var(--sky-100); }

details { margin-top: 1rem; border: 1px solid var(--border); border-radius: 0.85rem; background: var(--sky-050); }
summary { min-height: 44px; padding: 0.65rem 1rem; color: var(--blue-900); font-weight: 800; cursor: pointer; }
.details-body { padding: 0 1rem 1rem; }
.aside-link { margin-top: 1.5rem; border-left: 3px solid var(--blue-700); padding: 0.8rem 0 0.8rem 1rem; color: var(--muted); }
.aside-link a { font-weight: 800; }

.code-wrap { position: relative; margin: 1rem 0; }
pre {
  max-width: 100%;
  overflow-x: auto;
  margin: 0;
  border-radius: 0.85rem;
  padding: 1.1rem 4.2rem 1.1rem 1.1rem;
  color: #eef8ff;
  background: var(--blue-950);
  font: 0.92rem/1.7 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
  overflow-wrap: anywhere;
  white-space: pre-wrap;
}
.copy-button {
  position: absolute;
  top: 0.55rem;
  right: 0.55rem;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.32);
  border-radius: 0.65rem;
  padding: 0;
  color: transparent;
  background-color: rgba(255, 255, 255, 0.12);
  background-position: center;
  background-repeat: no-repeat;
  background-size: 21px 21px;
  cursor: pointer;
  transition: background-color 160ms ease, border-color 160ms ease, transform 160ms ease;
}
.copy-button[data-copy-state="idle"] {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'%3E%3Crect x='8' y='8' width='11' height='11' rx='2'/%3E%3Cpath d='M16 8V6a2 2 0 0 0-2-2H6a2 2 0 0 0-2 2v8a2 2 0 0 0 2 2h2'/%3E%3C/svg%3E");
}
.copy-button[data-copy-state="copied"] {
  border-color: rgba(190, 243, 218, 0.7);
  background-color: rgba(26, 140, 89, 0.55);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2.2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m5 12 4 4L19 6'/%3E%3C/svg%3E");
}
.copy-button[data-copy-state="failed"] {
  border-color: rgba(255, 210, 210, 0.75);
  background-color: rgba(180, 51, 51, 0.62);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2.2' stroke-linecap='round'%3E%3Cpath d='m7 7 10 10M17 7 7 17'/%3E%3C/svg%3E");
}
.copy-button:hover { border-color: rgba(255, 255, 255, 0.72); background-color: rgba(255, 255, 255, 0.22); }
.copy-button:active { transform: scale(0.94); }
.copy-button:focus-visible { outline: 3px solid #f8d17f; outline-offset: 2px; }
.sr-only { position: absolute; width: 1px; height: 1px; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; }

.tool-links,
.next-reading { margin-top: 2rem; padding: clamp(1.25rem, 4vw, 2rem); }
.link-grid,
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 14rem), 1fr)); gap: 1rem; }
.link-card {
  display: flex;
  min-height: 6.5rem;
  flex-direction: column;
  justify-content: center;
  border: 1px solid var(--border);
  border-radius: 0.9rem;
  padding: 1rem;
  color: var(--text);
  background: var(--sky-050);
  text-decoration: none;
}
.link-card:hover { border-color: var(--blue-700); background: var(--sky-100); }
.link-card strong { color: var(--blue-900); }
.link-card small { color: var(--muted); }

.site-footer { padding: 1.6rem 1rem 5.5rem; color: #dceef9; background: var(--blue-950); }
.footer-inner { width: min(70rem, 100%); margin: auto; }
.site-footer a { color: #f8d17f; }
.footer-inner p { margin-top: 0; }
.footer-meta { display: flex; flex-wrap: wrap; gap: 0.5rem 1rem; font-size: 0.9rem; }

.music-launcher { position: fixed; z-index: 700; right: 1rem; }
.music-launcher {
  bottom: 1rem;
  display: grid;
  width: 68px;
  height: 68px;
  place-items: center;
  border: 1px solid rgba(74, 144, 197, 0.24);
  border-radius: 50%;
  padding: 0;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 12px 30px rgba(9, 67, 112, 0.2), 0 2px 8px rgba(9, 67, 112, 0.1);
  transition: transform 160ms ease, box-shadow 160ms ease;
}
.music-launcher::after {
  content: attr(data-music-hint);
  position: absolute;
  right: calc(100% + 0.65rem);
  border-radius: 999px;
  padding: 0.42rem 0.7rem;
  color: #fff;
  background: rgba(8, 43, 79, 0.92);
  box-shadow: 0 5px 16px rgba(3, 28, 53, 0.18);
  font-size: 0.78rem;
  font-weight: 700;
  line-height: 1;
  white-space: nowrap;
  opacity: 0;
  transform: translateX(0.35rem);
  pointer-events: none;
  transition: opacity 160ms ease, transform 160ms ease;
}
.music-launcher:hover,
.music-launcher:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 14px 32px rgba(9, 67, 112, 0.26), 0 3px 9px rgba(9, 67, 112, 0.12);
}
.music-launcher:hover::after,
.music-launcher:focus-visible::after {
  opacity: 1;
  transform: translateX(0);
}
.record-icon {
  position: relative;
  width: 56px;
  height: 56px;
  overflow: hidden;
  border-radius: 50%;
  background: radial-gradient(circle, #2e8ac1 0 67%, #0a436f 68% 82%, #dcebf4 83% 86%, #0a355c 87% 100%);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.7), 0 3px 7px rgba(8, 43, 79, 0.26);
}
.vinyl {
  position: absolute;
  z-index: 1;
  inset: 7px;
  border-radius: 50%;
  background:
    radial-gradient(circle, #f7fbfd 0 5%, #17699f 6% 17%, transparent 18%),
    repeating-radial-gradient(circle, #262b31 0 1.5px, #0e1217 2px 4px);
  box-shadow: 0 2px 6px rgba(0, 18, 34, 0.42), inset 0 0 0 1px rgba(255, 255, 255, 0.12);
  will-change: transform;
}
.tonearm {
  position: absolute;
  z-index: 2;
  top: 7px;
  right: 7px;
  width: 22px;
  height: 31px;
  border: 3px solid #e7eff4;
  border-bottom-color: transparent;
  border-left-color: transparent;
  border-radius: 50%;
  filter: drop-shadow(0 1px 2px rgba(0, 18, 34, 0.5));
  transform: rotate(16deg);
}
.tonearm::before {
  content: '';
  position: absolute;
  top: -5px;
  right: -5px;
  width: 8px;
  height: 8px;
  border: 2px solid #f7fbfd;
  border-radius: 50%;
  background: #718899;
}
.tonearm::after {
  content: '';
  position: absolute;
  right: 13px;
  bottom: -2px;
  width: 8px;
  height: 5px;
  border-radius: 2px;
  background: #eef4f7;
  box-shadow: 0 0 0 1px #61798a;
  transform: rotate(28deg);
}
.record-play {
  position: absolute;
  z-index: 3;
  top: 50%;
  left: 50%;
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.88);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.76);
  box-shadow: 0 3px 12px rgba(8, 43, 79, 0.24);
  backdrop-filter: blur(4px);
  opacity: 1;
  transform: translate(-50%, -50%);
  transition: opacity 220ms ease, transform 220ms ease;
}
.record-play[data-state='paused']::before {
  content: '';
  width: 0;
  height: 0;
  margin-left: 2px;
  border-top: 6px solid transparent;
  border-bottom: 6px solid transparent;
  border-left: 10px solid var(--blue-800);
}
.record-play[data-state='playing']::before,
.record-play[data-state='playing']::after {
  content: '';
  position: absolute;
  top: 9px;
  width: 4px;
  height: 16px;
  border-radius: 2px;
  background: var(--blue-800);
}
.record-play[data-state='playing']::before { left: 10px; }
.record-play[data-state='playing']::after { right: 10px; }
.record-play.is-hidden { opacity: 0; transform: translate(-50%, -50%) scale(0.82); }
.music-launcher:focus-visible .record-play { opacity: 1; transform: translate(-50%, -50%); }
body.music-playing .vinyl { animation: record-spin 7s linear infinite; }
@keyframes record-spin { to { transform: rotate(1turn); } }

.compact-header { padding: 1.25rem 1rem; color: var(--paper); background: linear-gradient(135deg, var(--blue-950), var(--blue-700)); }
.compact-header-inner { width: min(70rem, 100%); margin: auto; }
.back-link { display: inline-flex; min-height: 44px; align-items: center; color: var(--paper); font-weight: 800; }
.page-main .back-link { border: 1px solid var(--blue-700); color: var(--blue-950); background: var(--sky-100); }
.page-main { padding: 3rem 0 5rem; }
.page-main h1 { margin: 0 0 0.5rem; font-size: clamp(2rem, 7vw, 3.5rem); }
.page-lead { color: var(--muted); font-size: 1.08rem; }
.page-card { margin-top: 1.25rem; padding: clamp(1.15rem, 4vw, 2rem); }
.page-card h2 { margin-top: 0; color: var(--blue-900); }
.page-card h3 { color: var(--blue-800); }
.label { display: inline-block; margin-right: 0.4rem; border-radius: 999px; padding: 0.12rem 0.55rem; font-size: 0.78rem; font-weight: 800; }
.label-official { color: var(--blue-950); background: var(--sky-200); }
.label-personal { color: var(--success); background: var(--success-soft); }
.label-third { color: var(--warning); background: var(--sand-soft); }
.label-commercial { color: var(--danger); background: var(--danger-soft); }
.pricing-table { width: 100%; margin-top: 1rem; border-collapse: collapse; table-layout: fixed; }
.pricing-table th,
.pricing-table td { border-bottom: 1px solid var(--border); padding: 0.75rem 0.65rem; text-align: left; vertical-align: top; }
.pricing-table thead th { color: var(--blue-950); background: var(--sky-100); }
.pricing-table tbody th { width: 22%; color: var(--blue-900); }
.pricing-table small { color: var(--muted); }
.wechat-link {
  position: relative;
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  border: 0;
  padding: 0 0.15rem;
  color: var(--blue-800);
  background: transparent;
  font: inherit;
  font-weight: 800;
  text-decoration: underline;
  text-underline-offset: 0.18em;
  cursor: pointer;
}
.wechat-preview {
  position: absolute;
  z-index: 5;
  bottom: calc(100% + 0.4rem);
  left: 50%;
  width: 11rem;
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  padding: 0.4rem;
  background: var(--paper);
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translate(-50%, 0.25rem);
  pointer-events: none;
  transition: opacity 160ms ease, transform 160ms ease;
}
.wechat-link:hover .wechat-preview,
.wechat-link:focus-visible .wechat-preview { opacity: 1; transform: translate(-50%, 0); }
.wechat-preview img,
.wechat-dialog img { display: block; width: 100%; height: auto; }
.wechat-dialog {
  position: relative;
  width: min(28rem, calc(100% - 2rem));
  max-height: calc(100vh - 2rem);
  max-height: calc(100dvh - 2rem);
  border: 0;
  border-radius: 1rem;
  padding: 1.25rem;
  color: var(--text);
  background: var(--paper);
  box-shadow: var(--shadow);
}
.wechat-dialog::backdrop { background: rgba(3, 28, 53, 0.65); }
.wechat-dialog h3 { margin: 0 3rem 1rem 0; color: var(--blue-950); font-size: 1.25rem; }
.wechat-dialog p { margin: 0.8rem 0 0; color: var(--muted); font-size: 0.88rem; }
.wechat-close { position: absolute; top: 0.85rem; right: 0.85rem; }
.share-dialog {
  position: relative;
  width: min(26rem, calc(100% - 2rem));
  border: 0;
  border-radius: 1rem;
  padding: 1.35rem;
  color: var(--text);
  background: var(--paper);
  box-shadow: var(--shadow);
}
.share-dialog::backdrop { background: rgba(3, 28, 53, 0.65); }
.share-dialog h2 { margin: 0 3rem 0.75rem 0; color: var(--blue-950); font-size: 1.35rem; }
.share-dialog p { margin-bottom: 0; }
.share-close { position: absolute; top: 0.85rem; right: 0.85rem; }
.virtual-card-note h3 { margin-top: 0; }
.virtual-card-note p { margin-bottom: 0; }
.not-found { min-height: 100vh; min-height: 100dvh; display: grid; place-items: center; padding: 1rem; background: linear-gradient(160deg, var(--sky-100), var(--paper)); }
.not-found .page-card { width: min(34rem, 100%); text-align: center; }
.not-found-code { margin: 0; color: var(--blue-700); font-size: 5rem; font-weight: 900; line-height: 1; }

/* Content-first homepage and article pages */
.header-link { min-height: 44px; display: inline-flex; align-items: center; color: inherit; font-weight: 700; text-decoration: none; }
.hero { min-height: 62vh; min-height: 62dvh; }
.hero-content { width: min(62rem, calc(100% - 2rem)); padding-block: 6rem 4rem; }
.hero h1 { max-width: 48rem; font-size: clamp(2.5rem, 6vw, 4.6rem); }
.hero-title-break { display: block; }
.tutorial-wrap { width: min(62rem, calc(100% - 2rem)); padding-block: clamp(2rem, 5vw, 3.5rem); }
.intro-card { border: 0; border-radius: 0; padding: clamp(1rem, 3vw, 2rem) 0 clamp(2rem, 5vw, 3.5rem); background: transparent; box-shadow: none; }
.intro-card h2 { max-width: none; font-size: clamp(1.9rem, 4vw, 2.8rem); }
.story-lead { max-width: 46rem; margin-bottom: 1.25rem; line-height: 1.85; text-wrap: pretty; }
.network-term { position: relative; display: inline-block; color: var(--blue-900); cursor: help; outline: none; }
.network-term strong { border-bottom: 1px dashed var(--blue-700); }
.network-term:focus-visible strong { outline: 3px solid rgba(23, 105, 159, 0.28); outline-offset: 3px; border-radius: 0.15rem; }
.network-tooltip {
  position: absolute;
  z-index: 30;
  left: 50%;
  bottom: calc(100% + 0.65rem);
  width: min(19rem, calc(100vw - 2rem));
  border-radius: 0.75rem;
  padding: 0.75rem 0.85rem;
  color: #fff;
  background: var(--blue-950);
  box-shadow: 0 12px 28px rgba(8, 43, 79, 0.22);
  font-size: 0.88rem;
  font-weight: 400;
  line-height: 1.65;
  text-align: left;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translate(-50%, 0.35rem);
  transition: opacity 160ms ease, transform 160ms ease, visibility 160ms ease;
}
.network-term:hover .network-tooltip,
.network-term:focus-within .network-tooltip { opacity: 1; visibility: visible; transform: translate(-50%, 0); }
.network-check { margin: 1.25rem 0; border: 1px solid var(--border); border-radius: 0.8rem; padding: 0.8rem 1rem; color: var(--blue-950); background: var(--sky-050); }
.network-check strong { color: var(--blue-900); }
.service-note { margin: 1.3rem 0; border-left: 3px solid var(--blue-700); padding: 0.65rem 0 0.65rem 1rem; color: var(--muted); }
.service-note a { font-weight: 800; }
.account-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin: 1.5rem 0 0; padding: 0; list-style-position: inside; }
.account-list li { border-top: 1px solid var(--border); padding-top: 0.85rem; }
.verification-help { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 1.25rem; margin-top: 1.5rem; border: 1px solid var(--border); border-radius: 0.8rem; padding: 1rem; background: var(--sky-050); }
.verification-help h3 { margin: 0 0 0.45rem; color: var(--blue-950); font-size: 1.08rem; }
.verification-alert { margin-right: 0.35rem; color: var(--danger); font-size: 1.25em; font-weight: 900; }
.verification-help p { margin: 0.45rem 0 0; color: var(--muted); font-size: 0.92rem; }
.verification-logo { width: 162px; height: auto; }
.core-grid { margin-top: 0; }
.core-card { border-radius: 0.85rem; padding: clamp(1.25rem, 3vw, 1.75rem); box-shadow: none; }
.core-card h2 { font-size: clamp(1.45rem, 3vw, 1.9rem); }
.quick-start { margin-top: 1.5rem; border-width: 1px 0; border-radius: 0; padding-inline: 0; background: transparent; }
.compact-reading { margin-top: 2rem; padding-top: 2rem; }
.compact-reading h2 { font-size: 1.5rem; }
.reading-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; }
.reading-columns h3 { margin: 0 0 0.5rem; color: var(--blue-950); font-size: 1rem; }
.reading-columns a { display: block; min-height: 38px; padding-block: 0.28rem; text-decoration-thickness: 1px; }
.reading-column-heading { display: flex; min-height: 44px; align-items: center; justify-content: space-between; gap: 0.75rem; margin-bottom: 0.5rem; }
.reading-column-heading h3 { margin: 0; }
.more-articles-button { display: inline-flex; align-items: center; gap: 0.45rem; margin-top: 0.25rem; border: 0; padding-inline: 0.15rem; color: var(--blue-700); background: transparent; font-size: 0.9rem; font-weight: 700; text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 0.2em; }
.more-articles-button::after { width: 0.45rem; height: 0.45rem; border-right: 2px solid currentColor; border-bottom: 2px solid currentColor; content: ""; transform: rotate(45deg) translate(-0.1rem, 0.1rem); transition: transform var(--transition); }
.more-articles-button[aria-expanded="true"]::after { transform: rotate(225deg) translate(-0.05rem, -0.05rem); }
.more-articles-button:hover { color: var(--blue-950); background: transparent; text-decoration-thickness: 2px; }
.related-link-rows { display: grid; gap: 0.55rem; margin-top: 1.5rem; border-top: 1px solid var(--border); padding-top: 1rem; }
.related-link-row { display: flex; flex-wrap: wrap; align-items: center; gap: 0.35rem 1rem; }
.related-link-row span { min-width: 7.5rem; color: var(--muted); font-weight: 800; }
.related-link-row a { display: inline-flex; min-height: 44px; align-items: center; }
.logo-link { display: inline-flex; align-items: center; gap: 0.42rem; }
.link-logo { width: 20px; height: 20px; flex: 0 0 20px; border-radius: 0.28rem; object-fit: contain; }
.footer-simple { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 0.75rem 2rem; }
.footer-contact { display: flex; flex-wrap: wrap; align-items: baseline; margin: 0; }
.footer-contact span { color: #dceef9; font-weight: 700; }
.footer-contact a { font-weight: 800; }
.footer-simple .footer-meta { justify-content: flex-end; }

.article-page { width: min(48rem, calc(100% - 2rem)); }
.article-page h1 { max-width: none; font-size: clamp(2rem, 6vw, 3rem); line-height: 1.2; letter-spacing: -0.025em; }
.article-title-break { display: block; }
.mobile-title-break { display: none; }
.mobile-title-line { white-space: nowrap; }
.title-keep { white-space: nowrap; }
.article-meta { margin: 0.35rem 0 2rem; color: var(--muted); font-size: 0.9rem; }
.article-section { margin-top: 2.4rem; }
.article-section h2 { margin: 0 0 0.7rem; color: var(--blue-950); font-size: clamp(1.45rem, 4vw, 2rem); }
.article-section h3 { margin: 1.5rem 0 0.45rem; color: var(--blue-900); }
.article-section .article-suboption { margin: 1.25rem 0 0.4rem; color: var(--blue-900); font-size: 1rem; }
.article-section p { margin-block: 0.75rem; }
.article-section blockquote { margin: 1.25rem 0; border-left: 3px solid var(--blue-700); padding: 0.25rem 0 0.25rem 1rem; color: var(--muted); }
.article-figure { margin: 1.4rem 0; overflow: hidden; border: 1px solid var(--border); border-radius: 0.8rem; background: var(--paper); }
.article-figure img,
.article-figure svg { display: block; width: 100%; height: auto; }
.article-figure figcaption { padding: 0.65rem 0.85rem; color: var(--muted); font-size: 0.82rem; }
.install-options { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.install-option { border-top: 2px solid var(--sky-200); padding-top: 0.8rem; }
.win-key-symbol { display: inline-flex; align-items: center; gap: 0.12em; white-space: nowrap; }
.win-key-icon { width: 1.05em; height: auto; object-fit: contain; }
.install-option h3 { margin: 0; }
.workspace-path { display: inline-block; border-radius: 0.45rem; padding: 0.15rem 0.45rem; color: var(--blue-950); background: var(--sky-100); font-weight: 800; }

@media (min-width: 68rem) {
  body.music-open .tutorial-wrap { margin-left: max(2rem, calc((100vw - 68rem) / 2)); margin-right: 22rem; }
  .hero-content { margin-left: max(2rem, calc((100vw - 70rem) / 2)); }
}

@media (max-width: 42rem) {
  .site-header { padding-inline: 1rem; }
  .site-header { gap: 0.5rem; }
  .brand { font-size: 0.92rem; }
  .header-actions { gap: 0.25rem; }
  .header-share { padding-inline: 0.55rem; }
  .hero { min-height: 72vh; min-height: 72dvh; }
  .hero-content { padding-top: 5.5rem; padding-bottom: 4rem; }
  .hero h1 { font-size: clamp(2.35rem, 13vw, 3.7rem); }
  .hero-title-break { display: none; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-credit { right: 1rem; bottom: 4.5rem; left: 1rem; text-align: right; }
  .intro-card { border-radius: 1.25rem; }
  .network-card { grid-template-columns: 1fr; }
  .service-button { width: 100%; }
  .account-steps ol { grid-template-columns: 1fr; }
  .account-list,
  .reading-columns,
  .install-options { grid-template-columns: 1fr; }
  .verification-help { grid-template-columns: 1fr; }
  .core-grid { grid-template-columns: 1fr; }
  .article-page h1 { line-height: 1.16; }
  .article-page h1.title-skills { font-size: clamp(1.5rem, 6.7vw, 1.8rem); }
  .article-page h1.title-workspace { font-size: clamp(1.7rem, 7.2vw, 2rem); }
  .mobile-title-break { display: block; }
  .related-link-rows { gap: 0.85rem; }
  .related-link-row {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.5rem;
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 0.85rem;
    background: rgba(255, 255, 255, 0.72);
  }
  .related-link-row span { grid-column: 1 / -1; min-width: 0; }
  .related-link-row a {
    justify-content: flex-start;
    border-radius: 0.7rem;
    padding: 0.45rem 0.55rem;
    background: var(--paper);
  }
  .step { padding: 2.6rem 0; }
  .music-launcher { right: 0.5rem; bottom: 0.5rem; }
  .network-tooltip { left: -3.5rem; transform: translateY(0.35rem); }
  .network-term:hover .network-tooltip,
  .network-term:focus-within .network-tooltip { transform: translateY(0); }
  .plan-term .network-tooltip { left: calc(50% - 0.5rem); transform: translate(-50%, 0.35rem); }
  .plan-term:hover .network-tooltip,
  .plan-term:focus-within .network-tooltip { transform: translate(-50%, 0); }
  .footer-simple { grid-template-columns: 1fr; }
  .footer-simple .footer-meta { justify-content: flex-start; }
  pre { font-size: 0.82rem; }
}

@media (max-height: 30rem) {
  #step-1 .network-tooltip { left: -3.5rem; transform: translateY(0.35rem); }
  #step-1 .network-term:hover .network-tooltip,
  #step-1 .network-term:focus-within .network-tooltip { transform: translateY(0); }
}

@media (hover: none) {
  .wechat-preview { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after { scroll-behavior: auto !important; transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; }
}