:root {
  --dawn: #dfe8f4;
  --pearl: #c6caeb;
  --iris: #8f7bc7;
  --violet: #4a3f72;
  --midnight: #171425;
  --ember: #9a4057;
  --coral: #e9795c;
  --sand: #f1aa83;
  --paper: #f8f5f2;
  --ink: #171522;
  --line-dark: rgba(23, 21, 34, 0.2);
  --line-light: rgba(255, 255, 255, 0.28);
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  color: var(--ink);
  background: var(--dawn);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  background: var(--dawn);
}

body {
  min-width: 320px;
  margin: 0;
  overflow-x: hidden;
  background: var(--dawn);
  color: var(--ink);
  text-rendering: optimizeLegibility;
}

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

button {
  color: inherit;
  font: inherit;
}

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

button:focus-visible,
a:focus-visible {
  outline: 2px solid currentColor;
  outline-offset: 5px;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 12px;
  padding: 10px 16px;
  transform: translateY(-180%);
  border-radius: 999px;
  background: var(--ink);
  color: white;
}

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

.site-header {
  position: fixed;
  z-index: 50;
  top: 0;
  left: 0;
  display: grid;
  width: 100%;
  height: 82px;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0 3.2vw;
  color: var(--ink);
  transition: height 220ms ease, background-color 220ms ease, color 220ms ease;
}

.site-header.is-scrolled {
  height: 64px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.09);
  background: rgba(23, 20, 37, 0.94);
  color: var(--paper);
}

.wordmark {
  display: inline-flex;
  align-items: center;
  justify-self: start;
  gap: 10px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.wordmark img,
.footer-brand img {
  display: block;
  border-radius: 50%;
  object-fit: cover;
}

.primary-nav {
  display: flex;
  gap: clamp(22px, 3vw, 46px);
  justify-self: center;
  font-size: 12px;
}

.primary-nav a {
  padding: 8px 0;
  opacity: 0.72;
  transition: opacity 160ms ease;
}

.primary-nav a:hover {
  opacity: 1;
}

.header-cta {
  justify-self: end;
  padding: 10px 17px;
  border: 1px solid currentColor;
  border-radius: 999px;
  font-size: 12px;
}

.scroll-meter {
  position: fixed;
  z-index: 55;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: rgba(255, 255, 255, 0.08);
}

.scroll-meter span {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background: linear-gradient(90deg, #8c70bf, #f09a79);
}

.act {
  position: relative;
  isolation: isolate;
  min-height: 100svh;
  overflow: clip;
  contain: layout paint;
}

.act-copy {
  position: relative;
  z-index: 5;
}

h1,
h2,
h3,
p {
  text-wrap: pretty;
}

h1,
h2 {
  margin: 0;
  font-family: "Songti SC", STSong, "SimSun", serif;
  font-weight: 500;
  letter-spacing: -0.06em;
}

h1 {
  font-size: clamp(56px, 7.6vw, 130px);
  line-height: 0.95;
}

h2 {
  font-size: clamp(48px, 6.5vw, 108px);
  line-height: 1.02;
}

/* 第一幕：珠光清晨。底部颜色与第二幕顶部完全一致。 */
.hero-act {
  display: grid;
  grid-template-columns: 0.82fr 1.35fr 0.55fr;
  align-items: end;
  padding: 120px 3.2vw 42px;
  background:
    radial-gradient(circle at 61% 42%, rgba(255, 255, 255, 0.82) 0 7%, transparent 32%),
    linear-gradient(180deg, var(--dawn) 0%, var(--pearl) 46%, var(--iris) 100%);
}

.hero-act::after,
.courses-act::after,
.practice-act::after,
.stores-act::after {
  position: absolute;
  z-index: 0;
  right: 10%;
  bottom: -12vh;
  width: 44vw;
  height: 30vh;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  filter: blur(50px);
  content: "";
  pointer-events: none;
}

.hero-type {
  position: absolute;
  z-index: 0;
  top: 51%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: rgba(255, 255, 255, 0.36);
  font-family: "Songti SC", STSong, serif;
  font-size: clamp(150px, 26vw, 430px);
  font-style: italic;
  line-height: 0.75;
  letter-spacing: -0.16em;
  white-space: nowrap;
}

.hero-copy {
  align-self: end;
  padding-bottom: 42px;
}

.hero-copy > p {
  margin: 28px 0 0;
  font-size: 13px;
  line-height: 1.9;
}

.resonance {
  position: relative;
  z-index: 3;
  width: min(52vw, 760px);
  aspect-ratio: 1;
  align-self: center;
  justify-self: center;
  transform: translateY(2%);
}

.resonance-glow {
  position: absolute;
  inset: 19%;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.46);
  box-shadow: 0 0 90px rgba(255, 255, 255, 0.45);
}

.resonance-ring {
  position: absolute;
  top: 50%;
  left: 50%;
  border: 1px solid rgba(255, 255, 255, 0.64);
  border-radius: 50%;
  transform: translate(-50%, -50%);
}

.ring-a {
  width: 92%;
  height: 64%;
  transform: translate(-50%, -50%) rotate(18deg);
}

.ring-b {
  width: 72%;
  height: 96%;
  transform: translate(-50%, -50%) rotate(-24deg);
}

.ring-c {
  width: 82%;
  height: 82%;
  border-color: rgba(69, 57, 105, 0.36);
  transform: translate(-50%, -50%) rotate(48deg);
}

.guitar-strings,
.final-lines {
  position: absolute;
  z-index: 2;
  top: 8%;
  bottom: 8%;
  left: 50%;
  display: flex;
  gap: clamp(7px, 1vw, 15px);
  transform: translateX(-50%) rotate(8deg);
}

.guitar-strings i,
.final-lines i {
  display: block;
  width: 1px;
  height: 100%;
  background: linear-gradient(180deg, transparent, rgba(255, 255, 255, 0.9) 20% 80%, transparent);
}

.bear-seal {
  position: absolute;
  z-index: 4;
  top: 50%;
  left: 50%;
  width: 45%;
  aspect-ratio: 1;
  transform: translate(-50%, -50%);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.72);
  border-radius: 50%;
  background: rgba(245, 246, 255, 0.78);
  box-shadow: 0 24px 70px rgba(42, 33, 79, 0.28);
}

.bear-seal img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.scroll-hint {
  position: relative;
  z-index: 5;
  align-self: end;
  margin: 0 0 26px;
  font-size: 10px;
  line-height: 1.8;
  letter-spacing: 0.12em;
}

/* 第二幕：沿用同一紫色，逐步落入深夜。 */
.courses-act {
  display: grid;
  grid-template-columns: 0.82fr 1fr 0.78fr;
  align-items: center;
  gap: 2vw;
  padding: 112px 3.2vw 70px;
  background: linear-gradient(180deg, var(--iris) 0%, #675991 40%, var(--violet) 100%);
  color: var(--paper);
}

.courses-copy {
  align-self: start;
  padding-top: 8vh;
}

.course-visual {
  position: relative;
  z-index: 2;
  display: grid;
  width: min(46vw, 650px);
  aspect-ratio: 1;
  place-items: center;
  justify-self: center;
}

.guitar-body {
  position: relative;
  width: 72%;
  height: 92%;
  border: 1px solid rgba(255, 255, 255, 0.54);
  border-radius: 46% 54% 44% 56% / 57% 48% 52% 43%;
  background: linear-gradient(135deg, rgba(227, 235, 255, 0.35), rgba(74, 55, 118, 0.28));
  box-shadow: inset 34px 18px 50px rgba(255, 255, 255, 0.08), 0 32px 72px rgba(22, 15, 45, 0.18);
  transform: rotate(-5deg);
}

.guitar-body::before {
  position: absolute;
  top: -15%;
  left: 50%;
  width: 17%;
  height: 35%;
  transform: translateX(-50%);
  border-right: 1px solid rgba(255, 255, 255, 0.42);
  border-left: 1px solid rgba(255, 255, 255, 0.42);
  background: rgba(226, 231, 255, 0.1);
  content: "";
}

.sound-hole {
  position: absolute;
  z-index: 2;
  top: 45%;
  left: 50%;
  display: grid;
  width: 43%;
  aspect-ratio: 1;
  transform: translate(-50%, -50%);
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.72);
  border-radius: 50%;
  background: rgba(45, 33, 77, 0.68);
  box-shadow: 0 0 0 12px rgba(255, 255, 255, 0.08), 0 0 0 20px rgba(42, 29, 75, 0.12);
}

.sound-hole b {
  font-family: "Songti SC", STSong, serif;
  font-size: clamp(28px, 3.7vw, 55px);
  font-weight: 500;
}

.course-strings {
  position: absolute;
  z-index: 4;
  top: -15%;
  bottom: 6%;
  left: 50%;
  display: flex;
  gap: clamp(5px, 0.65vw, 10px);
  transform: translateX(-50%);
}

.course-strings i {
  display: block;
  width: 1px;
  height: 100%;
  background: rgba(255, 255, 255, 0.66);
}

.guitar-bridge {
  position: absolute;
  z-index: 5;
  bottom: 17%;
  left: 50%;
  width: 42%;
  height: 8px;
  transform: translateX(-50%);
  border: 1px solid rgba(255, 255, 255, 0.5);
}

.course-panel {
  position: relative;
  z-index: 5;
  align-self: end;
  padding-bottom: 3vh;
}

.course-description {
  min-height: 4em;
  margin: 0 0 30px;
  font-size: 13px;
  line-height: 1.85;
}

.course-list {
  border-top: 1px solid var(--line-light);
}

.course-item {
  display: block;
  width: 100%;
  padding: 16px 0;
  border: 0;
  border-bottom: 1px solid var(--line-light);
  background: transparent;
  text-align: left;
  cursor: pointer;
  opacity: 0.48;
  transition: opacity 160ms ease, padding 160ms ease;
}

.course-item span {
  font-family: "Songti SC", STSong, serif;
  font-size: clamp(24px, 2.4vw, 38px);
}

.course-item:hover,
.course-item.is-active {
  padding-left: 12px;
  opacity: 1;
}

/* 第三幕：与第二幕同色衔接，只在中段加深。 */
.practice-act {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 5vw;
  padding: 116px 6vw 82px;
  background: linear-gradient(180deg, var(--violet) 0%, #2a2545 44%, var(--midnight) 100%);
  color: var(--paper);
}

.practice-visual {
  position: relative;
  z-index: 2;
  width: min(58vw, 760px);
  aspect-ratio: 1;
  justify-self: center;
}

.practice-tab {
  position: absolute;
  top: 50%;
  right: 4%;
  left: 4%;
  display: grid;
  height: 54%;
  grid-template-rows: repeat(6, 1fr);
  transform: translateY(-50%) rotate(-4deg);
}

.practice-tab > i {
  display: block;
  border-top: 1px solid rgba(218, 221, 255, 0.34);
}

.practice-tab > i:last-of-type {
  border-bottom: 1px solid rgba(218, 221, 255, 0.34);
}

.tab-mark {
  position: absolute;
  z-index: 2;
  display: grid;
  width: 17%;
  aspect-ratio: 1;
  border: 1px solid rgba(255, 255, 255, 0.58);
  border-radius: 50%;
  background: #2d2746;
  place-items: center;
  text-align: center;
}

.tab-mark b {
  align-self: end;
  font-family: "Songti SC", STSong, serif;
  font-size: clamp(16px, 2vw, 28px);
  font-weight: 500;
}

.tab-mark small {
  align-self: start;
  font-family: Arial, sans-serif;
  font-size: 8px;
  opacity: 0.52;
}

.tab-one {
  top: -3%;
  left: 8%;
}

.tab-two {
  top: 30%;
  left: 34%;
}

.tab-three {
  top: 7%;
  right: 24%;
}

.tab-four {
  right: 3%;
  bottom: -4%;
}

.metronome-mark {
  position: absolute;
  z-index: 1;
  top: 14%;
  left: 48%;
  display: grid;
  width: 72px;
  height: 68%;
  grid-template-rows: auto 1fr auto;
  justify-items: center;
  transform: rotate(8deg);
  color: rgba(255, 255, 255, 0.52);
  font-family: Arial, sans-serif;
  font-size: 8px;
}

.metronome-mark span {
  position: absolute;
  top: 9%;
  bottom: 9%;
  width: 1px;
  background: rgba(255, 255, 255, 0.42);
}

.metronome-mark i {
  position: relative;
  z-index: 2;
  align-self: center;
  width: 14px;
  aspect-ratio: 1;
  border: 1px solid rgba(255, 255, 255, 0.72);
  border-radius: 50%;
  background: #2d2746;
}

.practice-copy > p {
  max-width: 480px;
  margin: 32px 0 0;
  color: rgba(248, 245, 242, 0.7);
  font-size: 14px;
  line-height: 1.95;
}

/* 第四幕：从黑紫经过酒红进入暖橙，避免直接跳色。 */
.stores-act {
  display: grid;
  grid-template-columns: 0.86fr 1.14fr;
  align-items: center;
  gap: 5vw;
  padding: 116px 6vw 78px;
  background: linear-gradient(180deg, var(--midnight) 0%, #4d263c 34%, var(--ember) 68%, var(--coral) 100%);
  color: var(--paper);
}

.stores-copy {
  align-self: start;
  padding-top: 7vh;
}

.store-list {
  position: relative;
  z-index: 3;
  border-top: 1px solid var(--line-light);
}

.store-card {
  display: grid;
  grid-template-columns: 1.1fr 0.8fr auto;
  align-items: center;
  gap: 24px;
  padding: 30px 0;
  border-bottom: 1px solid var(--line-light);
}

.store-card header span {
  display: block;
  margin-bottom: 8px;
  font-size: 9px;
  letter-spacing: 0.16em;
  opacity: 0.65;
}

.store-card h3 {
  margin: 0;
  font-family: "Songti SC", STSong, serif;
  font-size: clamp(28px, 3vw, 48px);
  font-weight: 500;
}

.store-card > p {
  margin: 0;
  font-size: 10px;
  line-height: 1.85;
  opacity: 0.7;
}

.store-card button {
  padding: 12px 0 12px 18px;
  border: 0;
  background: transparent;
  color: white;
  font-size: 11px;
  cursor: pointer;
}

.store-card button span {
  margin-left: 8px;
}

.connect-section {
  position: relative;
  display: grid;
  min-height: 92svh;
  grid-template-columns: 1fr 0.82fr;
  align-items: center;
  gap: 5vw;
  overflow: clip;
  padding: 120px 8vw 84px;
  background: linear-gradient(180deg, var(--coral) 0%, var(--sand) 46%, #f0c2a4 100%);
  color: #24151b;
}

.connect-copy {
  position: relative;
  z-index: 3;
}

.connect-copy > p {
  max-width: 590px;
  margin: 32px 0;
  font-size: 14px;
  line-height: 1.95;
}

.copy-action {
  display: grid;
  width: min(100%, 480px);
  grid-template-columns: 1fr auto;
  align-items: center;
  padding: 7px 7px 7px 22px;
  border: 1px solid rgba(36, 21, 27, 0.55);
  border-radius: 999px;
  background: transparent;
  color: #24151b;
  text-align: left;
  cursor: pointer;
}

.copy-action span {
  font-size: 12px;
}

.copy-action b {
  padding: 14px 21px;
  border-radius: 999px;
  background: #24151b;
  color: var(--paper);
  font-size: 13px;
}

.final-seal {
  position: relative;
  z-index: 2;
  display: grid;
  width: min(40vw, 560px);
  aspect-ratio: 1;
  place-items: center;
  justify-self: center;
  border: 1px solid rgba(255, 255, 255, 0.52);
  border-radius: 50%;
  background: rgba(255, 242, 231, 0.16);
}

.final-seal::before,
.final-seal::after {
  position: absolute;
  border: 1px solid rgba(36, 21, 27, 0.18);
  border-radius: 50%;
  content: "";
}

.final-seal::before {
  inset: 9%;
}

.final-seal::after {
  inset: 19%;
}

.final-seal img {
  position: relative;
  z-index: 3;
  width: 48%;
  height: 48%;
  border-radius: 50%;
  object-fit: cover;
}

.final-lines {
  z-index: 1;
  top: 10%;
  bottom: 10%;
}

.final-lines i {
  background: linear-gradient(180deg, transparent, rgba(36, 21, 27, 0.36) 20% 80%, transparent);
}

.site-footer {
  display: grid;
  min-height: 150px;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
  padding: 32px 3.2vw;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  background: #171425;
  color: var(--paper);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 13px;
}

.footer-brand p {
  display: flex;
  margin: 0;
  flex-direction: column;
  gap: 4px;
}

.footer-brand strong {
  font-size: 13px;
}

.footer-brand span,
.legal {
  font-size: 9px;
  opacity: 0.62;
}

.site-footer nav {
  display: flex;
  gap: 28px;
  font-size: 11px;
}

.legal {
  display: flex;
  margin: 0;
  flex-direction: column;
  gap: 5px;
  justify-self: end;
  text-align: right;
}

.toast {
  position: fixed;
  z-index: 90;
  right: 24px;
  bottom: 24px;
  max-width: min(360px, calc(100vw - 48px));
  padding: 13px 17px;
  transform: translateY(24px);
  border-radius: 999px;
  background: rgba(23, 20, 37, 0.94);
  color: white;
  font-size: 12px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 180ms ease, transform 180ms ease;
}

.toast.is-visible {
  transform: translateY(0);
  opacity: 1;
}

/* 只对进入视口的内容做一次轻量位移动画，避免整页持续重绘。 */
.act-copy,
.course-panel,
.course-visual,
.practice-visual,
.store-list {
  transform: translateY(24px);
  opacity: 0;
  transition: transform 700ms cubic-bezier(0.16, 1, 0.3, 1), opacity 500ms ease;
}

.act.is-visible .act-copy,
.act.is-visible .course-panel,
.act.is-visible .course-visual,
.act.is-visible .practice-visual,
.act.is-visible .store-list {
  transform: translateY(0);
  opacity: 1;
}

.act.is-visible .course-panel,
.act.is-visible .store-list {
  transition-delay: 90ms;
}

@media (min-width: 761px) and (prefers-reduced-motion: no-preference) {
  .hero-act.is-visible .resonance {
    animation: resonance-float 8s ease-in-out infinite;
  }
}

@keyframes resonance-float {
  0%, 100% { transform: translateY(2%); }
  50% { transform: translateY(-1%); }
}

@media (max-width: 1080px) {
  .hero-act {
    grid-template-columns: 0.9fr 1.2fr 0.45fr;
  }

  .courses-act {
    grid-template-columns: 0.72fr 0.9fr 0.75fr;
  }

  .store-card {
    grid-template-columns: 1fr auto;
  }

  .store-card > p {
    grid-column: 1 / -1;
    grid-row: 2;
  }
}

@media (max-width: 760px) {
  .site-header {
    height: 66px;
    grid-template-columns: 1fr auto;
    padding: 0 18px;
  }

  .site-header.is-scrolled {
    height: 58px;
  }

  .wordmark > span,
  .primary-nav {
    display: none;
  }

  .wordmark img {
    width: 38px;
    height: 38px;
  }

  .header-cta {
    padding: 8px 12px;
    font-size: 10px;
  }

  .act {
    min-height: auto;
    contain: layout paint;
  }

  h1 {
    font-size: clamp(52px, 16vw, 76px);
  }

  h2 {
    font-size: clamp(46px, 14vw, 68px);
  }

  .hero-act {
    display: block;
    min-height: 100svh;
    padding: 94px 20px 30px;
    background:
      radial-gradient(circle at 50% 52%, rgba(255, 255, 255, 0.72), transparent 28%),
      linear-gradient(180deg, var(--dawn), var(--pearl) 54%, var(--iris));
  }

  .hero-type {
    top: 51%;
    font-size: 46vw;
  }

  .hero-copy {
    padding: 0;
  }

  .hero-copy > p {
    font-size: 11px;
  }

  .resonance {
    position: absolute;
    top: 55%;
    left: 50%;
    width: min(104vw, 520px);
    transform: translate(-50%, -50%);
  }

  .scroll-hint {
    position: absolute;
    right: 20px;
    bottom: 24px;
    margin: 0;
    text-align: right;
  }

  .courses-act {
    display: flex;
    min-height: 1150px;
    padding: 96px 20px 50px;
    flex-direction: column;
    gap: 24px;
    background: linear-gradient(180deg, var(--iris), #65588f 42%, var(--violet));
  }

  .courses-copy {
    align-self: stretch;
    padding: 0;
  }

  .course-visual {
    width: min(96vw, 490px);
    margin: 10px auto;
  }

  .course-panel {
    width: 100%;
    padding: 0;
  }

  .course-item {
    padding: 14px 0;
  }

  .course-item span {
    font-size: 27px;
  }

  .practice-act {
    display: flex;
    min-height: 980px;
    padding: 94px 20px 82px;
    flex-direction: column-reverse;
    gap: 12px;
    justify-content: center;
    background: linear-gradient(180deg, var(--violet), #292441 48%, var(--midnight));
  }

  .practice-copy > p {
    margin-top: 22px;
    font-size: 12px;
  }

  .practice-visual {
    width: min(100vw, 520px);
    margin: 0 auto;
  }

  .tab-mark {
    width: 21%;
  }

  .stores-act {
    display: block;
    min-height: 900px;
    padding: 96px 20px 58px;
    background: linear-gradient(180deg, var(--midnight), #4d263c 35%, var(--ember) 68%, var(--coral));
  }

  .stores-copy {
    padding: 0;
  }

  .store-list {
    margin-top: 90px;
  }

  .store-card {
    grid-template-columns: 1fr auto;
    gap: 15px;
    padding: 25px 0;
  }

  .store-card button {
    grid-column: 2;
    grid-row: 1;
  }

  .connect-section {
    display: flex;
    min-height: 930px;
    padding: 96px 20px 68px;
    flex-direction: column;
    justify-content: center;
    background: linear-gradient(180deg, var(--coral), var(--sand) 48%, #f0c2a4);
  }

  .connect-copy > p {
    margin: 24px 0;
    font-size: 12px;
  }

  .final-seal {
    width: min(92vw, 470px);
    margin-top: 60px;
  }

  .site-footer {
    grid-template-columns: 1fr;
    align-items: start;
    padding: 34px 20px;
  }

  .site-footer nav {
    order: 3;
  }

  .legal {
    justify-self: start;
    text-align: left;
  }

  .toast {
    right: 16px;
    bottom: 16px;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

.reduced-motion .act-copy,
.reduced-motion .course-panel,
.reduced-motion .course-visual,
.reduced-motion .practice-visual,
.reduced-motion .store-list {
  transform: none;
  opacity: 1;
}