/* ============================================================
   Little Tree Mix · 小树音乐工作室
   Serif editorial system — charcoal / sage / sand on paper
   ============================================================ */

:root {
  --paper:      #f4f1e8;
  --paper-2:    #ece7d9;
  --ink:        #1d201b;
  --ink-soft:   #45493f;
  --mute:       #7e8375;
  --sage:       #6d7c59;
  --sage-deep:  #49553c;
  --sand:       #c2b48f;
  --hairline:   rgba(29, 32, 27, .16);
  --hairline-2: rgba(29, 32, 27, .34);
  --ease-out:   cubic-bezier(.22, 1, .36, 1);
  --serif: "Cormorant Garamond", "EB Garamond", "Noto Serif SC",
           "Songti SC", "STSong", "SimSun", serif;
  --maxw: 1160px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

::selection { background: var(--sage); color: var(--paper); }

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }
:focus-visible { outline: 1px dashed var(--sage); outline-offset: 3px; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(20px, 4vw, 48px); }

/* ---------- background watermark ---------- */
.watermark {
  position: fixed;
  right: -14vw; top: 8vh;
  width: 52vw;
  opacity: .045;
  pointer-events: none;
  z-index: 0;
  filter: grayscale(20%);
}

/* ---------- header ---------- */
.site-head {
  position: fixed; inset: 0 0 auto 0;
  z-index: 50;
  border-bottom: 1px solid transparent;
  transition: background .5s ease, border-color .5s ease;
}
.site-head.stuck {
  background: rgba(244, 241, 232, .92);
  backdrop-filter: blur(10px);
  border-bottom-color: var(--hairline);
}
.head-in {
  display: flex; align-items: center; justify-content: space-between;
  gap: 24px;
  padding-top: 14px; padding-bottom: 14px;
}
.brand { display: flex; align-items: center; gap: 14px; }
.brand img { height: 40px; width: auto; }
.brand-name { line-height: 1.15; }
.brand-name .en {
  display: block;
  font-size: 15px; font-weight: 600;
  letter-spacing: .14em; text-transform: uppercase;
}
.brand-name .zh {
  display: block;
  font-size: 12px; color: var(--mute);
  letter-spacing: .42em;
}

.site-nav { display: flex; align-items: center; gap: clamp(18px, 3vw, 40px); }
.nav-link {
  position: relative;
  font-size: 13px;
  letter-spacing: .22em;
  padding: 4px 0;
  color: var(--ink-soft);
  transition: color .4s ease;
}
.nav-link small {
  display: block;
  font-size: 10px;
  letter-spacing: .3em;
  text-transform: uppercase;
  color: var(--mute);
  line-height: 1.2;
  transition: color .4s ease;
}
.nav-link::after {
  content: ""; position: absolute; left: 0; bottom: -2px;
  width: 100%; height: 1px;
  background: var(--ink);
  transform: scaleX(0); transform-origin: left;
  transition: transform .5s var(--ease-out);
}
.nav-link:hover::after, .nav-link.active::after { transform: scaleX(1); }
.nav-link.active { color: var(--ink); }
.nav-link.ext small::after { content: " ↗"; }

.lang-toggle {
  font-size: 12px;
  letter-spacing: .2em;
  border: 1px solid var(--hairline-2);
  border-radius: 999px;
  padding: 5px 14px 4px;
  color: var(--ink-soft);
  transition: background .4s ease, color .4s ease, border-color .4s ease;
}
.lang-toggle:hover { background: var(--ink); color: var(--paper); border-color: var(--ink); }

/* ---------- type primitives ---------- */
.overline {
  font-size: 11px;
  letter-spacing: .38em;
  text-transform: uppercase;
  color: var(--sage-deep);
}
.overline .zh-acc { letter-spacing: .5em; color: var(--mute); }

.display {
  font-weight: 500;
  line-height: 1.12;
  letter-spacing: .01em;
}

.latin-acc {
  font-style: italic;
  font-weight: 500;
  color: var(--sage-deep);
  letter-spacing: .02em;
}

/* ---------- hero ---------- */
.hero {
  position: relative;
  min-height: 96vh;
  display: flex; flex-direction: column; justify-content: center;
  padding-top: 120px;
  z-index: 1;
}
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, .75fr);
  gap: clamp(24px, 5vw, 72px);
  align-items: center;
}
.hero h1 {
  font-size: clamp(44px, 7.2vw, 96px);
  margin: 26px 0 10px;
}
.hero .latin-acc { font-size: clamp(20px, 2.6vw, 32px); display: block; }
.hero-sub {
  max-width: 34em;
  margin-top: 26px;
  color: var(--ink-soft);
  font-size: clamp(16px, 1.4vw, 19px);
}
.hero-ctas { margin-top: 42px; display: flex; gap: 36px; flex-wrap: wrap; }

.hero-logo { position: relative; }
.hero-logo img {
  width: min(100%, 380px);
  margin-left: auto;
  animation: breathe 7s ease-in-out infinite;
  transform-origin: 50% 90%;
}
@keyframes breathe {
  0%, 100% { transform: scale(1); }
  50%      { transform: scale(1.022); }
}

/* text links with sliding underline + arrow drift */
.t-link {
  display: inline-flex; align-items: baseline; gap: 10px;
  font-size: 15px; letter-spacing: .12em;
  padding-bottom: 5px;
  background: linear-gradient(currentColor, currentColor) left bottom / 100% 1px no-repeat;
  transition: color .4s ease;
}
.t-link small {
  font-size: 11px; letter-spacing: .3em; text-transform: uppercase;
  color: var(--mute); transition: color .4s ease;
}
.t-link .arr { transition: transform .45s var(--ease-out); }
.t-link:hover { color: var(--sage-deep); }
.t-link:hover small { color: var(--sage); }
.t-link:hover .arr { transform: translateX(7px); }

/* ---------- equalizer bars (grove motif) ---------- */
.eq {
  display: flex; align-items: flex-end; gap: 7px;
  height: 58px;
}
.eq span {
  display: block;
  width: 5px;
  height: calc(var(--h) * 1%);
  background: var(--c, var(--ink));
  border-radius: 3px;
  transform-origin: bottom;
  animation: eq-grow 2.6s ease-in-out infinite alternate;
  animation-delay: var(--d, 0s);
}
@keyframes eq-grow {
  from { transform: scaleY(.35); }
  to   { transform: scaleY(1); }
}
.eq.static span { animation: none; }
.hero-eq { margin-top: clamp(48px, 9vh, 96px); }

/* ---------- sections ---------- */
.section { position: relative; padding: clamp(72px, 11vh, 130px) 0; z-index: 1; }
.section + .section { border-top: 1px solid var(--hairline); }

.sec-head { margin-bottom: clamp(40px, 6vh, 72px); }
.sec-head .no {
  display: inline-block;
  font-size: 13px; letter-spacing: .3em; color: var(--mute);
  margin-bottom: 14px;
}
.sec-head h2 { font-size: clamp(30px, 4.2vw, 52px); font-weight: 500; line-height: 1.2; }
.sec-head h2 .latin-acc { font-size: .62em; margin-left: .35em; }

.split { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: clamp(24px, 5vw, 80px); }
.split .side { color: var(--mute); font-size: 13px; letter-spacing: .2em; }
.lead { font-size: clamp(19px, 2vw, 24px); line-height: 1.9; }
.lead + p { margin-top: 1.2em; }
.muted { color: var(--ink-soft); }

/* ---------- archive rows ---------- */
.rows { border-top: 1px solid var(--hairline); }
.row-line {
  display: grid;
  grid-template-columns: 3.2em minmax(0, 1.5fr) minmax(0, 1fr) auto 2em;
  gap: 18px; align-items: baseline;
  padding: 26px 4px;
  border-bottom: 1px solid var(--hairline);
  transition: background .45s ease, padding .45s var(--ease-out);
}
.row-line:hover { background: rgba(109, 124, 89, .06); padding-left: 14px; }
.row-line .idx { font-size: 13px; color: var(--mute); letter-spacing: .12em; }
.row-line .ttl { font-size: clamp(19px, 1.9vw, 24px); font-weight: 500; }
.row-line .ttl small {
  display: block; font-size: 12px; font-style: italic;
  color: var(--mute); letter-spacing: .06em; font-weight: 400;
}
.row-line .meta { font-size: 13px; color: var(--ink-soft); letter-spacing: .06em; }
.row-line .meta .tagdot { color: var(--sand); padding: 0 2px; }
.row-line .dur { font-size: 13px; color: var(--mute); font-variant-numeric: tabular-nums; }
.row-line .arr { color: var(--mute); transition: transform .45s var(--ease-out), color .4s; }
.row-line:hover .arr { transform: translateX(6px); color: var(--sage-deep); }

/* service rows reuse .rows but with roman numerals + wider meta */
.row-line .roman { font-size: 13px; color: var(--sage-deep); letter-spacing: .2em; }

/* ---------- parent band ---------- */
.parent-band { text-align: left; }
.parent-band .big {
  font-size: clamp(30px, 4.6vw, 58px);
  font-weight: 500; line-height: 1.25;
}
.parent-band .big a {
  background: linear-gradient(var(--sage), var(--sage)) left bottom / 0% 2px no-repeat;
  transition: background-size .6s var(--ease-out), color .4s;
  padding-bottom: 4px;
}
.parent-band .big a:hover { background-size: 100% 2px; color: var(--sage-deep); }

/* ---------- footer ---------- */
.site-foot {
  margin-top: clamp(60px, 10vh, 120px);
  background: var(--ink);
  color: var(--paper);
  padding: clamp(56px, 8vh, 96px) 0 40px;
  position: relative; z-index: 1;
}
.foot-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr);
  gap: 48px;
  align-items: end;
}
.foot-brand .en { font-size: 24px; letter-spacing: .12em; font-weight: 600; }
.foot-brand .zh { font-size: 13px; letter-spacing: .5em; color: var(--sand); margin-top: 6px; }
.foot-eq { justify-content: flex-end; }
.foot-eq .eq span { background: var(--sand); opacity: .85; }
.foot-eq .eq span:nth-child(3n) { background: var(--sage); }
.foot-links { margin-top: 34px; display: flex; gap: 30px; flex-wrap: wrap; font-size: 13px; letter-spacing: .1em; }
.foot-links a { color: rgba(244,241,232,.72); border-bottom: 1px solid rgba(244,241,232,.25); padding-bottom: 2px; transition: color .4s, border-color .4s; }
.foot-links a:hover { color: var(--paper); border-color: var(--paper); }
.foot-legal {
  margin-top: 42px; padding-top: 22px;
  border-top: 1px solid rgba(244,241,232,.14);
  font-size: 12.5px; letter-spacing: .06em;
  color: rgba(244,241,232,.55);
  display: flex; justify-content: space-between; gap: 18px; flex-wrap: wrap;
}
.foot-legal a { color: var(--sand); border-bottom: 1px solid rgba(194,180,143,.4); }
.foot-legal a:hover { color: var(--paper); }

/* ============================================================
   Library page
   ============================================================ */
.lib-hero { padding: 150px 0 30px; }
.lib-hero h1 { font-size: clamp(38px, 5.6vw, 68px); font-weight: 500; margin-top: 20px; }
.lib-hero h1 .latin-acc { font-size: .55em; margin-left: .3em; }
.lib-count { color: var(--mute); font-size: 13px; letter-spacing: .2em; margin-top: 12px; }

.lib-tools {
  position: sticky; top: 69px; z-index: 40;
  background: rgba(244, 241, 232, .94);
  backdrop-filter: blur(10px);
  border-top: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
  padding: 18px 0 14px;
  margin-bottom: 8px;
}
.search-line { display: flex; align-items: baseline; gap: 14px; }
.search-line label { font-size: 12px; letter-spacing: .3em; text-transform: uppercase; color: var(--sage-deep); white-space: nowrap; }
.search-line input {
  flex: 1;
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--hairline-2);
  font-family: var(--serif);
  font-size: 17px;
  color: var(--ink);
  padding: 6px 2px 8px;
  transition: border-color .4s;
}
.search-line input::placeholder { color: var(--mute); font-style: italic; }
.search-line input:focus { outline: none; border-bottom-color: var(--ink); }
.search-clear { font-size: 12px; letter-spacing: .2em; color: var(--mute); visibility: hidden; }
.search-clear.show { visibility: visible; }
.search-clear:hover { color: var(--ink); }

.chips { display: flex; flex-wrap: wrap; gap: 8px 22px; margin-top: 14px; }
.chip {
  font-size: 13px; letter-spacing: .14em;
  color: var(--ink-soft);
  padding: 3px 0;
  position: relative;
  transition: color .35s;
}
.chip small { font-size: 10px; letter-spacing: .26em; text-transform: uppercase; color: var(--mute); margin-left: 6px; transition: color .35s; }
.chip::after {
  content: ""; position: absolute; left: 0; bottom: -1px; height: 1px; width: 100%;
  background: var(--sage-deep);
  transform: scaleX(0); transform-origin: left;
  transition: transform .45s var(--ease-out);
}
.chip:hover { color: var(--ink); }
.chip.on { color: var(--sage-deep); font-weight: 600; }
.chip.on small { color: var(--sage); }
.chip.on::after { transform: scaleX(1); }

/* track rows */
.track { border-bottom: 1px solid var(--hairline); }
.track:first-child { border-top: 1px solid var(--hairline); }
.track-head {
  width: 100%;
  display: grid;
  grid-template-columns: 3.2em minmax(0, 1.5fr) minmax(0, 1fr) auto 2.4em;
  gap: 18px; align-items: baseline;
  padding: 26px 4px;
  text-align: left;
  transition: background .45s ease, padding .45s var(--ease-out);
}
.track-head:hover { background: rgba(109, 124, 89, .06); padding-left: 14px; }
.track.open .track-head { background: rgba(109, 124, 89, .08); }
.track-head .idx { font-size: 13px; color: var(--mute); letter-spacing: .12em; }
.track-head .ttl { font-size: clamp(19px, 1.9vw, 24px); font-weight: 500; color: var(--ink); }
.track-head .ttl small { display: block; font-size: 12px; font-style: italic; color: var(--mute); font-weight: 400; letter-spacing: .06em; }
.track-head .meta { font-size: 13px; color: var(--ink-soft); letter-spacing: .06em; }
.track-head .meta .tagdot { color: var(--sand); padding: 0 2px; }
.track-head .dur { font-size: 13px; color: var(--mute); font-variant-numeric: tabular-nums; }
.track-head .fold {
  justify-self: end;
  width: 26px; height: 26px;
  display: grid; place-items: center;
  color: var(--mute);
  transition: transform .5s var(--ease-out), color .4s;
}
.track.open .track-head .fold { transform: rotate(45deg); color: var(--sage-deep); }

/* expandable panel — grid-rows trick */
.track-panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows .6s var(--ease-out);
}
.track.open .track-panel { grid-template-rows: 1fr; }
.panel-clip { overflow: hidden; min-height: 0; }
.panel-in {
  padding: 8px 4px 44px calc(3.2em + 22px);
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, .65fr);
  gap: clamp(28px, 4vw, 64px);
  opacity: 0;
  transform: translateY(-6px);
  transition: opacity .5s ease .08s, transform .5s var(--ease-out) .08s;
}
.track.open .panel-in { opacity: 1; transform: none; }

/* player */
.player .intro { color: var(--ink-soft); font-size: 15.5px; line-height: 1.9; margin-bottom: 26px; max-width: 36em; }
.transport { display: flex; align-items: center; gap: 20px; }
.play-btn {
  width: 52px; height: 52px; flex: none;
  border: 1px solid var(--ink);
  border-radius: 50%;
  display: grid; place-items: center;
  transition: background .4s ease, transform .3s var(--ease-out);
}
.play-btn:hover { background: rgba(29,32,27,.06); transform: scale(1.05); }
.play-btn svg { width: 17px; height: 17px; fill: var(--ink); }
.play-btn .ic-pause { display: none; }
.play-btn.playing { background: var(--ink); }
.play-btn.playing svg { fill: var(--paper); }
.play-btn.playing .ic-play { display: none; }
.play-btn.playing .ic-pause { display: block; }

.seek { flex: 1; height: 26px; display: flex; align-items: center; cursor: pointer; }
.seek-rail { position: relative; width: 100%; height: 2px; background: var(--hairline-2); }
.seek-fill {
  position: absolute; inset: 0 auto 0 0;
  width: 0%;
  background: var(--sage-deep);
}
.seek-fill::after {
  content: ""; position: absolute; right: -5px; top: 50%;
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--sage-deep);
  transform: translateY(-50%) scale(0);
  transition: transform .3s var(--ease-out);
}
.seek:hover .seek-fill::after { transform: translateY(-50%) scale(1); }
.times { font-size: 12.5px; color: var(--mute); font-variant-numeric: tabular-nums; letter-spacing: .08em; white-space: nowrap; }

.transport-2 { display: flex; align-items: center; gap: 26px; margin-top: 18px; }
.eq-mini { display: flex; align-items: flex-end; gap: 3px; height: 18px; width: 26px; }
.eq-mini span {
  flex: 1; background: var(--sage); border-radius: 1px;
  height: 30%;
  transform-origin: bottom;
}
.track.playing .eq-mini span { animation: eq-grow 1s ease-in-out infinite alternate; }
.track.playing .eq-mini span:nth-child(1) { animation-delay: 0s; }
.track.playing .eq-mini span:nth-child(2) { animation-delay: .22s; }
.track.playing .eq-mini span:nth-child(3) { animation-delay: .1s; }
.track.playing .eq-mini span:nth-child(4) { animation-delay: .34s; }

.dl-link {
  display: inline-flex; align-items: baseline; gap: 8px;
  font-size: 13.5px; letter-spacing: .16em;
  color: var(--ink);
  border-bottom: 1px solid var(--hairline-2);
  padding-bottom: 3px;
  transition: color .4s, border-color .4s;
}
.dl-link:hover { color: var(--sage-deep); border-color: var(--sage-deep); }
.dl-link svg { width: 12px; height: 12px; fill: currentColor; transform: translateY(1px); }

.license-note {
  margin-top: 24px;
  padding: 16px 18px;
  border-left: 2px solid var(--sand);
  background: rgba(194, 180, 143, .12);
  font-size: 13px; line-height: 1.9;
  color: var(--ink-soft);
}
.license-note a {
  color: var(--sage-deep); font-weight: 600;
  border-bottom: 1px solid rgba(73, 85, 60, .4);
  transition: border-color .4s;
}
.license-note a:hover { border-color: var(--sage-deep); }

/* lyrics */
.lyrics h3 {
  font-size: 12px; letter-spacing: .34em; text-transform: uppercase;
  color: var(--sage-deep); font-weight: 600;
  margin-bottom: 16px;
}
.lyrics h3 .zh-acc { letter-spacing: .3em; color: var(--mute); font-weight: 400; margin-left: 8px; }
.lyrics-body {
  border-top: 1px solid var(--hairline);
  padding-top: 18px;
  font-size: 14.5px; line-height: 2.2;
  color: var(--ink-soft);
  max-height: 300px; overflow-y: auto;
  scrollbar-width: thin;
}
.lyrics-body .none { color: var(--mute); font-style: italic; }
.lyrics-body .lrc-line { transition: color .4s, transform .4s var(--ease-out); }
.lyrics-body .lrc-line.now { color: var(--sage-deep); font-weight: 600; transform: translateX(6px); }

/* empty state */
.lib-empty {
  display: none;
  padding: 90px 0;
  text-align: center;
  color: var(--mute);
}
.lib-empty.show { display: block; }
.lib-empty .big { font-size: 24px; font-style: italic; margin-bottom: 8px; }

/* reveal on scroll (gentle) */
.rise { opacity: 0; transform: translateY(22px); transition: opacity .9s ease, transform .9s var(--ease-out); }
.rise.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition-duration: .01ms !important; }
  .rise { opacity: 1; transform: none; }
}

@media (max-width: 640px) {
  .head-in { gap: 10px; }
  .brand img { height: 32px; }
  .brand-name .zh { display: none; }
  .brand-name .en { font-size: 13px; letter-spacing: .1em; }
  .site-nav { gap: 13px; }
  .nav-link { font-size: 12px; letter-spacing: .1em; white-space: nowrap; padding: 4px 0; }
  .lang-toggle { padding: 4px 10px 3px; font-size: 11px; letter-spacing: .1em; }
  .lib-tools { top: 55px; }
  .chips { gap: 6px 16px; }
  .license-note { padding: 14px; }
}

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-logo img { margin: 40px auto 0; width: min(70vw, 300px); }
  .split { grid-template-columns: 1fr; }
  .panel-in { grid-template-columns: 1fr; padding-left: 4px; }
  .foot-grid { grid-template-columns: 1fr; align-items: start; }
  .foot-eq { justify-content: flex-start; }
  .row-line, .track-head { grid-template-columns: 2.4em minmax(0, 1.4fr) auto 2em; }
  .row-line .meta, .track-head .meta { display: none; }
  .site-nav .nav-link small { display: none; }
  .watermark { width: 90vw; right: -30vw; opacity: .05; }
  .lib-tools { top: 61px; }
}