/* ============================================================================
   KOKO Music — Australian design system
   Green & gold (eucalyptus + golden wattle) · warm bone canvas · charcoal ink
   Mascot: KOKO the koala. Tokens + primitives + app shell.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght@0,9..144,400..700;1,9..144,400..600&family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=Noto+Sans+SC:wght@400;500;700&display=swap');

:root {
  /* ---- surfaces (warm bone paper) ---- */
  --paper:    #F4ECDD;
  --paper-2:  #FBF5E9;
  --paper-3:  #FFFDF8;
  --paper-sink: #EDE3D0;

  /* ---- ink (charcoal, from KOKO's glasses) ---- */
  --ink:   #221F1A;
  --ink-2: #4B453B;
  --ink-3: #857C6C;
  --ink-on: #FBF5E9;            /* text on dark/brand */
  --line:  rgba(34,31,26,.10);
  --line-2:rgba(34,31,26,.06);

  /* ---- eucalyptus (primary brand green) ---- */
  --euc:      #2E5E4E;
  --euc-700:  #244C40;
  --euc-600:  #35705C;
  --euc-500:  #4C8F72;
  --euc-300:  #8FBFA3;
  --euc-tint: #E4EEE4;
  --euc-tint-2:#D3E4D6;

  /* ---- golden wattle (primary accent) ---- */
  --gold:      #E6A62B;
  --gold-600:  #D08E16;
  --gold-400:  #F0BD54;
  --gold-tint: #F8E9C1;

  /* ---- red-earth terracotta (secondary accent) ---- */
  --terra:      #C4562E;
  --terra-600:  #AC4622;
  --terra-tint: #F3DACB;

  /* ---- denim (KOKO's overalls) ---- */
  --denim:      #3D5A78;
  --denim-500:  #4C6E90;
  --denim-tint: #DCE6EF;

  /* ---- semantic ---- */
  --brand: var(--euc);
  --accent: var(--gold);
  --bg: var(--paper);
  --text: var(--ink);
  --ok: #3E7D52;
  --ok-tint: #E1EFDF;
  --warn: var(--gold-600);
  --danger: #C0402F;
  --danger-tint: #F5D9D2;

  /* ---- radii ---- */
  --r-xs: 8px;
  --r-sm: 12px;
  --r:    16px;
  --r-lg: 24px;
  --r-xl: 32px;
  --r-pill: 999px;

  /* ---- shadows (warm-tinted, layered — never flat gray) ---- */
  --shadow-xs: 0 1px 2px rgba(34,31,26,.05);
  --shadow-sm: 0 1px 2px rgba(34,31,26,.06), 0 3px 8px -2px rgba(34,31,26,.06);
  --shadow:    0 4px 14px -2px rgba(34,31,26,.10), 0 2px 5px -1px rgba(34,31,26,.06);
  --shadow-lg: 0 22px 48px -16px rgba(36,76,64,.30), 0 8px 20px -8px rgba(34,31,26,.12);
  --shadow-gold: 0 14px 34px -10px rgba(230,166,43,.50);
  --shadow-euc:  0 16px 40px -14px rgba(46,94,78,.42);

  /* ---- motion ---- */
  --ease-spring: cubic-bezier(.34,1.4,.5,1);
  --ease-out:    cubic-bezier(.16,1,.3,1);
  --t-fast: .16s;
  --t:      .26s;
  --t-slow: .5s;

  /* ---- type ---- */
  --font-display: 'Fraunces', 'Noto Sans SC', Georgia, serif;
  --font-ui: 'Plus Jakarta Sans', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: ui-monospace, 'SF Mono', 'Cascadia Code', Menlo, monospace;

  /* ---- layout ---- */
  --nav-h: 68px;
  --wrap: 1120px;
  --wrap-narrow: 760px;

  /* ---- paper grain (subtle) ---- */
  --grain: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.4'/%3E%3C/svg%3E");
}

/* ============================ base ============================ */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
html, body { max-width: 100vw; overflow-x: clip; }
@supports not (overflow: clip) { html, body { overflow-x: hidden; } }

body {
  margin: 0;
  min-height: 100dvh;
  font-family: var(--font-ui);
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    radial-gradient(1200px 620px at 12% -8%, rgba(76,143,114,.16), transparent 60%),
    radial-gradient(1000px 560px at 108% 4%, rgba(230,166,43,.14), transparent 58%),
    radial-gradient(900px 700px at 50% 118%, rgba(61,90,120,.10), transparent 60%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
/* faint paper grain over everything */
body::before {
  content: ""; position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image: var(--grain); opacity: .5; mix-blend-mode: multiply;
}
body > * { position: relative; z-index: 1; }

img, svg, video { max-width: 100%; height: auto; display: block; }
button { font-family: inherit; cursor: pointer; }
a { color: var(--euc-600); text-decoration: none; transition: color var(--t-fast); }
a:hover { color: var(--euc); }
::selection { background: var(--gold-tint); color: var(--ink); }

h1,h2,h3,h4 { font-family: var(--font-display); font-weight: 600; line-height: 1.1; letter-spacing: -.02em; color: var(--ink); margin: 0; }
:lang(zh) h1, :lang(zh) h2, :lang(zh) h3 { letter-spacing: 0; }

/* focus ring — accessible, on-brand */
:focus-visible { outline: 3px solid var(--gold-400); outline-offset: 2px; border-radius: 6px; }

/* thin scrollbar */
* { scrollbar-width: thin; scrollbar-color: var(--euc-300) transparent; }
*::-webkit-scrollbar { width: 9px; height: 9px; }
*::-webkit-scrollbar-thumb { background: var(--euc-300); border-radius: 9px; border: 2px solid transparent; background-clip: content-box; }
*::-webkit-scrollbar-thumb:hover { background: var(--euc-500); }

/* ============================ layout ============================ */
.wrap { width: 100%; max-width: var(--wrap); margin-inline: auto; padding-inline: clamp(16px, 4vw, 32px); }
.wrap-narrow { max-width: var(--wrap-narrow); }
.stack > * + * { margin-top: var(--gap, 16px); }
.hide { display: none !important; }
@media (max-width: 680px){ .sm-hide { display: none !important; } }

/* ============================ buttons ============================ */
.btn {
  --_bg: var(--euc); --_fg: var(--ink-on);
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 20px; border: 0; border-radius: var(--r-pill);
  font-family: var(--font-ui); font-weight: 700; font-size: 14.5px; letter-spacing: .01em;
  color: var(--_fg); background: var(--_bg);
  box-shadow: var(--shadow-sm);
  transition: transform var(--t-fast) var(--ease-spring), box-shadow var(--t), background var(--t), filter var(--t);
  -webkit-tap-highlight-color: transparent; white-space: nowrap; text-decoration: none;
}
.btn:hover { transform: translateY(-2px); box-shadow: var(--shadow-euc); filter: brightness(1.04); color: var(--_fg); }
.btn:active { transform: translateY(0) scale(.98); }
.btn:disabled, .btn[aria-disabled="true"] { opacity: .5; pointer-events: none; box-shadow: none; }
.btn svg { width: 18px; height: 18px; }

.btn-gold  { --_bg: var(--gold); --_fg: #3a2c05; }
.btn-gold:hover { box-shadow: var(--shadow-gold); }
.btn-terra { --_bg: var(--terra); --_fg: #fff; }
.btn-denim { --_bg: var(--denim); --_fg: #fff; }
.btn-ink   { --_bg: var(--ink); --_fg: var(--paper-2); }

.btn-ghost {
  background: transparent; color: var(--ink-2); box-shadow: none;
  border: 1.5px solid var(--line);
}
.btn-ghost:hover { background: var(--euc-tint); color: var(--euc-700); border-color: var(--euc-300); box-shadow: var(--shadow-sm); }

.btn-soft { background: var(--euc-tint); color: var(--euc-700); box-shadow: none; }
.btn-soft:hover { background: var(--euc-tint-2); box-shadow: var(--shadow-sm); color: var(--euc-700); }

.btn-lg { padding: 15px 30px; font-size: 16px; }
.btn-sm { padding: 8px 14px; font-size: 13px; }
.btn-icon { padding: 10px; border-radius: var(--r-pill); }
.btn-block { display: flex; width: 100%; }

/* icon-only ghost action (used in cards) */
.iconbtn {
  display: inline-grid; place-items: center; width: 38px; height: 38px;
  border-radius: var(--r-pill); border: 0; background: transparent; color: var(--ink-3);
  transition: background var(--t-fast), color var(--t-fast), transform var(--t-fast);
}
.iconbtn:hover { background: var(--euc-tint); color: var(--euc-700); transform: translateY(-1px); }
.iconbtn svg { width: 19px; height: 19px; }
.iconbtn.is-active { color: var(--gold-600); }

/* ============================ cards & surfaces ============================ */
.card {
  background: var(--paper-3); border: 1px solid var(--line);
  border-radius: var(--r-lg); box-shadow: var(--shadow); padding: clamp(18px, 3vw, 28px);
}
.card-flat { background: var(--paper-2); box-shadow: var(--shadow-xs); }
.panel { background: var(--paper-3); border: 1px solid var(--line); border-radius: var(--r-lg); box-shadow: var(--shadow-sm); }

/* eyebrow label */
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12px; font-weight: 700; letter-spacing: .14em; text-transform: uppercase;
  color: var(--euc-600);
}
.eyebrow::before { content: ""; width: 22px; height: 2px; border-radius: 2px; background: var(--gold); }

/* ============================ chips / tags ============================ */
.chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 15px; border-radius: var(--r-pill);
  background: var(--paper-2); color: var(--ink-2); border: 1.5px solid var(--line);
  font-size: 13.5px; font-weight: 600; cursor: pointer; white-space: nowrap;
  transition: all var(--t-fast) var(--ease-out);
}
.chip:hover { border-color: var(--euc-300); background: var(--euc-tint); color: var(--euc-700); transform: translateY(-1px); }
.chip.is-active, .chip[aria-pressed="true"] {
  background: var(--euc); color: var(--ink-on); border-color: var(--euc);
  box-shadow: var(--shadow-sm);
}

.badge {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 3px 10px; border-radius: var(--r-pill);
  font-size: 11.5px; font-weight: 700; letter-spacing: .02em;
  background: var(--gold-tint); color: var(--gold-600);
}
.badge-euc { background: var(--euc-tint); color: var(--euc-700); }
.badge-denim { background: var(--denim-tint); color: var(--denim); }
.badge-terra { background: var(--terra-tint); color: var(--terra-600); }
.badge-demo { background: var(--paper-sink); color: var(--ink-3); }

/* ============================ inputs ============================ */
.field { display: block; margin-bottom: 4px; }
.label {
  display: block; font-size: 13px; font-weight: 700; color: var(--ink-2);
  margin-bottom: 8px; letter-spacing: .01em;
}
.input, .textarea, .select {
  width: 100%; font-family: var(--font-ui); font-size: 15px; color: var(--ink);
  background: var(--paper-2); border: 1.5px solid var(--line);
  border-radius: var(--r); padding: 13px 16px; transition: border-color var(--t-fast), box-shadow var(--t-fast), background var(--t-fast);
}
.input::placeholder, .textarea::placeholder { color: var(--ink-3); }
.input:focus, .textarea:focus, .select:focus {
  outline: none; border-color: var(--euc-500); background: var(--paper-3);
  box-shadow: 0 0 0 4px var(--euc-tint);
}
.textarea { resize: vertical; min-height: 120px; line-height: 1.65; }
.select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='20' height='20' viewBox='0 0 24 24' fill='none' stroke='%23857C6C' stroke-width='2.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 14px center; padding-right: 42px;
}

/* toggle switch */
.switch { position: relative; display: inline-flex; align-items: center; gap: 10px; cursor: pointer; user-select: none; }
.switch input { position: absolute; opacity: 0; width: 0; height: 0; }
.switch .track {
  width: 46px; height: 27px; border-radius: var(--r-pill); background: var(--paper-sink);
  border: 1.5px solid var(--line); transition: background var(--t), border-color var(--t); flex: none;
}
.switch .track::after {
  content: ""; position: absolute; top: 4px; left: 4px; width: 21px; height: 21px;
  border-radius: 50%; background: #fff; box-shadow: var(--shadow-sm);
  transition: transform var(--t) var(--ease-spring);
}
.switch input:checked + .track { background: var(--euc); border-color: var(--euc); }
.switch input:checked + .track::after { transform: translateX(19px); }

/* segmented control (mode toggle 傻瓜/专业) */
.segment { display: inline-flex; padding: 5px; gap: 4px; background: var(--paper-sink); border-radius: var(--r-pill); border: 1px solid var(--line-2); }
.segment button {
  border: 0; background: transparent; color: var(--ink-2); font-weight: 700; font-size: 14px;
  padding: 9px 20px; border-radius: var(--r-pill); transition: all var(--t) var(--ease-out); white-space: nowrap;
}
.segment button.is-active { background: var(--paper-3); color: var(--euc-700); box-shadow: var(--shadow-sm); }

/* ============================ app shell: nav ============================ */
.nav {
  position: sticky; top: 0; z-index: 100; height: var(--nav-h);
  background: color-mix(in srgb, var(--paper-2) 82%, transparent);
  backdrop-filter: blur(16px) saturate(1.3); -webkit-backdrop-filter: blur(16px) saturate(1.3);
  border-bottom: 1px solid var(--line);
}
.nav-inner { height: 100%; display: flex; align-items: center; gap: 18px; }
.brand { display: inline-flex; align-items: center; gap: 11px; margin-right: auto; }
.brand-badge {
  width: 42px; height: 42px; border-radius: 13px; flex: none;
  background: radial-gradient(120% 120% at 30% 20%, var(--euc-500), var(--euc-700));
  display: grid; place-items: center; box-shadow: var(--shadow-euc); overflow: hidden;
  border: 1.5px solid rgba(255,255,255,.14);
}
.brand-badge img { width: 128%; height: auto; margin-top: 16%; filter: drop-shadow(0 2px 3px rgba(0,0,0,.25)); }
.brand-text { display: flex; flex-direction: column; gap: 2px; line-height: 1.05; }
.brand-name { font-family: var(--font-display); font-weight: 600; font-size: 21px; letter-spacing: -.02em; color: var(--ink); line-height: 1; }
.brand-name b { color: var(--euc); font-weight: 600; }
.brand-sub { font-size: 11px; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--ink-3); }

.nav-tabs { display: flex; gap: 4px; }
.nav-tab {
  display: inline-flex; align-items: center; gap: 7px; padding: 9px 15px; border-radius: var(--r-pill);
  color: var(--ink-2); font-weight: 600; font-size: 14px; background: transparent; border: 0;
  transition: all var(--t-fast) var(--ease-out);
}
.nav-tab svg { width: 17px; height: 17px; opacity: .8; }
.nav-tab:hover { background: var(--euc-tint); color: var(--euc-700); }
.nav-tab.is-active { background: var(--euc); color: var(--ink-on); box-shadow: var(--shadow-sm); }
.nav-tab.is-active svg { opacity: 1; }

.nav-right { display: flex; align-items: center; gap: 10px; }
.credits-pill {
  display: inline-flex; align-items: center; gap: 7px; padding: 7px 14px; border-radius: var(--r-pill);
  background: var(--gold-tint); color: var(--gold-600); font-weight: 700; font-size: 13.5px;
  border: 1.5px solid color-mix(in srgb, var(--gold) 34%, transparent);
}
.credits-pill svg { width: 15px; height: 15px; }
.lang-toggle {
  display: inline-flex; align-items: center; gap: 4px; padding: 7px 12px; border-radius: var(--r-pill);
  background: transparent; border: 1.5px solid var(--line); color: var(--ink-2); font-weight: 700; font-size: 13px;
  transition: all var(--t-fast);
}
.lang-toggle:hover { border-color: var(--euc-300); color: var(--euc-700); background: var(--euc-tint); }

/* mobile bottom tab bar */
.tabbar { display: none; }
@media (max-width: 860px) {
  .nav-tabs { display: none; }
  .tabbar {
    display: flex; position: fixed; bottom: 0; left: 0; right: 0; z-index: 100;
    background: color-mix(in srgb, var(--paper-2) 92%, transparent);
    backdrop-filter: blur(16px); border-top: 1px solid var(--line);
    padding: 8px 6px calc(8px + env(safe-area-inset-bottom));
    justify-content: space-around;
  }
  .tabbar .nav-tab { flex-direction: column; gap: 3px; font-size: 10.5px; padding: 4px 8px; border-radius: var(--r-sm); }
  .tabbar .nav-tab svg { width: 21px; height: 21px; }
  .tabbar .nav-tab.is-active { background: transparent; color: var(--euc); }
  main.app-main { padding-bottom: 96px; }
}

/* ============================ footer ============================ */
.foot { border-top: 1px solid var(--line); margin-top: 64px; padding: 28px 0; }
.foot-inner { display: flex; flex-wrap: wrap; gap: 12px 20px; align-items: center; justify-content: space-between; }
.foot .brand-name { font-size: 16px; }
.foot small { color: var(--ink-3); font-size: 12.5px; }

/* ============================ toasts ============================ */
.toast-wrap { position: fixed; top: calc(var(--nav-h) + 12px); right: 16px; z-index: 300; display: flex; flex-direction: column; gap: 10px; max-width: 360px; }
.toast {
  display: flex; align-items: flex-start; gap: 11px; padding: 13px 16px; border-radius: var(--r);
  background: var(--paper-3); border: 1px solid var(--line); box-shadow: var(--shadow-lg);
  font-size: 14px; font-weight: 500; color: var(--ink); animation: toastIn .34s var(--ease-spring);
  border-left: 4px solid var(--euc);
}
.toast.is-error { border-left-color: var(--danger); }
.toast.is-success { border-left-color: var(--ok); }
.toast.is-warn { border-left-color: var(--gold); }
.toast .t-ico { flex: none; width: 20px; height: 20px; margin-top: 1px; }
@keyframes toastIn { from { opacity: 0; transform: translateX(24px) scale(.96); } to { opacity: 1; transform: none; } }
@keyframes toastOut { to { opacity: 0; transform: translateX(24px) scale(.96); } }

/* ============================ modal ============================ */
.modal-backdrop {
  position: fixed; inset: 0; z-index: 250; display: grid; place-items: center; padding: 20px;
  background: rgba(28,25,20,.5); backdrop-filter: blur(4px); animation: fade .2s var(--ease-out);
}
.modal {
  width: 100%; max-width: 480px; background: var(--paper-3); border-radius: var(--r-xl);
  box-shadow: var(--shadow-lg); border: 1px solid var(--line); padding: 28px;
  animation: modalIn .32s var(--ease-spring);
}
.modal h3 { font-size: 22px; margin-bottom: 8px; }
.modal-actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 22px; }
@keyframes fade { from { opacity: 0; } }
@keyframes modalIn { from { opacity: 0; transform: translateY(16px) scale(.96); } }

/* ============================ spinner / loading ============================ */
.spinner { width: 20px; height: 20px; border-radius: 50%; border: 2.5px solid var(--euc-tint-2); border-top-color: var(--euc); animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* equalizer bars (music loading) */
.eq { display: inline-flex; align-items: flex-end; gap: 3px; height: 22px; }
.eq span { width: 4px; border-radius: 3px; background: var(--euc); animation: eq 1s ease-in-out infinite; }
.eq span:nth-child(1){ animation-delay: -.9s } .eq span:nth-child(2){ animation-delay: -.7s; background: var(--gold) }
.eq span:nth-child(3){ animation-delay: -.5s } .eq span:nth-child(4){ animation-delay: -.3s; background: var(--terra) }
.eq span:nth-child(5){ animation-delay: -.1s }
@keyframes eq { 0%,100%{ height: 5px } 50%{ height: 22px } }

/* skeleton shimmer */
.skel { background: linear-gradient(100deg, var(--paper-sink) 30%, var(--paper-2) 50%, var(--paper-sink) 70%); background-size: 200% 100%; animation: shimmer 1.4s infinite; border-radius: var(--r-sm); }
@keyframes shimmer { to { background-position: -200% 0; } }

/* ============================ empty state (mascot) ============================ */
.empty { text-align: center; padding: 48px 20px; }
.empty img.koko { width: min(210px, 52vw); margin: 0 auto 18px; filter: drop-shadow(0 18px 24px rgba(46,94,78,.25)); animation: bob 4s ease-in-out infinite; }
.empty h3 { font-size: 22px; margin-bottom: 8px; }
.empty p { color: var(--ink-3); max-width: 400px; margin: 0 auto 20px; }
@keyframes bob { 0%,100%{ transform: translateY(0) rotate(-.5deg) } 50%{ transform: translateY(-10px) rotate(.5deg) } }

/* ============================ helpers ============================ */
.muted { color: var(--ink-3); }
.mono { font-family: var(--font-mono); }
.divider { height: 1px; background: var(--line); border: 0; margin: 20px 0; }
.wave-rule { height: 8px; background: repeating-linear-gradient(90deg, var(--euc-300) 0 6px, transparent 6px 12px); mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='40' height='8'%3E%3Cpath d='M0 4 Q5 0 10 4 T20 4 T30 4 T40 4' fill='none' stroke='%23000' stroke-width='2'/%3E%3C/svg%3E") repeat-x; opacity: .5; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; scroll-behavior: auto !important; }
}