:root {
  --bg: #f5f5f7;
  --card: rgba(255, 255, 255, 0.86);
  --card-solid: #ffffff;
  --ink: #1d1d1f;
  --ink-2: #424245;
  --ink-3: #86868b;
  --line: rgba(0, 0, 0, 0.08);
  --fill: rgba(118, 118, 128, 0.12);
  --blue: #0071e3;
  --blue-hover: #0077ed;
  --red: #ff3b30;
  --green: #34c759;
  --orange: #ff9500;
  --shadow: 0 1px 1px rgba(0, 0, 0, 0.03), 0 12px 32px rgba(0, 0, 0, 0.06);
  --radius: 22px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --card: rgba(28, 28, 30, 0.86);
    --card-solid: #1c1c1e;
    --ink: #f5f5f7;
    --ink-2: #d1d1d6;
    --ink-3: #8e8e93;
    --line: rgba(255, 255, 255, 0.1);
    --fill: rgba(118, 118, 128, 0.24);
    --blue: #0a84ff;
    --blue-hover: #409cff;
    --red: #ff453a;
    --green: #30d158;
    --orange: #ff9f0a;
    --shadow: 0 1px 1px rgba(0, 0, 0, 0.4), 0 12px 32px rgba(0, 0, 0, 0.35);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: var(--font); background: var(--bg); color: var(--ink);
  line-height: 1.5; -webkit-font-smoothing: antialiased; min-height: 100vh;
  display: flex; flex-direction: column;
}
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible { outline: 3px solid color-mix(in srgb, var(--blue) 45%, transparent); outline-offset: 2px; }
[hidden] { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

/* 顶栏：毛玻璃 */
.topbar {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 max(16px, calc((100vw - 880px) / 2)); height: 52px;
  background: color-mix(in srgb, var(--bg) 72%, transparent);
  backdrop-filter: saturate(180%) blur(20px); -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 600; font-size: 15px; }
.brand:hover { text-decoration: none; }
.brand-mark {
  width: 28px; height: 28px; border-radius: 8px; display: grid; place-items: center;
  background: linear-gradient(135deg, #5e5ce6, #0a84ff); color: #fff; font-size: 15px;
}
.topbar-links { display: flex; gap: 18px; font-size: 13px; }
.topbar-links a { color: var(--ink-3); }
.topbar-links a:hover { color: var(--ink); text-decoration: none; }

.page { width: 100%; max-width: 880px; margin: 0 auto; padding: 48px 16px 64px; flex: 1; }
.intro { text-align: center; margin-bottom: 32px; }
.intro h1 { font-size: clamp(28px, 5vw, 40px); font-weight: 700; letter-spacing: -0.02em; line-height: 1.15; }
.intro p { color: var(--ink-3); font-size: 16px; margin: 14px auto 0; max-width: 560px; }
.br-mobile { display: none; }

.card {
  background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow);
  border: 1px solid var(--line);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
}

/* 输入 */
.composer { padding: 6px; }
.composer textarea {
  width: 100%; border: none; resize: vertical; min-height: 128px; background: transparent;
  font: inherit; font-size: 17px; line-height: 1.7; color: var(--ink); padding: 16px 18px; border-radius: 16px;
}
.composer textarea:focus { outline: none; background: var(--fill); }
.composer textarea::placeholder { color: var(--ink-3); }
.composer-foot { display: flex; align-items: flex-end; gap: 12px; padding: 8px 10px 10px 12px; flex-wrap: wrap; }
.samples { display: flex; gap: 8px; flex-wrap: wrap; flex: 1; min-width: 0; }
.chip {
  border: none; background: var(--fill); color: var(--ink-2); font: inherit; font-size: 12.5px;
  padding: 6px 12px; border-radius: 999px; cursor: pointer; max-width: 100%;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; transition: background .2s, transform .1s;
}
.chip:hover { background: color-mix(in srgb, var(--blue) 14%, transparent); color: var(--blue); }
.chip:active { transform: scale(0.97); }
.actions { display: flex; align-items: center; gap: 14px; margin-left: auto; }
.counter { font-size: 12px; color: var(--ink-3); font-variant-numeric: tabular-nums; }

.btn-primary {
  position: relative; border: none; cursor: pointer; font: inherit; font-size: 15px; font-weight: 600;
  color: #fff; background: var(--blue); padding: 10px 26px; border-radius: 999px; min-width: 92px;
  transition: background .2s, transform .1s, opacity .2s;
}
.btn-primary:hover { background: var(--blue-hover); }
.btn-primary:active { transform: scale(0.97); }
.btn-primary:disabled { opacity: .6; cursor: progress; }
.spinner {
  display: none; position: absolute; inset: 0; margin: auto; width: 18px; height: 18px;
  border: 2px solid rgba(255, 255, 255, .35); border-top-color: #fff; border-radius: 50%;
  animation: spin .8s linear infinite;
}
.btn-primary.loading .btn-label { visibility: hidden; }
.btn-primary.loading .spinner { display: block; }
@keyframes spin { to { transform: rotate(360deg); } }
.btn-ghost {
  border: none; background: var(--fill); color: var(--blue); font: inherit; font-size: 13px; font-weight: 500;
  padding: 5px 12px; border-radius: 999px; cursor: pointer;
}
.btn-ghost:hover { background: color-mix(in srgb, var(--blue) 14%, transparent); }

.error {
  margin-top: 16px; padding: 12px 16px; border-radius: 14px; font-size: 14px;
  background: color-mix(in srgb, var(--red) 12%, transparent); color: var(--red);
}

/* 结果 */
.results { display: grid; gap: 16px; margin-top: 20px; }
.results .card { padding: 22px 24px 24px; animation: rise .5s cubic-bezier(.2, .8, .2, 1) both; }
.results .card:nth-child(2) { animation-delay: .06s; }
@keyframes rise { from { opacity: 0; transform: translateY(14px) scale(.99); } to { opacity: 1; transform: none; } }
.card-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 14px; }
.card-head h2 { font-size: 13px; font-weight: 600; color: var(--ink-3); letter-spacing: .02em; }

/* 注音：每个字一列，拼音居中在字的正上方，整齐成行 */
.ruby-text { display: flex; flex-wrap: wrap; align-items: flex-end; row-gap: 14px; font-size: 24px; line-height: 1.2; color: var(--ink); }
.ruby-text ruby { display: inline-flex; flex-direction: column-reverse; align-items: center; min-width: 1.15em; padding: 0 2px; }
.ruby-text rt { display: block; font-size: 12px; line-height: 1.4; color: var(--blue); font-weight: 500; letter-spacing: 0; white-space: nowrap; }
.ruby-text .plain { color: var(--ink-2); white-space: pre-wrap; }

.pill { font-size: 13px; font-weight: 600; padding: 4px 12px; border-radius: 999px; background: var(--fill); }
.pill.pos { background: color-mix(in srgb, var(--green) 16%, transparent); color: var(--green); }
.pill.neg { background: color-mix(in srgb, var(--red) 14%, transparent); color: var(--red); }
.pill.mid { background: color-mix(in srgb, var(--orange) 16%, transparent); color: var(--orange); }

.gauge { margin: 6px 0 14px; }
.gauge-track {
  position: relative; height: 10px; border-radius: 999px;
  background: linear-gradient(90deg, var(--red), var(--orange) 50%, var(--green));
}
.gauge-thumb {
  position: absolute; top: 50%; left: 50%; width: 22px; height: 22px; border-radius: 50%;
  background: var(--card-solid); border: 3px solid var(--ink); transform: translate(-50%, -50%);
  box-shadow: 0 2px 8px rgba(0, 0, 0, .2); transition: left .9s cubic-bezier(.2, .8, .2, 1);
}
.gauge-scale { display: flex; justify-content: space-between; font-size: 12px; color: var(--ink-3); margin-top: 8px; }
.score-line { font-size: 15px; color: var(--ink-2); }
.score-line strong { font-size: 22px; font-variant-numeric: tabular-nums; color: var(--ink); margin: 0 4px; }
.hint { font-size: 12.5px; color: var(--ink-3); }

.sentences { list-style: none; margin-top: 18px; display: grid; gap: 2px; }
.sentences:empty { display: none; }
.sentences li {
  display: grid; grid-template-columns: 1fr 120px 48px; align-items: center; gap: 14px;
  padding: 10px 12px; border-radius: 12px; font-size: 14.5px;
}
.sentences li:nth-child(odd) { background: var(--fill); }
.sent-bar { height: 6px; border-radius: 999px; background: var(--line); overflow: hidden; }
.sent-bar span { display: block; height: 100%; border-radius: inherit; transition: width .8s cubic-bezier(.2, .8, .2, 1); }
.sent-score { text-align: right; font-variant-numeric: tabular-nums; color: var(--ink-3); font-size: 13px; }

.footer { text-align: center; font-size: 12px; color: var(--ink-3); padding: 24px 16px 32px; }

@media (max-width: 600px) {
  .page { padding-top: 32px; }
  .br-mobile { display: inline; }
  .actions { width: 100%; justify-content: space-between; }
  .ruby-text { font-size: 21px; }
  .sentences li { grid-template-columns: 1fr 64px 40px; gap: 10px; }
  .results .card { padding: 18px; }
}
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}