:root {
  color-scheme: light dark;
  --fg: #1c1c1e;
  --fg-dim: #6b6b70;
  --bg: #ffffff;
  --card: #f5f5f7;
  --line: #e3e3e8;
  --accent: #2e7dff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --fg: #f2f2f5;
    --fg-dim: #9a9aa1;
    --bg: #121214;
    --card: #1c1c1f;
    --line: #2c2c31;
    --accent: #6aa8ff;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.75 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 56px 22px 8px;
}

.hero { padding-bottom: 8px; }

h1 {
  margin: 0;
  font-size: 2.2rem;
  letter-spacing: -0.02em;
}

.tagline {
  margin: 6px 0 22px;
  color: var(--accent);
  font-size: 1rem;
  letter-spacing: 0.02em;
}

.lead { font-size: 1.02rem; }

h2 {
  margin: 44px 0 14px;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
}

p { margin: 0 0 14px; }

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover { text-decoration: underline; }

.features {
  margin: 0;
  padding: 0;
  list-style: none;
}

.features li {
  padding: 12px 16px;
  margin-bottom: 8px;
  background: var(--card);
  border-radius: 12px;
  font-size: 0.96rem;
}

.btn {
  display: inline-block;
  margin-top: 8px;
  padding: 12px 22px;
  background: var(--accent);
  color: #fff;
  border-radius: 999px;
  font-size: 0.98rem;
  font-weight: 600;
}

.btn:hover { text-decoration: none; opacity: 0.92; }

.note {
  display: inline-block;
  margin-top: 8px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--fg-dim);
  font-size: 0.9rem;
}

footer {
  max-width: 720px;
  margin: 48px auto 0;
  padding: 22px;
  border-top: 1px solid var(--line);
  text-align: center;
  font-size: 0.88rem;
}

footer p { margin: 6px 0; }

.muted {
  color: var(--fg-dim);
  font-size: 0.82rem;
}

/* ---- 法律文本页 ---- */

.doc { max-width: 720px; }

.doc .doc-meta {
  color: var(--fg-dim);
  font-size: 0.85rem;
  margin-bottom: 28px;
}

.doc h2 {
  margin: 34px 0 10px;
  font-size: 1.05rem;
}

.doc p {
  font-size: 0.96rem;
  color: var(--fg);
}

.doc .intro {
  padding: 14px 16px;
  background: var(--card);
  border-radius: 12px;
  font-size: 0.92rem;
  color: var(--fg-dim);
}

.doc .back {
  display: inline-block;
  margin-top: 32px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  width: 100%;
}

/* ==================== 首页：图标 + 界面示意 ==================== */

.app-icon {
  display: block;
  width: 84px;
  height: 84px;
  border-radius: 22px;
  margin-bottom: 18px;
  box-shadow: 0 8px 26px rgba(46, 125, 255, 0.22);
}

.phones {
  display: flex;
  gap: 16px;
  padding: 4px 2px 10px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.phones::-webkit-scrollbar { height: 6px; }
.phones::-webkit-scrollbar-thumb { background: var(--line); border-radius: 3px; }

.phone {
  flex: 0 0 208px;
  margin: 0;
  scroll-snap-align: center;
}

.phone .screen {
  position: relative;
  width: 100%;
  aspect-ratio: 9 / 19.2;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: #ffffff;
  color: #1c1c1e;
  border: 8px solid #17171b;
  border-radius: 30px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.18);
  font-size: 12px;
  line-height: 1.45;
}

.phone figcaption {
  margin-top: 10px;
  text-align: center;
  font-size: 0.78rem;
  color: var(--fg-dim);
}

.fig-note {
  margin: 6px 0 0;
  text-align: center;
  font-size: 0.76rem;
  color: var(--fg-dim);
}

.statusbar {
  display: flex;
  justify-content: space-between;
  padding: 9px 15px 0;
  font-size: 9px;
  color: #9a9aa1;
  letter-spacing: 0.02em;
}

.sbar-right { letter-spacing: 1px; }

/* ---- 屏幕一：词汇 ---- */

.app-head { padding: 8px 16px 2px; }
.app-head h3 { margin: 0; font-size: 19px; letter-spacing: -0.02em; }
.app-head p { margin: 3px 0 0; font-size: 10.5px; color: #8a8a90; }

.stat-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 4px;
  margin: 12px 14px 0;
  padding: 10px 6px;
  background: #f5f6f9;
  border-radius: 14px;
  text-align: center;
}

.stat b { display: block; font-size: 16px; letter-spacing: -0.02em; }
.stat span { font-size: 9.5px; color: #8a8a90; }

.cta {
  margin: 12px 14px 0;
  padding: 10px;
  border-radius: 12px;
  background: linear-gradient(135deg, #2e7dff, #5f9dff);
  color: #fff;
  font-weight: 600;
  font-size: 12.5px;
  text-align: center;
}

.mini-card {
  margin: 12px 14px 0;
  padding: 10px 12px 8px;
  border: 1px solid #eef0f4;
  border-radius: 14px;
}

.mini-title { font-size: 10.5px; color: #8a8a90; }

.bars {
  display: flex;
  align-items: flex-end;
  gap: 6px;
  height: 40px;
  margin: 8px 0 6px;
}

.bars i {
  flex: 1;
  border-radius: 4px 4px 2px 2px;
  background: linear-gradient(180deg, #7fb0ff, #2e7dff);
}

.mini-foot { font-size: 9.5px; color: #a0a0a6; }

.tabbar {
  display: flex;
  justify-content: space-around;
  margin-top: auto;
  padding: 8px 4px 12px;
  border-top: 1px solid #f0f0f3;
  font-size: 9px;
  color: #9a9aa1;
}

.tabbar span {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.tabbar svg {
  width: 17px;
  height: 17px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.tabbar .on { color: #2e7dff; }

/* ---- 屏幕二：单词卡 ---- */

.word-card {
  margin: 18px 14px 0;
  padding: 18px 14px 14px;
  border-radius: 18px;
  background: linear-gradient(160deg, #f3f7ff, #eef1f8);
  text-align: center;
}

.word { font-size: 25px; font-weight: 700; letter-spacing: -0.02em; }
.phonetic { margin-top: 4px; font-size: 11.5px; color: #8a8a90; }
.def { margin-top: 10px; font-size: 12.5px; }

.wave {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 3px;
  height: 32px;
  margin: 12px 0 4px;
}

.wave i {
  width: 4px;
  border-radius: 3px;
  background: #2e7dff;
  opacity: 0.7;
}

.score { font-size: 10.5px; color: #8a8a90; }
.score b { font-size: 13px; color: #2e7dff; }

.opt-list {
  display: grid;
  gap: 8px;
  margin: 14px 14px 0;
}

.opt {
  padding: 10px 12px;
  border-radius: 12px;
  background: #f5f6f9;
  font-size: 11.5px;
}

.opt:first-child {
  background: #eef4ff;
  box-shadow: inset 0 0 0 1.5px #2e7dff;
}

.hint { margin-top: 12px; text-align: center; font-size: 9.5px; color: #a0a0a6; }

/* ---- 屏幕三：我 ---- */

.profile-card {
  display: flex;
  align-items: center;
  gap: 11px;
  margin: 16px 14px 0;
  padding: 12px;
  background: #f5f6f9;
  border-radius: 16px;
}

.avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 25%, #7fb0ff, #2e7dff 70%);
  box-shadow: inset 0 0 0 2px rgba(255, 255, 255, 0.55),
              inset 0 0 0 8px rgba(255, 255, 255, 0.16);
  flex: 0 0 auto;
}

.profile-text b { display: block; font-size: 12.5px; }
.profile-text span { display: block; margin-top: 2px; font-size: 9.5px; color: #8a8a90; }

.rows {
  margin: 12px 14px 0;
  border: 1px solid #eef0f4;
  border-radius: 14px;
  overflow: hidden;
}

.row {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 9px 12px;
  font-size: 11.5px;
  border-bottom: 1px solid #f3f5f8;
}

.row:last-child { border-bottom: 0; }

.ic {
  width: 16px;
  height: 16px;
  border-radius: 5px;
  flex: 0 0 auto;
  opacity: 0.9;
}

.chev { margin-left: auto; color: #bfc2c9; font-size: 13px; }

@media (max-width: 620px) {
  .phone { flex: 0 0 216px; }
}