:root{
  --ink:#0f2233; --muted:#5b7086; --faint:#8a9bad;
  --line:#e4ebf1; --line-soft:#eef3f7;
  --accent:#0e7c7b; --accent-2:#0a5c68; --accent-soft:#e7f4f3;
  --amber:#b3730a; --amber-soft:#fdf3e0;
  --good:#0f7a4f; --good-soft:#e7f6ee;
  --danger:#c0392b;
  --bg:#eef2f5; --card:#ffffff;
  --shadow:0 1px 2px rgba(16,40,60,.04), 0 8px 24px -12px rgba(16,40,60,.14);
  --radius:16px;
  --appbar-h:52px; --tabbar-h:60px;
  --safe-top:env(safe-area-inset-top,0px);
  --safe-bottom:env(safe-area-inset-bottom,0px);
}
*{box-sizing:border-box; -webkit-tap-highlight-color:transparent;}
html,body{margin:0; height:100%;}
body{
  color:var(--ink);
  background:
    radial-gradient(1200px 600px at 100% -10%, #dcefee 0%, transparent 55%),
    radial-gradient(900px 500px at -10% 0%, #e6ecf7 0%, transparent 45%),
    var(--bg);
  background-attachment:fixed;
  font:16px/1.6 system-ui,-apple-system,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;
  -webkit-font-smoothing:antialiased;
  overscroll-behavior-y:none;
}
button{font:inherit; color:inherit; border:0; background:none; cursor:pointer;}
input,textarea{font:inherit; color:inherit;}

/* ---------- appbar ---------- */
.appbar{
  position:fixed; top:0; left:0; right:0; z-index:20;
  padding-top:var(--safe-top);
  background:rgba(255,255,255,.82); backdrop-filter:saturate(180%) blur(12px);
  border-bottom:1px solid var(--line);
}
.appbar-inner{
  height:var(--appbar-h); display:flex; align-items:center; justify-content:space-between;
  padding:0 16px; max-width:640px; margin:0 auto;
}
.appbar-title{font-size:18px; font-weight:700; letter-spacing:-.01em;}
.icon-btn{
  width:38px; height:38px; border-radius:50%; background:var(--accent-soft);
  color:var(--accent-2); font-weight:700; font-size:14px; display:grid; place-items:center;
}

/* ---------- screen ---------- */
.screen{
  max-width:640px; margin:0 auto;
  padding:calc(var(--appbar-h) + var(--safe-top) + 14px) 16px
          calc(var(--tabbar-h) + var(--safe-bottom) + 20px);
  min-height:100%;
}

/* ---------- tabbar ---------- */
.tabbar{
  position:fixed; bottom:0; left:0; right:0; z-index:20;
  height:calc(var(--tabbar-h) + var(--safe-bottom));
  padding-bottom:var(--safe-bottom);
  display:flex; background:rgba(255,255,255,.9); backdrop-filter:saturate(180%) blur(12px);
  border-top:1px solid var(--line);
}
.tab{
  flex:1; display:flex; flex-direction:column; align-items:center; justify-content:center;
  gap:3px; color:var(--faint); position:relative; transition:color .15s;
}
.tab.active{color:var(--accent-2);}
.tab-ico{font-size:20px; line-height:1;}
.tab-label{font-size:11px; font-weight:600;}
.badge{
  position:absolute; top:6px; left:calc(50% + 8px);
  min-width:17px; height:17px; padding:0 4px; border-radius:9px;
  background:var(--danger); color:#fff; font-size:10px; font-weight:700;
  display:grid; place-items:center;
}

/* ---------- generic cards ---------- */
.card{
  background:var(--card); border:1px solid var(--line); border-radius:var(--radius);
  box-shadow:var(--shadow); padding:18px 18px; margin-bottom:14px;
}
.card h2{font-size:12px; letter-spacing:.06em; text-transform:uppercase; color:var(--accent); margin:0 0 4px;}
.card h3{font-size:11px; letter-spacing:.05em; text-transform:uppercase; color:var(--faint); margin:18px 0 9px; font-weight:700;}
.card h3:first-of-type{margin-top:2px;}
.card-sub{margin:0 0 12px; color:var(--faint); font-size:13px;}
.muted{color:var(--muted);}
.faint{color:var(--faint);}

/* ---------- buttons ---------- */
.btn{
  border-radius:12px; padding:13px 16px; font-weight:600; font-size:15px;
  transition:transform .06s, box-shadow .18s, background .18s, border-color .18s;
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
}
.btn:active{transform:translateY(1px);}
.btn:disabled{opacity:.5;}
.btn.block{width:100%;}
.btn.primary{background:linear-gradient(180deg,var(--accent) 0%,var(--accent-2) 100%); color:#fff; box-shadow:0 6px 16px -8px rgba(14,124,123,.7);}
.btn.secondary{background:#fff; color:var(--accent-2); border:1px solid var(--line);}
.btn.ghost{background:var(--line-soft); color:var(--muted);}
.btn-row{display:flex; gap:10px; margin-top:12px;}
.btn-row .btn{flex:1;}

/* ---------- home / today ---------- */
.hero{
  background:linear-gradient(150deg,#0e7c7b 0%,#0a5c68 100%); color:#fff;
  border-radius:var(--radius); padding:22px 20px; margin-bottom:16px;
  box-shadow:0 10px 30px -14px rgba(10,92,104,.7);
}
.hero .eyebrow{font-size:11px; letter-spacing:.16em; opacity:.8; font-weight:700;}
.hero .big{font-size:30px; font-weight:800; margin:6px 0 2px; letter-spacing:-.01em;}
.hero .sub{opacity:.9; font-size:14px;}
.hero .stats{display:flex; gap:18px; margin-top:16px;}
.hero .stat b{font-size:22px; display:block; line-height:1.1;}
.hero .stat span{font-size:12px; opacity:.85;}
.hero .btn.primary{background:#fff; color:var(--accent-2); margin-top:16px; box-shadow:none;}

.meter{height:9px; background:var(--line-soft); border-radius:999px; overflow:hidden; margin:8px 0;}
.meter i{display:block; height:100%; border-radius:999px; background:linear-gradient(90deg,var(--accent),#37b0a8); transition:width .4s cubic-bezier(.4,0,.2,1);}
.mini-stat-row{display:flex; gap:10px;}
.mini-stat{flex:1; background:var(--card); border:1px solid var(--line); border-radius:14px; padding:14px; text-align:center; box-shadow:var(--shadow);}
.mini-stat b{font-size:24px; display:block; color:var(--accent-2);}
.mini-stat span{font-size:12px; color:var(--faint);}

/* ---------- study flow ---------- */
.study{max-width:640px; margin:0 auto;}
.study-top{
  position:fixed; top:0; left:0; right:0; z-index:21; padding-top:var(--safe-top);
  background:rgba(255,255,255,.9); backdrop-filter:blur(12px); border-bottom:1px solid var(--line);
}
.study-top-inner{height:var(--appbar-h); display:flex; align-items:center; gap:12px; padding:0 12px; max-width:640px; margin:0 auto;}
.study-top .close{width:36px; height:36px; border-radius:50%; background:var(--line-soft); color:var(--muted); font-size:20px; display:grid; place-items:center;}
.study-progress{flex:1;}
.study-progress .meter{margin:0;}
.study-progress .cap{font-size:11px; color:var(--faint); margin-top:4px;}
.step-dots{display:flex; gap:6px;}
.step-dots i{width:8px; height:8px; border-radius:50%; background:var(--line);}
.step-dots i.on{background:var(--accent);}
.step-dots i.done{background:var(--good);}

.word-hero{text-align:center; padding:8px 0 4px;}
.word-hero .word{font-size:46px; font-weight:800; letter-spacing:-.02em; line-height:1.1;}
.word-hero .phon{color:var(--muted); font-size:14px; margin-top:8px;}
.word-hero .phon span{color:var(--faint); font-size:12px; margin-right:3px;}
.word-hero .phon em{margin:0 6px; color:var(--line);}
.pos-tabs{display:flex; gap:8px; justify-content:center; flex-wrap:wrap; margin-top:14px;}
.pos-tabs button{background:#fff; border:1px solid var(--line); color:var(--muted); border-radius:999px; padding:7px 15px; font-size:13px; font-weight:600;}
.pos-tabs button.active{background:var(--accent-soft); border-color:#c7e5e3; color:var(--accent-2);}

.play{
  display:inline-flex; align-items:center; gap:8px; background:var(--amber-soft); color:var(--amber);
  border:1px solid #f2e0bb; border-radius:999px; padding:9px 16px; font-size:14px; font-weight:600;
}
.play:active{background:#fbeccf;}
.play.round{width:44px; height:44px; padding:0; justify-content:center; border-radius:50%; flex:0 0 auto;}
.play.big{padding:12px 20px; font-size:15px;}
.play .ico{font-size:13px;}
.play-center{display:flex; justify-content:center; margin:16px 0 4px;}

/* listen-first sentence */
.lsent{display:flex; align-items:center; gap:11px; padding:11px 12px; border:1px solid var(--line); border-radius:13px; background:var(--line-soft); margin:9px 0;}
.lsent .body{flex:1; min-width:0;}
.lsent .veil{color:var(--faint); font-size:13px; font-style:italic;}
.lsent .text{display:none; color:#263b4d; font-size:15px;}
.lsent.shown{background:#fff;}
.lsent.shown .veil{display:none;}
.lsent.shown .text{display:block; animation:fade .3s ease;}
.lsent .reveal{flex:0 0 auto; border:1px solid var(--line); color:var(--muted); border-radius:9px; padding:8px 11px; font-size:12px; background:#fff;}
@keyframes fade{from{opacity:0; transform:translateY(3px);} to{opacity:1; transform:none;}}

.core{border:1px dashed #c7e5e3; background:linear-gradient(180deg,#f4fbfa,#fff); border-radius:13px; padding:14px 15px;}
.core .row{display:flex; align-items:center; gap:10px; flex-wrap:wrap;}
.core .definition{font-size:17px; margin:12px 0 0; color:#193343; display:none;}
.core.shown .definition{display:block; animation:fade .3s ease;}
.core.shown .row .reveal{display:none;}
.core .reveal{border:1px solid var(--line); color:var(--accent-2); border-radius:9px; padding:9px 13px; font-size:13px; background:#fff;}

.sense{padding:12px 0; border-top:1px solid var(--line-soft);}
.sense:first-of-type{border-top:0; padding-top:2px;}
.sense .zh{font-weight:700;}
.sense .en{color:var(--muted); font-size:14px; margin-top:2px;}
.tag{display:inline-block; background:var(--accent-soft); color:var(--accent-2); padding:4px 12px; border-radius:999px; font-size:13px; font-weight:600;}
.colloc{margin:2px 0;}
.forms{font-family:ui-monospace,Menlo,Consolas,monospace; background:var(--line-soft); border-radius:11px; padding:12px 14px; color:#26485a; font-size:14px;}
.family-item{border:1px solid var(--line); border-radius:12px; padding:12px 13px; background:#fff; margin:9px 0;}
.family-item .hd{display:flex; align-items:baseline; gap:8px;}
.family-item strong{color:var(--accent-2); font-size:15px;}
.family-item .k{color:var(--faint); font-size:12px;}
.family-item .gloss{color:var(--muted); font-size:13px; margin:5px 0 2px;}
.syn{padding:11px 0; border-top:1px solid var(--line-soft);}
.syn:first-of-type{border-top:0; padding-top:2px;}
.syn .note{color:var(--muted); font-size:14px; margin:5px 0 2px;}

/* quiz */
.q{padding:14px 0; border-top:1px solid var(--line-soft);}
.q:first-child{border-top:0; padding-top:2px;}
.q .label{font-weight:700; margin-bottom:6px;}
.q .hintline{color:var(--muted); font-size:14px; margin-bottom:8px;}
.q input,.q textarea{width:100%; padding:12px 13px; border:1px solid var(--line); border-radius:11px; background:#fff;}
.q textarea{resize:vertical; min-height:80px;}
.q input:focus,.q textarea:focus{outline:0; border-color:var(--accent); box-shadow:0 0 0 3px var(--accent-soft);}
.q .row2{display:flex; flex-direction:column; gap:9px; margin-top:9px;}
.feedback{min-height:18px; font-weight:600; font-size:14px; margin-top:9px;}
.feedback.ok{color:var(--good);}
.feedback.hint{color:var(--amber);}

.study-nav{display:flex; gap:10px; margin-top:6px;}
.study-nav .btn{flex:1;}

/* ---------- library ---------- */
.search{width:100%; padding:12px 14px; border:1px solid var(--line); border-radius:12px; background:#fff; margin-bottom:12px;}
.filter-row{display:flex; gap:8px; margin-bottom:12px; overflow-x:auto; padding-bottom:2px;}
.chip{white-space:nowrap; border:1px solid var(--line); background:#fff; color:var(--muted); border-radius:999px; padding:7px 14px; font-size:13px; font-weight:600;}
.chip.active{background:var(--accent-soft); border-color:#c7e5e3; color:var(--accent-2);}
.word-row{display:flex; align-items:center; gap:12px; padding:13px 14px; background:var(--card); border:1px solid var(--line); border-radius:13px; margin-bottom:9px; box-shadow:var(--shadow);}
.word-row .info{flex:1; min-width:0;}
.word-row .w{font-weight:700; font-size:16px;}
.word-row .m{color:var(--faint); font-size:12px; margin-top:1px;}
.word-row .st{font-size:12px; font-weight:700; padding:4px 10px; border-radius:999px;}
.st.new{background:var(--line-soft); color:var(--faint);}
.st.learning{background:var(--amber-soft); color:var(--amber);}
.st.learned{background:var(--good-soft); color:var(--good);}

/* ---------- toast ---------- */
.toast{
  position:fixed; left:50%; transform:translateX(-50%);
  bottom:calc(var(--tabbar-h) + var(--safe-bottom) + 14px); z-index:40;
  background:#0f2233; color:#fff; padding:11px 16px; border-radius:12px; font-size:14px;
  box-shadow:0 12px 30px -10px rgba(0,0,0,.5); max-width:90%;
  display:flex; align-items:center; gap:12px; animation:fade .3s ease;
}
.toast button{color:#7fe3dd; font-weight:700;}

.empty{text-align:center; color:var(--faint); padding:40px 20px;}
.empty .em{font-size:40px; display:block; margin-bottom:10px;}

/* ---------- 没听懂标记 ---------- */
.lsent .markbtn{flex:0 0 auto; width:38px; height:38px; border-radius:50%; border:1px solid var(--line); background:#fff; color:var(--faint); font-size:17px; line-height:1;}
.lsent.marked{background:var(--amber-soft); border-color:#f2e0bb;}
.lsent.marked .markbtn{color:var(--amber); border-color:#efd39b;}
.lsent.marked.shown{background:var(--amber-soft);}

/* ---------- 已掌握开关（学习流程内） ---------- */
.master-chip{border:1px solid var(--line); background:#fff; color:var(--muted); border-radius:999px; padding:9px 18px; font-size:13px; font-weight:600;}
.master-chip.on{background:var(--good-soft); border-color:#bfe6d0; color:var(--good);}

/* ---------- 模式选择 ---------- */
.mode-opt{border:1px solid var(--line); border-radius:13px; padding:13px 14px; margin-bottom:10px; cursor:pointer; transition:border-color .15s, background .15s;}
.mode-opt:last-child{margin-bottom:0;}
.mode-opt.active{border-color:#c7e5e3; background:var(--accent-soft);}
.mode-hd{display:flex; align-items:center; gap:9px; font-size:15px;}
.mode-hd b{color:var(--ink);}
.mode-opt.active .mode-hd b{color:var(--accent-2);}
.mode-hd .pick{font-size:11px; font-weight:700; color:#fff; background:var(--accent); padding:2px 9px; border-radius:999px;}
.mode-desc{color:var(--muted); font-size:13px; margin-top:6px;}

/* 词库/复习行的状态按钮可点 */
.word-row .st{border:0; cursor:pointer;}

/* ---------- 句子里的可点击单词 / 困难词 ---------- */
.lsent .text .tok{cursor:pointer; border-radius:5px; padding:0 1px; transition:background .12s;}
.lsent .text .tok:active{background:var(--line-soft);}
.lsent .text .tok.hard{background:var(--amber-soft); color:var(--amber); font-weight:700; box-shadow:inset 0 -2px 0 #e6b45f;}

/* 困难词列表（我的页） */
.hardword-wrap{display:flex; flex-wrap:wrap; gap:8px; margin-top:4px;}
.hardword{display:inline-flex; align-items:center; gap:6px; background:var(--amber-soft); color:var(--amber); border:1px solid #f2e0bb; border-radius:999px; padding:6px 10px 6px 13px; font-size:14px; font-weight:600;}
.hardword .say{cursor:pointer; opacity:.75; font-size:12px;}
.hardword .del{cursor:pointer; width:18px; height:18px; border-radius:50%; background:#fff; color:var(--amber); display:grid; place-items:center; font-size:13px; line-height:1; border:1px solid #f2e0bb;}