/* ============ 基础与主题 ============ */
:root{
  --bg:#f4f6fb; --bg2:#e9edf7; --card:#ffffff; --card2:#f7f9ff;
  --text:#1a1f2e; --text2:#5b6478; --text3:#9aa3b5;
  --line:#e6eaf3; --shadow:0 6px 20px rgba(26,31,46,.08);
  --brand:#4a6cf7; --brand2:#6f8bff; --brand-soft:#eaf0ff;
  --ok:#22c07d; --warn:#f5a524; --bad:#f2536d;
  --radius:18px;
  --safe-b:env(safe-area-inset-bottom, 0px);
}
html[data-theme="dark"]{
  --bg:#0f1420; --bg2:#161d2c; --card:#1a2130; --card2:#212a3b;
  --text:#eef2fb; --text2:#a3aec4; --text3:#6f7c93;
  --line:#263043; --shadow:0 6px 20px rgba(0,0,0,.35);
  --brand:#6f8bff; --brand2:#8aa2ff; --brand-soft:#232f4d;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0;height:100%}
body{
  background:var(--bg2);
  color:var(--text);
  font:15px/1.55 -apple-system,BlinkMacSystemFont,"PingFang SC","Helvetica Neue","Microsoft YaHei",sans-serif;
  overscroll-behavior:none;
}
button{font-family:inherit;color:inherit;border:0;background:none;cursor:pointer}
input,select,textarea{font-family:inherit;font-size:16px;color:inherit}
.hide{display:none !important}

/* ============ 外壳：手机上全屏，电脑上居中成手机框 ============ */
#app{
  max-width:480px;margin:0 auto;height:100dvh;min-height:100dvh;
  display:flex;flex-direction:column;position:relative;overflow:hidden;
  background:var(--bg);
}
@media (min-width:520px){
  body{display:flex;align-items:center;justify-content:center;padding:16px}
  #app{height:min(880px,calc(100dvh - 32px));border-radius:28px;box-shadow:0 20px 60px rgba(0,0,0,.18);border:1px solid var(--line)}
}

/* ============ 顶栏 ============ */
.topbar{
  flex:0 0 auto;padding:calc(env(safe-area-inset-top,0px) + 12px) 16px 10px;
  display:flex;align-items:center;gap:10px;background:var(--card);
  border-bottom:1px solid var(--line);z-index:5
}
.topbar h1{font-size:17px;margin:0;font-weight:700;letter-spacing:.2px}
.topbar .spacer{flex:1}
.icon-btn{width:34px;height:34px;border-radius:11px;display:grid;place-items:center;background:var(--card2);font-size:16px}
.icon-btn:active{transform:scale(.94)}

/* ============ 视图区 ============ */
main{flex:1;overflow-y:auto;-webkit-overflow-scrolling:touch;padding:14px 14px 24px}
.view{display:none;animation:fade .22s ease}
.view.active{display:block}
@keyframes fade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}

/* ============ 底部导航 ============ */
.tabbar{
  flex:0 0 auto;display:flex;background:var(--card);border-top:1px solid var(--line);
  padding-bottom:var(--safe-b);z-index:6
}
.tabbar button{
  flex:1;padding:8px 0 7px;display:flex;flex-direction:column;align-items:center;gap:3px;
  color:var(--text3);font-size:11px
}
.tabbar button .ic{font-size:19px;line-height:1}
.tabbar button.on{color:var(--brand);font-weight:600}

/* ============ 通用块 ============ */
.card{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px;margin-bottom:14px;border:1px solid var(--line)}
.card.tight{padding:12px 14px}
.row{display:flex;align-items:center;gap:10px}
.row .spacer{flex:1}
.muted{color:var(--text2);font-size:13px}
.tiny{font-size:12px;color:var(--text3)}
.sec-title{font-size:13px;color:var(--text2);font-weight:600;margin:18px 2px 8px}
.btn{
  display:block;width:100%;padding:13px;border-radius:14px;background:var(--brand);
  color:#fff;font-size:16px;font-weight:600;text-align:center;box-shadow:0 6px 16px rgba(74,108,247,.28)
}
.btn:active{transform:scale(.985)}
.btn.ghost{background:var(--card2);color:var(--text);box-shadow:none;border:1px solid var(--line)}
.btn.warn{background:var(--bad);box-shadow:0 6px 16px rgba(242,83,109,.25)}
.btn.sm{padding:9px;font-size:14px;border-radius:12px}

/* ============ 首页 ============ */
.hero{
  background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff;border-radius:22px;
  padding:18px;margin-bottom:14px;box-shadow:0 10px 24px rgba(74,108,247,.3)
}
.hero .date{font-size:12px;opacity:.85}
.hero .big{font-size:30px;font-weight:800;margin:6px 0 2px;line-height:1.1}
.hero .sub{font-size:13px;opacity:.9}
.hero .cta{
  margin-top:14px;background:#fff;color:var(--brand);border-radius:14px;padding:12px;
  font-weight:700;text-align:center;font-size:16px
}
.hero .cta:active{transform:scale(.985)}
.hero.done{background:linear-gradient(135deg,var(--ok),#4ad4a0)}
.hero.done .cta{color:var(--ok)}
.ring-wrap{display:flex;align-items:center;gap:16px}
.ring{--p:0;width:92px;height:92px;border-radius:50%;flex:0 0 auto;display:grid;place-items:center;
  background:conic-gradient(var(--brand) calc(var(--p)*1%),var(--brand-soft) 0)}
.ring i{width:70px;height:70px;border-radius:50%;background:var(--card);display:grid;place-items:center;font-style:normal;font-weight:800;font-size:19px}
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-bottom:14px}
.stat{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:12px 10px;text-align:center}
.stat b{display:block;font-size:20px;font-weight:800}
.stat span{font-size:11px;color:var(--text2)}
.chips{display:flex;gap:8px;flex-wrap:wrap}
.chip{padding:6px 12px;border-radius:999px;background:var(--card2);border:1px solid var(--line);font-size:13px}
.chip.on{background:var(--brand-soft);color:var(--brand);border-color:transparent;font-weight:600}

/* ============ 学习卡片 ============ */
.study-head{display:flex;align-items:center;gap:10px;margin-bottom:10px}
.progress-line{flex:1;height:6px;border-radius:99px;background:var(--card2);overflow:hidden}
.progress-line i{display:block;height:100%;background:var(--brand);border-radius:99px;transition:width .25s}
.flag{font-size:11px;padding:3px 8px;border-radius:99px;background:var(--brand-soft);color:var(--brand);font-weight:600}
.flag.new{background:#e6f9f1;color:var(--ok)}
html[data-theme="dark"] .flag.new{background:#17342a;color:#4ad4a0}

.flip{perspective:1200px}
.flip-inner{position:relative;transition:transform .45s cubic-bezier(.4,.2,.2,1);transform-style:preserve-3d;min-height:340px}
.flip.show .flip-inner{transform:rotateY(180deg)}
.face{
  position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;
  background:var(--card);border:1px solid var(--line);border-radius:22px;box-shadow:var(--shadow);
  padding:24px 20px;display:flex;flex-direction:column
}
.face.front{align-items:center;justify-content:center;text-align:center;gap:8px}
.face.back{transform:rotateY(180deg);overflow-y:auto}
.word{font-size:38px;font-weight:800;letter-spacing:.5px;word-break:break-word;line-height:1.15}
.phon{color:var(--text2);font-size:15px}
.spk{font-size:13px;color:var(--brand);border:1px solid var(--line);background:var(--card2);padding:5px 12px;border-radius:99px;margin-top:6px}
.tap-hint{margin-top:auto;font-size:12px;color:var(--text3)}
.cn{font-size:19px;font-weight:700;margin:2px 0 12px}
.ex{border-left:3px solid var(--brand);padding:8px 0 8px 12px;background:var(--card2);border-radius:0 10px 10px 0;margin-top:10px}
.ex p{margin:0;font-size:14px}
.ex .t{color:var(--text2);font-size:13px;margin-top:4px}

.spell-box{margin-top:14px}
.spell-box input{
  width:100%;padding:12px 14px;border-radius:13px;border:1.5px solid var(--line);
  background:var(--card2);outline:none;font-size:17px;letter-spacing:1px
}
.spell-box input:focus{border-color:var(--brand)}
.spell-res{margin-top:8px;font-size:14px;font-weight:600;min-height:20px}
.spell-res.ok{color:var(--ok)}
.spell-res.no{color:var(--bad)}

.grade{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:14px}
.grade button{
  padding:14px 6px;border-radius:15px;font-weight:700;font-size:15px;border:1px solid var(--line);background:var(--card2)
}
.grade button small{display:block;font-weight:400;font-size:11px;color:var(--text2);margin-top:2px}
.grade button[data-g="0"]{background:rgba(242,83,109,.12);color:var(--bad);border-color:transparent}
.grade button[data-g="1"]{background:rgba(245,165,36,.14);color:#d98908;border-color:transparent}
.grade button[data-g="2"]{background:rgba(34,192,125,.14);color:var(--ok);border-color:transparent}
.grade button:active{transform:scale(.97)}
.kbd-tip{text-align:center;font-size:11px;color:var(--text3);margin-top:10px}

/* ============ 列表 ============ */
.list-item{
  display:flex;align-items:center;gap:10px;padding:11px 2px;border-bottom:1px solid var(--line)
}
.list-item:last-child{border-bottom:0}
.list-item .w{font-weight:700;font-size:15px}
.list-item .c{font-size:12px;color:var(--text2);overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:60vw}
.list-item .meta{margin-left:auto;font-size:11px;color:var(--text3);text-align:right;flex:0 0 auto}
.dot{width:8px;height:8px;border-radius:50%;background:var(--text3);flex:0 0 auto}
.dot.new{background:var(--text3)}
.dot.learning{background:var(--warn)}
.dot.done{background:var(--ok)}
.book-row{display:flex;align-items:center;gap:12px;padding:13px 0;border-bottom:1px solid var(--line)}
.book-row:last-child{border-bottom:0}
.switch{width:46px;height:26px;border-radius:99px;background:var(--line);position:relative;transition:.2s;flex:0 0 auto}
.switch i{position:absolute;top:3px;left:3px;width:20px;height:20px;border-radius:50%;background:#fff;transition:.2s}
.switch.on{background:var(--brand)}
.switch.on i{left:23px}

/* ============ 图表 ============ */
.bars{display:flex;align-items:flex-end;gap:5px;height:110px}
.bars .b{flex:1;display:flex;flex-direction:column;justify-content:flex-end;align-items:center;gap:4px;height:100%}
.bars .b i{display:block;width:100%;max-width:22px;background:var(--brand);border-radius:5px 5px 0 0;min-height:3px}
.bars .b span{font-size:9px;color:var(--text3)}
.legend{display:flex;gap:14px;font-size:12px;color:var(--text2);margin-top:8px}
.legend em{font-style:normal;display:inline-block;width:8px;height:8px;border-radius:2px;margin-right:4px}

/* ============ 设置表单 ============ */
.field{display:flex;align-items:center;gap:10px;padding:12px 0;border-bottom:1px solid var(--line)}
.field:last-child{border-bottom:0}
.field label{flex:1;font-size:14px}
.field label small{display:block;color:var(--text3);font-size:11px}
.field input[type=number]{width:66px;padding:7px 8px;border-radius:10px;border:1px solid var(--line);background:var(--card2);text-align:center}
.field select{padding:7px 10px;border-radius:10px;border:1px solid var(--line);background:var(--card2)}

/* ============ 弹层 ============ */
.modal{position:absolute;inset:0;background:rgba(10,14,24,.45);display:flex;align-items:flex-end;z-index:20}
.modal-in{
  width:100%;background:var(--card);border-radius:22px 22px 0 0;padding:18px 16px calc(18px + var(--safe-b));
  max-height:82%;overflow-y:auto;animation:up .25s ease
}
@keyframes up{from{transform:translateY(100%)}to{transform:none}}
.modal-in h3{margin:0 0 10px;font-size:16px}
.modal-in textarea{
  width:100%;min-height:120px;border-radius:12px;border:1px solid var(--line);background:var(--card2);
  padding:10px;font-size:13px;resize:vertical;line-height:1.5
}
.toast{
  position:absolute;left:50%;bottom:84px;transform:translateX(-50%);background:rgba(20,26,40,.92);color:#fff;
  padding:9px 16px;border-radius:99px;font-size:13px;z-index:30;animation:up .2s ease;max-width:88%;text-align:center
}
.empty{text-align:center;color:var(--text3);padding:34px 10px;font-size:14px}
.empty .ic{font-size:38px;display:block;margin-bottom:8px;opacity:.6}