:root{
  --pri:#4f46e5; --pri2:#7c3aed; --bg:#f4f5fb; --card:#fff;
  --ink:#1f2233; --sub:#6b7088; --line:#eceef5;
  --green:#16a34a; --yellow:#d97706; --red:#dc2626; --blue:#2563eb;
  --radius:18px; --tab-h:62px;
}
*{margin:0;padding:0;box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{height:100%}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--ink);font-size:15px;overflow:hidden}
button{font-family:inherit;border:none;background:none;cursor:pointer;color:inherit}
#app{max-width:480px;margin:0 auto;height:100%;position:relative;overflow:hidden}

.view{position:absolute;inset:0;display:none;flex-direction:column;padding:env(safe-area-inset-top) 16px calc(var(--tab-h) + env(safe-area-inset-bottom));overflow-y:auto;-webkit-overflow-scrolling:touch}
.view.active{display:flex;animation:fade .22s ease}
@keyframes fade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}

/* ---------- 首页 ---------- */
.home-head{display:flex;justify-content:space-between;align-items:center;padding:18px 2px 10px}
.hello h1{font-size:26px;background:linear-gradient(120deg,var(--pri),var(--pri2));-webkit-background-clip:text;background-clip:text;color:transparent}
.trial-tag{font-size:10.5px;font-weight:600;letter-spacing:1px;color:#fff;-webkit-text-fill-color:#fff;background:linear-gradient(130deg,#f59e0b,#ef4444);padding:3px 9px;border-radius:20px;margin-left:9px;vertical-align:middle;box-shadow:0 2px 6px rgba(239,68,68,.25)}
.hello p{color:var(--sub);font-size:13px;margin-top:3px}
.streak{background:#fff3e6;color:#ea580c;border-radius:30px;padding:7px 14px;font-size:15px;box-shadow:0 2px 8px rgba(234,88,12,.12)}
.streak b{margin:0 2px} .streak span{font-size:12px}

.rings{display:flex;gap:10px;margin:8px 0 16px}
.ring-card{flex:1;background:var(--card);border-radius:var(--radius);padding:14px 6px 10px;text-align:center;box-shadow:0 2px 10px rgba(31,34,51,.05)}
.ring-card p{font-size:12px;color:var(--sub);margin-top:4px}
.ring{width:74px;height:74px;margin:0 auto;position:relative}
.ring svg{width:100%;height:100%;transform:rotate(-90deg)}
.ring circle{fill:none;stroke-width:7;stroke-linecap:round}
.ring .bg{stroke:var(--line)} .ring .fg{stroke:var(--pri);stroke-dasharray:213.6;stroke-dashoffset:213.6;transition:stroke-dashoffset .6s}
.ring .fg2{stroke:var(--pri2);stroke-dasharray:213.6;stroke-dashoffset:213.6;transition:stroke-dashoffset .6s}
.ring-txt{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;flex-direction:column}
.ring-txt b{font-size:19px} .ring-txt i{font-style:normal;font-size:10px;color:var(--sub)}
.ring.mini-stat{display:flex;align-items:center;justify-content:center}
.ring.mini-stat b{font-size:26px;color:var(--pri)}

.start-btn{width:100%;background:linear-gradient(120deg,var(--pri),var(--pri2));color:#fff;border-radius:var(--radius);padding:17px 20px;display:flex;align-items:center;gap:14px;box-shadow:0 8px 20px rgba(79,70,229,.32);margin-bottom:14px}
.start-btn:active{transform:scale(.985)}
.start-btn .start-ico{width:38px;height:38px;background:rgba(255,255,255,.22);border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:15px;flex:none}
.start-btn span:last-child{display:flex;flex-direction:column;text-align:left}
.start-btn b{font-size:17px;letter-spacing:.5px} .start-btn i{font-style:normal;font-size:12px;opacity:.85;margin-top:2px}
.start-btn.small{justify-content:center;padding:14px;margin-top:14px}

.seg-wrap{display:flex;justify-content:center;margin-bottom:14px}
.seg{background:#e9eaf5;border-radius:30px;padding:4px;display:flex;gap:2px}
.seg button{padding:8px 26px;border-radius:30px;font-size:14px;color:var(--sub)}
.seg button.on{background:#fff;color:var(--pri);font-weight:600;box-shadow:0 2px 6px rgba(31,34,51,.08)}

.grid2{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.tile{background:var(--card);border-radius:var(--radius);padding:16px 14px;text-align:left;box-shadow:0 2px 10px rgba(31,34,51,.05);display:flex;flex-direction:column;gap:6px;min-height:104px}
.tile:active{transform:scale(.97)}
.tile-ico{font-size:22px} .tile b{font-size:15px} .tile i{font-style:normal;font-size:11.5px;color:var(--sub)}
.foot-tip{text-align:center;color:#a2a6bb;font-size:11px;margin:18px 8px 10px;line-height:1.6}

/* ---------- 学习页 ---------- */
.study-head{display:flex;align-items:center;gap:10px;padding:12px 0}
.icon-btn{font-size:22px;color:var(--sub);width:36px;height:36px;flex:none}
.study-prog{flex:1;height:7px;background:#e6e8f2;border-radius:6px;overflow:hidden}
.study-prog i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--pri),var(--pri2));border-radius:6px;transition:width .3s}
.study-count{font-size:13px;color:var(--sub);flex:none;min-width:42px;text-align:right}

.stage{flex:1;display:flex;align-items:center;justify-content:center;perspective:1400px;padding:6px 0}
.flash{width:100%;height:100%;max-height:520px}
.flash-inner{position:relative;width:100%;height:100%;transition:transform .55s;transform-style:preserve-3d}
.flash.flipped .flash-inner{transform:rotateY(180deg)}
.face{position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;background:var(--card);border-radius:22px;box-shadow:0 10px 30px rgba(31,34,51,.10);padding:24px 20px;display:flex;flex-direction:column;align-items:center;overflow-y:auto}
.face-back{transform:rotateY(180deg);align-items:stretch}
.tag{align-self:flex-start;font-size:11px;background:#eef0ff;color:var(--pri);border-radius:20px;padding:3px 10px;margin-bottom:10px}
.big-word{font-size:38px;text-align:center;letter-spacing:.5px;margin-top:18px}
.phon{color:var(--sub);margin-top:8px;font-size:15px}
.speak-big{margin:26px 0 14px;width:64px;height:64px;border-radius:50%;background:linear-gradient(135deg,var(--pri),var(--pri2));color:#fff;font-size:26px;box-shadow:0 8px 18px rgba(79,70,229,.35)}
.speak-big:active{transform:scale(.93)}
.tap-hint{color:#aab0c6;font-size:13px;margin-top:auto}

.back-top{display:flex;justify-content:space-between;align-items:center}
.speak-mini{font-size:12px;background:#eef0ff;color:var(--pri);border-radius:20px;padding:5px 12px}
.face-back h3{font-size:27px;margin:6px 0 2px}
.meaning{background:#f7f8fd;border-radius:12px;padding:11px 13px;font-size:14px;line-height:1.65;margin:10px 0 12px}
.sent-box{display:flex;flex-direction:column;gap:10px}
.sent-en{font-size:16px;line-height:1.6;font-weight:500}
.sent-en b,.sent-en mark{background:#fef3c7;color:#92400e;border-radius:3px;padding:0 2px;font-weight:700}
.sent-zh{font-size:13.5px;color:var(--sub);line-height:1.55;margin-top:3px}
.sent-idx{font-size:11px;color:#b4b9cc;margin-top:2px}
.more-sent{margin-top:12px;align-self:center;font-size:13px;color:var(--pri);background:#eef0ff;border-radius:20px;padding:8px 16px}
.more-sent:disabled{color:#b4b9cc;background:#f2f3f8}

.grade-row{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:12px}
.grade{border-radius:14px;padding:12px 4px;display:flex;flex-direction:column;gap:3px;color:#fff;background:#cdd1e4}
.grade b{font-size:14px} .grade i{font-style:normal;font-size:10.5px;opacity:.9}
.grade.g0{background:var(--red)} .grade.g1{background:var(--yellow)} .grade.g2{background:var(--blue)} .grade.g3{background:var(--green)}
.grade:active{transform:scale(.95)}
.flip-btn{margin-top:10px;width:100%;padding:14px;border-radius:14px;background:#fff;color:var(--pri);font-weight:600;font-size:15px;box-shadow:0 2px 10px rgba(31,34,51,.06)}
.flip-btn.hide{display:none} .grade-row.hide{display:none}

/* ---------- 记忆库 ---------- */
.sub-head{display:flex;align-items:center;gap:6px;padding:14px 0}
.sub-head h2{font-size:19px}
.search-box{margin-bottom:10px}
.search-box input{width:100%;border:none;background:#fff;border-radius:12px;padding:12px 14px;font-size:14px;outline:none;box-shadow:0 2px 8px rgba(31,34,51,.04)}
.bank-tabs{display:flex;gap:6px;margin-bottom:10px;overflow-x:auto}
.bank-tabs button{padding:7px 15px;border-radius:20px;background:#fff;color:var(--sub);font-size:13px;flex:none;box-shadow:0 2px 8px rgba(31,34,51,.04)}
.bank-tabs button.on{background:var(--pri);color:#fff}
.pick-kind{display:none;gap:8px;margin-bottom:10px}
.pick-kind.show{display:flex}
.pick-kind button{flex:1;padding:9px 0;border-radius:11px;background:#fff;color:var(--sub);font-size:13.5px;box-shadow:0 2px 8px rgba(31,34,51,.04)}
.pick-kind button.on{background:#eeeaff;color:var(--pri);font-weight:700}
.set-group label.disabled{opacity:.4;pointer-events:none}
.bank-list{display:flex;flex-direction:column;gap:8px;padding-bottom:14px}
.bank-item{background:#fff;border-radius:14px;padding:13px 15px;display:flex;align-items:center;gap:12px;box-shadow:0 2px 8px rgba(31,34,51,.04)}
.bank-item:active{background:#fafbff}
.bank-main{flex:1;min-width:0}
.bank-main b{font-size:16px} .bank-main p{font-size:12px;color:var(--sub);margin-top:2px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.bank-badge{font-size:10.5px;border-radius:10px;padding:2px 8px;flex:none}
.bb-hard{background:#fee2e2;color:var(--red)} .b-new{background:#eef0ff;color:var(--pri)}
.bb-master{background:#dcfce7;color:var(--green)} .bb-learn{background:#fef3c7;color:#b45309}
.bank-voice{font-size:18px;flex:none;width:34px;height:34px}

/* 单词列表选词 */
.pick-row .pick-box{width:23px;height:23px;border-radius:50%;border:2px solid #c9cde0;flex:none;display:flex;align-items:center;justify-content:center;font-size:13px;color:#fff;transition:all .15s}
.pick-row.on{background:#f2f1ff}
.pick-row.on .pick-box{background:linear-gradient(135deg,var(--pri),var(--pri2));border-color:transparent}
.pick-bar{display:none;align-items:center;gap:8px;position:sticky;bottom:calc(env(safe-area-inset-bottom) + 70px);margin-top:auto;background:#fff;border-radius:16px;padding:9px 10px;box-shadow:0 6px 24px rgba(31,34,51,.16);z-index:20}
.pick-bar.show{display:flex}
.pick-mini{flex:none;font-size:13px;color:var(--pri);background:#f0efff;border-radius:10px;padding:9px 12px}
.pick-start{flex:1;font-size:15px;font-weight:700;color:#fff;background:linear-gradient(135deg,var(--pri),var(--pri2));border-radius:12px;padding:11px 10px}
.pick-start:disabled{opacity:.45}
.load-more{width:100%;padding:13px;color:var(--sub);font-size:13.5px;background:#fff;border-radius:14px;box-shadow:0 2px 8px rgba(31,34,51,.04)}
.empty-tip{text-align:center;color:#aab0c6;font-size:13px;padding:60px 20px;line-height:1.8}

/* ---------- 设置 ---------- */
.set-group{background:#fff;border-radius:var(--radius);padding:6px 16px;margin-bottom:14px;box-shadow:0 2px 10px rgba(31,34,51,.04)}
.set-group label{display:block;padding:14px 0;border-bottom:1px solid var(--line);font-size:14.5px}
.set-group label b{float:right;color:var(--pri)}
.set-group input[type=range]{width:100%;margin-top:10px;accent-color:var(--pri)}
.switch-row{display:flex;justify-content:space-between;align-items:center}
.switch-row span{font-size:14.5px}
.switch-row input{width:20px;height:20px;accent-color:var(--pri)}
.line-btn{width:100%;text-align:left;padding:15px 0;font-size:14.5px;color:var(--blue)}
.line-btn.danger{color:var(--red)}
.set-group .line-btn+.line-btn{border-top:1px solid var(--line)}

/* ---------- 结束页 ---------- */
.view-done{justify-content:center;align-items:center;text-align:center}
.done-card{width:100%;background:#fff;border-radius:24px;padding:34px 24px;box-shadow:0 10px 30px rgba(31,34,51,.08)}
.done-emoji{font-size:52px} .done-card h2{margin:12px 0 20px;font-size:21px}
.done-stats{display:flex;justify-content:space-around}
.done-stats b{display:block;font-size:26px;color:var(--pri)} .done-stats i{font-style:normal;font-size:12px;color:var(--sub)}
#done-tip{color:var(--sub);font-size:13px;margin-top:18px}

/* ---------- 底部导航 ---------- */
.tabbar{position:absolute;left:0;right:0;bottom:0;height:calc(var(--tab-h) + env(safe-area-inset-bottom));padding-bottom:env(safe-area-inset-bottom);background:#fff;display:flex;border-top:1px solid var(--line);z-index:30;max-width:480px;margin:0 auto}
.tab{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;font-size:11px;color:#9aa0b8}
.tab span{font-size:20px} .tab.on{color:var(--pri);font-weight:600}

/* ---------- 强化弹层 ---------- */
.sheet-mask{position:absolute;inset:0;background:rgba(20,22,40,.5);z-index:50;display:none;align-items:flex-end}
.sheet-mask.show{display:flex;animation:fade .2s}
.sheet{background:#fff;width:100%;max-width:480px;margin:0 auto;border-radius:22px 22px 0 0;padding:22px 20px calc(20px + env(safe-area-inset-bottom));max-height:82%;overflow-y:auto;animation:up .28s ease}
@keyframes up{from{transform:translateY(100%)}to{transform:none}}
.sheet h3{font-size:19px;margin-bottom:4px} .sheet-sub{color:var(--sub);font-size:13px;margin-bottom:14px}
.sheet .sent-box{margin-bottom:6px}
.sheet .sent-card{background:#f7f8fd;border-radius:14px;padding:13px 15px;margin-bottom:10px}
.sheet .speak-sent{float:right;font-size:15px}

.toast{position:fixed;left:50%;bottom:110px;transform:translateX(-50%) translateY(20px);background:rgba(30,32,50,.92);color:#fff;padding:10px 20px;border-radius:24px;font-size:13.5px;opacity:0;pointer-events:none;transition:.25s;z-index:80;max-width:84%;text-align:center}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}

@media (min-height:780px){.flash{max-height:560px}}