/* ============ 英语小达人 · Duolingo 风格样式 ============ */
:root{
  --green:#58cc02; --green-dark:#46a302; --green-light:#d7ffb8;
  --blue:#1cb0f6; --blue-dark:#1899d6;
  --red:#ff4b4b; --red-light:#ffdfe0;
  --yellow:#ffc800; --purple:#ce82ff;
  --gray:#f7f7f7; --gray-border:#e5e5e5; --gray-text:#777;
  --ink:#4b4b4b; --white:#fff;
  --radius:16px;
}
*{box-sizing:border-box;margin:0;padding:0;}
html,body{height:100%;}
body{
  font-family:'Nunito','Segoe UI','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
  color:var(--ink); background:#fff; -webkit-font-smoothing:antialiased;
}
button{font-family:inherit;cursor:pointer;border:none;background:none;color:inherit;font-size:16px;}
.hidden{display:none !important;}
#app{max-width:640px;margin:0 auto;padding:0 16px 90px;min-height:100vh;}

/* ---------- 顶栏 ---------- */
.topbar{
  position:sticky;top:0;z-index:20;display:flex;justify-content:space-between;
  align-items:center;padding:12px 0;background:#fff;border-bottom:2px solid var(--gray-border);
}
.brand{font-weight:900;font-size:19px;color:var(--green);letter-spacing:.5px;}
.chip{
  display:inline-flex;align-items:center;gap:4px;background:var(--gray);
  border-radius:999px;padding:5px 13px;font-weight:800;font-size:14px;margin-left:8px;
}

/* ---------- 底部标签栏 ---------- */
.tabbar{
  position:sticky;top:55px;z-index:19;display:grid;grid-template-columns:repeat(4,1fr);
  gap:6px;padding:10px 0 12px;background:#fff;
}
.tab{padding:10px 4px;border-radius:12px;font-weight:800;font-size:14px;color:var(--gray-text);transition:all .15s;}
.tab.active{background:var(--green);color:#fff;box-shadow:0 3px 0 var(--green-dark);}

/* ---------- 通用按钮 ---------- */
.btn{
  display:inline-block;padding:12px 22px;border-radius:14px;font-weight:900;font-size:16px;
  transition:transform .1s, box-shadow .1s;user-select:none;
}
.btn:active{transform:translateY(2px);}
.btn-green{background:var(--green);color:#fff;box-shadow:0 4px 0 var(--green-dark);}
.btn-green:active{box-shadow:0 2px 0 var(--green-dark);}
.btn-ghost{background:var(--white);color:var(--gray-text);border:2px solid var(--gray-border);}
.btn-big{width:100%;padding:15px;font-size:18px;border-radius:16px;margin-top:12px;}
.btn.disabled{opacity:.45;pointer-events:none;}

/* ---------- 首页 ---------- */
.hero{
  display:flex;align-items:center;gap:16px;margin-top:14px;padding:22px;
  background:linear-gradient(135deg,#58cc02 0%,#7ed957 100%);color:#fff;
  border-radius:24px;box-shadow:0 6px 0 var(--green-dark);
}
.hero .mascot{font-size:66px;animation:bounce 2s infinite;}
.hero h2{font-size:22px;font-weight:900;margin-bottom:4px;}
.hero p{font-size:15px;opacity:.95;}
.quick{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px;}
.qchip{background:var(--gray);border-radius:999px;padding:8px 15px;font-weight:800;font-size:14px;}
.page-title{font-size:22px;font-weight:900;margin:16px 0 4px;}
.theme-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin-top:12px;}
.theme-card{
  border:2px solid var(--gray-border);border-radius:20px;padding:18px 12px;
  text-align:center;background:#fff;transition:border-color .15s, transform .1s;
}
.theme-card:hover{border-color:var(--green);}
.theme-card.locked{opacity:.6;}
.tc-icon{
  width:58px;height:58px;border-radius:50%;display:flex;align-items:center;
  justify-content:center;font-size:30px;margin:0 auto 8px;
}
.tc-name{font-weight:900;font-size:16px;margin-bottom:6px;}
.tc-stars{font-size:13px;letter-spacing:1px;color:var(--gray-text);}
.star-on{color:var(--yellow);} .star-off{color:#ddd;}

/* ---------- 路径页 ---------- */
.unit{margin-top:18px;}
.unit-head{display:flex;align-items:center;gap:10px;margin-bottom:10px;}
.unit-icon{width:42px;height:42px;border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:22px;}
.unit-name{font-weight:900;font-size:18px;flex:1;}
.unit-count{font-size:13px;color:var(--gray-text);font-weight:800;}
.unit-done{font-size:13px;color:var(--green);font-weight:900;}
.nodes{display:flex;flex-direction:column;align-items:center;gap:0;}
.connector{width:4px;height:30px;background:var(--gray-border);}
.unit.done .connector{background:var(--green-light);}
.node{
  width:72px;display:flex;flex-direction:column;align-items:center;gap:3px;
  padding:0;position:relative;
}
.node-icon{
  width:64px;height:64px;border-radius:50%;display:flex;align-items:center;
  justify-content:center;font-size:28px;color:#fff;transition:transform .15s;
}
.node.done .node-icon{background:var(--green);box-shadow:0 4px 0 var(--green-dark);}
.node.current .node-icon{background:var(--blue);box-shadow:0 4px 0 var(--blue-dark);}
.node.next .node-icon{animation:pulse 1.4s infinite;}
.node.locked .node-icon{background:var(--gray-border);color:#aaa;font-size:24px;}
.node:hover .node-icon{transform:scale(1.08);}
.node-name{font-size:12px;font-weight:800;color:var(--gray-text);}
.node-stars{font-size:11px;letter-spacing:0;color:var(--yellow);}

/* ---------- 课程页 ---------- */
.lesson-head{display:flex;align-items:center;gap:10px;padding:14px 0 6px;}
.icon-btn{font-size:20px;padding:8px 10px;border-radius:10px;background:var(--gray);font-weight:900;}
.progress-wrap{flex:1;height:16px;background:var(--gray-border);border-radius:999px;overflow:hidden;}
.progress-fill{height:100%;background:var(--green);border-radius:999px;transition:width .3s ease;}
.counter{font-weight:900;font-size:14px;color:var(--gray-text);white-space:nowrap;}
.lesson-title{font-weight:900;font-size:16px;color:var(--gray-text);margin:4px 0 10px;}
.lesson-card{min-height:320px;}
.q-emoji{text-align:center;padding:18px 0 6px;}
.big-emoji{font-size:88px;display:block;animation:pop .35s ease;}
.q-zh{font-size:18px;font-weight:800;color:var(--gray-text);margin-top:6px;}
.q-prompt{font-size:17px;font-weight:900;text-align:center;margin:12px 0;}
.opt-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;}
.opt{
  border:2px solid var(--gray-border);border-radius:16px;padding:14px 8px;min-height:104px;
  display:flex;flex-direction:column;align-items:center;justify-content:center;gap:4px;
  transition:background .15s, border-color .15s;
}
.opt:hover{border-color:var(--green);background:#f7fff0;}
.opt-en{font-weight:900;font-size:20px;}
.opt-zh{font-size:13px;color:var(--gray-text);}
.opt.correct{border-color:var(--green);background:var(--green-light);}
.opt.wrong{border-color:var(--red);background:var(--red-light);animation:shake .4s;}
.opt-grid.locked{pointer-events:none;}
.replay{
  display:block;margin:6px auto 0;font-size:30px;background:var(--gray);
  border-radius:50%;width:64px;height:64px;line-height:64px;text-align:center;
}
.replay:active{transform:scale(.92);}
.word-big{font-size:44px;font-weight:900;text-align:center;padding-top:22px;}
.sentence{font-size:22px;font-weight:800;text-align:center;padding:16px 8px 4px;line-height:1.6;}
.sentence .blank{color:var(--blue);text-decoration:underline;text-underline-offset:5px;}
.sentence-zh{text-align:center;font-size:14px;color:var(--gray-text);}
.slots{display:flex;justify-content:center;gap:8px;margin:16px 0;}
.slot{
  width:48px;height:52px;border:2px solid var(--gray-border);border-bottom-width:4px;
  border-radius:12px;font-size:24px;font-weight:900;text-transform:lowercase;
  display:flex;align-items:center;justify-content:center;background:#fff;
}
.slot.empty{border-style:dashed;}
.bank{display:flex;justify-content:center;flex-wrap:wrap;gap:8px;margin:10px 0 16px;}
.letter{
  width:48px;height:52px;border:2px solid var(--gray-border);border-radius:12px;
  font-size:22px;font-weight:900;text-transform:lowercase;background:var(--gray);
  display:flex;align-items:center;justify-content:center;transition:transform .1s;
}
.letter:hover{background:#eef7e2;transform:scale(1.06);}
.letter.off{opacity:.25;pointer-events:none;}
.match-wrap{display:flex;gap:12px;}
.match-col{flex:1;display:flex;flex-direction:column;gap:10px;}
.match-btn{
  border:2px solid var(--gray-border);border-radius:14px;padding:14px 6px;
  font-weight:900;font-size:17px;background:#fff;min-height:52px;transition:background .15s,border-color .15s;
}
.match-btn.left{font-size:20px;}
.match-btn:hover{border-color:var(--blue);}
.match-btn.selected{border-color:var(--blue);background:#ddf4ff;}
.match-btn.matched{border-color:var(--green);background:var(--green-light);pointer-events:none;opacity:.75;}
.match-btn.wrong{border-color:var(--red);background:var(--red-light);animation:shake .4s;}
.feedback-bar{min-height:52px;display:flex;align-items:center;justify-content:center;font-weight:900;font-size:17px;margin-top:14px;border-radius:14px;}
.feedback-bar.good{color:var(--green-dark);}
.feedback-bar.bad{color:var(--red);}

/* ---------- 结果弹窗 ---------- */
.overlay{
  position:fixed;inset:0;background:rgba(0,0,0,.45);display:flex;align-items:center;
  justify-content:center;z-index:50;padding:20px;
}
.result-card{
  background:#fff;border-radius:24px;padding:26px 24px;text-align:center;
  max-width:400px;width:100%;animation:pop .3s ease;
}
.result-card h2{font-size:24px;font-weight:900;margin-bottom:6px;}
.stars-big{font-size:46px;margin:10px 0 12px;letter-spacing:4px;}
.result-rows{font-size:16px;font-weight:800;color:var(--ink);line-height:2;}
.perfect-tag{display:inline-block;margin-top:8px;background:var(--yellow);color:#fff;font-weight:900;padding:6px 16px;border-radius:999px;font-size:14px;}

/* ---------- 徽章页 ---------- */
.badge-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin-top:12px;}
.badge-card{border:2px solid var(--gray-border);border-radius:18px;padding:16px 10px;text-align:center;background:#fff;}
.badge-card.earned{border-color:var(--green);background:#f7fff0;}
.badge-card.locked{opacity:.55;filter:grayscale(1);}
.badge-icon{font-size:40px;display:block;margin-bottom:6px;}
.badge-name{font-weight:900;font-size:15px;margin-bottom:2px;}
.badge-desc{font-size:12px;color:var(--gray-text);}

/* ---------- 统计页 ---------- */
.stat-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin-top:12px;}
.stat-card{background:var(--gray);border-radius:16px;padding:16px;text-align:center;}
.stat-num{font-size:30px;font-weight:900;color:var(--green-dark);}
.stat-label{font-size:13px;color:var(--gray-text);font-weight:800;margin-top:2px;}
.danger{margin-top:24px;color:var(--red);}

/* ---------- 彩带 ---------- */
.confetti{position:fixed;inset:0;pointer-events:none;z-index:60;}

/* ---------- 动画 ---------- */
@keyframes bounce{0%,100%{transform:translateY(0);}50%{transform:translateY(-8px);}}
@keyframes pop{0%{transform:scale(.5);opacity:0;}100%{transform:scale(1);opacity:1;}}
@keyframes shake{0%,100%{transform:translateX(0);}20%{transform:translateX(-6px);}40%{transform:translateX(6px);}60%{transform:translateX(-4px);}80%{transform:translateX(4px);}}
@keyframes pulse{
  0%{box-shadow:0 4px 0 var(--blue-dark),0 0 0 0 rgba(28,176,246,.5);}
  70%{box-shadow:0 4px 0 var(--blue-dark),0 0 0 14px rgba(28,176,246,0);}
  100%{box-shadow:0 4px 0 var(--blue-dark),0 0 0 0 rgba(28,176,246,0);}
}
@media (max-width:420px){
  .big-emoji{font-size:72px;}
  .word-big{font-size:36px;}
}