/* LinguaMind v2 — Study-friendly UI (light theme)
   ------------------------------------------------
   设计关键词：清爽、阅读友好、卡片化、可运营、可扩展
   你后续可以把变量换成品牌色或深色模式。
*/

:root{
  --bg: #f7f8fb;
  --card: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --faint: #9ca3af;
  --line: #e5e7eb;

  --primary: #4f46e5; /* indigo */
  --primary-weak: rgba(79, 70, 229, .10);
  --accent: #10b981;  /* emerald */
  --warn: #f59e0b;    /* amber */
  --bad: #ef4444;     /* red */

  --shadow: 0 12px 30px rgba(17,24,39,.08);
  --radius: 16px;
  --radius2: 12px;

  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --sans: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
}

*{ box-sizing: border-box; }
html, body{ height: 100%; }
body{
  margin: 0;
  font-family: var(--sans);
  color: var(--text);
  background: radial-gradient(1200px 650px at 20% -10%, rgba(79,70,229,.10), transparent 60%),
              radial-gradient(900px 500px at 90% 0%, rgba(16,185,129,.08), transparent 55%),
              var(--bg);
}

a{ color: inherit; text-decoration: none; }
button, input, textarea, select{ font-family: inherit; }

.container{
  max-width: 1280px;
  margin: 0 auto;
  padding: 18px;
}

.app{
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 14px;
  min-height: calc(100vh - 36px);
}

@media (max-width: 980px){
  .app{ grid-template-columns: 1fr; }
  .sidebar{ position: relative !important; top: 0 !important; height: auto !important; }
}

.sidebar{
  position: sticky;
  top: 18px;
  height: calc(100vh - 36px);
  background: rgba(255,255,255,.55);
  backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 14px;
  overflow: hidden;
}

.brand{
  display: flex;
  gap: 10px;
  align-items: center;
  padding: 10px 10px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: var(--card);
}
.logo{
  width: 38px;
  height: 38px;
  border-radius: 14px;
  background: radial-gradient(circle at 30% 30%, rgba(255,255,255,.9), transparent 45%),
              linear-gradient(135deg, rgba(79,70,229,.95), rgba(16,185,129,.85));
  box-shadow: 0 10px 24px rgba(79,70,229,.18);
}
.brand h1{
  font-size: 14px;
  margin: 0;
  letter-spacing: .2px;
}
.brand .sub{
  margin-top: 2px;
  font-size: 12px;
  color: var(--muted);
}

.nav{
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.nav .item{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.75);
  cursor: pointer;
  user-select: none;
  transition: .12s ease;
  color: var(--muted);
}
.nav .item:hover{ transform: translateY(-1px); box-shadow: 0 10px 18px rgba(17,24,39,.06); }
.nav .item.active{
  color: var(--text);
  border-color: rgba(79,70,229,.35);
  background: var(--primary-weak);
}

.pill{
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--muted);
  background: rgba(255,255,255,.8);
  white-space: nowrap;
}

.main{
  background: rgba(255,255,255,.55);
  backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.topbar{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  background: rgba(255,255,255,.8);
}

.title{
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.title .h{
  font-size: 16px;
  font-weight: 750;
  letter-spacing: .2px;
}
.title .s{
  font-size: 12px;
  color: var(--muted);
}

.actions{
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
  justify-content: flex-end;
}
.btn{
  display: inline-flex;
  gap: 8px;
  align-items: center;
  justify-content: center;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.9);
  cursor: pointer;
  font-size: 13px;
  transition: .12s ease;
}
.btn:hover{ transform: translateY(-1px); box-shadow: 0 10px 18px rgba(17,24,39,.06); }
.btn.primary{
  background: linear-gradient(135deg, rgba(79,70,229,.95), rgba(79,70,229,.75));
  border-color: rgba(79,70,229,.35);
  color: white;
}
.btn.ghost{
  background: rgba(255,255,255,.55);
  color: var(--muted);
}

.body{
  padding: 16px;
}

.grid{
  display: grid;
  grid-template-columns: 1.2fr .8fr;
  gap: 14px;
}
@media (max-width: 980px){
  .grid{ grid-template-columns: 1fr; }
}

.card{
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
  box-shadow: 0 10px 22px rgba(17,24,39,.05);
  overflow: hidden;
}
.card .hd{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  background: rgba(249,250,251,.7);
}
.card .hd h2{ margin: 0; font-size: 13px; }
.card .bd{ padding: 12px 14px; }

.muted{ color: var(--muted); }
.faint{ color: var(--faint); }

.kpis{
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}
@media (max-width: 1100px){
  .kpis{ grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 620px){
  .kpis{ grid-template-columns: 1fr; }
}
.kpi .k{ font-size: 12px; color: var(--muted); }
.kpi .v{ font-size: 22px; font-weight: 800; letter-spacing: .2px; }
.kpi .d{ font-size: 12px; color: var(--muted); margin-top: 2px; }

.tag{
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.85);
  color: var(--muted);
}
.tag.good{ border-color: rgba(16,185,129,.25); background: rgba(16,185,129,.10); color: #065f46; }
.tag.warn{ border-color: rgba(245,158,11,.25); background: rgba(245,158,11,.10); color: #92400e; }
.tag.bad{ border-color: rgba(239,68,68,.25); background: rgba(239,68,68,.10); color: #7f1d1d; }

.row{
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}
.sep{ height: 1px; background: var(--line); margin: 12px 0; }

input[type="text"], textarea, select{
  width: 100%;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.95);
  outline: none;
  font-size: 13px;
}
textarea{ min-height: 90px; resize: vertical; }

.two{
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
@media (max-width: 740px){
  .two{ grid-template-columns: 1fr; }
}

.code{
  font-family: var(--mono);
  font-size: 12px;
  white-space: pre-wrap;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(249,250,251,.9);
  padding: 10px 12px;
  color: #111827;
}

.badgeDot{
  display:inline-block;
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: var(--accent);
  margin-right: 6px;
  box-shadow: 0 0 0 4px rgba(16,185,129,.12);
}

/* Chat UI */
.chat{
  display:flex;
  flex-direction:column;
  height: 62vh;
  min-height: 520px;
}
.chatList{
  flex: 1;
  overflow: auto;
  padding: 10px 10px 6px;
  display:flex;
  flex-direction:column;
  gap: 10px;
}
.msg{
  max-width: 88%;
  border-radius: 16px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.95);
  line-height: 1.45;
  font-size: 14px;
}
.msg.you{
  margin-left: auto;
  background: rgba(79,70,229,.08);
  border-color: rgba(79,70,229,.22);
}
.msg.ai{
  margin-right: auto;
}
.msg .meta{
  margin-top: 6px;
  display:flex;
  gap: 8px;
  align-items:center;
  flex-wrap: wrap;
  color: var(--muted);
  font-size: 12px;
}
.composer{
  border-top: 1px solid var(--line);
  padding: 12px;
  display:flex;
  gap: 10px;
  align-items:flex-end;
  background: rgba(249,250,251,.7);
}
.composer textarea{ min-height: 48px; }

.smallLink{
  color: var(--primary);
  cursor: pointer;
  font-weight: 650;
}

/* Training */
.qList{
  display:flex;
  flex-direction:column;
  gap: 10px;
}
.qItem{
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(249,250,251,.7);
}
.qItem .t{ font-weight: 700; font-size: 13px; }
.qItem .s{ font-size: 12px; color: var(--muted); margin-top: 4px; line-height: 1.35; }

/* Skill bars */
.bar{
  height: 10px;
  border-radius: 999px;
  background: #eef2ff;
  border: 1px solid rgba(79,70,229,.18);
  overflow: hidden;
  margin-top: 6px;
}
.bar > i{
  display:block;
  height: 100%;
  width: 50%;
  background: linear-gradient(90deg, rgba(79,70,229,.85), rgba(16,185,129,.75));
  border-radius: 999px;
}

/* Community feed */
.feed{
  display:flex;
  flex-direction:column;
  gap: 10px;
}
.post{
  border: 1px solid var(--line);
  background: rgba(255,255,255,.95);
  border-radius: 16px;
  padding: 12px 12px;
  cursor: pointer;
  transition: .12s ease;
}
.post:hover{ transform: translateY(-1px); box-shadow: 0 10px 18px rgba(17,24,39,.06); }
.post .top{
  display:flex; align-items:flex-start; justify-content:space-between; gap: 10px;
}
.post .title{ font-weight: 800; font-size: 14px; }
.post .meta{ margin-top: 6px; font-size: 12px; color: var(--muted); display:flex; gap: 8px; align-items:center; flex-wrap: wrap; }
.post .excerpt{ margin-top: 8px; color: #374151; font-size: 13px; line-height: 1.4; }
.vote{
  display:flex; gap: 6px; align-items:center;
  border: 1px solid var(--line);
  background: rgba(249,250,251,.9);
  border-radius: 999px;
  padding: 6px 10px;
  font-size: 12px;
  color: var(--muted);
  white-space: nowrap;
}
.vote b{ color: #111827; }

/* Modal */
.modalBackdrop{
  position: fixed;
  inset: 0;
  background: rgba(17,24,39,.35);
  display:none;
  align-items:center;
  justify-content:center;
  padding: 18px;
  z-index: 50;
}
.modalBackdrop.show{ display:flex; }
.modal{
  width: min(980px, 100%);
  max-height: 86vh;
  overflow: auto;
  background: white;
  border-radius: 18px;
  border: 1px solid var(--line);
  box-shadow: 0 18px 60px rgba(17,24,39,.25);
}
.modal .mhd{
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  display:flex; justify-content:space-between; gap: 10px; align-items:flex-start;
  background: rgba(249,250,251,.7);
}
.modal .mhd .ttl{ font-size: 14px; font-weight: 850; }
.modal .mbd{ padding: 12px 14px; }

.comment{
  border: 1px solid var(--line);
  background: rgba(249,250,251,.7);
  border-radius: 14px;
  padding: 10px 12px;
  margin-top: 10px;
}
.comment .who{ font-size: 12px; color: var(--muted); }
.comment .txt{ margin-top: 6px; font-size: 13px; line-height: 1.4; }

/* Toast */
.toast{
  position: fixed;
  right: 18px;
  bottom: 18px;
  max-width: 360px;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.92);
  box-shadow: 0 18px 55px rgba(17,24,39,.12);
  display:none;
  z-index: 60;
  font-size: 13px;
  line-height: 1.35;
}
.toast.show{ display:block; animation: pop .16s ease-out; }
@keyframes pop{
  from{ transform: translateY(6px); opacity: .7; }
  to{ transform: translateY(0); opacity: 1; }
}

/* Utility */
.hidden{ display:none !important; }