:root{
  --text:#f3f5fb;
  --text-dim:#a5adc9;
  --text-faint:#707b9c;
  --panel:rgba(255,255,255,.055);
  --panel-strong:rgba(255,255,255,.09);
  --line:rgba(255,255,255,.08);
  --blue:#5aa9ff;
  --pink:#ff8fae;
  --purple:#8f7bff;
  --amber:#f7b955;
  --user-grad:linear-gradient(135deg,#7b6cf6,#5aa9ff);
  --radius:18px;
  --shadow:0 10px 30px rgba(0,0,0,.25);
}

*{box-sizing:border-box;margin:0;padding:0}
[hidden]{display:none!important}
html,body{height:100%}
body{
  font-family:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  color:var(--text);
  background:
    radial-gradient(1100px 750px at 85% -10%, rgba(143,123,255,.20), transparent 60%),
    radial-gradient(900px 650px at -10% 110%, rgba(90,169,255,.16), transparent 55%),
    linear-gradient(160deg,#12162b 0%,#1b2140 55%,#2a2042 100%);
  overflow:hidden;
}
button{font-family:inherit;cursor:pointer;border:none;background:none;color:inherit}
input,textarea{font-family:inherit;color:var(--text)}

/* ===== 布局 ===== */
.app{display:flex;height:100vh;height:100dvh}

/* ===== 侧栏 ===== */
.sidebar{
  width:286px;flex:none;display:flex;flex-direction:column;gap:18px;
  padding:22px 16px 16px;
  background:var(--panel);
  border-right:1px solid var(--line);
  backdrop-filter:blur(14px);
  z-index:30;
}
.brand{display:flex;align-items:center;gap:12px;padding:4px 6px}
.brand-logo{
  width:46px;height:46px;border-radius:14px;display:grid;place-items:center;font-size:24px;
  background:linear-gradient(135deg,rgba(247,185,85,.9),rgba(255,143,174,.75));
  box-shadow:0 6px 18px rgba(247,185,85,.28);
}
.brand-name{font-size:17px;font-weight:700;letter-spacing:.5px}
.brand-sub{font-size:12px;color:var(--text-faint);margin-top:2px}

.btn-start{
  display:flex;align-items:center;justify-content:center;gap:8px;
  padding:13px 14px;border-radius:14px;
  font-size:15px;font-weight:600;color:#241a05;
  background:linear-gradient(135deg,#ffd08a,#f7b955 55%,#ff9d7a);
  box-shadow:0 8px 22px rgba(247,185,85,.25);
  transition:transform .15s, box-shadow .15s, opacity .15s;
}
.btn-start:hover{transform:translateY(-1px);box-shadow:0 10px 26px rgba(247,185,85,.32)}
.btn-start:disabled{opacity:.55;transform:none;cursor:default}
.btn-start-icon{font-size:17px}

.sidebar-section{flex:1;min-height:0;display:flex;flex-direction:column;gap:10px}
.section-title{font-size:12px;color:var(--text-faint);letter-spacing:2px;padding:0 6px}
.day-list{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:6px;padding-right:2px}
.day-empty{font-size:13px;color:var(--text-faint);padding:8px 6px}
.day-item{
  display:flex;flex-direction:column;gap:3px;padding:10px 12px;border-radius:12px;
  background:transparent;border:1px solid transparent;text-align:left;
  transition:background .15s,border-color .15s;
}
.day-item:hover{background:rgba(255,255,255,.05)}
.day-item.active{background:rgba(90,169,255,.14);border-color:rgba(90,169,255,.35)}
.day-item-top{display:flex;align-items:center;justify-content:space-between;gap:8px}
.day-label{font-size:14px;font-weight:600}
.day-count{font-size:11px;color:var(--text-faint)}
.day-topic{font-size:12px;color:var(--text-dim);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

.sidebar-footer{padding-top:4px;border-top:1px solid var(--line)}
.btn-ghost{
  width:100%;padding:10px 12px;border-radius:12px;font-size:14px;color:var(--text-dim);
  background:rgba(255,255,255,.04);border:1px solid var(--line);
  transition:background .15s,color .15s;
}
.btn-ghost:hover{background:rgba(255,255,255,.09);color:var(--text)}
.sidebar-mask{position:fixed;inset:0;background:rgba(5,8,18,.55);z-index:20;backdrop-filter:blur(2px)}

/* ===== 聊天主区 ===== */
.chat{flex:1;min-width:0;display:flex;flex-direction:column;position:relative}
.chat-header{
  flex:none;display:flex;align-items:center;gap:12px;
  padding:14px 18px;
  background:rgba(18,22,43,.72);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(12px);
  z-index:10;
}
.chat-title{flex:1;min-width:0}
.chat-name{font-size:16px;font-weight:700}
.chat-meta{font-size:12px;color:var(--text-faint);margin-top:2px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.member-avatars{display:flex}
.mini-avatar{
  width:34px;height:34px;border-radius:50%;display:grid;place-items:center;font-size:17px;
  border:2px solid rgba(255,255,255,.12);
}
.mini-avatar+.mini-avatar{margin-left:-8px}
.li-avatar{background:linear-gradient(135deg,#3f7fe0,#7fb6ff)}
.nuan-avatar{background:linear-gradient(135deg,#f0719c,#ffb7cd)}
.icon-btn{
  width:38px;height:38px;border-radius:12px;font-size:17px;color:var(--text-dim);
  display:grid;place-items:center;background:rgba(255,255,255,.05);
}
.icon-btn:hover{background:rgba(255,255,255,.1)}
.menu-btn{display:none}

.chat-scroll{flex:1;overflow-y:auto;padding:22px 18px 18px}
.messages{max-width:760px;margin:0 auto;display:flex;flex-direction:column;gap:16px}

/* 空状态 */
.hero{text-align:center;padding:54px 24px 30px;animation:fadeUp .5s ease both}
.hero-icon{font-size:56px;margin-bottom:14px}
.hero h2{font-size:24px;font-weight:700;letter-spacing:1px}
.hero p{color:var(--text-dim);font-size:14px;line-height:1.8;margin:12px auto 0;max-width:460px}
.hero-tags{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin-top:18px}
.hero-tag{font-size:12px;padding:6px 12px;border-radius:999px;background:rgba(255,255,255,.06);border:1px solid var(--line);color:var(--text-dim)}
.hero-start{margin:26px auto 0;width:auto;display:inline-flex;padding:14px 30px;font-size:15px}
@keyframes fadeUp{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}

/* 今日话题卡片 */
.topic-banner{
  text-align:center;margin:4px auto 2px;padding:14px 18px;border-radius:16px;max-width:560px;
  background:linear-gradient(135deg,rgba(247,185,85,.16),rgba(255,143,174,.14));
  border:1px solid rgba(247,185,85,.3);
  animation:fadeUp .45s ease both;
}
.topic-banner .topic-label{font-size:11px;color:var(--amber);letter-spacing:2px}
.topic-banner .topic-text{font-size:16px;font-weight:600;margin-top:5px;line-height:1.5}
.topic-banner .topic-opening{font-size:13px;color:var(--text-dim);margin-top:8px;line-height:1.7}

/* 消息 */
.msg{display:flex;gap:10px;animation:fadeUp .35s ease both;max-width:88%}
.msg.user{align-self:flex-end;flex-direction:row-reverse}
.msg-avatar{
  width:40px;height:40px;border-radius:50%;flex:none;display:grid;place-items:center;font-size:20px;
  box-shadow:var(--shadow);
}
.msg.li .msg-avatar{background:linear-gradient(135deg,#3f7fe0,#7fb6ff)}
.msg.nuan .msg-avatar{background:linear-gradient(135deg,#f0719c,#ffb7cd)}
.msg.user .msg-avatar{background:var(--user-grad)}
.msg-body{display:flex;flex-direction:column;gap:5px;min-width:0}
.msg.user .msg-body{align-items:flex-end}
.msg-head{display:flex;align-items:baseline;gap:8px;font-size:12px;color:var(--text-faint);padding:0 2px}
.msg.user .msg-head{flex-direction:row-reverse}
.msg-name{font-weight:600;color:var(--text-dim)}
.msg.user .msg-name{color:var(--blue)}
.msg-time{font-size:11px}
.bubble{
  padding:11px 14px;border-radius:16px;font-size:14.5px;line-height:1.75;
  white-space:pre-wrap;word-break:break-word;
  background:var(--panel-strong);border:1px solid var(--line);
  border-top-left-radius:4px;
}
.msg.user .bubble{
  background:var(--user-grad);border:none;border-top-right-radius:4px;
  box-shadow:0 8px 20px rgba(90,169,255,.22);
}

/* 输入中 */
.typing{display:flex;align-items:center;gap:10px;max-width:760px;margin:16px auto 0;animation:fadeUp .25s ease both}
.typing-avatar{
  width:40px;height:40px;border-radius:50%;display:grid;place-items:center;font-size:20px;
  background:var(--panel-strong);border:1px solid var(--line);
}
.typing-bubble{
  display:flex;gap:5px;align-items:center;padding:13px 16px;border-radius:16px;
  background:var(--panel-strong);border:1px solid var(--line);border-top-left-radius:4px;
}
.dot{width:7px;height:7px;border-radius:50%;background:var(--text-dim);animation:blink 1.2s infinite}
.dot:nth-child(2){animation-delay:.2s}
.dot:nth-child(3){animation-delay:.4s}
@keyframes blink{0%,60%,100%{opacity:.25;transform:translateY(0)}30%{opacity:1;transform:translateY(-3px)}}
.typing-name{font-size:12px;color:var(--text-faint)}

/* 输入栏 */
.input-bar{
  flex:none;display:flex;align-items:flex-end;gap:10px;
  padding:12px 16px calc(12px + env(safe-area-inset-bottom));
  background:rgba(18,22,43,.72);border-top:1px solid var(--line);backdrop-filter:blur(12px);
}
.input-bar textarea{
  flex:1;resize:none;max-height:120px;padding:12px 14px;border-radius:14px;
  font-size:14.5px;line-height:1.6;outline:none;
  background:rgba(255,255,255,.07);border:1px solid var(--line);color:var(--text);
  transition:border-color .15s, background .15s;
}
.input-bar textarea:focus{border-color:rgba(90,169,255,.55);background:rgba(255,255,255,.09)}
.input-bar textarea::placeholder{color:var(--text-faint)}
.send-btn{
  flex:none;height:44px;padding:0 22px;border-radius:14px;font-size:15px;font-weight:600;
  background:var(--user-grad);color:#fff;box-shadow:0 6px 16px rgba(90,169,255,.3);
  transition:opacity .15s,transform .15s;
}
.send-btn:hover:not(:disabled){transform:translateY(-1px)}
.send-btn:disabled{opacity:.45;cursor:default;box-shadow:none}

/* 弹窗 */
.modal-mask{
  position:fixed;inset:0;background:rgba(5,8,18,.6);backdrop-filter:blur(4px);
  z-index:50;display:grid;place-items:center;padding:18px;
}
.modal{
  width:min(560px,100%);max-height:88vh;display:flex;flex-direction:column;border-radius:20px;
  background:linear-gradient(165deg,#20284a,#1a1f3a);border:1px solid var(--line);
  box-shadow:0 24px 60px rgba(0,0,0,.45);animation:fadeUp .3s ease both;
}
.modal-title{padding:20px 22px 0;font-size:18px}
.modal-body{padding:18px 22px;overflow-y:auto;display:flex;flex-direction:column;gap:16px}
.field{display:flex;flex-direction:column;gap:7px}
.field label{font-size:13px;color:var(--text-dim)}
.field input,.field textarea{
  padding:10px 12px;border-radius:11px;outline:none;font-size:14px;line-height:1.6;
  background:rgba(255,255,255,.06);border:1px solid var(--line);color:var(--text);
}
.field input:focus,.field textarea:focus{border-color:rgba(90,169,255,.55)}
.field textarea{resize:vertical;min-height:88px}
.field-row{display:flex;gap:12px}
.field-row .field{flex:1}
.field-emoji{max-width:110px}
.ai-card{
  padding:14px;border-radius:16px;background:rgba(255,255,255,.04);
  border:1px solid var(--line);display:flex;flex-direction:column;gap:12px;
}
.ai-card-li{border-color:rgba(90,169,255,.28)}
.ai-card-nuan{border-color:rgba(255,143,174,.28)}
.ai-card-head{display:flex;align-items:center;gap:10px}
.ai-card-head b{font-size:15px}
.tag{font-size:11px;padding:3px 9px;border-radius:999px;background:rgba(255,255,255,.08);color:var(--text-dim)}
.hint{font-size:12px;color:var(--text-faint);line-height:1.7}
.modal-footer{display:flex;justify-content:flex-end;gap:10px;padding:16px 22px;border-top:1px solid var(--line)}
.btn-primary{
  padding:10px 22px;border-radius:12px;font-size:14px;font-weight:600;color:#fff;
  background:var(--user-grad);box-shadow:0 6px 16px rgba(90,169,255,.28);
}

/* 提示 */
.toast{
  position:fixed;left:50%;bottom:calc(84px + env(safe-area-inset-bottom));transform:translateX(-50%);
  max-width:88vw;padding:11px 18px;border-radius:12px;font-size:13.5px;line-height:1.6;text-align:center;
  background:rgba(30,34,60,.96);border:1px solid var(--line);box-shadow:var(--shadow);z-index:60;
  animation:fadeUp .25s ease both;
}

/* 滚动条 */
::-webkit-scrollbar{width:8px;height:8px}
::-webkit-scrollbar-thumb{background:rgba(255,255,255,.14);border-radius:8px}
::-webkit-scrollbar-thumb:hover{background:rgba(255,255,255,.22)}

/* 手机端 */
@media (max-width:860px){
  .menu-btn{display:grid}
  .sidebar{
    position:fixed;top:0;bottom:0;left:0;width:286px;
    transform:translateX(-102%);transition:transform .28s ease;
  }
  .sidebar.open{transform:none}
  .chat-header{padding:12px 14px}
  .chat-scroll{padding:16px 12px}
  .msg{max-width:92%}
  .hero h2{font-size:21px}
  .send-btn{padding:0 18px}
}