/* ==========================================================================
   AI助学 · 设计系统
   视觉：柔和渐变 + 淡阴影，色彩用于区分状态而非装饰
   文字与交互：克制、少解释
   ========================================================================== */

:root{
  /* 画布 */
  --bg:#F4F6FB;
  --surface:#FFFFFF;
  --surface-2:#FAFBFE;

  /* 文字 */
  --ink:#0F172A;
  --ink-2:#475569;
  --ink-3:#94A3B8;

  /* 线条 */
  --line:#E6EAF2;
  --line-2:#F1F4F9;

  /* 主色 */
  --brand:#4F46E5;
  --brand-2:#7C3AED;
  --brand-soft:#EEF0FF;
  --brand-ink:#3730A3;

  /* 语音 */
  --voice:#FF5A5F;
  --voice-soft:#FFF0F0;

  /* 状态 */
  --none:#CBD5E1;
  --bad:#EF4444;
  --warn:#F59E0B;
  --ok:#10B981;

  /* 圆角 */
  --r-sm:10px;
  --r:14px;
  --r-lg:20px;
  --r-xl:28px;

  /* 阴影 */
  --sh-1:0 1px 2px rgba(15,23,42,.05), 0 4px 14px rgba(15,23,42,.05);
  --sh-2:0 10px 34px rgba(15,23,42,.09);
  --sh-voice:0 12px 30px rgba(255,90,95,.38);

  /* 新别名（页面统一用这个） */
  --accent:var(--brand);
  --accent-hi:#4338CA;
  --accent-soft:var(--brand-soft);
  --brand-strong:#3730A3;
  --sh-brand:0 10px 26px rgba(79,70,229,.30);

  --nav-h:64px;
  --page-max:1120px;
}

*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
body{
  font-family:"PingFang SC","Microsoft YaHei","Hiragino Sans GB",-apple-system,BlinkMacSystemFont,"Helvetica Neue",sans-serif;
  background:var(--bg);
  color:var(--ink);
  font-size:14px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  padding-bottom:86px;
}
a{color:inherit;text-decoration:none}
button{font-family:inherit;font-size:inherit;cursor:pointer;border:none;background:none;color:inherit}
input,textarea,select{font-family:inherit;font-size:inherit}
svg{display:block}
img{max-width:100%}

/* ============================ 顶栏 ============================ */
.topbar{
  position:sticky;top:0;z-index:60;
  height:var(--nav-h);
  display:flex;align-items:center;gap:26px;
  padding:0 26px;
  background:rgba(255,255,255,.86);
  -webkit-backdrop-filter:blur(14px);
  backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
}
.brand{display:flex;align-items:center;gap:11px;flex-shrink:0}
.logo{
  width:36px;height:36px;border-radius:11px;
  background:linear-gradient(135deg,var(--brand),var(--brand-2));
  color:#fff;font-weight:700;font-size:13px;letter-spacing:-.4px;
  display:grid;place-items:center;
  box-shadow:0 6px 16px rgba(79,70,229,.32);
}
.brand-name{font-size:16px;font-weight:700;letter-spacing:.3px}
.brand-sub{font-size:11px;color:var(--ink-3);letter-spacing:.3px}

.mainnav{display:flex;gap:4px;margin-left:6px}
.mainnav a{
  padding:8px 14px;border-radius:10px;
  font-size:14px;color:var(--ink-2);font-weight:500;
  transition:.18s;
}
.mainnav a:hover{background:var(--brand-soft);color:var(--brand-ink)}
.mainnav a.active{
  background:var(--brand);color:#fff;
  box-shadow:0 6px 16px rgba(79,70,229,.28);
}

.topbar-right{margin-left:auto;display:flex;align-items:center;gap:12px}
.grade-chip{
  font-size:12.5px;color:var(--ink-2);
  background:var(--surface-2);border:1px solid var(--line);
  padding:6px 12px;border-radius:99px;font-weight:500;
}
.avatar{
  width:32px;height:32px;border-radius:50%;
  background:linear-gradient(135deg,#FBBF24,#F59E0B);
  color:#fff;font-weight:700;font-size:13px;display:grid;place-items:center;
}

/* ============================ 布局 ============================ */
.page{max-width:var(--page-max);margin:0 auto;padding:28px 24px}

.page-head{display:flex;align-items:flex-end;justify-content:space-between;gap:18px;
  margin-bottom:22px;flex-wrap:wrap}
.page-title{font-size:26px;font-weight:700;letter-spacing:-.3px;line-height:1.25}
.page-desc{font-size:13px;color:var(--ink-3);margin-top:6px;max-width:620px;line-height:1.6}
.page-actions{display:flex;gap:10px;flex-wrap:wrap}

.grid{display:grid;gap:16px}
.g-2{grid-template-columns:repeat(2,1fr)}
.g-3{grid-template-columns:repeat(3,1fr)}
.g-4{grid-template-columns:repeat(4,1fr)}
.g-main{grid-template-columns:1fr 320px}

.card{
  background:var(--surface);
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  box-shadow:var(--sh-1);
  padding:22px;
}
.card-tight{padding:16px}
.card-h{display:flex;align-items:flex-start;justify-content:space-between;gap:14px;margin-bottom:16px}
.card-title{font-size:15.5px;font-weight:650;letter-spacing:-.1px;display:flex;align-items:center;gap:8px}
.card-sub{font-size:12.5px;color:var(--ink-3);margin-top:4px;line-height:1.6}
.card-more{font-size:12.5px;color:var(--brand);font-weight:500;white-space:nowrap}
.card-more:hover{text-decoration:underline}

/* ============================ 按钮 ============================ */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:7px;
  padding:10px 19px;border-radius:12px;
  font-size:13.5px;font-weight:600;letter-spacing:0;
  transition:.18s;white-space:nowrap;
}
.btn:active{transform:translateY(1px)}
.btn-primary{background:var(--brand);color:#fff;box-shadow:0 6px 16px rgba(79,70,229,.26)}
.btn-primary:hover{background:var(--brand-ink);transform:translateY(-1px)}
.btn-ghost{background:var(--surface);color:var(--ink-2);border:1px solid var(--line)}
.btn-ghost:hover{border-color:#C7CEE0;color:var(--ink)}
.btn-soft{background:var(--brand-soft);color:var(--brand-ink)}
.btn-soft:hover{background:#E4E7FF}
.btn-voice{background:var(--voice);color:#fff;box-shadow:var(--sh-voice)}
.btn-voice:hover{background:#F04449;transform:translateY(-1px)}
.btn-sm{padding:7px 13px;font-size:12.5px;border-radius:9px}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none!important}

/* ============================ 状态点 ============================ */
.dot{width:9px;height:9px;border-radius:50%;flex-shrink:0;display:inline-block}
.dot-none{background:var(--none)}
.dot-bad{background:var(--bad)}
.dot-warn{background:var(--warn)}
.dot-ok{background:var(--ok)}

.kp{display:flex;align-items:center;gap:9px;font-size:13px;color:var(--ink-2)}
.kp-badge{font-size:11.5px;font-weight:600;padding:3px 9px;border-radius:99px}
.b-none{background:#F1F5F9;color:#64748B}
.b-bad{background:#FEF2F2;color:#B91C1C}
.b-warn{background:#FFFBEB;color:#B45309}
.b-ok{background:#ECFDF5;color:#047857}

.segbar{display:flex;height:9px;border-radius:99px;overflow:hidden;background:#F1F5F9}
.segbar i{display:block;height:100%}

/* ============================ 标签 ============================ */
.tag{
  display:inline-flex;align-items:center;gap:5px;
  font-size:11.5px;font-weight:600;
  padding:4px 10px;border-radius:99px;
  background:var(--surface-2);color:var(--ink-2);border:1px solid var(--line);
}
.tag-brand{background:var(--brand-soft);color:var(--brand-ink);border-color:transparent}
.tag-ok{background:#ECFDF5;color:#047857;border-color:transparent}
.tag-warn{background:#FFFBEB;color:#B45309;border-color:transparent}
.tag-bad{background:#FEF2F2;color:#B91C1C;border-color:transparent}
.tag-soon{background:#F1F5F9;color:#94A3B8;border-color:transparent}

.divider{height:1px;background:var(--line-2);margin:16px 0}
.muted{color:var(--ink-3)}
.small{font-size:12.5px}
.strong{font-weight:650}
.mono{font-variant-numeric:tabular-nums}

.lock-note{
  display:flex;align-items:center;gap:7px;
  font-size:12px;color:var(--ink-3);line-height:1.5;
}

.empty{text-align:center;padding:36px 20px}
.empty-ico{font-size:34px;margin-bottom:10px}
.empty-t{font-size:14px;font-weight:600;margin-bottom:6px}
.empty-d{font-size:12.5px;color:var(--ink-3);margin-bottom:16px}

/* ============================ 语音球 ============================ */
.voice-dock{
  position:fixed;right:26px;bottom:26px;z-index:80;
  display:flex;flex-direction:column;align-items:center;gap:8px;
}
.voice-orb{
  position:relative;
  width:64px;height:64px;border-radius:50%;
  background:linear-gradient(140deg,#FF7A7E,var(--voice));
  color:#fff;display:grid;place-items:center;
  box-shadow:var(--sh-voice);
  transition:.22s;
}
.voice-orb:hover{transform:scale(1.06)}
.voice-orb::before,.voice-orb::after{
  content:"";position:absolute;inset:0;border-radius:50%;
  border:2px solid rgba(255,90,95,.5);
  animation:pulse 2.6s ease-out infinite;
}
.voice-orb::after{animation-delay:1.3s}
@keyframes pulse{
  0%{transform:scale(1);opacity:.9}
  100%{transform:scale(1.75);opacity:0}
}
.voice-label{
  font-size:11.5px;font-weight:600;color:var(--voice);
  background:#fff;padding:4px 11px;border-radius:99px;
  box-shadow:var(--sh-1);
}

.voice-sheet{
  position:fixed;inset:0;z-index:90;
  background:rgba(15,23,42,.45);
  -webkit-backdrop-filter:blur(3px);backdrop-filter:blur(3px);
  display:none;align-items:flex-end;justify-content:center;
}
.voice-sheet.open{display:flex}
.voice-panel{
  width:min(720px,100%);background:#fff;
  border-radius:26px 26px 0 0;padding:26px;
  box-shadow:0 -20px 60px rgba(15,23,42,.22);
}
.voice-wave{display:flex;align-items:flex-end;gap:4px;height:44px;justify-content:center;margin:16px 0}
.voice-wave i{
  width:4px;border-radius:99px;background:var(--voice);
  animation:wave 1s ease-in-out infinite;
}
@keyframes wave{0%,100%{height:10px;opacity:.5}50%{height:38px;opacity:1}}
.voice-live{
  min-height:76px;background:var(--surface-2);
  border:1px solid var(--line);border-radius:var(--r);
  padding:14px 16px;font-size:16px;line-height:1.75;
}
.voice-live .interim{color:var(--ink-3);font-style:italic}

/* ============================ 底部导航 ============================ */
.tabbar{
  display:none;position:fixed;left:0;right:0;bottom:0;z-index:70;
  height:64px;background:rgba(255,255,255,.94);
  -webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);
  border-top:1px solid var(--line);
  padding-bottom:env(safe-area-inset-bottom);
}
.tabbar-inner{display:flex;height:64px}
.tabbar a{
  flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;
  font-size:10.5px;color:var(--ink-3);
}
.tabbar a.active{color:var(--brand);font-weight:600}
.tabbar .t-ico{font-size:17px;line-height:1}

/* ============================ 响应式 ============================ */
@media (max-width:1080px){
  .g-main{grid-template-columns:1fr}
  .g-4{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:860px){
  :root{--nav-h:58px;--page-max:100%}
  .topbar{padding:0 14px;gap:12px}
  .brand-sub{display:none}
  .mainnav{display:none}
  .grade-chip{display:none}
  .page{padding:16px}
  .g-2,.g-3,.g-4{grid-template-columns:1fr}
  .page-title{font-size:21px}
  .card{padding:18px;border-radius:16px}
  .tabbar{display:block}
  .voice-dock{right:16px;bottom:82px}
  .voice-orb{width:56px;height:56px}
  body{padding-bottom:74px}
}