/* ─── RESET ──────────────────────────────────────────────────────────── */
*{margin:0;padding:0;box-sizing:border-box}

/* ─── DESIGN TOKENS ──────────────────────────────────────────────────── */
:root{
  /* Brand */
  --red:#C8281E;--red-light:#FEE8E6;--red-mid:#F28B82;--red-dark:#9B1D15;
  --red-glow:rgba(200,40,30,0.18);

  /* Backgrounds */
  --bg:#F4F2EE;--surface:#FFFFFF;--surface2:#F9F8F5;--surface3:#F0EEE9;

  /* Sidebar */
  --sidebar:#141414;--sidebar-hover:#1E1E1E;--sidebar-active:#222222;
  --sidebar-text:#E8E4DC;--sidebar-muted:#6A6660;--sidebar-border:#252525;

  /* Text */
  --text:#1A1A1A;--text2:#6B6860;--text3:#A09D96;--text4:#C8C5BE;

  /* Borders */
  --border:#E8E5DF;--border2:#D4D0C8;--border3:#C0BCB4;

  /* Semantic */
  --green:#177A47;--green-light:#E8F5EE;--green-border:#A7D7BC;
  --amber:#A0510D;--amber-light:#FEF3C7;--amber-border:#F0C070;
  --blue:#1A4BD8;--blue-light:#EEF4FF;--blue-border:#A8C0F0;

  /* Shadows */
  --shadow-sm:0 1px 3px rgba(0,0,0,0.07),0 1px 2px rgba(0,0,0,0.05);
  --shadow-md:0 4px 12px rgba(0,0,0,0.08),0 2px 4px rgba(0,0,0,0.05);
  --shadow-lg:0 8px 28px rgba(0,0,0,0.10),0 4px 10px rgba(0,0,0,0.06);
  --shadow-focus:0 0 0 3px var(--red-glow);

  /* Shape */
  --radius:14px;--radius-sm:9px;--radius-xs:6px;

  /* Animation */
  --ease-spring:cubic-bezier(0.34,1.56,0.64,1);
  --ease-out:cubic-bezier(0.16,1,0.3,1);
  --duration:160ms;
}

/* ─── DARK MODE ──────────────────────────────────────────────────────── */
body.dark{
  --bg:#0F0F0F;--surface:#1A1A1A;--surface2:#1F1F1F;--surface3:#252525;
  --text:#E8E4DC;--text2:#9A9690;--text3:#5A5752;--text4:#3A3835;
  --border:#2A2825;--border2:#353230;--border3:#454240;
  --red-light:rgba(200,40,30,0.15);--red-mid:#C8281E;
  --green-light:rgba(23,122,71,0.15);--green-border:rgba(167,215,188,0.3);
  --amber-light:rgba(160,81,13,0.15);--amber-border:rgba(240,192,112,0.3);
  --blue-light:rgba(26,75,216,0.15);--blue-border:rgba(168,192,240,0.3);
  --shadow-sm:0 1px 3px rgba(0,0,0,0.3),0 1px 2px rgba(0,0,0,0.2);
  --shadow-md:0 4px 12px rgba(0,0,0,0.4),0 2px 4px rgba(0,0,0,0.2);
  --shadow-lg:0 8px 28px rgba(0,0,0,0.5),0 4px 10px rgba(0,0,0,0.3);
}
body.dark #sidebar{
  --sidebar:#0A0A0A;--sidebar-hover:#141414;--sidebar-active:#1A1A1A;
  --sidebar-border:#1A1A1A;--sidebar-muted:#4A4642;
}
body.dark .logo-text .zh{color:#E8E4DC}
body.dark .answer-input{background:var(--surface);color:var(--text)}
body.dark .form-group input,body.dark .form-group textarea{background:var(--surface);color:var(--text)}
body.dark table{color:var(--text)}
body.dark th{background:var(--surface2);color:var(--text3)}
body.dark .cancel-upload-btn{background:var(--surface)!important;color:var(--text2)!important;border-color:var(--border2)!important}
body.dark #back-articles-btn{background:var(--surface)!important;color:var(--text2)!important;border-color:var(--border2)!important}
body.dark .search-input{background:var(--surface);color:var(--text)}
body.dark #popup-vi-inp{background:#1A1A1A;color:#E8E4DC}

/* Dark mode toggle button */
#dark-toggle{
  position:relative;
  width:40px;height:22px;
  background:var(--surface3);
  border:1.5px solid var(--border2);
  border-radius:99px;
  cursor:pointer;
  transition:background 0.25s,border-color 0.25s;
  flex-shrink:0;
}
#dark-toggle::after{
  content:'';
  position:absolute;top:2px;left:2px;
  width:14px;height:14px;
  border-radius:50%;
  background:var(--text3);
  transition:transform 0.25s var(--ease-spring),background 0.25s;
}
body.dark #dark-toggle{background:var(--red);border-color:var(--red-dark)}
body.dark #dark-toggle::after{transform:translateX(18px);background:#fff}

/* ─── TRADITIONAL TOGGLE ─────────────────────────────────────────────── */
#trad-toggle{
  position:relative;
  width:40px;height:22px;
  background:var(--surface3);
  border:1.5px solid var(--border2);
  border-radius:99px;
  cursor:pointer;
  transition:background 0.25s,border-color 0.25s;
  flex-shrink:0;
}
#trad-toggle::after{
  content:'';
  position:absolute;top:2px;left:2px;
  width:14px;height:14px;
  border-radius:50%;
  background:var(--text3);
  transition:transform 0.25s var(--ease-spring),background 0.25s;
}
body.trad #trad-toggle{background:var(--red);border-color:var(--red-dark)}
body.trad #trad-toggle::after{transform:translateX(18px);background:#fff}

/* ─── MOBILE MENU ────────────────────────────────────────────────────── */
#menu-btn{
  display:none;
  position:fixed;top:14px;left:14px;z-index:900;
  width:38px;height:38px;
  background:var(--sidebar);
  border:none;border-radius:9px;
  cursor:pointer;
  align-items:center;justify-content:center;flex-direction:column;gap:4px;
  box-shadow:var(--shadow-md);
}
#menu-btn span{
  display:block;width:18px;height:2px;background:#C8C4BC;border-radius:1px;
  transition:all 0.2s;
}
#sidebar-overlay{
  display:none;position:fixed;inset:0;background:rgba(0,0,0,0.5);
  z-index:700;backdrop-filter:blur(2px);
}

/* ─── RESPONSIVE ─────────────────────────────────────────────────────── */
@media(max-width:768px){
  body{flex-direction:column;height:auto;overflow:auto}
  #sidebar{
    position:fixed;top:0;left:0;height:100dvh;z-index:800;
    transform:translateX(-100%);transition:transform 0.3s var(--ease-out);
    width:240px;min-width:240px;
  }
  #sidebar.open{transform:translateX(0)}
  #sidebar-overlay.open{display:block}
  #menu-btn{display:flex}
  #main{
    padding-top:62px;height:100dvh;overflow-y:auto;
  }
  .page{padding:20px 16px!important}
  .stats-grid{grid-template-columns:1fr 1fr!important;gap:10px}
  .mini-stats-row{grid-template-columns:1fr!important;gap:10px}
  .word-grid{grid-template-columns:1fr 1fr!important}
  #add.page.active{min-height:unset;padding:20px 16px!important}
  #add .card{max-width:100%!important}
  #review.page{max-width:100%}
  .review-card{padding:28px 20px}
  .review-word{font-size:28px}
  .diff-btns{grid-template-columns:repeat(2,1fr)!important}
  #read-article .page-header>div{flex-direction:column;align-items:flex-start!important;gap:8px}
  #article-read-grid{grid-template-columns:1fr!important}
  table{font-size:12px}
  th,td{padding:9px 10px}
  .page-header h1{font-size:20px}
}
@media(max-width:480px){
  .stats-grid{grid-template-columns:1fr!important}
  .word-grid{grid-template-columns:1fr!important}
  .diff-btns{grid-template-columns:repeat(2,1fr)!important}
}

/* ─── LOGIN SCREEN ───────────────────────────────────────────────────── */
#login-screen{
  position:fixed;inset:0;background:var(--bg);
  display:flex;align-items:center;justify-content:center;
  z-index:9997;flex-direction:column;
}
.login-card{
  background:var(--surface);border:1px solid var(--border);
  border-radius:20px;padding:44px 40px;text-align:center;
  box-shadow:var(--shadow-lg);width:100%;max-width:380px;
}
.login-logo{
  width:64px;height:64px;
  background:linear-gradient(145deg,var(--red),var(--red-dark));
  border-radius:18px;margin:0 auto 18px;
  display:flex;align-items:center;justify-content:center;
  font-family:'Noto Serif SC',serif;font-size:32px;color:#fff;font-weight:700;
  box-shadow:0 8px 24px var(--red-glow);
}
.login-title{font-size:22px;font-weight:700;margin-bottom:6px;letter-spacing:-0.02em}
.login-sub{font-size:14px;color:var(--text2);margin-bottom:32px;line-height:1.5}
.google-btn{
  display:flex;align-items:center;justify-content:center;gap:12px;
  width:100%;padding:13px 20px;
  background:var(--surface);border:1.5px solid var(--border2);
  border-radius:var(--radius-sm);cursor:pointer;
  font-size:14px;font-weight:600;color:var(--text);
  font-family:'DM Sans',sans-serif;
  transition:all 0.15s var(--ease-out);
  box-shadow:var(--shadow-sm);
}
.google-btn:hover{border-color:var(--border3);box-shadow:var(--shadow-md);transform:translateY(-1px)}
.google-btn:active{transform:none;box-shadow:var(--shadow-sm)}
.google-btn svg{flex-shrink:0}
.login-note{font-size:11px;color:var(--text4);margin-top:18px;line-height:1.6}
.login-err{font-size:13px;color:var(--red);margin-top:12px;min-height:18px}

/* ─── USER PROFILE in sidebar ────────────────────────────────────────── */
.user-row{
  display:flex;align-items:center;gap:9px;
  padding:12px 20px 10px;border-bottom:1px solid var(--sidebar-border);
}
.user-avatar{
  width:30px;height:30px;border-radius:50%;object-fit:cover;flex-shrink:0;
  border:1.5px solid var(--sidebar-border);
}
.user-avatar-fallback{
  width:30px;height:30px;border-radius:50%;flex-shrink:0;
  background:var(--red);display:flex;align-items:center;justify-content:center;
  font-size:13px;font-weight:700;color:#fff;
}
.user-info{flex:1;min-width:0}
.user-name{font-size:12px;font-weight:600;color:#C8C4BC;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.user-email{font-size:10px;color:var(--sidebar-muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.signout-btn{
  background:none;border:none;cursor:pointer;
  color:var(--sidebar-muted);padding:4px;border-radius:4px;
  transition:color 0.15s,background 0.15s;flex-shrink:0;
}
.signout-btn:hover{color:#F28B82;background:rgba(200,40,30,0.15)}

body{
  font-family:'DM Sans',sans-serif;
  background:var(--bg);
  color:var(--text);
  display:flex;
  height:100vh;
  overflow:hidden;
  font-feature-settings:'cv01','cv02';
  -webkit-font-smoothing:antialiased;
}

/* ─── SYNC BAR ───────────────────────────────────────────────────────── */
#sync-bar{
  position:fixed;top:0;left:0;right:0;height:2px;
  z-index:9999;transition:opacity 0.4s,background 0.4s;opacity:0;
}
#sync-bar.syncing{
  opacity:1;
  background:linear-gradient(90deg,var(--red-dark),var(--amber),var(--red));
  background-size:200%;
  animation:syncAnim 1.2s linear infinite;
}
#sync-bar.synced{opacity:1;background:var(--green);animation:fadeBarOut 2s ease 0.5s forwards;}
@keyframes syncAnim{0%{background-position:0%}100%{background-position:200%}}
@keyframes fadeBarOut{to{opacity:0}}
#sync-pill{
  position:fixed;bottom:20px;left:50%;transform:translateX(-50%) translateY(8px);
  background:#111;color:#fff;font-size:12px;font-weight:500;
  padding:8px 18px;border-radius:99px;
  display:none;align-items:center;gap:8px;z-index:9999;
  box-shadow:0 6px 20px rgba(0,0,0,0.3);
  opacity:0;transition:all 0.3s var(--ease-out);
  letter-spacing:0.01em;
}
#sync-pill.show{display:flex;opacity:1;transform:translateX(-50%) translateY(0)}
.sdot{width:7px;height:7px;border-radius:50%;flex-shrink:0}
.sdot.green{background:var(--green)}
.sdot.spin{background:var(--amber);animation:blink 0.8s ease-in-out infinite}
@keyframes blink{0%,100%{opacity:1}50%{opacity:0.2}}

/* ─── LOADING SCREEN ─────────────────────────────────────────────────── */
#loading{
  position:fixed;inset:0;background:var(--bg);
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  z-index:9998;gap:18px;
}
.big-logo{
  width:64px;height:64px;
  background:linear-gradient(145deg,var(--red),var(--red-dark));
  border-radius:18px;
  display:flex;align-items:center;justify-content:center;
  font-family:'Noto Serif SC',serif;font-size:32px;color:#fff;font-weight:700;
  box-shadow:0 8px 24px var(--red-glow),0 2px 6px rgba(200,40,30,0.2);
}
.spinner{
  width:22px;height:22px;
  border:2px solid var(--border2);
  border-top-color:var(--red);
  border-radius:50%;
  animation:spin 0.7s linear infinite;
}
@keyframes spin{to{transform:rotate(360deg)}}
#loading p{font-size:13px;color:var(--text3);letter-spacing:0.01em}

/* ─── SIDEBAR ────────────────────────────────────────────────────────── */
#sidebar{
  width:220px;min-width:220px;
  background:var(--sidebar);
  display:flex;flex-direction:column;overflow-y:auto;
  border-right:1px solid rgba(255,255,255,0.04);
}
.sidebar-logo{
  padding:22px 20px 18px;
  border-bottom:1px solid var(--sidebar-border);
  display:flex;align-items:center;gap:11px;
}
.logo-icon{
  width:34px;height:34px;
  background:linear-gradient(145deg,var(--red),var(--red-dark));
  border-radius:9px;
  display:flex;align-items:center;justify-content:center;
  font-family:'Noto Serif SC',serif;font-size:19px;color:#fff;font-weight:700;
  flex-shrink:0;
  box-shadow:0 3px 8px rgba(200,40,30,0.35);
}
.logo-text .zh{
  font-family:'Noto Serif SC',serif;font-size:15px;font-weight:600;color:#fff;line-height:1;
}
.logo-text .sub{font-size:10px;color:var(--sidebar-muted);letter-spacing:0.05em;margin-top:3px}

.sidebar-nav{padding:10px 0;flex:1}
.nav-item{
  display:flex;align-items:center;gap:10px;
  padding:10px 20px;
  cursor:pointer;
  color:var(--sidebar-muted);font-size:13.5px;font-weight:500;
  transition:color var(--duration),background var(--duration);
  border-left:2.5px solid transparent;
  position:relative;
}
.nav-item:hover{color:#C8C4BC;background:var(--sidebar-hover)}
.nav-item.active{
  color:#fff;background:var(--sidebar-active);
  border-left-color:var(--red);
}
.nav-item.active::before{
  content:'';position:absolute;left:0;top:50%;transform:translateY(-50%);
  width:2.5px;height:70%;border-radius:0 2px 2px 0;
  background:var(--red);box-shadow:0 0 10px var(--red-glow);
  display:none;
}
.nav-item svg{width:16px;height:16px;flex-shrink:0;opacity:0.8}
.nav-item.active svg{opacity:1}

.sidebar-footer{
  padding:16px 20px;border-top:1px solid var(--sidebar-border);
  font-size:11px;color:#444;line-height:2;
}

/* ─── MAIN AREA ──────────────────────────────────────────────────────── */
#main{flex:1;overflow-y:auto;background:var(--bg);display:flex;flex-direction:column;align-items:center}
.page{display:none;padding:40px 44px;width:100%;max-width:1100px;box-sizing:border-box}
.page.active{display:block;animation:pageIn 0.22s var(--ease-out) both}
@keyframes pageIn{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}

#add.page.active{display:flex;flex-direction:column;align-items:center;max-width:100%;padding:36px 40px}
#add .page-header{text-align:center;width:100%;max-width:560px}
#add .card{width:100%;max-width:560px;margin:0}
#review.page{max-width:760px}

.page-header{margin-bottom:30px}
.page-header h1{font-size:27px;font-weight:600;letter-spacing:-0.025em;color:var(--text)}
.page-header p{font-size:14px;color:var(--text2);margin-top:5px}

/* ─── STAT CARDS ─────────────────────────────────────────────────────── */
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-bottom:16px}
.stat-card{
  background:var(--surface);
  border:1px solid var(--border);border-radius:var(--radius);
  padding:20px;
  display:flex;align-items:flex-start;justify-content:space-between;
  box-shadow:var(--shadow-sm);
}
.stat-card .label{font-size:12px;color:var(--text2);font-weight:500;margin-bottom:10px;letter-spacing:0.01em}
.stat-card .value{font-size:28px;font-weight:600;letter-spacing:-0.04em;line-height:1}
.stat-icon{
  width:38px;height:38px;border-radius:10px;
  display:flex;align-items:center;justify-content:center;
  font-size:17px;flex-shrink:0;
}
.icon-red{background:var(--red-light)}
.icon-green{background:var(--green-light)}
.icon-amber{background:var(--amber-light)}
.icon-blue{background:var(--blue-light)}

.stat-clickable{
  cursor:pointer;
  transition:transform var(--duration) var(--ease-out),box-shadow var(--duration),border-color var(--duration);
}
.stat-clickable:hover{
  transform:translateY(-2px);
  border-color:var(--border3);
  box-shadow:var(--shadow-md);
}
.stat-clickable:active{transform:translateY(0);box-shadow:var(--shadow-sm)}

/* ─── CARDS ──────────────────────────────────────────────────────────── */
.card{
  background:var(--surface);
  border:1px solid var(--border);border-radius:var(--radius);
  padding:24px;margin-bottom:14px;
  box-shadow:var(--shadow-sm);
}
.card-title{
  font-size:11.5px;font-weight:600;
  color:var(--text3);text-transform:uppercase;letter-spacing:0.08em;
  margin-bottom:16px;
}

/* ─── MINI STAT CARDS ────────────────────────────────────────────────── */
.mini-stats-row{display:grid;grid-template-columns:1fr 1fr 1fr;gap:14px;margin-bottom:14px}
.streak-row{display:flex;align-items:center;gap:9px}
.streak-num{font-size:30px;font-weight:700;letter-spacing:-0.04em;line-height:1}
.streak-label{font-size:12.5px;color:var(--text2)}

/* ─── DUE BANNER ─────────────────────────────────────────────────────── */
#due-banner{
  background:linear-gradient(125deg,var(--red-dark) 0%,var(--red) 60%,#E05048 100%);
  border:none!important;color:#fff;cursor:pointer;
  margin-bottom:14px;display:none;
  box-shadow:0 6px 20px var(--red-glow),var(--shadow-sm)!important;
  transition:transform var(--duration) var(--ease-out),box-shadow var(--duration)!important;
}
#due-banner:hover{transform:translateY(-2px);box-shadow:0 10px 28px rgba(200,40,30,0.28),var(--shadow-sm)!important}
#due-banner:active{transform:translateY(0)}

/* ─── WORD GRID ──────────────────────────────────────────────────────── */
.word-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.word-tile{
  background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius-sm);padding:14px 16px;
  transition:border-color var(--duration),box-shadow var(--duration),transform var(--duration) var(--ease-out);
  cursor:default;
}
.word-tile:hover{border-color:var(--border3);box-shadow:var(--shadow-md);transform:translateY(-1px)}
.word-tile .zh{font-family:'Noto Serif SC',serif;font-size:22px;font-weight:600;margin-bottom:4px;line-height:1.2}
.word-tile .py{font-size:11.5px;color:var(--red);margin-bottom:3px;font-weight:500}
.word-tile .vi{font-size:12px;color:var(--text2)}

/* ─── HEATMAP ────────────────────────────────────────────────────────── */
.heatmap-grid{display:flex;gap:4px;flex-wrap:wrap}
.heatmap-week{display:flex;flex-direction:column;gap:4px}
.heatmap-cell{
  width:12px;height:12px;border-radius:3px;
  background:var(--surface3);
  transition:transform 0.1s;
}
.heatmap-cell:hover{transform:scale(1.3)}
.heatmap-cell.l1{background:#FCCACA}
.heatmap-cell.l2{background:#F28B82}
.heatmap-cell.l3{background:var(--red)}
.heatmap-cell.l4{background:var(--red-dark)}

/* ─── REVIEW PAGE ────────────────────────────────────────────────────── */
.review-progress{
  background:var(--surface3);border-radius:99px;height:4px;
  margin-bottom:34px;overflow:hidden;
}
.review-progress-fill{
  height:100%;background:var(--red);border-radius:99px;
  transition:width 0.5s var(--ease-out);
  box-shadow:0 0 8px var(--red-glow);
}
.review-card{
  background:var(--surface);border:1px solid var(--border);
  border-radius:20px;padding:44px 40px;text-align:center;
  margin-bottom:20px;box-shadow:var(--shadow-lg);
}
.review-vi{
  font-size:11px;font-weight:600;color:var(--text3);
  text-transform:uppercase;letter-spacing:0.12em;margin-bottom:10px;
}
.review-word{
  font-size:38px;font-weight:600;margin-bottom:6px;
  line-height:1.25;letter-spacing:-0.02em;
}
.answer-input{
  width:100%;padding:15px 20px;
  font-size:24px;font-family:'Noto Sans SC',sans-serif;
  border:1.5px solid var(--border2);border-radius:var(--radius-sm);
  background:var(--surface);color:var(--text);text-align:center;
  outline:none;margin-top:24px;
  transition:border-color 0.2s,box-shadow 0.2s;
}
.answer-input::placeholder{color:var(--text4);font-size:18px}
.answer-input:focus{border-color:var(--red);box-shadow:var(--shadow-focus)}
.answer-input.correct{border-color:var(--green);background:var(--green-light);box-shadow:0 0 0 3px rgba(23,122,71,0.12)}
.answer-input.wrong{border-color:var(--red);background:var(--red-light);box-shadow:var(--shadow-focus)}

/* Check button */
.check-btn{
  margin-top:14px;padding:13px 32px;
  background:linear-gradient(160deg,var(--red),var(--red-dark));
  color:#fff;border:none;border-radius:var(--radius-sm);
  font-size:15px;font-weight:600;cursor:pointer;
  font-family:'DM Sans',sans-serif;
  width:100%;
  box-shadow:0 4px 0 var(--red-dark),0 2px 10px var(--red-glow);
  transition:transform 0.1s,box-shadow 0.1s,opacity 0.15s;
  position:relative;top:0;
}
.check-btn:hover{opacity:0.92}
.check-btn:active{transform:translateY(3px);box-shadow:0 1px 0 var(--red-dark),0 1px 6px var(--red-glow)}
.check-btn:disabled{opacity:0.38;cursor:not-allowed;box-shadow:none;transform:none}

/* Difficulty buttons */
.diff-btns{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-top:16px}
.diff-btn{
  padding:13px 8px;
  border:1.5px solid var(--border2);border-radius:var(--radius-sm);
  font-size:13px;font-weight:600;cursor:pointer;background:var(--surface);
  transition:all 0.15s var(--ease-out);
  font-family:'DM Sans',sans-serif;text-align:center;line-height:1.4;
  box-shadow:var(--shadow-sm);
}
.diff-btn:hover{transform:translateY(-2px);box-shadow:var(--shadow-md)}
.diff-btn:active{transform:translateY(0)}
.diff-btn .emoji{font-size:20px;display:block;margin-bottom:5px}
.diff-btn .label{color:var(--text);display:block}
.diff-btn .interval{font-size:11px;color:var(--text2);display:block;font-weight:400;margin-top:2px}
.diff-btn.again:hover{border-color:var(--red);background:var(--red-light)}
.diff-btn.hard:hover{border-color:var(--amber-border);background:var(--amber-light)}
.diff-btn.good:hover{border-color:var(--green-border);background:var(--green-light)}
.diff-btn.easy:hover{border-color:var(--blue-border);background:var(--blue-light)}

/* Feedback */
.feedback-bar{
  padding:12px 18px;border-radius:var(--radius-xs);font-size:14px;font-weight:500;
  margin-top:14px;display:none;animation:feedIn 0.2s var(--ease-spring) both;
}
@keyframes feedIn{from{opacity:0;transform:scale(0.96)}to{opacity:1;transform:none}}
.feedback-bar.correct{background:var(--green-light);color:var(--green);border:1px solid var(--green-border);display:block}
.feedback-bar.wrong{background:var(--red-light);color:var(--red);border:1px solid var(--red-mid);display:block}
.correct-answer{font-size:14px;color:var(--green);font-weight:500;margin-top:10px}
.review-pinyin{font-size:14px;color:var(--red);margin-top:6px;font-weight:500;min-height:22px}

/* ─── ADD FORM ───────────────────────────────────────────────────────── */
.form-group{margin-bottom:20px}
.form-group label{display:block;font-size:13px;font-weight:500;color:var(--text2);margin-bottom:7px}
.form-group input,.form-group textarea{
  width:100%;padding:11px 15px;
  border:1.5px solid var(--border2);border-radius:var(--radius-xs);
  font-size:14px;font-family:'DM Sans',sans-serif;
  background:var(--surface);color:var(--text);outline:none;
  transition:border-color 0.2s,box-shadow 0.2s;
}
.form-group input:focus,.form-group textarea:focus{
  border-color:var(--red);box-shadow:var(--shadow-focus);
}
.form-group textarea{resize:vertical;min-height:68px;line-height:1.6}
.pinyin-preview{font-size:13px;color:var(--red);margin-top:5px;font-weight:500;min-height:18px}

/* Dict lookup */
.dict-result{margin-top:7px;min-height:20px}
.dict-chip{
  display:inline-flex;align-items:center;gap:7px;
  background:var(--green-light);border:1px solid var(--green-border);
  border-radius:var(--radius-xs);padding:6px 12px;
  font-size:13px;color:var(--green);font-weight:500;
  cursor:pointer;transition:background 0.15s,transform 0.1s;
  max-width:100%;flex-wrap:wrap;
}
.dict-chip:hover{background:#D2EDD9;transform:translateY(-1px)}
.dict-chip .dict-arrow{opacity:0.5;font-size:11px}
.dict-chip .dict-vi{color:var(--text2);font-size:12px}
.dict-chip .dict-apply{
  font-size:11px;font-weight:700;color:var(--green);
  margin-left:4px;background:rgba(23,122,71,0.14);
  border-radius:4px;padding:1px 7px;
}
.dict-searching{font-size:12px;color:var(--text3);font-style:italic}
.dict-notfound{font-size:12px;color:var(--text3)}

/* Submit button */
.submit-btn{
  padding:12px 28px;
  background:linear-gradient(160deg,var(--red),var(--red-dark));
  color:#fff;border:none;border-radius:var(--radius-sm);
  font-size:14px;font-weight:600;cursor:pointer;
  font-family:'DM Sans',sans-serif;
  box-shadow:0 4px 0 var(--red-dark),0 2px 10px var(--red-glow);
  transition:transform 0.1s,box-shadow 0.1s,opacity 0.15s;
}
.submit-btn:hover{opacity:0.92}
.submit-btn:active{transform:translateY(3px);box-shadow:0 1px 0 var(--red-dark)}

.optional-tag{font-size:11px;color:var(--text3);font-weight:400;margin-left:4px}

/* ─── WORD LIST ──────────────────────────────────────────────────────── */
.wordlist-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}
.search-input{
  padding:9px 15px;border:1.5px solid var(--border2);border-radius:var(--radius-sm);
  font-size:13px;font-family:'DM Sans',sans-serif;
  background:var(--surface);color:var(--text);outline:none;width:230px;
  transition:border-color 0.2s,box-shadow 0.2s;
}
.search-input:focus{border-color:var(--red);box-shadow:var(--shadow-focus)}
.search-input::placeholder{color:var(--text4)}

table{width:100%;border-collapse:collapse;font-size:13.5px}
thead{position:sticky;top:0;z-index:1}
th{
  text-align:left;padding:11px 16px;
  font-size:10.5px;font-weight:700;color:var(--text3);
  text-transform:uppercase;letter-spacing:0.09em;
  border-bottom:1px solid var(--border);
  background:var(--surface2);
}
th:first-child{border-radius:var(--radius-xs) 0 0 0}
th:last-child{border-radius:0 var(--radius-xs) 0 0}
td{
  padding:13px 16px;border-bottom:1px solid var(--border);
  vertical-align:middle;transition:background 0.12s;
}
tr:last-child td{border-bottom:none}
td { box-sizing:border-box; }
tbody td:last-child { white-space:nowrap; }
tbody tr{transition:background 0.12s}
tbody tr:hover td{background:var(--surface2)}

.badge{display:inline-block;padding:3px 10px;border-radius:99px;font-size:11px;font-weight:600}
.badge-new{background:var(--green-light);color:var(--green)}
.badge-learning{background:var(--amber-light);color:var(--amber)}
.badge-review{background:var(--blue-light);color:var(--blue)}
.badge-mastered{background:var(--surface3);color:var(--text2)}

.del-btn{
  background:none;border:none;cursor:pointer;
  color:var(--text4);font-size:15px;padding:4px 8px;border-radius:var(--radius-xs);
  transition:color 0.15s,background 0.15s;
}
.del-btn:hover{color:var(--red);background:var(--red-light)}

.filter-pill{
  display:inline-flex;align-items:center;gap:7px;
  padding:5px 14px;border-radius:99px;font-size:12px;font-weight:600;margin-bottom:14px;
}
.filter-pill.fall{background:var(--red-light);color:var(--red)}
.filter-pill.fdue{background:var(--amber-light);color:var(--amber)}
.filter-pill.flearned{background:var(--green-light);color:var(--green)}
.filter-pill.fmastered{background:var(--blue-light);color:var(--blue)}
.filter-clear{cursor:pointer;opacity:0.55;font-size:13px;transition:opacity 0.15s}
.filter-clear:hover{opacity:1}

/* ─── MISC ───────────────────────────────────────────────────────────── */
.empty-state{text-align:center;padding:64px 20px}
.empty-state .emoji{font-size:52px;margin-bottom:14px}
.empty-state h3{font-size:18px;font-weight:600;margin-bottom:7px}
.empty-state p{font-size:14px;color:var(--text2)}

::-webkit-scrollbar{width:5px;height:5px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--border2);border-radius:99px}
::-webkit-scrollbar-thumb:hover{background:var(--border3)}

/* ─── ARTICLE CARDS ─────────────────────────────────────────────────── */
.article-card{
  background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius);padding:20px 24px;
  margin-bottom:12px;box-shadow:var(--shadow-sm);
  cursor:pointer;transition:all var(--duration) var(--ease-out);
  display:flex;align-items:flex-start;justify-content:space-between;gap:16px;
}
.article-card:hover{border-color:var(--border3);box-shadow:var(--shadow-md);transform:translateY(-1px)}
.article-card-title{font-size:16px;font-weight:600;margin-bottom:5px;font-family:'Noto Serif SC',serif}
.article-card-meta{font-size:12px;color:var(--text3)}
.article-card-preview{font-size:13px;color:var(--text2);margin-top:7px;line-height:1.6;font-family:'Noto Sans SC',sans-serif}
.article-card-actions{display:flex;gap:6px;flex-shrink:0}
.article-del-btn{
  background:none;border:none;cursor:pointer;color:var(--text4);
  font-size:14px;padding:6px 9px;border-radius:var(--radius-xs);
  transition:all 0.15s;
}
.article-del-btn:hover{color:var(--red);background:var(--red-light)}
.article-edit-btn{
  background:none;border:none;cursor:pointer;color:var(--text4);
  font-size:14px;padding:6px 9px;border-radius:var(--radius-xs);
  transition:all 0.15s;
}
.article-edit-btn:hover{color:var(--blue);background:var(--blue-light)}

/* highlight effect */
.word-highlight{
  background:rgba(200,40,30,0.12);
  border-radius:3px;
  color:var(--red);
  border-bottom:1.5px solid var(--red-mid);
  cursor:pointer;
  transition:background 0.15s;
}
.word-highlight:hover{background:rgba(200,40,30,0.2)}

#selection-popup input::placeholder{color:#666}

.toast{
  position:fixed;bottom:28px;right:28px;
  background:#111;color:#fff;
  padding:12px 20px;border-radius:var(--radius-sm);
  font-size:13.5px;font-weight:500;z-index:9999;
  animation:toastIn 0.28s var(--ease-spring) both;
  pointer-events:none;
  box-shadow:0 8px 24px rgba(0,0,0,0.25);
  letter-spacing:0.01em;
}
@keyframes toastIn{from{transform:translateY(12px) scale(0.95);opacity:0}to{transform:none;opacity:1}}

/* Sort pills */
.sort-pill{
  padding:5px 14px;border-radius:99px;font-size:12px;font-weight:600;
  border:1.5px solid var(--border2);background:var(--surface);color:var(--text2);
  cursor:pointer;font-family:'DM Sans',sans-serif;transition:all 0.15s;
}
.sort-pill:hover{border-color:var(--border3);color:var(--text)}
.sort-pill.active{background:var(--red);border-color:var(--red);color:#fff}

/* Article image */
.article-card-img{
  width:72px;height:72px;flex-shrink:0;border-radius:var(--radius-xs);
  object-fit:cover;border:1px solid var(--border);
}

/* Added words panel */
.added-word-row{
  display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 8px;
  padding:7px 0;border-bottom:1px solid var(--border);
  word-break:break-word;
}
.added-word-zh{font-family:'Noto Serif SC',serif;font-size:16px;font-weight:600;flex-shrink:0}
.added-word-py{font-size:11px;color:var(--red);flex-shrink:0}
.added-word-vi{font-size:12px;color:var(--text2);line-height:1.4;flex:1;min-width:60px}

/* ─── WORD TYPE SELECTOR ─────────────────────────────────────────────── */
.wtype-tag{
  display:inline-flex;align-items:center;gap:4px;
  padding:5px 11px;border-radius:99px;
  border:1.5px solid var(--wt-color,#ccc);
  background:var(--wt-bg,#f5f5f5);
  color:var(--wt-color,#333);
  font-size:12px;font-weight:600;cursor:pointer;
  font-family:'DM Sans',sans-serif;
  transition:all 0.15s;white-space:nowrap;
}
.wtype-tag:hover{opacity:0.8;transform:translateY(-1px)}
.wtype-tag.active{
  background:var(--wt-color);
  color:#fff;
  border-color:var(--wt-color);
  box-shadow:0 2px 8px rgba(0,0,0,0.15);
}
.wtype-vi{font-size:10px;opacity:0.8}

/* Tags nhỏ trong selection popup */
#popup-word-type-selector .wtype-tag { 
  padding:3px 8px; 
  font-size:10px;
  border-width:1px;
}
#popup-word-type-selector .wtype-vi { display:none; }
#popup-word-type-selector .wtype-tag.active { color:#fff; }

/* ─── WORD TABLE ACTION BUTTONS ─────────────────────────────────────── */
.edit-btn{
  background:none;border:none;cursor:pointer;
  font-size:14px;padding:4px 6px;border-radius:var(--radius-xs);
  opacity:0.4;transition:opacity 0.15s,background 0.15s;
}
.edit-btn:hover{opacity:1;background:var(--blue-light)}

.wt-add-btn{
  width:15px;height:15px;border-radius:50%;flex-shrink:0;
  background:linear-gradient(135deg,#ff6b8a,#e8194b);
  color:#fff;border:none;cursor:pointer;
  font-size:10px;font-weight:700;
  display:inline-flex;align-items:center;justify-content:center;
  line-height:1;padding:0;transition:transform 0.15s,opacity 0.15s;
}
.wt-add-btn:hover{transform:scale(1.15);opacity:0.9}

/* Container cho badge + nút + trong cột Loại từ */
.wt-cell{
  display:flex;align-items:center;gap:5px;flex-wrap:nowrap;
}
.wt-badges{
  display:flex;flex-wrap:wrap;gap:3px;align-items:center;
}

/* ─── WORD EDIT MODAL ────────────────────────────────────────────────── */
#word-edit-overlay{
  display:none;position:fixed;inset:0;
  background:rgba(0,0,0,0.45);z-index:3000;
  align-items:center;justify-content:center;
}
#word-edit-overlay.open{display:flex}

/* ─── RICH TEXT EDITOR (Article upload) ─────────────────────────────── */
.rich-toolbar{
  display:flex;align-items:center;gap:3px;flex-wrap:wrap;
  padding:6px 8px;background:var(--surface2);
  border:1.5px solid var(--border2);border-bottom:none;
  border-radius:var(--radius-sm) var(--radius-sm) 0 0;
}
.rtb-btn{
  padding:4px 9px;border:none;background:transparent;
  border-radius:5px;cursor:pointer;font-size:13px;font-weight:600;
  color:var(--text2);font-family:'DM Sans',sans-serif;
  transition:background 0.12s,color 0.12s;line-height:1.4;
}
.rtb-btn:hover{background:var(--border);color:var(--text);}
.rtb-btn.active{background:var(--red-light);color:var(--red);}
.rtb-sep{width:1px;height:18px;background:var(--border2);margin:0 3px;flex-shrink:0;}
.rich-editor{
  width:100%;min-height:220px;max-height:480px;overflow-y:auto;
  padding:12px 14px;
  border:1.5px solid var(--border2);border-radius:0 0 var(--radius-sm) var(--radius-sm);
  font-family:'Noto Sans SC',sans-serif;font-size:15px;line-height:1.8;
  color:var(--text);background:var(--surface);outline:none;
  transition:border-color 0.15s,box-shadow 0.15s;
}
.rich-editor:focus{border-color:var(--red);box-shadow:var(--shadow-focus);}
.rich-editor:empty:before{content:attr(data-placeholder);color:var(--text4);pointer-events:none;}
.rich-editor h2{font-size:20px;font-weight:700;margin:10px 0 4px;color:var(--text);}
.rich-editor h3{font-size:16px;font-weight:700;margin:8px 0 4px;color:var(--text);}
.rich-editor p{margin:4px 0;}
.rich-editor ul,.rich-editor ol{padding-left:20px;margin:4px 0;}
body.dark .rich-editor{background:var(--surface);border-color:var(--border2);}
body.dark .rich-toolbar{background:var(--surface2);border-color:var(--border2);}

/* ─── NOTE HINT TOGGLE ────────────────────────────────────── */
#hint-toggle-btn:hover, #art-hint-toggle-btn:hover {
  background: var(--surface3);
  border-color: var(--red);
  color: var(--red);
}
#hint-content, #art-hint-content {
  animation: fadeIn 0.18s ease;
}
@keyframes fadeIn { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: none; } }

/* ═══════════════════════════════════════════════════════════════
   HSK BOOKS — Nav badge
   ═══════════════════════════════════════════════════════════════ */
.nav-badge {
  margin-left: auto;
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.04em;
  background: var(--red);
  color: #fff;
  padding: 2px 6px;
  border-radius: 99px;
  line-height: 1.4;
}

/* ═══════════════════════════════════════════════════════════════
   HSK BOOKS — Breadcrumb
   ═══════════════════════════════════════════════════════════════ */
.hsk-breadcrumb {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text3);
  margin-bottom: 22px;
  flex-wrap: wrap;
}
.hsk-breadcrumb-item {
  cursor: pointer;
  color: var(--red);
  font-weight: 500;
  transition: opacity 0.15s;
}
.hsk-breadcrumb-item:hover { opacity: 0.75; }
.hsk-breadcrumb-sep { color: var(--text4); font-size: 11px; }
.hsk-breadcrumb-current { color: var(--text2); font-weight: 500; }

/* ═══════════════════════════════════════════════════════════════
   HSK BOOKS — Book grid
   ═══════════════════════════════════════════════════════════════ */
.hsk-books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
}
.hsk-book-card {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  cursor: pointer;
  transition: all 0.18s var(--ease-out);
  position: relative;
  overflow: hidden;
}
.hsk-book-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  border-radius: var(--radius) var(--radius) 0 0;
}
.hsk-book-card.level-1::before { background: #16A34A; }
.hsk-book-card.level-2::before { background: #0284C7; }
.hsk-book-card.level-3::before { background: #9333EA; }
.hsk-book-card.level-4::before { background: var(--amber); }
.hsk-book-card.level-5::before { background: var(--red); }
.hsk-book-card.level-6::before { background: #141414; }
.hsk-book-card:hover {
  border-color: var(--border3);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.hsk-book-card:active { transform: none; box-shadow: var(--shadow-sm); }
.hsk-book-icon {
  font-size: 36px;
  margin-bottom: 12px;
  display: block;
}
.hsk-book-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 4px;
  letter-spacing: -0.01em;
}
.hsk-book-meta {
  font-size: 12px;
  color: var(--text3);
  margin-bottom: 14px;
}
.hsk-book-progress-bar {
  height: 4px;
  background: var(--surface3);
  border-radius: 99px;
  overflow: hidden;
  margin-bottom: 6px;
}
.hsk-book-progress-fill {
  height: 100%;
  border-radius: 99px;
  background: var(--green);
  transition: width 0.4s var(--ease-out);
}
.hsk-book-progress-text {
  font-size: 11px;
  color: var(--text3);
  font-weight: 500;
}
.hsk-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  padding: 60px 0;
  color: var(--text3);
  font-size: 14px;
  grid-column: 1/-1;
}

/* ═══════════════════════════════════════════════════════════════
   HSK BOOKS — Unit grid
   ═══════════════════════════════════════════════════════════════ */
.hsk-units-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px;
}
.hsk-unit-card {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  cursor: pointer;
  transition: all 0.18s var(--ease-out);
  display: flex;
  align-items: center;
  gap: 16px;
}
.hsk-unit-card:hover {
  border-color: var(--border3);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}
.hsk-unit-number {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--red-light);
  color: var(--red);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 700;
  flex-shrink: 0;
  font-family: 'Noto Serif SC', serif;
}
.hsk-unit-info { flex: 1; min-width: 0; }
.hsk-unit-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 3px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.hsk-unit-count {
  font-size: 12px;
  color: var(--text3);
}
.hsk-unit-added-badge {
  font-size: 11px;
  font-weight: 600;
  color: var(--green);
  background: var(--green-light);
  padding: 2px 8px;
  border-radius: 99px;
  white-space: nowrap;
}
.hsk-unit-arrow {
  color: var(--text4);
  font-size: 16px;
  flex-shrink: 0;
}

/* ═══════════════════════════════════════════════════════════════
   HSK BOOKS — Word grid
   ═══════════════════════════════════════════════════════════════ */
.hsk-unit-progress-wrap {
  text-align: right;
  flex-shrink: 0;
}
.hsk-unit-big-progress {
  font-size: 28px;
  font-weight: 700;
  color: var(--green);
  line-height: 1;
}
.hsk-unit-big-label {
  font-size: 11px;
  color: var(--text3);
  margin-top: 2px;
}

.hsk-words-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 12px;
}
.hsk-word-card {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 16px;
  cursor: pointer;
  transition: all 0.18s var(--ease-out);
  text-align: center;
  position: relative;
}
.hsk-word-card:hover {
  border-color: var(--red-mid);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.hsk-word-card.in-dict {
  border-color: var(--green-border);
  background: var(--green-light);
}
.hsk-word-card.in-dict::after {
  content: '✓';
  position: absolute;
  top: 8px; right: 10px;
  font-size: 11px;
  font-weight: 700;
  color: var(--green);
}
.hsk-word-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: 28px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 6px;
  line-height: 1.2;
}
.hsk-word-py {
  font-size: 13px;
  color: var(--red);
  font-weight: 500;
  margin-bottom: 5px;
}
.hsk-word-vi {
  font-size: 12px;
  color: var(--text2);
  line-height: 1.4;
}

/* ═══════════════════════════════════════════════════════════════
   HSK BOOKS — Word detail page
   ═══════════════════════════════════════════════════════════════ */
.hsk-detail-header {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
  margin-bottom: 20px;
  position: relative;
}
.hsk-detail-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: 72px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.1;
  margin-bottom: 10px;
}
.hsk-detail-py {
  font-size: 22px;
  color: var(--red);
  font-weight: 500;
  margin-bottom: 14px;
  letter-spacing: 0.03em;
}
.hsk-detail-vi {
  font-size: 18px;
  color: var(--text2);
  font-weight: 500;
  margin-bottom: 16px;
}
.hsk-detail-add-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 24px;
  background: var(--red);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: all 0.15s;
  box-shadow: 0 3px 10px var(--red-glow);
}
.hsk-detail-add-btn:hover { background: var(--red-dark); transform: translateY(-1px); box-shadow: 0 5px 16px var(--red-glow); }
.hsk-detail-add-btn:active { transform: none; }
.hsk-detail-add-btn.added {
  background: var(--green);
  box-shadow: none;
  cursor: default;
}
.hsk-detail-add-btn.added:hover { transform: none; background: var(--green); }

.hsk-detail-section {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 16px;
}
.hsk-detail-section-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text3);
  text-transform: uppercase;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Stroke order container */
#hsk-stroke-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}
.hsk-stroke-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
.hsk-stroke-char-label {
  font-family: 'Noto Sans SC', sans-serif;
  font-size: 13px;
  color: var(--text3);
  font-weight: 600;
}
.hsk-stroke-controls {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-top: 16px;
  flex-wrap: wrap;
}
.hsk-stroke-btn {
  padding: 8px 16px;
  background: var(--surface2);
  border: 1.5px solid var(--border2);
  border-radius: var(--radius-xs);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  color: var(--text2);
  font-family: 'DM Sans', sans-serif;
  transition: all 0.15s;
}
.hsk-stroke-btn:hover { border-color: var(--red); color: var(--red); background: var(--red-light); }
.hsk-stroke-btn.primary { background: var(--red); color: #fff; border-color: var(--red); }
.hsk-stroke-btn.primary:hover { background: var(--red-dark); border-color: var(--red-dark); color: #fff; }

/* Memory tip */
.hsk-memory-tip {
  background: var(--amber-light);
  border: 1.5px solid var(--amber-border);
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  font-size: 14px;
  color: var(--text);
  line-height: 1.7;
  white-space: pre-wrap;
}

/* Examples */
.hsk-example-item {
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
}
.hsk-example-item:last-child { border-bottom: none; padding-bottom: 0; }
.hsk-example-zh {
  font-family: 'Noto Sans SC', sans-serif;
  font-size: 16px;
  color: var(--text);
  margin-bottom: 5px;
  line-height: 1.5;
}
.hsk-example-vi {
  font-size: 13px;
  color: var(--text2);
  line-height: 1.5;
}

/* SRS status row */
.hsk-srs-status {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  background: var(--surface2);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}
.hsk-srs-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}
.hsk-srs-label { font-size: 13px; color: var(--text2); flex: 1; }
.hsk-srs-next { font-size: 12px; color: var(--text3); }

/* Chinese definition block */
.hsk-zhdef-block {
  font-family: 'Noto Sans SC', sans-serif;
  font-size: 15px;
  color: var(--text2);
  line-height: 1.8;
  padding: 14px 18px;
  background: var(--surface2);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

/* Word nav buttons */
.hsk-word-nav {
  display: flex;
  gap: 10px;
  margin-top: 20px;
  justify-content: space-between;
}
.hsk-word-nav-btn {
  flex: 1;
  padding: 11px 16px;
  background: var(--surface);
  border: 1.5px solid var(--border2);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  color: var(--text2);
  font-family: 'DM Sans', sans-serif;
  transition: all 0.15s;
  text-align: center;
}
.hsk-word-nav-btn:hover { border-color: var(--border3); color: var(--text); box-shadow: var(--shadow-sm); }
.hsk-word-nav-btn:disabled { opacity: 0.35; cursor: default; }

/* ── Responsive for HSK ── */
@media(max-width:768px) {
  .hsk-books-grid { grid-template-columns: 1fr 1fr; }
  .hsk-words-grid { grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); }
  .hsk-detail-zh { font-size: 52px; }
  .hsk-detail-header { padding: 24px 20px; }
  .hsk-units-grid { grid-template-columns: 1fr; }
}
@media(max-width:480px) {
  .hsk-books-grid { grid-template-columns: 1fr; }
  .hsk-words-grid { grid-template-columns: 1fr 1fr; }
}

/* ═══════════════════════════════════════════════════════════════
   HSK READER — single-word layout
   ═══════════════════════════════════════════════════════════════ */

/* Top bar */
.hsk-reader-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}
.hsk-reader-unit-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--text2);
}
.hsk-reader-counter {
  font-size: 13px;
  color: var(--text3);
  font-weight: 500;
}

/* Progress dots */
.hsk-reader-dots {
  display: flex;
  gap: 5px;
  align-items: center;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.hsk-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--border2);
  cursor: pointer;
  transition: all 0.2s;
  flex-shrink: 0;
}
.hsk-dot.active {
  background: var(--red);
  width: 22px;
  border-radius: 4px;
}
.hsk-dot.done {
  background: var(--green);
}
.hsk-dot:hover:not(.active) { background: var(--border3); }

/* Main layout with side arrows */
.hsk-reader-layout {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

/* Arrow buttons */
.hsk-arrow-btn {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1.5px solid var(--border2);
  background: var(--surface);
  color: var(--text2);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s var(--ease-out);
  box-shadow: var(--shadow-sm);
  margin-top: 60px; /* aligns with card header */
}
.hsk-arrow-btn:hover:not(:disabled) {
  border-color: var(--red);
  color: var(--red);
  box-shadow: var(--shadow-md);
  transform: scale(1.05);
}
.hsk-arrow-btn:disabled {
  opacity: 0.25;
  cursor: default;
}
.hsk-arrow-next {
  /* visually stronger — primary direction */
  background: var(--red);
  border-color: var(--red);
  color: #fff;
  box-shadow: 0 3px 10px var(--red-glow);
}
.hsk-arrow-next:hover:not(:disabled) {
  background: var(--red-dark);
  border-color: var(--red-dark);
  color: #fff;
}
.hsk-arrow-next:disabled {
  background: var(--surface);
  border-color: var(--border2);
  color: var(--text4);
  box-shadow: none;
}

/* ── The main card ── */
.hsk-reader-card {
  flex: 1;
  background: #F7FBF8; /* light green-white like PREP */
  border: 1.5px solid #C6E6D0;
  border-radius: 20px;
  overflow: hidden;
  box-shadow: var(--shadow-md);
}
body.dark .hsk-reader-card {
  background: #0F1A12;
  border-color: #1E3A25;
}

/* Card header (index number + big character) */
.hsk-card-header {
  background: linear-gradient(135deg, #E8F5EE 0%, #D4EFE0 100%);
  border-bottom: 1.5px solid #C6E6D0;
  padding: 28px 32px;
  text-align: center;
  position: relative;
}
body.dark .hsk-card-header {
  background: linear-gradient(135deg, #0A1F10 0%, #0F2818 100%);
  border-bottom-color: #1E3A25;
}
.hsk-card-index {
  position: absolute;
  top: 16px;
  left: 20px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: #177A47;
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}
.hsk-card-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: 80px;
  font-weight: 700;
  color: #1A3A28;
  line-height: 1;
  margin-bottom: 8px;
}
body.dark .hsk-card-zh { color: #A8DFC0; }
.hsk-card-py {
  font-size: 20px;
  color: #177A47;
  font-weight: 600;
  margin-bottom: 6px;
  letter-spacing: 0.05em;
}
.hsk-card-vi {
  font-size: 17px;
  color: #2D5A3D;
  font-weight: 500;
  margin-bottom: 14px;
}
body.dark .hsk-card-vi { color: #7DBFA0; }
.hsk-card-actions {
  display: flex;
  gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
}
.hsk-srs-badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 99px;
  border: 1px solid;
  margin-bottom: 10px;
}

/* Card body: two columns */
.hsk-card-body {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
}
.hsk-card-left {
  padding: 24px 28px;
  border-right: 1px solid #C6E6D0;
}
body.dark .hsk-card-left { border-right-color: #1E3A25; }
.hsk-card-right {
  padding: 24px 28px;
}
.hsk-card-section-label {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: #177A47;
  text-transform: uppercase;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
}
body.dark .hsk-card-section-label { color: #4A9E6A; }
.hsk-card-hanviet {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  font-family: 'Noto Sans SC', sans-serif;
}
.hsk-card-zhdef {
  font-size: 14px;
  font-family: 'Noto Sans SC', sans-serif;
  color: var(--text2);
  line-height: 1.7;
  background: rgba(23,122,71,0.07);
  padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid rgba(23,122,71,0.15);
}
.hsk-card-tip {
  font-size: 13.5px;
  color: var(--text);
  line-height: 1.75;
  background: #FFFBEB;
  border: 1px solid #F0C070;
  border-radius: 10px;
  padding: 14px 16px;
}
body.dark .hsk-card-tip {
  background: rgba(160,81,13,0.12);
  border-color: rgba(240,192,112,0.25);
}
.hsk-card-ex {
  background: rgba(23,122,71,0.06);
  border: 1px solid rgba(23,122,71,0.15);
  border-radius: 10px;
  padding: 14px 16px;
}
.hsk-card-ex-zh {
  font-family: 'Noto Sans SC', sans-serif;
  font-size: 16px;
  font-weight: 500;
  color: #1A3A28;
  margin-bottom: 4px;
}
body.dark .hsk-card-ex-zh { color: #A8DFC0; }
.hsk-card-ex-py {
  font-size: 12px;
  color: #177A47;
  margin-bottom: 6px;
}
.hsk-card-ex-vi {
  font-size: 13px;
  color: var(--text2);
}

/* Stroke canvas */
.hsk-stroke-canvas {
  border: 1.5px solid rgba(23,122,71,0.25);
  border-radius: 10px;
  background: #fff;
  overflow: hidden;
  display: inline-block;
}
body.dark .hsk-stroke-canvas {
  background: #0F0F0F;
  border-color: rgba(23,122,71,0.3);
}

/* Admin button */
.hsk-admin-btn {
  padding: 8px 16px;
  background: #141414;
  color: #F0C070;
  border: 1.5px solid #F0C070;
  border-radius: var(--radius-xs);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: all 0.15s;
}
.hsk-admin-btn:hover { background: #1E1A00; }

/* Admin form */
.hsk-admin-form {
  margin-top: 24px;
  background: #1A1500;
  border: 1.5px solid #F0C070;
  border-radius: var(--radius);
  padding: 24px;
}
body:not(.dark) .hsk-admin-form {
  background: #FFFBEB;
  border-color: var(--amber-border);
}
.hsk-admin-form-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--amber);
  margin-bottom: 18px;
}
.hsk-admin-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.hsk-admin-full { grid-column: 1 / -1; }
.hsk-admin-field label {
  display: block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--text3);
  text-transform: uppercase;
  margin-bottom: 5px;
}
.hsk-admin-field input,
.hsk-admin-field textarea {
  width: 100%;
  padding: 9px 12px;
  border: 1.5px solid var(--border2);
  border-radius: var(--radius-xs);
  background: var(--surface);
  color: var(--text);
  font-size: 13px;
  font-family: 'DM Sans', sans-serif;
  outline: none;
  box-sizing: border-box;
  resize: vertical;
}
.hsk-admin-field input:focus,
.hsk-admin-field textarea:focus {
  border-color: var(--amber);
  box-shadow: 0 0 0 3px rgba(160,81,13,0.12);
}

/* ── Responsive ── */
@media(max-width: 768px) {
  .hsk-reader-layout { gap: 6px; }
  .hsk-arrow-btn { width: 36px; height: 36px; margin-top: 50px; }
  .hsk-card-zh { font-size: 56px; }
  .hsk-card-body { grid-template-columns: 1fr; }
  .hsk-card-left { border-right: none; border-bottom: 1px solid #C6E6D0; padding: 20px; }
  .hsk-card-right { padding: 20px; }
  .hsk-card-header { padding: 22px 18px; }
  .hsk-admin-grid { grid-template-columns: 1fr; }
}
@media(max-width: 480px) {
  .hsk-card-zh { font-size: 48px; }
  .hsk-arrow-btn { display: none; }
}