*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --primary:#8A9BA8;
  --primary-hover:#6F8291;
  --primary-light:#E8EDF0;
  --primary-dark:#5A6C7A;
  --success:#9BA893;
  --success-bg:#EDF1EA;
  --warn:#C4A46C;
  --warn-bg:#F4EDE0;
  --danger:#C48A8A;
  --danger-bg:#F4E8E8;
  --bg:#ffffff;
  --bg2:#F8F9FA;
  --bg3:#F1F3F5;
  --border:#E4E7EB;
  --border2:#CDD2D9;
  --text:#1a1a1a;
  --text2:#6B7280;
  --text3:#9CA3AF;
  --radius:10px;
  --radius-lg:14px;
  --shadow:0 1px 4px rgba(0,0,0,0.07);
  --shadow-lg:0 4px 20px rgba(0,0,0,0.1);
}
@media(prefers-color-scheme:dark){
  :root{
    --bg:#1C1C1E;--bg2:#2C2C2E;--bg3:#3A3A3C;
    --border:#38383A;--border2:#48484A;
    --text:#F2F2F7;--text2:#AEAEB2;--text3:#636366;
    --primary-light:#292e32;--shadow:0 1px 4px rgba(0,0,0,0.3);
  }
}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;background:var(--bg3);color:var(--text);min-height:100vh;display:flex;align-items:flex-start;justify-content:center;padding:0}

.app{width:100%;max-width:480px;min-height:100vh;background:var(--bg);display:flex;flex-direction:column;position:relative;overflow:hidden;box-shadow:var(--shadow-lg)}
.screen{display:none;flex-direction:column;flex:1;animation:fadeIn .2s ease}
.screen.active{display:flex}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}

.app-header{display:flex;align-items:center;justify-content:space-between;padding:16px 20px 12px;border-bottom:1px solid var(--border);background:var(--bg)}
.header-title{font-size:17px;font-weight:600;color:var(--text);display:flex;align-items:center;gap:8px}
.header-title .dot{width:8px;height:8px;border-radius:50%;background:var(--primary)}
.icon-btn{width:36px;height:36px;border-radius:var(--radius);border:1px solid var(--border);background:var(--bg);color:var(--text2);cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:18px;transition:all .15s}
.icon-btn:hover{background:var(--bg2);color:var(--text)}

.bottom-nav{display:flex;border-top:1px solid var(--border);background:var(--bg);padding:8px 4px 12px}
.nav-item{flex:1;display:flex;flex-direction:column;align-items:center;gap:3px;padding:6px 4px;border:none;background:none;cursor:pointer;color:var(--text3);font-size:11px;transition:color .15s;border-radius:var(--radius)}
.nav-item svg{width:22px;height:22px;stroke:currentColor;fill:none;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
.nav-item.active{color:var(--primary)}

#screen-login{align-items:center;justify-content:center;padding:40px 32px;background:var(--bg)}
.login-logo{width:72px;height:72px;border-radius:22px;background:var(--primary);display:flex;align-items:center;justify-content:center;margin:0 auto 20px;font-size:36px}
.login-title{font-size:26px;font-weight:700;color:var(--text);text-align:center;margin-bottom:8px}
.login-sub{font-size:15px;color:var(--text2);text-align:center;line-height:1.6;margin-bottom:36px}
.feature-list{width:100%;background:var(--bg2);border-radius:var(--radius-lg);padding:18px 20px;margin-bottom:32px;display:flex;flex-direction:column;gap:12px}
.feat{display:flex;align-items:center;gap:12px;font-size:14px;color:var(--text2)}
.feat-icon{width:32px;height:32px;border-radius:10px;background:var(--primary-light);display:flex;align-items:center;justify-content:center;font-size:16px;flex-shrink:0}
.google-btn{width:100%;display:flex;align-items:center;justify-content:center;gap:12px;padding:14px 20px;background:var(--bg);border:1.5px solid var(--border2);border-radius:var(--radius-lg);font-size:16px;font-weight:500;color:var(--text);cursor:pointer;transition:all .15s}
.google-btn:hover{border-color:var(--primary);background:var(--primary-light);color:var(--primary)}
.google-svg{width:22px;height:22px}

#screen-home{padding-bottom:0}
.home-scroll{flex:1;overflow-y:auto;padding:20px}
.section-head{font-size:12px;font-weight:600;color:var(--text3);text-transform:uppercase;letter-spacing:.08em;margin-bottom:10px}

.diff-row{display:flex;gap:8px;margin-bottom:20px}
.diff-chip{flex:1;padding:10px 6px;border-radius:var(--radius);border:1.5px solid var(--border);background:var(--bg);color:var(--text2);cursor:pointer;font-size:13px;font-weight:500;text-align:center;transition:all .15s}
.diff-chip small{display:block;font-size:10px;color:var(--text3);font-weight:400;margin-top:2px}
.diff-chip.sel{border-color:var(--primary);background:var(--primary-light);color:var(--primary)}
.diff-chip.sel small{color:var(--primary)}

.scenario-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-bottom:24px}
.sc-card{padding:14px 6px 12px;border-radius:var(--radius);border:1.5px solid var(--border);background:var(--bg);cursor:pointer;text-align:center;transition:all .15s}
.sc-card .sc-icon{font-size:22px;margin-bottom:5px;display:flex;align-items:center;justify-content:center}
.sc-card span{font-size:12px;color:var(--text2);font-weight:500}
.sc-card.sel{border-color:var(--primary);background:var(--primary-light)}
.sc-card.sel span{color:var(--primary)}

.custom-input{width:100%;padding:10px 14px;border:1.5px solid var(--border);border-radius:var(--radius);background:var(--bg);color:var(--text);font-size:14px;margin-bottom:24px;display:none}
.custom-input:focus{outline:none;border-color:var(--primary)}

.start-btn{width:100%;padding:16px;background:var(--primary);color:#fff;border:none;border-radius:var(--radius-lg);font-size:17px;font-weight:600;cursor:pointer;transition:all .15s;margin-bottom:24px}
.start-btn:hover{filter:brightness(0.9)}
.start-btn:active{transform:scale(.98)}

.recent-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-bottom:8px}
.rc-card{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);padding:14px;cursor:pointer;transition:all .15s}
.rc-card:hover{border-color:var(--border2)}
.rc-label{font-size:11px;color:var(--text3);margin-bottom:4px}
.rc-title{font-size:14px;font-weight:600;color:var(--text);margin-bottom:8px}
.rc-meta{display:flex;align-items:center;gap:6px}
.score-pill{font-size:11px;padding:3px 10px;border-radius:20px;background:var(--success-bg);color:var(--success);font-weight:600}

#screen-practice{padding:0}
.practice-top{display:flex;align-items:center;justify-content:space-between;padding:14px 20px 10px;border-bottom:1px solid var(--border);background:var(--bg);gap:8px}
.back-btn{display:flex;align-items:center;gap:6px;border:none;background:none;color:var(--text2);font-size:14px;cursor:pointer;padding:0;white-space:nowrap}
.back-btn:hover{color:var(--text)}
.tag-row{display:flex;gap:6px}
.tag{font-size:12px;padding:4px 10px;border-radius:20px;font-weight:500}
.tag-blue{background:var(--primary-light);color:var(--primary)}
.tag-gray{background:var(--bg2);color:var(--text2)}

.chat-wrap{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:14px;background:var(--bg3)}

.msg{display:flex;gap:10px;max-width:88%}
.msg.ai{align-self:flex-start}
.msg.user{align-self:flex-end;flex-direction:row-reverse}
.avatar{width:30px;height:30px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:14px;flex-shrink:0;font-weight:600}
.ai .avatar{background:var(--primary-light);color:var(--primary)}
.user .avatar{background:var(--bg2);color:var(--text2)}
.bubble{padding:10px 14px;border-radius:16px;font-size:14px;line-height:1.6;color:var(--text)}
.ai .bubble{background:var(--bg);border-bottom-left-radius:4px;box-shadow:var(--shadow)}
.user .bubble{background:var(--primary);color:#fff;border-bottom-right-radius:4px}

.feedback{margin-top:8px;background:var(--bg);border-radius:var(--radius);border-left:3px solid var(--primary);padding:10px 12px;box-shadow:var(--shadow)}
.fb-head{font-size:11px;font-weight:600;color:var(--primary);text-transform:uppercase;letter-spacing:.06em;margin-bottom:8px}
.fb-row{display:flex;align-items:flex-start;gap:8px;font-size:13px;color:var(--text2);margin-bottom:6px;line-height:1.5}
.fb-row.err{color:var(--danger)}
.fb-dot{width:6px;height:6px;border-radius:50%;flex-shrink:0;margin-top:5px}
.fb-dot.ok{background:var(--success)}
.fb-dot.warn{background:var(--warn)}
.fb-dot.err{background:var(--danger)}
.alts{display:flex;gap:6px;flex-wrap:wrap;margin-top:8px}
.alt-chip{padding:4px 12px;background:var(--primary-light);color:var(--primary);border-radius:20px;font-size:12px;cursor:pointer;font-weight:500;border:none;transition:all .15s}
.alt-chip:hover{background:var(--primary);color:#fff}

.typing-dots{display:flex;gap:4px;align-items:center;padding:2px 0}
.typing-dots span{width:6px;height:6px;border-radius:50%;background:var(--text3);animation:blink 1.2s infinite}
.typing-dots span:nth-child(2){animation-delay:.2s}
.typing-dots span:nth-child(3){animation-delay:.4s}
@keyframes blink{0%,80%,100%{opacity:.3}40%{opacity:1}}

.practice-bottom{background:var(--bg);border-top:1px solid var(--border);padding:14px 16px}
.speed-row{display:flex;align-items:center;gap:10px;margin-bottom:12px}
.speed-label{font-size:12px;color:var(--text3);flex-shrink:0}
.speed-btns{display:flex;gap:4px}
.spd{padding:4px 12px;border-radius:20px;border:1px solid var(--border);background:var(--bg);color:var(--text2);font-size:12px;font-weight:500;cursor:pointer;transition:all .15s}
.spd.active{background:var(--text);color:var(--bg);border-color:var(--text)}

.input-row{display:flex;align-items:flex-end;gap:10px}
.mic-btn{width:52px;height:52px;border-radius:50%;border:none;background:var(--primary);color:#fff;cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:24px;flex-shrink:0;transition:all .15s;line-height:1}
.mic-btn.rec{background:#E24B4A;animation:pulse 1.2s infinite}
.mic-btn:hover{transform:scale(1.05)}
@keyframes pulse{0%,100%{box-shadow:0 0 0 0 rgba(226,75,74,.3)}50%{box-shadow:0 0 0 12px rgba(226,75,74,0)}}
.right-input{flex:1;display:flex;flex-direction:column;gap:6px}
.transcript{min-height:44px;max-height:100px;overflow-y:auto;padding:10px 13px;background:var(--bg2);border:1.5px solid var(--border);border-radius:var(--radius);font-size:14px;color:var(--text);line-height:1.5;cursor:text;outline:none;white-space:pre-wrap;word-break:break-word}
.transcript:focus{border-color:var(--primary)}
.transcript:empty::before{content:attr(data-placeholder);color:var(--text3);font-style:italic;pointer-events:none}
.send-btn{align-self:flex-end;padding:8px 18px;background:var(--primary);color:#fff;border:none;border-radius:20px;font-size:13px;font-weight:600;cursor:pointer;transition:all .15s;display:flex;align-items:center;gap:5px}
.send-btn:disabled{opacity:.35;cursor:not-allowed}
.send-btn:not(:disabled):hover{filter:brightness(0.9)}

#screen-vocab{padding:0}
.search-bar{padding:14px 20px 10px;background:var(--bg);border-bottom:1px solid var(--border)}
.search-wrap{position:relative}
.search-wrap input{width:100%;padding:10px 14px 10px 40px;border:1.5px solid var(--border);border-radius:var(--radius);background:var(--bg2);color:var(--text);font-size:15px;outline:none;transition:border .15s}
.search-wrap input:focus{border-color:var(--primary);background:var(--bg)}
.search-icon{position:absolute;left:12px;top:50%;transform:translateY(-50%);font-size:18px;color:var(--text3)}
.vocab-scroll{flex:1;overflow-y:auto;padding:16px}
.vocab-card{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);padding:18px;margin-bottom:14px}
.vocab-word{font-size:24px;font-weight:700;color:var(--text);margin-bottom:2px}
.vocab-phon{font-size:14px;color:var(--text3);margin-bottom:4px;font-family:Georgia,serif}
.vocab-pos{display:inline-block;padding:2px 10px;background:var(--primary-light);color:var(--primary);border-radius:20px;font-size:12px;font-weight:600;margin-bottom:8px}
.vocab-meanings{display:flex;flex-direction:column;gap:12px;margin-bottom:12px}
.vocab-meaning{padding-bottom:12px;border-bottom:1px solid var(--bg3)}
.vocab-meaning:last-child{padding-bottom:0;border-bottom:none}
.vocab-trans{font-size:16px;font-weight:600;color:var(--primary);margin-bottom:4px}
.vocab-def{font-size:14px;color:var(--text);line-height:1.6}
.vocab-ex{font-size:13px;color:var(--text2);font-style:italic;padding:10px 14px;background:var(--bg2);border-radius:var(--radius);margin-bottom:14px;line-height:1.6}
.vocab-actions{display:flex;gap:8px;flex-wrap:wrap}
.action-btn{padding:7px 14px;border:1px solid var(--border);border-radius:20px;background:var(--bg);color:var(--text2);font-size:13px;cursor:pointer;display:flex;align-items:center;gap:5px;transition:all .15s}
.action-btn:hover{border-color:var(--primary);color:var(--primary);background:var(--primary-light)}
.action-btn.saved{border-color:var(--success);color:var(--success);background:var(--success-bg)}
.syn-section{margin-top:12px}
.syn-label{font-size:12px;font-weight:600;color:var(--text3);text-transform:uppercase;letter-spacing:.06em;margin-bottom:8px}
.syn-chips{display:flex;gap:6px;flex-wrap:wrap}
.syn-chip{padding:5px 13px;background:var(--bg2);border-radius:20px;font-size:13px;color:var(--text2);cursor:pointer;transition:all .15s;border:none}
.syn-chip:hover{background:var(--primary-light);color:var(--primary)}
.vocab-empty{text-align:center;padding:48px 20px;color:var(--text3)}
.vocab-empty .em-icon{font-size:40px;margin-bottom:12px}

#screen-notebook{padding:0}
.nb-tabs{display:flex;gap:4px;padding:12px 16px;background:var(--bg);border-bottom:1px solid var(--border)}
.nb-tab{flex:1;padding:8px;border-radius:var(--radius);border:none;background:var(--bg2);color:var(--text2);font-size:14px;font-weight:500;cursor:pointer;transition:all .15s}
.nb-tab.active{background:var(--primary);color:#fff}
.nb-scroll{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:8px}
.nb-item{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);padding:13px 14px;display:flex;align-items:center;gap:12px;transition:all .15s}
.nb-item:hover{border-color:var(--border2)}
.nb-body{flex:1;min-width:0}
.nb-word{font-size:15px;font-weight:600;color:var(--text);margin-bottom:2px}
.nb-trans{font-size:14px;font-weight:600;color:var(--primary);margin-bottom:2px}
.nb-def{font-size:13px;color:var(--text2);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.nb-sent{font-size:13px;color:var(--text);line-height:1.5;margin-bottom:4px}
.nb-meta{font-size:11px;color:var(--text3)}
.nb-actions{display:flex;gap:4px;flex-shrink:0}
.nb-icon{width:30px;height:30px;border-radius:var(--radius);border:1px solid var(--border);background:none;color:var(--text3);cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:15px;transition:all .15s}
.nb-icon:hover{color:var(--danger);border-color:var(--danger)}
.nb-empty{text-align:center;padding:48px 20px;color:var(--text3);font-size:14px}

#screen-settings{padding:0}
.settings-scroll{flex:1;overflow-y:auto;padding:16px}
.profile-card{display:flex;align-items:center;gap:14px;padding:16px;background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);margin-bottom:20px}
.p-avatar{width:48px;height:48px;border-radius:50%;background:var(--primary-light);display:flex;align-items:center;justify-content:center;font-size:20px;font-weight:700;color:var(--primary);flex-shrink:0}
.p-name{font-size:16px;font-weight:600;color:var(--text)}
.p-email{font-size:13px;color:var(--text2);margin-top:1px}
.signout-btn{margin-left:auto;padding:7px 14px;border:1px solid var(--border);border-radius:20px;background:none;color:var(--text2);font-size:13px;cursor:pointer;transition:all .15s;white-space:nowrap}
.signout-btn:hover{color:var(--danger);border-color:var(--danger)}

.settings-group{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);overflow:hidden;margin-bottom:16px}
.settings-group-label{font-size:12px;font-weight:600;color:var(--text3);text-transform:uppercase;letter-spacing:.08em;padding:12px 16px 4px}
.setting-row{display:flex;align-items:center;justify-content:space-between;padding:13px 16px;border-top:1px solid var(--border)}
.setting-row:first-of-type{border-top:none}
.s-label{font-size:15px;color:var(--text)}
.s-sub{font-size:12px;color:var(--text3);margin-top:2px}
.s-ctrl{flex-shrink:0}
.s-select{padding:6px 10px;border:1px solid var(--border);border-radius:var(--radius);background:var(--bg2);color:var(--text);font-size:14px;cursor:pointer;outline:none}
.s-select:focus{border-color:var(--primary)}
.toggle{width:44px;height:26px;background:var(--border2);border-radius:13px;position:relative;cursor:pointer;transition:background .2s;border:none;flex-shrink:0}
.toggle.on{background:var(--primary)}
.toggle::after{content:'';position:absolute;left:3px;top:3px;width:20px;height:20px;border-radius:50%;background:#fff;transition:left .2s;box-shadow:0 1px 3px rgba(0,0,0,.2)}
.toggle.on::after{left:21px}
.color-picks{display:flex;gap:8px}
.cp{width:28px;height:28px;border-radius:50%;cursor:pointer;border:3px solid transparent;transition:all .15s}
.cp.active{border-color:var(--text);transform:scale(1.1)}

.api-banner{display:flex;flex-direction:column;align-items:stretch;gap:10px;padding:12px 14px;background:var(--warn-bg);border-radius:var(--radius);margin-bottom:16px;font-size:13px;color:var(--warn);line-height:1.5}
.api-banner a{color:var(--primary);text-decoration:none}
.api-key-row{display:flex;gap:8px;margin-top:6px}
.api-key-input{flex:1;padding:8px 12px;border:1px solid var(--border);border-radius:var(--radius);background:var(--bg);color:var(--text);font-size:13px;font-family:monospace;outline:none}
.api-key-input:focus{border-color:var(--primary)}
.save-key-btn{padding:8px 14px;background:var(--primary);color:#fff;border:none;border-radius:var(--radius);font-size:13px;cursor:pointer;white-space:nowrap}

.auth-input{width:100%;padding:14px 16px;border:1.5px solid var(--border);border-radius:var(--radius-lg);background:var(--bg2);color:var(--text);font-size:15px;outline:none;transition:border .15s}
.auth-input:focus{border-color:var(--primary);background:var(--bg)}
.link-btn{background:none;border:none;color:var(--primary);cursor:pointer;font-size:13px;font-weight:600;padding:0}
.link-btn:hover{text-decoration:underline}
.login-divider{display:flex;align-items:center;gap:12px;width:100%;max-width:360px;margin:16px 0;color:var(--text3);font-size:13px}
.login-divider::before,.login-divider::after{content:'';flex:1;height:1px;background:var(--border)}
.ghost-btn{width:100%;max-width:360px;padding:14px;border:1.5px dashed var(--border2);border-radius:var(--radius-lg);background:transparent;color:var(--text2);font-size:14px;font-weight:500;cursor:pointer;transition:all .15s;text-align:center}
.ghost-btn:hover{border-color:var(--primary);color:var(--primary);background:var(--primary-light)}
.login-error{font-size:13px;color:var(--danger);text-align:center;margin-top:12px;min-height:20px;width:100%;max-width:360px}

.toast{position:fixed;bottom:80px;left:50%;transform:translateX(-50%) translateY(20px);background:var(--text);color:var(--bg);padding:10px 20px;border-radius:20px;font-size:14px;opacity:0;transition:all .25s;pointer-events:none;z-index:999;white-space:nowrap}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}
.toast svg{display:inline;vertical-align:middle}

[data-icon]{display:inline-flex;align-items:center;justify-content:center}
[data-icon] svg{display:block}

::-webkit-scrollbar{width:4px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--border2);border-radius:2px}