@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@700;900&family=DM+Sans:wght@300;400;500;600&display=swap');

:root {
  --bg:#ffffff;--bg2:#f7f6f3;--ink:#0a0a0a;--ink2:#1a1a1a;
  --muted:#888880;--border:#e8e6e0;--gold:#b8860b;
  --green:#2d6a4f;--red:#c1121f;--card-bg:#ffffff;
  --shadow:0 4px 40px rgba(0,0,0,.07);
  --shadow-lg:0 12px 60px rgba(0,0,0,.12);
  --radius:16px;
}
[data-theme="dark"]{
  --bg:#0d0d0d;--bg2:#171717;--ink:#f0ede8;--ink2:#d0ccc5;
  --muted:#666660;--border:#2a2a28;--gold:#d4a017;
  --green:#4ade80;--red:#f87171;--card-bg:#151513;
  --shadow:0 4px 40px rgba(0,0,0,.4);
  --shadow-lg:0 12px 60px rgba(0,0,0,.6);
}

*,*::before,*::after{margin:0;padding:0;box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{font-family:'DM Sans',sans-serif;background:var(--bg);color:var(--ink);min-height:100vh;transition:background .3s,color .3s;overflow-x:hidden;}
body::after{content:'';position:fixed;inset:0;background-image:url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.025'/%3E%3C/svg%3E");pointer-events:none;z-index:9999;opacity:.35;}
a{color:var(--gold);text-decoration:none;}a:hover{text-decoration:underline;}

.screen{display:none;min-height:100vh;flex-direction:column;}.screen.active{display:flex;}

.theme-toggle{position:fixed;top:24px;right:28px;width:40px;height:40px;border-radius:50%;background:var(--bg2);border:1px solid var(--border);display:flex;align-items:center;justify-content:center;cursor:pointer;z-index:50;font-size:18px;transition:transform .2s,box-shadow .2s;}
.theme-toggle:hover{transform:scale(1.1);box-shadow:var(--shadow);}
.theme-toggle-sm{width:36px;height:36px;border-radius:50%;background:var(--bg2);border:1px solid var(--border);display:flex;align-items:center;justify-content:center;cursor:pointer;font-size:16px;transition:transform .2s;}
.theme-toggle-sm:hover{transform:scale(1.1);}

#home{align-items:center;justify-content:center;padding:80px 24px;position:relative;}
.bg-ring{position:absolute;border-radius:50%;border:1px solid var(--border);top:50%;left:50%;transform:translate(-50%,-50%);animation:ringPulse 7s ease-in-out infinite;pointer-events:none;}
.r1{width:640px;height:640px;}.r2{width:420px;height:420px;animation-delay:1.2s;}.r3{width:220px;height:220px;animation-delay:2.4s;}
@keyframes ringPulse{0%,100%{opacity:.3;transform:translate(-50%,-50%) scale(1);}50%{opacity:.06;transform:translate(-50%,-50%) scale(1.04);}}

.home-content{position:relative;z-index:1;text-align:center;max-width:640px;width:100%;animation:fadeUp .8s ease both;}
.logo{font-family:'Playfair Display',serif;font-size:76px;font-weight:900;letter-spacing:-3.5px;line-height:1;margin-bottom:10px;color:var(--ink);}
.logo-sm{font-family:'Playfair Display',serif;font-size:26px;font-weight:900;letter-spacing:-1px;color:var(--ink);}
.dot{color:var(--gold);}
.tagline{font-size:13px;font-weight:500;letter-spacing:3px;text-transform:uppercase;color:var(--muted);margin-bottom:48px;}
.home-desc{font-size:17px;line-height:1.75;color:var(--muted);margin-bottom:44px;font-weight:300;}

.free-badge{background:rgba(45,106,79,.12);color:var(--green);font-size:10px;font-weight:700;letter-spacing:1.5px;text-transform:uppercase;padding:3px 8px;border-radius:20px;margin-left:8px;vertical-align:middle;}

.api-section{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius);padding:24px 28px;margin-bottom:36px;text-align:left;}
.field-label{font-size:11px;font-weight:600;letter-spacing:2.5px;text-transform:uppercase;color:var(--muted);margin-bottom:10px;text-align:left;}
.text-input{width:100%;border:1.5px solid var(--border);border-radius:10px;padding:13px 16px;font-family:'DM Sans',sans-serif;font-size:14px;background:var(--bg);color:var(--ink);outline:none;transition:border-color .2s,background .3s;}
.text-input:focus{border-color:var(--ink);}.text-input::placeholder{color:var(--muted);}
.field-note{font-size:12px;color:var(--muted);margin-top:8px;}

.topic-grid{display:grid;grid-template-columns:1fr 1fr 1fr;gap:12px;margin-bottom:8px;text-align:left;}
.topic-card{border:1.5px solid var(--border);border-radius:var(--radius);padding:16px 18px;cursor:pointer;background:var(--card-bg);transition:all .2s ease;}
.topic-card:hover{border-color:var(--ink);transform:translateY(-2px);box-shadow:var(--shadow);}
.topic-card.selected{border-color:var(--ink);background:var(--ink);}
.topic-card.selected .topic-title{color:var(--bg);}.topic-card.selected .topic-sub{color:rgba(255,255,255,.45);}.topic-card.selected .topic-icon{filter:grayscale(1) brightness(10);}
[data-theme="dark"] .topic-card.selected .topic-title{color:#0d0d0d;}[data-theme="dark"] .topic-card.selected .topic-sub{color:rgba(0,0,0,.4);}[data-theme="dark"] .topic-card.selected .topic-icon{filter:none;}
.topic-icon{font-size:20px;margin-bottom:8px;}.topic-title{font-size:14px;font-weight:600;margin-bottom:3px;}.topic-sub{font-size:12px;color:var(--muted);}

.dur-row{display:flex;gap:10px;margin-bottom:40px;}
.dur-btn{flex:1;padding:13px;border:1.5px solid var(--border);border-radius:10px;background:var(--card-bg);font-family:'DM Sans',sans-serif;font-size:14px;font-weight:500;cursor:pointer;transition:all .2s;color:var(--ink);}
.dur-btn:hover{border-color:var(--ink);}.dur-btn.selected{background:var(--ink);color:var(--bg);border-color:var(--ink);}

.btn-primary{background:var(--ink);color:var(--bg);border:none;border-radius:14px;padding:19px 52px;font-family:'Playfair Display',serif;font-size:18px;font-weight:700;cursor:pointer;transition:all .25s ease;letter-spacing:-.3px;position:relative;overflow:hidden;}
.btn-primary::before{content:'';position:absolute;inset:0;background:linear-gradient(135deg,rgba(255,255,255,.08) 0%,transparent 60%);opacity:0;transition:opacity .2s;}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 32px rgba(0,0,0,.25);}.btn-primary:hover::before{opacity:1;}
.btn-primary:active{transform:translateY(0);}.btn-primary:disabled{opacity:.35;cursor:not-allowed;transform:none;}

.btn-ghost{background:transparent;color:var(--ink);border:1.5px solid var(--border);border-radius:12px;padding:13px 24px;font-family:'DM Sans',sans-serif;font-size:14px;font-weight:500;cursor:pointer;transition:all .2s;}
.btn-ghost:hover{border-color:var(--ink);background:var(--bg2);}
.btn-danger{background:transparent;color:var(--red);border:1.5px solid rgba(193,18,31,.25);border-radius:12px;padding:13px 24px;font-family:'DM Sans',sans-serif;font-size:14px;font-weight:500;cursor:pointer;transition:all .2s;}
[data-theme="dark"] .btn-danger{border-color:rgba(248,113,113,.2);}
.btn-danger:hover{background:rgba(193,18,31,.06);border-color:var(--red);}

.session-header{display:flex;align-items:center;justify-content:space-between;padding:22px 40px;border-bottom:1px solid var(--border);animation:fadeDown .4s ease both;background:var(--bg);}
.session-meta{display:flex;align-items:center;gap:20px;}
.topic-badge{background:var(--bg2);border:1px solid var(--border);border-radius:20px;padding:5px 16px;font-size:12px;font-weight:500;color:var(--muted);}
.timer{font-family:'Playfair Display',serif;font-size:28px;font-weight:700;letter-spacing:-1px;min-width:80px;text-align:right;transition:color .3s;}
.timer.urgent{color:var(--red);animation:urgentPulse 1s ease-in-out infinite;}
@keyframes urgentPulse{0%,100%{opacity:1;}50%{opacity:.45;}}

.session-body{flex:1;display:flex;flex-direction:column;padding:28px 40px;gap:16px;max-width:800px;margin:0 auto;width:100%;}

.ai-bubble{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius);padding:22px 26px;position:relative;animation:fadeUp .4s ease both;transition:background .3s;}
.ai-bubble-label{font-size:10px;font-weight:700;letter-spacing:3px;text-transform:uppercase;color:var(--muted);margin-bottom:10px;display:flex;align-items:center;gap:8px;}
.ai-avatar{width:22px;height:22px;border-radius:50%;background:var(--ink);color:var(--bg);display:inline-flex;align-items:center;justify-content:center;font-size:11px;font-weight:700;font-family:'Playfair Display',serif;}
.ai-status{margin-left:auto;font-size:10px;color:var(--gold);font-weight:500;letter-spacing:1px;text-transform:lowercase;animation:statusPulse 2s ease-in-out infinite;}
@keyframes statusPulse{0%,100%{opacity:1;}50%{opacity:.4;}}
.ai-bubble-text{font-size:17px;line-height:1.72;color:var(--ink);font-weight:400;min-height:26px;}

.typing-dots{display:inline-flex;gap:5px;align-items:center;}
.typing-dots span{width:7px;height:7px;border-radius:50%;background:var(--muted);animation:dotBounce 1.2s ease infinite;}
.typing-dots span:nth-child(2){animation-delay:.2s;}.typing-dots span:nth-child(3){animation-delay:.4s;}
@keyframes dotBounce{0%,60%,100%{transform:translateY(0);opacity:.35;}30%{transform:translateY(-7px);opacity:1;}}

.speaking-bar{display:flex;align-items:center;gap:3px;margin-top:12px;}
.speaking-bar span{width:3px;border-radius:3px;background:var(--gold);animation:speakWave .7s ease-in-out infinite alternate;}
.speaking-bar span:nth-child(1){height:5px;}.speaking-bar span:nth-child(2){height:12px;animation-delay:.1s;}.speaking-bar span:nth-child(3){height:20px;animation-delay:.2s;}.speaking-bar span:nth-child(4){height:14px;animation-delay:.3s;}.speaking-bar span:nth-child(5){height:8px;animation-delay:.4s;}.speaking-bar span:nth-child(6){height:5px;animation-delay:.5s;}
@keyframes speakWave{from{transform:scaleY(.5);opacity:.5;}to{transform:scaleY(1.5);opacity:1;}}

.conv-history{display:flex;flex-direction:column;gap:6px;max-height:160px;overflow-y:auto;}
.conv-history:empty{display:none;}
.conv-history::-webkit-scrollbar{width:3px;}.conv-history::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px;}
.conv-msg{padding:9px 13px;border-radius:10px;font-size:13px;line-height:1.55;animation:fadeIn .3s ease both;}
.conv-msg.user{background:var(--bg2);border:1px solid var(--border);color:var(--ink2);align-self:flex-end;max-width:90%;border-bottom-right-radius:4px;}
.conv-msg.ai-prev{background:transparent;color:var(--muted);align-self:flex-start;max-width:90%;padding-left:2px;}
.conv-msg.ai-prev::before{content:'↳ ';color:var(--gold);}

.stats-row{display:flex;gap:12px;}
.stat-card{flex:1;background:var(--bg2);border:1px solid var(--border);border-radius:12px;padding:14px 16px;text-align:center;transition:background .3s;}
.stat-val{font-family:'Playfair Display',serif;font-size:26px;font-weight:700;letter-spacing:-1px;line-height:1;margin-bottom:4px;}
.stat-label{font-size:10px;color:var(--muted);font-weight:500;letter-spacing:1px;text-transform:uppercase;}

.waveform{display:flex;align-items:center;justify-content:center;gap:3px;height:38px;}
.w-bar{width:3px;border-radius:3px;background:var(--ink);height:5px;transition:height .08s ease;animation:waveIdle 2s ease-in-out infinite;opacity:.2;}
.w-bar:nth-child(even){animation-delay:.35s;}.w-bar:nth-child(3n){animation-delay:.7s;}
@keyframes waveIdle{0%,100%{height:5px;opacity:.2;}50%{height:12px;opacity:.4;}}
.w-bar.live{animation:none;opacity:.9;}

.mic-hint{text-align:center;font-size:13px;color:var(--muted);transition:opacity .4s;}
.mic-hint.hidden{opacity:0;pointer-events:none;}

.controls{display:flex;align-items:center;justify-content:center;gap:18px;}
.mic-btn{width:66px;height:66px;border-radius:50%;background:var(--ink);color:var(--bg);border:none;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .25s ease;position:relative;overflow:hidden;}
.mic-btn::before{content:'';position:absolute;width:100%;height:100%;border-radius:50%;background:inherit;transform:scale(0);opacity:0;}
.mic-btn.listening{background:var(--red);}
.mic-btn.listening::before{animation:ripple 1.6s ease-out infinite;}
@keyframes ripple{0%{transform:scale(1);opacity:.4;}100%{transform:scale(2.3);opacity:0;}}
.mic-btn:hover{transform:scale(1.07);}.mic-btn:active{transform:scale(.95);}

#report{background:var(--bg);}
.report-top{padding:56px 40px 36px;border-bottom:1px solid var(--border);max-width:900px;margin:0 auto;width:100%;animation:fadeUp .6s ease both;position:relative;}
.report-heading{font-family:'Playfair Display',serif;font-size:56px;font-weight:900;letter-spacing:-3px;line-height:1.05;margin-bottom:10px;}
.report-meta{font-size:14px;color:var(--muted);font-weight:400;}
.report-body{padding:40px;max-width:900px;margin:0 auto;width:100%;display:flex;flex-direction:column;gap:26px;}

.score-block{background:var(--ink);color:var(--bg);border-radius:20px;padding:38px 44px;display:flex;align-items:center;gap:44px;animation:fadeUp .6s .1s ease both;}
.score-ring-wrap{position:relative;width:130px;height:130px;flex-shrink:0;}
.score-ring-wrap svg{transform:rotate(-90deg);}
.ring-bg{fill:none;stroke:rgba(255,255,255,.1);stroke-width:8;}
.ring-fill{fill:none;stroke:var(--bg);stroke-width:8;stroke-linecap:round;stroke-dasharray:352;stroke-dashoffset:352;transition:stroke-dashoffset 1.6s cubic-bezier(.16,1,.3,1);}
.score-num{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;font-family:'Playfair Display',serif;font-size:34px;font-weight:900;color:var(--bg);line-height:1;}
.score-num small{font-size:12px;font-family:'DM Sans',sans-serif;font-weight:400;opacity:.55;}
.score-info{flex:1;}.score-grade{font-family:'Playfair Display',serif;font-size:20px;font-weight:700;margin-bottom:10px;}
.score-summary{font-size:15px;line-height:1.7;opacity:.65;font-weight:300;}

.sub-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;animation:fadeUp .6s .2s ease both;}
.sub-card{border:1.5px solid var(--border);border-radius:var(--radius);padding:22px;position:relative;overflow:hidden;background:var(--card-bg);transition:transform .2s,box-shadow .2s,background .3s;}
.sub-card:hover{transform:translateY(-3px);box-shadow:var(--shadow);}
.sub-card::after{content:'';position:absolute;bottom:0;left:0;right:0;height:3px;background:var(--ink);transform:scaleX(0);transform-origin:left;transition:transform 1s .4s cubic-bezier(.16,1,.3,1);}
.sub-card.go::after{transform:scaleX(var(--w));}
.sub-label{font-size:10px;font-weight:600;letter-spacing:2px;text-transform:uppercase;color:var(--muted);margin-bottom:8px;}
.sub-val{font-family:'Playfair Display',serif;font-size:38px;font-weight:900;letter-spacing:-2px;line-height:1;}

.rep-section{border:1.5px solid var(--border);border-radius:var(--radius);overflow:hidden;animation:fadeUp .6s .3s ease both;background:var(--card-bg);transition:background .3s;}
.rep-section-head{padding:16px 26px;border-bottom:1px solid var(--border);background:var(--bg2);font-size:12px;font-weight:600;letter-spacing:2px;text-transform:uppercase;transition:background .3s;}
.rep-section-body{padding:24px 26px;}

.fb-item{display:flex;gap:14px;margin-bottom:16px;padding-bottom:16px;border-bottom:1px solid var(--border);animation:fadeIn .35s ease both;}
.fb-item:last-child{margin-bottom:0;padding-bottom:0;border-bottom:none;}
.fb-icon{width:28px;height:28px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:12px;flex-shrink:0;margin-top:2px;}
.fb-icon.g{background:rgba(45,106,79,.12);color:var(--green);}
.fb-icon.r{background:rgba(193,18,31,.09);color:var(--red);}
.fb-icon.y{background:rgba(184,134,11,.12);color:var(--gold);}
.fb-title{font-size:15px;font-weight:600;margin-bottom:3px;}.fb-desc{font-size:14px;color:var(--muted);line-height:1.6;font-weight:300;}

.fix-item{background:var(--bg2);border-radius:10px;padding:14px 18px;margin-bottom:10px;border-left:3px solid var(--red);animation:fadeIn .35s ease both;transition:background .3s;}
.fix-orig{font-size:14px;color:var(--red);margin-bottom:5px;text-decoration:line-through;opacity:.75;}
.fix-good{font-size:14px;color:var(--green);font-weight:500;margin-bottom:5px;}.fix-why{font-size:12px;color:var(--muted);}

.vocab-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;}
.vocab-item{background:var(--bg2);border-radius:10px;padding:13px 16px;border:1px solid var(--border);transition:background .3s;}
.vocab-word{font-size:15px;font-weight:600;margin-bottom:3px;}.vocab-level{font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:1px;}.vocab-note{font-size:12px;color:var(--muted);margin-top:4px;font-weight:300;}
.full-tx{font-size:15px;line-height:1.85;color:var(--muted);font-weight:300;white-space:pre-wrap;}

/* sub score progress bar */
.sub-bar-track{height:3px;background:var(--border);border-radius:3px;margin-top:10px;overflow:hidden;}
.sub-bar-fill{height:100%;border-radius:3px;transition:width 1s .4s cubic-bezier(.16,1,.3,1);}

/* priority box */
.priority-box{
  font-size:17px;line-height:1.75;font-weight:500;
  background:var(--bg2);border-radius:12px;padding:18px 22px;
  border-left:4px solid var(--gold);color:var(--ink);
  transition:background .3s;
}

/* grammar fix badges */
.fix-row{display:flex;align-items:flex-start;gap:10px;}
.fix-badge{
  font-size:10px;font-weight:700;letter-spacing:1.5px;text-transform:uppercase;
  padding:3px 9px;border-radius:20px;flex-shrink:0;margin-top:2px;
}
.fix-badge.wrong{background:rgba(193,18,31,.1);color:var(--red);}
.fix-badge.right{background:rgba(45,106,79,.1);color:var(--green);}

/* vocab badge */
.vocab-badge{
  font-size:10px;font-weight:700;letter-spacing:1px;text-transform:uppercase;
  padding:2px 8px;border-radius:20px;
}

/* conv replay */
.conv-replay{display:flex;flex-direction:column;gap:10px;}
.conv-replay-item{padding:14px 18px;border-radius:12px;}
.conv-replay-item.was-ai{background:var(--bg2);border:1px solid var(--border);}
.conv-replay-item.was-user{border:1px solid var(--border);border-left:3px solid var(--gold);}
.conv-replay-label{font-size:10px;font-weight:700;letter-spacing:2px;text-transform:uppercase;color:var(--muted);margin-bottom:6px;}
.conv-replay-text{font-size:14px;line-height:1.6;color:var(--ink2);}

.report-actions{display:flex;gap:14px;justify-content:center;padding:36px 40px;border-top:1px solid var(--border);}

.gen-overlay{position:fixed;inset:0;background:var(--bg);display:flex;flex-direction:column;align-items:center;justify-content:center;z-index:100;gap:22px;transition:background .3s;}
.gen-msg{font-size:15px;color:var(--muted);animation:fadeUp .4s .1s ease both;}
.gen-bar{width:220px;height:2px;background:var(--border);border-radius:2px;overflow:hidden;animation:fadeUp .4s .2s ease both;}
.gen-fill{height:100%;background:var(--ink);border-radius:2px;animation:genAnim 2.8s ease-in-out infinite;}
@keyframes genAnim{0%{width:0%;margin-left:0;}50%{width:65%;margin-left:0;}100%{width:0%;margin-left:100%;}}

.toast{position:fixed;bottom:30px;left:50%;transform:translateX(-50%) translateY(80px);background:var(--ink2);color:var(--bg);padding:13px 22px;border-radius:12px;font-size:14px;z-index:200;transition:transform .3s ease;box-shadow:var(--shadow-lg);pointer-events:none;}
.toast.show{transform:translateX(-50%) translateY(0);}

@keyframes fadeUp{from{opacity:0;transform:translateY(20px);}to{opacity:1;transform:translateY(0);}}
@keyframes fadeDown{from{opacity:0;transform:translateY(-16px);}to{opacity:1;transform:translateY(0);}}
@keyframes fadeIn{from{opacity:0;transform:translateX(-8px);}to{opacity:1;transform:translateX(0);}}

@media(max-width:680px){
  .logo{font-size:54px;}.topic-grid{grid-template-columns:1fr 1fr;}.sub-grid{grid-template-columns:1fr 1fr;}
  .score-block{flex-direction:column;text-align:center;}.vocab-grid{grid-template-columns:1fr;}
  .session-header{padding:18px 20px;}.session-body{padding:20px;}
  .report-top{padding:36px 20px 28px;}.report-body{padding:20px;}
  .report-heading{font-size:38px;}.report-actions{padding:28px 20px;flex-direction:column;}
}