/* === Reshalka — учебный AI. Paper-grid mint theme === */
*,*::before,*::after{box-sizing:border-box}
html,body{margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:'Space Grotesk',system-ui,-apple-system,Segoe UI,sans-serif;
  font-size:16px;line-height:1.6;
  color:#0f1f1a;
  background:#f4faf6;
  min-height:100vh;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
img,svg{display:block;max-width:100%;height:auto}
a{color:inherit;text-decoration:none}
button{font:inherit;cursor:pointer;border:0;background:none;color:inherit}
ul,ol{margin:0;padding:0;list-style:none}
h1,h2,h3,h4,p,blockquote{margin:0}
code{
  font-family:'JetBrains Mono','SF Mono',Consolas,monospace;
  font-size:.92em;background:#e6f5ee;padding:1px 6px;border-radius:4px;color:#0a4a3a;
}

.wrap{max-width:1200px;margin:0 auto;padding:0 28px}
@media(max-width:640px){.wrap{padding:0 18px}}

/* === paper grid background === */
.grid-paper{
  position:fixed;inset:0;z-index:-2;pointer-events:none;
  background:
    linear-gradient(#dceee5 1px, transparent 1px) 0 0/24px 24px,
    linear-gradient(90deg, #dceee5 1px, transparent 1px) 0 0/24px 24px,
    radial-gradient(900px 600px at 80% -10%, rgba(31,143,111,.08) 0%, transparent 60%),
    radial-gradient(700px 500px at 5% 100%, rgba(59,130,246,.06) 0%, transparent 60%),
    #f4faf6;
}

/* === navbar === */
.navbar{
  position:sticky;top:0;z-index:50;
  background:rgba(244,250,246,.85);
  backdrop-filter:saturate(150%) blur(14px);
  -webkit-backdrop-filter:saturate(150%) blur(14px);
  border-bottom:1px solid #d6ebe1;
}
.nav-row{
  display:flex;align-items:center;justify-content:space-between;
  height:68px;gap:24px;
}
.logo{display:inline-flex;align-items:center;gap:10px}
.logo-tile{
  width:34px;height:34px;border-radius:8px;
  background:linear-gradient(135deg,#1f8f6f 0%, #166e54 100%);
  display:grid;place-items:center;
  box-shadow:0 4px 12px rgba(31,143,111,.3);
}
.logo-tile.small{width:22px;height:22px;border-radius:5px;display:inline-grid}
.logo-text{
  font-family:'Space Grotesk',sans-serif;
  font-size:21px;font-weight:700;color:#0f1f1a;letter-spacing:-.02em;
}
.dot-green{color:#1f8f6f}
.nav{display:flex;gap:24px;align-items:center}
.nav a{
  font-family:'JetBrains Mono',monospace;
  font-size:13px;font-weight:500;color:#5a7268;
  padding:6px 0;transition:color .2s;
}
.nav a:hover{color:#1f8f6f}
@media(max-width:780px){.nav{display:none}}

/* === MAX cta === */
.cta{
  position:relative;display:inline-flex;align-items:center;justify-content:center;gap:10px;
  padding:11px 20px 11px 14px;
  font-family:'Space Grotesk',sans-serif;font-weight:600;font-size:14px;letter-spacing:.005em;
  color:#fff;
  background:#0f1f1a;
  border-radius:10px;
  box-shadow:
    0 1px 0 rgba(255,255,255,.08) inset,
    0 8px 22px rgba(15,31,26,.25),
    0 2px 6px rgba(0,0,0,.15);
  transition:transform .15s ease, box-shadow .2s, background .2s;
  white-space:nowrap;cursor:pointer;
  isolation:isolate;overflow:hidden;
}
.cta:hover{transform:translateY(-1px);background:#172c25;
  box-shadow:0 1px 0 rgba(255,255,255,.1) inset,0 12px 30px rgba(15,31,26,.35),0 4px 10px rgba(0,0,0,.18)}
.cta:active{transform:translateY(0)}
.cta::before{
  content:'';position:absolute;inset:0;border-radius:inherit;
  background:linear-gradient(110deg,transparent 35%, rgba(255,255,255,.18) 50%, transparent 65%);
  background-size:200% 100%;background-position:200% 0;
  pointer-events:none;animation:cta-shine 5s ease-in-out infinite;z-index:1;
}
@keyframes cta-shine{0%{background-position:200% 0}55%{background-position:-200% 0}100%{background-position:-200% 0}}
.cta__icon{
  width:26px;height:26px;display:grid;place-items:center;
  background:#fff;border-radius:7px;
  box-shadow:0 1px 3px rgba(0,0,0,.18);
  z-index:2;
}
.cta__icon img{width:18px;height:18px;object-fit:contain}
.cta > span:last-child{position:relative;z-index:2}
.cta--sm{padding:8px 16px 8px 10px;font-size:13px;border-radius:9px}
.cta--sm .cta__icon{width:22px;height:22px;border-radius:6px}
.cta--sm .cta__icon img{width:15px;height:15px}
.cta--lg{padding:16px 28px 16px 18px;font-size:16px;border-radius:12px}
.cta--lg .cta__icon{width:32px;height:32px;border-radius:9px}
.cta--lg .cta__icon img{width:22px;height:22px}
.cta--green{
  background:linear-gradient(180deg,#1f8f6f 0%, #166e54 100%);
  box-shadow:0 1px 0 rgba(255,255,255,.2) inset,0 14px 36px rgba(31,143,111,.45),0 4px 10px rgba(0,0,0,.18);
}
.cta--green:hover{background:linear-gradient(180deg,#26a884 0%, #1f8f6f 100%)}
.cta--loading{pointer-events:none;opacity:.85}
.cta--loading .cta__icon{animation:loadSpin .9s linear infinite}
@keyframes loadSpin{to{transform:rotate(360deg)}}

/* === hero === */
.hero{padding:64px 0 80px}
@media(max-width:640px){.hero{padding:36px 0 56px}}
.hero-grid{
  display:grid;grid-template-columns:1.05fr 1fr;gap:60px;align-items:center;
}
@media(max-width:920px){.hero-grid{grid-template-columns:1fr;gap:48px}}
.tag{
  font-family:'JetBrains Mono',monospace;
  font-size:12px;color:#1f8f6f;letter-spacing:.04em;
  display:inline-block;margin-bottom:24px;
  padding:6px 12px;background:#dff3ea;border-radius:6px;
}
.title{
  font-family:'Space Grotesk',sans-serif;
  font-weight:700;letter-spacing:-.025em;
  font-size:clamp(36px,6vw,68px);line-height:1.05;
  color:#0a1612;margin-bottom:24px;
}
.hl{
  background:linear-gradient(120deg,#1f8f6f 0%, #3b82f6 100%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
  position:relative;
}
.hl::after{
  content:'';position:absolute;left:-2%;right:-2%;bottom:4px;height:6px;
  background:rgba(31,143,111,.18);z-index:-1;border-radius:2px;
}
.sub{
  font-size:clamp(15px,1.5vw,18px);
  color:#3a4d44;max-width:540px;line-height:1.65;
}
.sub b{color:#0f1f1a;font-weight:600}
.hero-actions{display:flex;align-items:center;gap:18px;margin:32px 0 0;flex-wrap:wrap}
.hint{font-family:'JetBrains Mono',monospace;font-size:12px;color:#5a7268}
.badges{
  display:flex;gap:36px;margin-top:48px;
  padding-top:32px;border-top:1px dashed #c5dfd2;
  flex-wrap:wrap;
}
.badges b{
  font-family:'Space Grotesk',sans-serif;
  font-size:32px;font-weight:700;color:#0f1f1a;letter-spacing:-.02em;
  display:block;line-height:1;
}
.badges span{
  font-family:'JetBrains Mono',monospace;font-size:12px;color:#5a7268;
  display:block;margin-top:4px;
}

/* === phone mock === */
.hero-mock{display:flex;justify-content:center}
.phone{
  width:100%;max-width:340px;
  background:#0f1f1a;
  border-radius:36px;
  padding:14px;
  box-shadow:
    0 30px 80px rgba(15,31,26,.3),
    0 12px 30px rgba(15,31,26,.18),
    0 1px 0 rgba(255,255,255,.05) inset;
  position:relative;
}
.phone-notch{
  width:120px;height:24px;background:#0f1f1a;border-radius:0 0 14px 14px;
  position:absolute;top:14px;left:50%;transform:translateX(-50%);z-index:2;
}
.phone-screen{
  background:#fff;border-radius:24px;padding:40px 18px 18px;
  min-height:540px;
  display:flex;flex-direction:column;gap:14px;
  border:1px solid rgba(0,0,0,.05);
}
.screen-top{
  display:flex;align-items:center;gap:6px;padding-bottom:10px;
  border-bottom:1px solid #eef4f0;
}
.screen-dot{width:8px;height:8px;border-radius:50%;background:#d4ddd8}
.screen-dot:first-child{background:#ff6058}
.screen-dot:nth-child(2){background:#ffbd2e}
.screen-dot:nth-child(3){background:#27ca3f}
.screen-title{
  font-family:'JetBrains Mono',monospace;
  font-size:11px;color:#7a8a83;margin-left:auto;
}
.upload-card{
  background:linear-gradient(180deg,#f4faf6 0%, #e6f5ee 100%);
  border:1.5px dashed #1f8f6f;
  border-radius:14px;padding:24px 18px;text-align:center;
}
.upload-icon{margin:0 auto 12px}
.upload-title{font-weight:600;color:#0f1f1a;font-size:15px;margin-bottom:4px}
.upload-sub{font-family:'JetBrains Mono',monospace;font-size:11px;color:#5a7268;margin-bottom:14px}
.upload-btn{
  background:#1f8f6f;color:#fff;font-weight:600;font-size:13px;
  padding:8px 18px;border-radius:8px;
  box-shadow:0 4px 12px rgba(31,143,111,.3);
}
.answer-card{
  background:#fafdfb;border:1px solid #e3eee8;border-radius:12px;padding:14px;
  display:flex;flex-direction:column;gap:10px;
}
.ans-q{font-size:13px;color:#0f1f1a;font-weight:500;margin-bottom:4px}
.ans-step{display:flex;gap:10px;align-items:flex-start}
.ans-step span{
  flex-shrink:0;width:20px;height:20px;border-radius:50%;
  background:#1f8f6f;color:#fff;display:grid;place-items:center;
  font-family:'JetBrains Mono',monospace;font-size:11px;font-weight:700;
}
.ans-step p{font-size:12px;color:#3a4d44;line-height:1.5}
.ans-tag{
  font-family:'JetBrains Mono',monospace;font-size:11px;
  color:#1f8f6f;font-weight:600;margin-top:4px;
  border-top:1px dashed #d6ebe1;padding-top:8px;
}

/* === section common === */
.section-tag{
  font-family:'JetBrains Mono',monospace;
  font-size:12px;color:#1f8f6f;letter-spacing:.04em;
  margin-bottom:14px;
}
.section-title{
  font-family:'Space Grotesk',sans-serif;
  font-weight:700;letter-spacing:-.02em;
  font-size:clamp(26px,3.6vw,42px);line-height:1.15;
  color:#0a1612;margin-bottom:14px;
}

/* === subjects === */
.subjects{padding:80px 0;border-top:1px solid #d6ebe1}
@media(max-width:640px){.subjects{padding:56px 0}}
.subj-grid{
  margin-top:36px;
  display:grid;grid-template-columns:repeat(4,1fr);gap:16px;
}
@media(max-width:1000px){.subj-grid{grid-template-columns:repeat(3,1fr)}}
@media(max-width:720px){.subj-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:440px){.subj-grid{grid-template-columns:1fr}}
.subj-grid li{
  background:#fff;border:1px solid #e3eee8;border-radius:14px;
  padding:24px 20px;
  transition:transform .2s ease, border-color .2s, box-shadow .2s;
}
.subj-grid li:hover{transform:translateY(-3px);border-color:#1f8f6f;
  box-shadow:0 10px 28px rgba(31,143,111,.12)}
.subj-ico{
  width:42px;height:42px;border-radius:10px;
  display:grid;place-items:center;
  background:color-mix(in srgb, var(--c, #1f8f6f) 14%, white);
  color:var(--c, #1f8f6f);
  font-family:'JetBrains Mono',monospace;font-size:22px;font-weight:700;
  margin-bottom:14px;
}
.subj-grid h3{font-size:16px;font-weight:600;color:#0f1f1a;margin-bottom:6px}
.subj-grid p{font-size:13px;color:#5a7268;line-height:1.5}

/* === how === */
.how{padding:80px 0;border-top:1px solid #d6ebe1}
@media(max-width:640px){.how{padding:56px 0}}
.how-steps{
  margin-top:40px;
  display:grid;grid-template-columns:repeat(3,1fr);gap:24px;
}
@media(max-width:880px){.how-steps{grid-template-columns:1fr}}
.how-steps li{
  background:#fff;border:1px solid #e3eee8;border-radius:16px;
  padding:32px 28px;
  position:relative;
  display:flex;flex-direction:column;gap:10px;
}
.step-n{
  font-family:'JetBrains Mono',monospace;
  font-size:13px;font-weight:700;color:#1f8f6f;
  background:#dff3ea;padding:4px 10px;border-radius:6px;
  align-self:flex-start;letter-spacing:.04em;
  margin-bottom:6px;
}
.how-steps h3{
  font-family:'Space Grotesk',sans-serif;
  font-size:20px;font-weight:600;color:#0f1f1a;
}
.how-steps p{color:#3a4d44;font-size:14px;line-height:1.6}

/* === examples === */
.examples{padding:80px 0;border-top:1px solid #d6ebe1}
@media(max-width:640px){.examples{padding:56px 0}}
.ex-grid{
  margin-top:36px;
  display:grid;grid-template-columns:repeat(3,1fr);gap:20px;
}
@media(max-width:880px){.ex-grid{grid-template-columns:1fr}}
.ex-card{
  background:linear-gradient(180deg,#fff 0%, #fbfdfc 100%);
  border:1px solid #e3eee8;border-radius:14px;
  padding:28px 24px;
  display:flex;flex-direction:column;gap:18px;
  transition:transform .2s, border-color .2s;
}
.ex-card:hover{transform:translateY(-2px);border-color:#bdd7cb}
.ex-text{
  font-size:15px;color:#0f1f1a;line-height:1.65;
  position:relative;padding-left:14px;
}
.ex-text::before{
  content:'';position:absolute;left:0;top:4px;bottom:4px;width:3px;
  background:linear-gradient(180deg,#1f8f6f, #3b82f6);border-radius:2px;
}
.ex-card footer{
  display:flex;flex-direction:column;gap:2px;
  padding-top:14px;border-top:1px dashed #d6ebe1;
}
.ex-card footer b{font-size:14px;font-weight:600;color:#0f1f1a}
.ex-card footer span{
  font-family:'JetBrains Mono',monospace;font-size:11px;color:#5a7268;
}

/* === faq === */
.faq{padding:80px 0;border-top:1px solid #d6ebe1}
@media(max-width:640px){.faq{padding:56px 0}}
.faq-list{margin-top:24px;max-width:780px}
.faq details{
  background:#fff;border:1px solid #e3eee8;border-radius:12px;
  padding:18px 22px;margin-bottom:10px;
  transition:border-color .2s;
}
.faq details[open]{border-color:#1f8f6f}
.faq summary{
  font-weight:600;font-size:15px;color:#0f1f1a;
  cursor:pointer;list-style:none;
  display:flex;align-items:center;justify-content:space-between;gap:14px;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{
  content:'+';font-family:'JetBrains Mono',monospace;
  font-size:20px;color:#1f8f6f;font-weight:600;
  transition:transform .25s ease;
}
.faq details[open] summary::after{transform:rotate(45deg)}
.faq details p{
  margin-top:12px;color:#3a4d44;font-size:14px;line-height:1.65;
  padding-top:12px;border-top:1px dashed #d6ebe1;
}

/* === cta-section === */
.cta-section{padding:80px 0 100px}
@media(max-width:640px){.cta-section{padding:56px 0 80px}}
.cta-block{
  text-align:center;
  background:#0f1f1a;
  color:#fff;
  border-radius:24px;
  padding:64px 32px;
  position:relative;overflow:hidden;
  box-shadow:0 30px 80px rgba(15,31,26,.25);
}
.cta-block::before{
  content:'';position:absolute;inset:0;border-radius:inherit;
  background:
    radial-gradient(500px 250px at 50% -20%, rgba(31,143,111,.45), transparent),
    linear-gradient(180deg, transparent 0%, rgba(31,143,111,.06) 100%);
  pointer-events:none;
}
.cta-block .section-tag{color:#7be0c0;position:relative;z-index:1}
.cta-block .section-title{color:#fff;position:relative;z-index:1;max-width:680px;margin:0 auto 14px}
.cta-block .sub{color:#b4cdc3;max-width:520px;margin:0 auto 28px;text-align:center;position:relative;z-index:1}
.cta-block .cta{position:relative;z-index:1}
.legal-note{
  margin-top:18px;font-family:'JetBrains Mono',monospace;
  font-size:11px;color:#7a958c;position:relative;z-index:1;
}
.legal-note a{color:#7be0c0;text-decoration:underline;text-decoration-color:rgba(123,224,192,.4)}
.legal-note a:hover{text-decoration-color:#7be0c0}

/* === footer === */
.footer{
  border-top:1px solid #d6ebe1;
  padding:32px 0;background:rgba(244,250,246,.6);
}
.foot-row{
  display:flex;align-items:center;justify-content:space-between;gap:20px;
  flex-wrap:wrap;
}
.foot-brand{
  display:inline-flex;align-items:center;gap:10px;
  font-weight:600;color:#0f1f1a;font-size:15px;
}
.foot-nav{display:flex;gap:24px}
.foot-nav a{
  font-family:'JetBrains Mono',monospace;font-size:12px;color:#5a7268;
}
.foot-nav a:hover{color:#1f8f6f}

/* === reduced motion === */
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation:none!important;transition:none!important}
}