/* ==========================================================================
   STARTUS — Design tokens
   ========================================================================== */
:root{
  --ink:        #16233F;
  --ink-soft:   #2A3A5C;
  --paper:      #F6F5F0;
  --paper-alt:  #EFEEE6;
  --card-blue:  #E7EBF5;
  --chalk:      #F2B705;
  --chalk-dark: #C99500;
  --pencil:     #45516B;
  --correct:    #2F9E5B;
  --white:      #FFFFFF;
  --line:       rgba(22,35,63,0.12);

  --font-display: 'Fraunces', serif;
  --font-body:    'Manrope', sans-serif;
  --font-mono:    'IBM Plex Mono', monospace;

  --radius-lg: 22px;
  --radius-md: 14px;
  --radius-sm: 8px;

  --shadow-card: 0 1px 2px rgba(22,35,63,0.04), 0 12px 32px -12px rgba(22,35,63,0.16);
}

*{ box-sizing: border-box; }

html{ scroll-behavior: smooth; }

body{
  font-family: var(--font-body);
  color: var(--pencil);
  background: var(--paper);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1,h2,h3,h4{
  font-family: var(--font-display);
  color: var(--ink);
  margin: 0;
}

a{ text-decoration: none; color: inherit; }

.su-mono{ font-family: var(--font-mono); letter-spacing: 0.02em; }
.su-dim{ color: var(--pencil); opacity: 0.6; }

/* ==========================================================================
   Buttons
   ========================================================================== */
.su-btn{
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 0.95rem;
  padding: 0.65rem 1.4rem;
  border-radius: 999px;
  border: 1.5px solid transparent;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease, color 0.18s ease;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}
.su-btn-lg{ padding: 0.85rem 1.9rem; font-size: 1rem; }

.su-btn-primary{
  background: var(--ink);
  color: var(--white);
  box-shadow: 0 6px 0 0 var(--chalk-dark);
}
.su-btn-primary:hover{
  color: var(--white);
  transform: translateY(2px);
  box-shadow: 0 4px 0 0 var(--chalk-dark);
}
.su-btn-primary:active{ transform: translateY(6px); box-shadow: 0 0 0 0 var(--chalk-dark); }

.su-btn-outline{
  background: transparent;
  border-color: var(--ink);
  color: var(--ink);
}
.su-btn-outline:hover{
  background: var(--ink);
  color: var(--white);
}

/* ==========================================================================
   Nav
   ========================================================================== */
.su-nav{
  background: rgba(246,245,240,0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  padding: 1.1rem 0;
  transition: all 0.25s ease;
  z-index: 1050;
}
.su-nav.su-nav-scrolled{
  padding: 0.65rem 0;
  border-bottom-color: var(--line);
  box-shadow: 0 4px 20px rgba(22,35,63,0.06);
}
.su-brand{
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.35rem;
  color: var(--ink);
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
}
.su-brand-mark{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px; height: 34px;
  background: var(--ink);
  color: var(--chalk);
  border-radius: 9px;
  font-weight: 700;
  font-size: 1.05rem;
}
.su-brand-tag{
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--pencil);
  border-left: 1px solid var(--line);
  padding-left: 0.6rem;
  margin-left: 0.1rem;
}
.su-nav .nav-link{
  color: var(--ink-soft);
  font-weight: 600;
  font-size: 0.93rem;
  padding: 0.5rem 0.85rem !important;
  position: relative;
}
.su-nav .nav-link:hover{ color: var(--ink); }

/* ==========================================================================
   Hero
   ========================================================================== */
.su-hero{
  padding: 9.5rem 0 5rem;
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(600px 300px at 90% -10%, rgba(242,183,5,0.14), transparent 60%),
    var(--paper);
}
.su-eyebrow{
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--chalk-dark);
  background: rgba(242,183,5,0.14);
  border: 1px solid rgba(242,183,5,0.35);
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  margin-bottom: 1.4rem;
}
.su-eyebrow-light{
  color: var(--chalk);
  background: rgba(242,183,5,0.12);
  border-color: rgba(242,183,5,0.3);
}
.su-h1{
  font-size: clamp(2.3rem, 4.4vw, 3.6rem);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -0.01em;
}
.su-underline{
  position: relative;
  white-space: nowrap;
}
.su-underline::after{
  content: "";
  position: absolute;
  left: -2px; right: -2px; bottom: 0.06em;
  height: 0.34em;
  background: var(--chalk);
  z-index: -1;
  border-radius: 3px;
}
.su-lead{
  font-size: 1.15rem;
  max-width: 46ch;
  margin-top: 1.3rem;
  color: var(--pencil);
}
.su-lead-light{ color: rgba(246,245,240,0.75); }

.su-hero-trust{
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
}
.su-hero-trust .su-mono{
  font-size: 0.7rem;
  color: var(--pencil);
  opacity: 0.55;
  display: block;
  margin-bottom: 0.6rem;
}
.su-trust-row{
  display: flex;
  flex-wrap: wrap;
  gap: 1.4rem;
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 0.98rem;
  color: var(--ink-soft);
  opacity: 0.75;
}

/* ---- Signature widget: live grading card ---- */
.su-grade-card{
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: 1.6rem;
  max-width: 460px;
  margin-left: auto;
  transform: rotate(0.6deg);
}
.su-grade-card-head{
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.72rem;
  padding-bottom: 1rem;
  margin-bottom: 1.1rem;
  border-bottom: 1px dashed var(--line);
}
.su-live{
  color: var(--correct);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}
.su-live i{ font-size: 0.5rem; animation: suPulse 1.6s infinite; }
@keyframes suPulse{ 0%,100%{opacity:1;} 50%{opacity:0.25;} }

.su-grade-q{
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: var(--ink);
  margin-bottom: 1.2rem;
}
.su-grade-answer-wrap{
  background: var(--paper-alt);
  border-radius: var(--radius-md);
  padding: 1rem 1.1rem;
  position: relative;
}
.su-grade-answer-wrap > .su-mono{ font-size: 0.68rem; display:block; margin-bottom: 0.4rem;}
.su-grade-answer{
  font-family: var(--font-mono);
  font-size: 1.15rem;
  color: var(--ink);
  min-height: 1.6rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.su-caret{
  display: inline-block;
  color: var(--chalk-dark);
  animation: suBlink 1s step-end infinite;
}
@keyframes suBlink{ 50%{ opacity: 0; } }
.su-mark{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px; height: 26px;
  border-radius: 50%;
  opacity: 0;
  transform: scale(0.5);
  transition: all 0.35s cubic-bezier(.34,1.56,.64,1);
}
.su-mark.show{ opacity: 1; transform: scale(1); }
.su-mark-correct{ background: rgba(47,158,91,0.14); color: var(--correct); }

.su-margin-note{
  font-family: var(--font-display);
  font-style: italic;
  font-size: 0.88rem;
  color: var(--chalk-dark);
  margin-top: 0.8rem;
  padding-top: 0.7rem;
  border-top: 1px dashed var(--line);
  opacity: 0;
  transform: translateY(4px);
  transition: all 0.4s ease;
}
.su-margin-note.show{ opacity: 1; transform: translateY(0); }

.su-grade-foot{
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 1.3rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line);
}
.su-ring-wrap{ position: relative; width: 64px; height: 64px; flex-shrink: 0; }
.su-ring{ width: 64px; height: 64px; transform: rotate(-90deg); }
.su-ring-track{ fill: none; stroke: var(--paper-alt); stroke-width: 6; }
.su-ring-bar{
  fill: none;
  stroke: var(--correct);
  stroke-width: 6;
  stroke-linecap: round;
  stroke-dasharray: 170;
  stroke-dashoffset: 170;
  transition: stroke-dashoffset 1.1s cubic-bezier(.45,0,.2,1);
}
.su-ring-label{
  position: absolute; inset: 0;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
}
.su-ring-label .su-mono{ font-size: 0.68rem; font-weight: 600; color: var(--ink); }
.su-ring-sub{ font-size: 0.55rem; color: var(--pencil); opacity: 0.6; text-transform: uppercase; letter-spacing: 0.05em; }
.su-grade-foot-text{
  display: flex; flex-direction: column; gap: 0.15rem;
  font-size: 0.88rem; color: var(--ink);
}
.su-grade-foot-text .su-mono{ font-size: 0.62rem; }

/* ==========================================================================
   Stats band
   ========================================================================== */
.su-stats{
  background: var(--ink);
  padding: 3.2rem 0;
}
.su-stat-num{
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 4vw, 2.9rem);
  font-weight: 600;
  color: var(--chalk);
}
.su-stat-num span{ font-size: 0.55em; opacity: 0.85; }
.su-stat-label{
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: rgba(246,245,240,0.65);
  margin-top: 0.3rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

/* ==========================================================================
   Sections
   ========================================================================== */
.su-section{ padding: 6rem 0; }
.su-section-alt{ background: var(--paper-alt); }
.su-section-dark{ background: var(--ink); }

.su-section-head{ max-width: 620px; margin-bottom: 3rem; }
.su-h2{
  font-size: clamp(1.7rem, 3vw, 2.3rem);
  font-weight: 600;
  line-height: 1.18;
  margin-top: 0.6rem;
}
.su-h2-light{ color: var(--white); }
.su-section-sub{ margin-top: 1rem; font-size: 1.03rem; }

/* Feature cards */
.su-feature-card{
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 1.9rem;
  height: 100%;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.su-feature-card:hover{ transform: translateY(-5px); box-shadow: var(--shadow-card); }
.su-feature-icon{
  width: 46px; height: 46px;
  border-radius: 12px;
  background: var(--card-blue);
  color: var(--ink);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.25rem;
  margin-bottom: 1.1rem;
}
.su-feature-card h3{ font-size: 1.1rem; font-weight: 600; margin-bottom: 0.5rem; }
.su-feature-card p{ font-size: 0.93rem; margin: 0; }

/* Steps */
.su-steps{ position: relative; }
.su-step{
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 2rem 1.8rem;
  height: 100%;
}
.su-step-num{
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--chalk-dark);
  background: rgba(242,183,5,0.15);
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  margin-bottom: 1.1rem;
}
.su-step h3{ font-size: 1.12rem; font-weight: 600; margin-bottom: 0.5rem; }
.su-step p{ font-size: 0.93rem; margin: 0; }

/* Subjects */
.su-subject-card{
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 1.6rem 1rem;
  text-align: center;
  transition: all 0.2s ease;
  height: 100%;
}
.su-subject-card i{
  font-size: 1.6rem;
  color: var(--ink);
  display: block;
  margin-bottom: 0.6rem;
}
.su-subject-card span{
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--ink-soft);
}
.su-subject-card:hover{
  background: var(--ink);
  border-color: var(--ink);
}
.su-subject-card:hover i, .su-subject-card:hover span{ color: var(--chalk); }

/* Quotes */
.su-quote-card{
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 1.9rem;
  height: 100%;
  border-left: 3px solid var(--chalk);
}
.su-quote-card p{
  font-family: var(--font-display);
  font-size: 1.08rem;
  font-style: italic;
  color: var(--ink);
  margin-bottom: 1.3rem;
}
.su-quote-foot{ display: flex; flex-direction: column; font-size: 0.85rem; }
.su-quote-foot strong{ color: var(--ink); }

/* Pricing */
.su-price-card{
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 2.2rem;
  height: 100%;
  position: relative;
}
.su-price-card-featured{
  border-color: var(--ink);
  box-shadow: var(--shadow-card);
  transform: translateY(-8px);
}
.su-price-badge{
  position: absolute;
  top: -13px; left: 50%;
  transform: translateX(-50%);
  background: var(--chalk);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  padding: 0.3rem 0.8rem;
  border-radius: 999px;
}
.su-price-card h3{ font-size: 1.15rem; font-weight: 600; }
.su-price{
  font-family: var(--font-display);
  font-size: 2.3rem;
  font-weight: 600;
  color: var(--ink);
  margin: 0.6rem 0 0.3rem;
}
.su-price span{ font-size: 1rem; font-weight: 500; opacity: 0.6; }
.su-price-list{ list-style: none; padding: 0; margin: 1.4rem 0 1.7rem; }
.su-price-list li{ padding: 0.35rem 0; font-size: 0.92rem; }
.su-price-list i{ color: var(--correct); margin-right: 0.5rem; }

/* Contact */
.su-contact-list{ list-style: none; padding: 0; margin-top: 2rem; }
.su-contact-list li{
  color: rgba(246,245,240,0.85);
  padding: 0.55rem 0;
  font-size: 0.95rem;
  display: flex; align-items: center; gap: 0.7rem;
}
.su-contact-list i{ color: var(--chalk); }

.su-form{
  background: rgba(246,245,240,0.04);
  border: 1px solid rgba(246,245,240,0.14);
  border-radius: var(--radius-lg);
  padding: 2rem;
}
.su-label{
  font-size: 0.8rem;
  font-weight: 700;
  color: rgba(246,245,240,0.8);
  margin-bottom: 0.4rem;
  display: inline-block;
}
.su-input{
  background: rgba(246,245,240,0.06);
  border: 1px solid rgba(246,245,240,0.18);
  color: var(--white);
  border-radius: var(--radius-sm);
  padding: 0.7rem 0.9rem;
}
.su-input::placeholder{ color: rgba(246,245,240,0.4); }
.su-input:focus{
  background: rgba(246,245,240,0.09);
  border-color: var(--chalk);
  color: var(--white);
  box-shadow: 0 0 0 3px rgba(242,183,5,0.18);
}
select.su-input option{ color: var(--ink); }

.su-spin{ animation: suSpin 0.8s linear infinite; }
@keyframes suSpin{ to{ transform: rotate(360deg); } }

/* ==========================================================================
   Footer
   ========================================================================== */
.su-footer{
  background: #101B33;
  color: rgba(246,245,240,0.6);
  padding: 4rem 0 1.5rem;
}
.su-brand-footer{ color: var(--white); }
.su-footer-tag{ margin-top: 0.9rem; font-size: 0.9rem; max-width: 28ch; }
.su-footer h4{
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: rgba(246,245,240,0.9);
  margin-bottom: 1rem;
}
.su-footer ul{ list-style: none; padding: 0; margin: 0; }
.su-footer ul li{ margin-bottom: 0.6rem; font-size: 0.9rem; }
.su-footer ul li a:hover{ color: var(--chalk); }
.su-social{ display: flex; gap: 0.9rem; }
.su-social a{
  width: 34px; height: 34px;
  border: 1px solid rgba(246,245,240,0.2);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
}
.su-social a:hover{ background: var(--chalk); color: var(--ink); border-color: var(--chalk); }
.su-footer-bottom{
  border-top: 1px solid rgba(246,245,240,0.12);
  margin-top: 3rem;
  padding-top: 1.5rem;
  font-size: 0.8rem;
}

/* Back to top */
.su-back-top{
  position: fixed;
  right: 1.4rem; bottom: 1.4rem;
  width: 46px; height: 46px;
  border-radius: 50%;
  background: var(--ink);
  color: var(--chalk);
  display: flex; align-items: center; justify-content: center;
  opacity: 0; visibility: hidden;
  transform: translateY(10px);
  transition: all 0.3s ease;
  z-index: 1040;
  box-shadow: 0 8px 20px rgba(22,35,63,0.25);
}
.su-back-top.show{ opacity: 1; visibility: visible; transform: translateY(0); }

/* ==========================================================================
   Reveal-on-scroll
   ========================================================================== */
[data-reveal]{
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
[data-reveal].is-visible{ opacity: 1; transform: translateY(0); }
[data-reveal-delay="1"]{ transition-delay: 0.08s; }
[data-reveal-delay="2"]{ transition-delay: 0.16s; }
[data-reveal-delay="3"]{ transition-delay: 0.24s; }

@media (prefers-reduced-motion: reduce){
  *{ animation: none !important; transition: none !important; }
  [data-reveal]{ opacity: 1; transform: none; }
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 991.98px){
  .su-hero{ padding: 8rem 0 3.5rem; }
  .su-grade-card{ margin: 0 auto; transform: none; }
  .su-nav .navbar-collapse{
    background: var(--paper);
    margin-top: 1rem;
    padding: 1rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
  }
  .su-price-card-featured{ transform: none; }
}

@media (max-width: 575.98px){
  .su-section{ padding: 4rem 0; }
  .su-lead{ max-width: 100%; }
}