:root{
  --bg:#0b0f14;
  --panel:#101722;
  --panel2:#0e1520;
  --text:#eaf1ff;
  --muted:#a9b6cc;
  --line:rgba(255,255,255,.08);
  --accent:#7aa2ff;
  --accent2:#a78bfa;
  --danger:#ff5c7a;

  --r:18px;
  --shadow: 0 18px 50px rgba(0,0,0,.45);
}

*{ box-sizing:border-box; }
html,body{ height:100%; }
body{
  margin:0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background:#0b0f14;
  color:var(--text);
}

body::before{
  content:"";
  position:fixed;
  inset:0;
  pointer-events:none;
  background:
    radial-gradient(700px 350px at 10% 0%, rgba(122,162,255,.12), transparent 60%),
    radial-gradient(600px 300px at 100% 0%, rgba(167,139,250,.10), transparent 60%);
}

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

.container{
  width:min(1100px, 92vw);
  margin:0 auto;
}

.header{
  position:sticky;
  top:0;
  z-index:50;
  backdrop-filter: blur(10px);
  background: rgba(11,15,20,.55);
  border-bottom:1px solid var(--line);
}

.header__inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding:14px 0;
  gap:16px;
}

.logo{
  font-weight:800;
  letter-spacing:.2px;
  font-size:18px;
}
.logo span{ color:var(--accent); }

.nav{
  display:flex;
  gap:10px;
  align-items:center;
}

.nav__link{
  padding:10px 12px;
  border-radius:999px;
  color:var(--muted);
  border:1px solid transparent;
  transition: .2s ease;
}
.nav__link:hover{
  border-color: var(--line);
  color:var(--text);
  transform: translateY(-1px);
}
.nav__link.active{
  color:var(--text);
  border-color: rgba(122,162,255,.35);
  background: rgba(122,162,255,.10);
}

.burger{
  display:none;
  width:44px;
  height:40px;
  border-radius:12px;
  border:1px solid var(--line);
  background: rgba(255,255,255,.04);
  color:var(--text);
  cursor:pointer;
}
.burger span{
  display:block;
  width:20px;
  height:2px;
  margin:5px auto;
  background: var(--text);
  border-radius:2px;
  opacity:.9;
}

.hero{
  display:grid;
  grid-template-columns: 1.1fr .9fr;
  gap:18px;
  padding:28px 0 10px;
  align-items:start;
}

.hero__text h1{
  margin:0 0 10px;
  font-size: clamp(28px, 3.2vw, 42px);
  letter-spacing:-.6px;
}

.muted{ color:var(--muted); }
.small{ font-size:13px; }

.hero__badges{
  display:flex;
  gap:10px;
  flex-wrap:wrap;
  margin:12px 0 14px;
}
.badge{
  padding:7px 10px;
  border-radius:999px;
  border:1px solid var(--line);
  background: rgba(255,255,255,.03);
  font-size:13px;
}

.card{
  background: linear-gradient(180deg, rgba(255,255,255,.06), rgba(255,255,255,.03));
  border:1px solid var(--line);
  border-radius: var(--r);
  padding:16px;
  box-shadow: var(--shadow);
  transition: .2s ease;
}
.card:hover{
  transform: translateY(-2px);
  border-color: rgba(122,162,255,.22);
}

.card__title{
  margin:0 0 12px;
  font-size:18px;
}

.field{ margin:12px 0; }
label{ display:block; margin:0 0 8px; color:var(--muted); font-size:14px; }

.input, .textarea{
  width:100%;
  border-radius:14px;
  border:1px solid var(--line);
  background: rgba(0,0,0,.18);
  color:var(--text);
  padding:12px 12px;
  outline:none;
  transition:.2s ease;
}
.textarea{ resize: vertical; min-height: 110px; }
.input:focus, .textarea:focus{
  border-color: rgba(122,162,255,.35);
  box-shadow: 0 0 0 4px rgba(122,162,255,.12);
}

.row{
  display:flex;
  gap:10px;
  align-items:center;
}
.row--wrap{ flex-wrap:wrap; }

.hint{ color:var(--muted); font-size:12px; }

.btn{
  border:none;
  cursor:pointer;
  border-radius:14px;
  padding:11px 14px;
  color: #06101f;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  font-weight:600;
  letter-spacing: 0.3px;
  transition: .2s ease;
}
.btn:hover{ transform: translateY(-2px); filter: brightness(1.04); }
.btn:active{ transform: translateY(0px); filter: brightness(.98); }

.btn--ghost{
  background: rgba(255,255,255,.06);
  color: var(--text);
  border:1px solid var(--line);
}
.btn--ghost:hover{ border-color: rgba(122,162,255,.22); }

.btn--danger{
  background: rgba(255,92,122,.14);
  color: var(--text);
  border:1px solid rgba(255,92,122,.35);
}

.segmented{
  display:flex;
  gap:8px;
}
.segmented__btn{
  flex:1;
  border-radius:14px;
  padding:10px 12px;
  border:1px solid var(--line);
  background: rgba(255,255,255,.04);
  color: var(--text);
  cursor:pointer;
  transition:.2s ease;
}
.segmented__btn:hover{ transform: translateY(-1px); }
.segmented__btn.is-active{
  border-color: rgba(122,162,255,.35);
  background: rgba(122,162,255,.12);
}

.divider{
  height:1px;
  background: var(--line);
  margin:14px 0;
}

.grid{
  display:grid;
  grid-template-columns: repeat(3, 1fr);
  gap:14px;
  padding:14px 0 28px;
}
.grid--2{
  grid-template-columns: repeat(2, 1fr);
}

.mini{
  border-radius: var(--r);
  border:1px solid var(--line);
  background: rgba(255,255,255,.03);
  padding:14px;
  transition:.2s ease;
}
.mini:hover{
  transform: translateY(-2px);
  border-color: rgba(167,139,250,.22);
}

.pagehead{
  padding: 22px 0 10px;
}

.list{
  margin:0;
  padding-left: 18px;
  color: var(--muted);
}
.list li{ margin: 7px 0; }

.codebox{
  border-radius: 16px;
  border:1px solid var(--line);
  background: rgba(0,0,0,.22);
  padding: 12px;
  overflow:auto;
}
pre{ margin:0; }
code{ color: #d6e2ff; }

.footer{
  position: relative;
  border-top: 1px solid var(--line);
  margin-top: 24px;
  background: #0b0f14;
  overflow: hidden;
}

.footer::before{
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(
    180deg,
    rgba(122,162,255,0.06),
    rgba(167,139,250,0.04) 45%,
    rgba(11,15,20,0) 100%
  );
}
.footer__inner{
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding: 14px 0;
}
.link:hover{ text-decoration: underline; }

.error{
  min-height: 18px;
  font-size: 12px;
  color: #ff9bb0;
  margin-top: 6px;
}

/* Modal */
.modal{
  position:fixed;
  inset:0;
  display:none;
  align-items:center;
  justify-content:center;
  z-index:100;
}
.modal.is-open{ display:flex; }
.modal__backdrop{
  position:absolute;
  inset:0;
  background: rgba(0,0,0,.55);
}
.modal__panel{
  position:relative;
  width:min(650px, 92vw);
  border-radius: 20px;
  border:1px solid var(--line);
  background: linear-gradient(180deg, rgba(16,23,34,.96), rgba(10,14,20,.96));
  box-shadow: var(--shadow);
  overflow:hidden;
  animation: pop .18s ease-out;
}
@keyframes pop{
  from{ transform: translateY(10px) scale(.98); opacity:.7; }
  to{ transform: translateY(0) scale(1); opacity:1; }
}
.modal__head, .modal__foot{
  padding: 14px 16px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  border-bottom:1px solid var(--line);
}
.modal__foot{
  border-bottom:none;
  border-top:1px solid var(--line);
  justify-content:flex-end;
}
.modal__body{ padding: 14px 16px; }

.iconbtn{
  border:1px solid var(--line);
  background: rgba(255,255,255,.05);
  color: var(--text);
  border-radius: 12px;
  width: 40px;
  height: 38px;
  cursor:pointer;
}
.iconbtn:hover{ border-color: rgba(122,162,255,.22); }

/* Toast */
.toast{
  position: fixed;
  left: 50%;
  bottom: 18px;
  transform: translateX(-50%);
  background: rgba(16,23,34,.92);
  border:1px solid var(--line);
  border-radius: 999px;
  padding: 10px 14px;
  color: var(--text);
  display:none;
  z-index:200;
  box-shadow: var(--shadow);
}
.toast.is-show{ display:block; animation: toast .18s ease-out; }
@keyframes toast{
  from{ transform: translateX(-50%) translateY(8px); opacity:.6; }
  to{ transform: translateX(-50%) translateY(0); opacity:1; }
}

/* Drawer (bruteforce list) */
.drawer{
  position:fixed;
  inset:0;
  display:none;
  z-index:120;
}
.drawer.is-open{ display:block; }
.drawer__backdrop{
  position:absolute;
  inset:0;
  background: rgba(0,0,0,.55);
}
.drawer__panel{
  position:absolute;
  right:0;
  top:0;
  height:100%;
  width:min(520px, 92vw);
  background: linear-gradient(180deg, rgba(16,23,34,.96), rgba(10,14,20,.96));
  border-left:1px solid var(--line);
  box-shadow: var(--shadow);
  display:flex;
  flex-direction:column;
  animation: slide .2s ease-out;
}
@keyframes slide{
  from{ transform: translateX(16px); opacity:.7; }
  to{ transform: translateX(0); opacity:1; }
}
.drawer__head{
  padding: 14px 16px;
  border-bottom:1px solid var(--line);
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
}
.drawer__body{
  padding: 12px 16px;
  overflow:auto;
}
.bruteItem{
  border:1px solid var(--line);
  border-radius: 14px;
  padding: 10px 12px;
  margin: 10px 0;
  background: rgba(255,255,255,.03);
}
.bruteItem__top{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
  margin-bottom: 8px;
}
.pill{
  border:1px solid var(--line);
  border-radius: 999px;
  padding: 4px 9px;
  font-size: 12px;
  color: var(--muted);
}

/* Adaptive */
@media (max-width: 920px){
  .hero{ grid-template-columns: 1fr; }
}

@media (max-width: 720px){
  .grid{ grid-template-columns: 1fr; }
  .grid--2{ grid-template-columns: 1fr; }

  .burger{ display:block; }

  .nav{
    position: absolute;
    right: 4vw;
    top: 64px;
    flex-direction: column;
    align-items: stretch;
    width: min(320px, 92vw);
    background: rgba(16,23,34,.96);
    border:1px solid var(--line);
    border-radius: 16px;
    padding: 10px;
    box-shadow: var(--shadow);
    display:none;
  }
  .nav.is-open{ display:flex; }
}
.hero-center{
display:flex;
justify-content:center;
align-items:center;
text-align:center;
min-height:60vh;
}

.center{
max-width:700px;
margin:auto;
}
.algorithms-preview {
  margin-top: 56px;
}

.section-head {
  margin-bottom: 24px;
}

.algo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}

.algo-card {
  display: block;
  padding: 20px;
  border-radius: 18px;
  text-decoration: none;
  color: inherit;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.algo-card:hover {
  transform: translateY(-6px) scale(1.01);
  border-color: rgba(255, 255, 255, 0.18);
  box-shadow: 0 12px 32px rgba(100, 150, 255, 0.15);
}

.algo-card h3 {
  margin: 0 0 10px;
}

.algo-card p {
  margin: 0;
}
.dropdown {
  position: relative;
}

.dropdown::after {
  content: "";
  position: absolute;
  left: 0;
  top: 100%;
  width: 100%;
  height: 10px;
}

.dropdown__toggle {
  background: none;
  border: 1px solid transparent;
  color: var(--muted);
  font: inherit;
  cursor: pointer;
  padding: 10px 12px;
  border-radius: 999px;
  transition: .2s ease;
}

.dropdown__toggle:hover {
  border-color: var(--line);
  color: var(--text);
  transform: translateY(-1px);
}

.dropdown__toggle.is-active {
  color: var(--text);
  border-color: rgba(122,162,255,.35);
  background: rgba(122,162,255,.10);
}
.dropdown__menu {
  position: absolute;
  top: calc(100% + 6px);
  left: 0;

  min-width: 220px;
  padding: 10px;

  display: flex;
  flex-direction: column;
  gap: 6px;

  background: rgba(20, 25, 40, 0.95);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 12px;

  opacity: 0;
  pointer-events: none;
  transform: translateY(-6px);

  transition: 0.2s ease;
  z-index: 100;
}

.dropdown__menu a {
  padding: 8px 10px;
  border-radius: 8px;
  text-decoration: none;
  color: inherit;
}

.dropdown__menu a:hover {
  background: rgba(255, 255, 255, 0.08);
}

.dropdown:hover .dropdown__menu {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}
.input.is-invalid,
.textarea.is-invalid {
  border-color: rgba(255, 92, 122, 0.7);
  box-shadow: 0 0 0 4px rgba(255, 92, 122, 0.12);
}
a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}