/* ================================================================
   S-AES Simulator — Cybersecurity Dashboard Theme
   ================================================================
   Design tokens, layout, components, animations.
   Fonts: Inter (UI) + JetBrains Mono (binary/hex code)
   ================================================================ */

/* ── Tokens ─────────────────────────────────────────────────────── */
:root {
  /* surface */
  --bg-deep:       #05080f;
  --bg-base:       #0b1120;
  --bg-card:       rgba(13,21,41,.72);
  --bg-card-hover: rgba(18,28,52,.82);
  --bg-input:      rgba(8,15,30,.92);
  --bg-badge:      rgba(56,189,248,.08);

  /* border */
  --bdr-subtle:  rgba(56,189,248,.08);
  --bdr-default: rgba(56,189,248,.18);
  --bdr-focus:   rgba(56,189,248,.50);

  /* text */
  --tx-1: #e8ecf4;
  --tx-2: #8b97b0;
  --tx-3: #576480;
  --tx-inv: #050a14;

  /* accent */
  --cyan:    #38bdf8;
  --indigo:  #818cf8;
  --violet:  #a78bfa;
  --emerald: #34d399;
  --amber:   #fbbf24;
  --rose:    #fb7185;
  --orange:  #fb923c;
  --teal:    #2dd4bf;

  /* gradients */
  --g-primary:  linear-gradient(135deg,#38bdf8,#818cf8);
  --g-success:  linear-gradient(135deg,#34d399,#38bdf8);
  --g-warm:     linear-gradient(135deg,#fbbf24,#fb923c);
  --g-violet:   linear-gradient(135deg,#818cf8,#a78bfa);
  --g-info:     linear-gradient(135deg,#38bdf8,#2dd4bf);

  /* operation colours */
  --op-subnibbles:    #818cf8;
  --op-shiftrows:     #38bdf8;
  --op-mixcolumns:    #34d399;
  --op-addroundkey:   #fbbf24;
  --op-keyexpansion:  #fb923c;
  --op-input:         #a78bfa;
  --op-inv-sub:       #c084fc;
  --op-inv-shift:     #22d3ee;
  --op-inv-mix:       #2dd4bf;

  /* misc */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --shadow-card: 0 4px 24px rgba(0,0,0,.45);
  --shadow-glow: 0 0 40px rgba(56,189,248,.12);
  --font-ui:   'Inter', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --ease: cubic-bezier(.4,0,.2,1);
}

/* ── Reset ──────────────────────────────────────────────────────── */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-font-smoothing:antialiased}
body{
  font-family:var(--font-ui);
  background:var(--bg-deep);
  color:var(--tx-1);
  line-height:1.6;
  min-height:100vh;
  overflow-x:hidden;
}

/* ── Animated Background ────────────────────────────────────────── */
.bg-grid{
  position:fixed;inset:0;z-index:0;pointer-events:none;
  background-image:
    linear-gradient(rgba(56,189,248,.03) 1px,transparent 1px),
    linear-gradient(90deg,rgba(56,189,248,.03) 1px,transparent 1px);
  background-size:48px 48px;
}
.bg-glow{
  position:fixed;z-index:0;pointer-events:none;
  border-radius:50%;filter:blur(100px);opacity:.35;
}
.bg-glow-1{width:600px;height:600px;top:-8%;right:-6%;background:radial-gradient(circle,rgba(56,189,248,.18),transparent 70%);animation:drift1 22s ease-in-out infinite}
.bg-glow-2{width:500px;height:500px;bottom:5%;left:-8%;background:radial-gradient(circle,rgba(129,140,248,.14),transparent 70%);animation:drift2 28s ease-in-out infinite}
.bg-glow-3{width:350px;height:350px;top:45%;left:40%;background:radial-gradient(circle,rgba(167,139,250,.10),transparent 70%);animation:drift3 18s ease-in-out infinite}
@keyframes drift1{0%,100%{transform:translate(0,0) scale(1)}50%{transform:translate(-35px,40px) scale(1.08)}}
@keyframes drift2{0%,100%{transform:translate(0,0)}50%{transform:translate(30px,-25px) scale(1.06)}}
@keyframes drift3{0%,100%{transform:scale(1)}50%{transform:scale(1.18)}}

/* ── Navbar ─────────────────────────────────────────────────────── */
.navbar{
  position:sticky;top:0;z-index:100;
  background:rgba(5,8,15,.82);
  backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px);
  border-bottom:1px solid var(--bdr-subtle);
  padding:.85rem 1.5rem;
}
.navbar-inner{
  max-width:960px;margin:0 auto;
  display:flex;align-items:center;justify-content:space-between;
}
.nav-brand{display:flex;align-items:center;gap:.75rem}
.nav-logo{
  padding:.35rem .55rem;border-radius:var(--radius-sm);
  background:var(--g-primary);
  display:grid;place-items:center;color:var(--tx-inv);
  font-weight:800;font-size:.7rem;letter-spacing:-.02em;
  box-shadow:0 0 18px rgba(56,189,248,.25);
  flex-shrink:0;white-space:nowrap;
}
.nav-title{font-size:1.2rem;font-weight:800;background:var(--g-primary);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.nav-sub{font-size:.65rem;font-weight:600;color:var(--tx-3);text-transform:uppercase;letter-spacing:.16em}
.nav-badges{display:flex;gap:.45rem}
.pill{
  font-size:.62rem;font-weight:700;padding:.2rem .65rem;
  border-radius:99px;text-transform:uppercase;letter-spacing:.08em;
}
.pill-filled{background:var(--g-primary);color:var(--tx-inv)}
.pill-outline{border:1px solid var(--bdr-default);color:var(--tx-3)}

/* ── Main Layout ────────────────────────────────────────────────── */
.main{
  position:relative;z-index:1;
  max-width:960px;margin:0 auto;
  padding:2rem 1.5rem 3rem;
  display:flex;flex-direction:column;gap:2rem;
}

/* ── Card (shared) ──────────────────────────────────────────────── */
.card{
  background:var(--bg-card);
  backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);
  border:1px solid var(--bdr-subtle);
  border-radius:var(--radius-xl);
  padding:1.75rem;
  box-shadow:var(--shadow-card);
  transition:border-color .25s var(--ease),box-shadow .25s var(--ease);
  animation:cardIn .45s var(--ease) both;
}
.card:hover{border-color:var(--bdr-default)}
@keyframes cardIn{from{opacity:0;transform:translateY(16px)}to{opacity:1;transform:translateY(0)}}

/* card header */
.card-hdr{display:flex;align-items:center;gap:.85rem;margin-bottom:1.4rem;flex-wrap:wrap}
.card-icon{
  width:42px;height:42px;border-radius:var(--radius-md);
  display:grid;place-items:center;flex-shrink:0;color:var(--tx-inv);
}
.card-icon svg{width:22px;height:22px}
.card-icon-primary{background:var(--g-primary)}
.card-icon-success{background:var(--g-success)}
.card-icon-warm{background:var(--g-warm)}
.card-icon-violet{background:var(--g-violet)}
.card-icon-info{background:var(--g-info)}
.card-hdr h2{font-size:1.1rem;font-weight:700;flex:1}

/* ── Form Fields ────────────────────────────────────────────────── */
.field{margin-bottom:1.1rem}
.field-label{display:flex;align-items:baseline;gap:.5rem;font-size:.8rem;font-weight:600;color:var(--tx-2);margin-bottom:.4rem}
.field-hint{font-size:.65rem;font-weight:400;color:var(--tx-3)}
.field-wrap{position:relative}
.inp{
  width:100%;padding:.7rem 1rem;padding-right:3.5rem;
  font-size:.9rem;font-family:var(--font-ui);color:var(--tx-1);
  background:var(--bg-input);border:1px solid var(--bdr-subtle);
  border-radius:var(--radius-sm);outline:none;
  transition:border-color .18s var(--ease),box-shadow .18s var(--ease);
}
.inp.mono{font-family:var(--font-mono);font-size:.85rem;letter-spacing:.12em}
.inp::placeholder{color:var(--tx-3);opacity:.55}
.inp:focus{border-color:var(--cyan);box-shadow:0 0 0 3px rgba(56,189,248,.14)}
.inp:hover:not(:focus){border-color:var(--bdr-default)}
.inp.err{border-color:var(--rose);box-shadow:0 0 0 3px rgba(251,113,133,.14)}
.char-cnt{position:absolute;right:12px;top:50%;transform:translateY(-50%);font-size:.66rem;font-family:var(--font-mono);color:var(--tx-3);pointer-events:none}

/* ── Mode Selector ──────────────────────────────────────────────── */
.mode-wrap{margin-bottom:1.1rem}
.mode-row{display:flex;gap:.55rem}
.mode-btn{
  flex:1;padding:.7rem 1rem;font-size:.82rem;font-weight:650;
  font-family:var(--font-ui);color:var(--tx-3);
  background:var(--bg-input);border:1px solid var(--bdr-subtle);
  border-radius:var(--radius-sm);cursor:pointer;
  display:inline-flex;align-items:center;justify-content:center;gap:.5rem;
  transition:all .18s var(--ease);
}
.mode-btn:hover{border-color:var(--bdr-default);color:var(--tx-2)}
.mode-btn.on{background:rgba(56,189,248,.09);border-color:var(--cyan);color:var(--cyan)}
.mode-btn svg{width:17px;height:17px}

/* ── Buttons ────────────────────────────────────────────────────── */
.btn-row{display:flex;gap:.55rem;margin-bottom:.85rem}
.btn{
  padding:.65rem 1.2rem;font-size:.82rem;font-weight:700;
  font-family:var(--font-ui);border:none;border-radius:var(--radius-sm);
  cursor:pointer;display:inline-flex;align-items:center;gap:.45rem;
  transition:all .18s var(--ease);text-transform:uppercase;letter-spacing:.05em;
}
.btn svg{width:17px;height:17px}
.btn-accent{
  flex:1;justify-content:center;
  background:var(--g-primary);color:var(--tx-inv);
  box-shadow:0 2px 16px rgba(56,189,248,.22);
}
.btn-accent:hover{transform:translateY(-1px);box-shadow:0 4px 24px rgba(56,189,248,.32)}
.btn-accent:active{transform:translateY(0)}
.btn-ghost{
  background:transparent;color:var(--tx-3);border:1px solid var(--bdr-subtle);
}
.btn-ghost:hover{background:rgba(255,255,255,.04);color:var(--tx-2);border-color:var(--bdr-default)}
.btn-link{
  background:none;border:none;color:var(--tx-3);font-size:.76rem;
  font-weight:500;padding:.45rem 0;cursor:pointer;text-transform:none;letter-spacing:normal;
  display:inline-flex;align-items:center;gap:.3rem;
  transition:color .18s var(--ease);
}
.btn-link:hover{color:var(--cyan)}

/* ── Error Toast ────────────────────────────────────────────────── */
.toast-err{
  display:flex;align-items:center;gap:.55rem;
  padding:.7rem 1rem;background:rgba(251,113,133,.09);
  border:1px solid rgba(251,113,133,.22);border-radius:var(--radius-sm);
  color:var(--rose);font-size:.82rem;font-weight:500;
  margin-bottom:.85rem;animation:shake .4s var(--ease);
}
.toast-err svg{width:16px;height:16px;flex-shrink:0}
@keyframes shake{0%{transform:translateX(-8px);opacity:0}25%{transform:translateX(4px)}50%{transform:translateX(-2px)}100%{transform:translateX(0);opacity:1}}

.test-link{text-align:center;padding-top:.6rem;border-top:1px solid var(--bdr-subtle)}

/* ── Result Card ────────────────────────────────────────────────── */
.result-box{
  background:var(--bg-input);border:1px solid var(--bdr-default);
  border-radius:var(--radius-lg);padding:1.6rem;text-align:center;
}
.result-row{
  display:grid;grid-template-columns:1fr 1fr;gap:1rem;
  margin-bottom:1rem;
}
.result-item{
  padding:1rem;background:rgba(56,189,248,.04);
  border:1px solid rgba(56,189,248,.10);border-radius:var(--radius-md);
}
.result-label{
  font-size:.65rem;font-weight:700;color:var(--tx-3);
  text-transform:uppercase;letter-spacing:.14em;margin-bottom:.55rem;
}
.result-value{
  font-family:var(--font-mono);font-size:1.1rem;font-weight:700;
  color:var(--cyan);word-break:break-all;letter-spacing:.08em;
}
.btn-copy{
  background:rgba(52,211,153,.08);color:var(--emerald);
  border:1px solid rgba(52,211,153,.2);
  padding:.45rem .9rem;font-size:.72rem;font-weight:700;
  border-radius:6px;cursor:pointer;font-family:var(--font-ui);
  display:inline-flex;align-items:center;gap:.35rem;
  text-transform:uppercase;letter-spacing:.06em;
  transition:all .18s var(--ease);
}
.btn-copy:hover{background:rgba(52,211,153,.18)}
.btn-copy.copied{background:var(--emerald);color:var(--tx-inv)}
.btn-copy svg{width:14px;height:14px}

/* ── Key Expansion Detail ───────────────────────────────────────── */
.ke-grid{
  display:grid;grid-template-columns:repeat(3,1fr);gap:.75rem;
  margin-bottom:1.2rem;
}
.ke-card{
  background:var(--bg-input);border:1px solid var(--bdr-subtle);
  border-radius:var(--radius-md);padding:1rem;text-align:center;
  transition:border-color .2s var(--ease);
}
.ke-card:hover{border-color:var(--bdr-default)}
.ke-label{
  font-size:.65rem;font-weight:750;color:var(--amber);
  font-family:var(--font-mono);text-transform:uppercase;
  letter-spacing:.08em;margin-bottom:.45rem;
}
.ke-value{
  font-family:var(--font-mono);font-size:.82rem;font-weight:600;
  color:var(--tx-1);letter-spacing:.06em;word-break:break-all;
}
.ke-hex{
  font-family:var(--font-mono);font-size:.68rem;color:var(--tx-3);
  margin-top:.2rem;
}
.ke-steps{
  background:var(--bg-input);border:1px solid var(--bdr-subtle);
  border-radius:var(--radius-md);padding:1rem 1.2rem;
}
.ke-steps-title{
  font-size:.72rem;font-weight:700;color:var(--tx-2);
  margin-bottom:.65rem;text-transform:uppercase;letter-spacing:.08em;
}
.ke-step-row{
  display:flex;align-items:baseline;gap:.55rem;
  padding:.3rem 0;border-bottom:1px solid rgba(56,189,248,.05);
  font-size:.78rem;
}
.ke-step-row:last-child{border-bottom:none}
.ke-step-label{
  font-weight:600;color:var(--tx-3);min-width:80px;font-size:.72rem;
}
.ke-step-val{
  font-family:var(--font-mono);color:var(--tx-1);font-size:.78rem;
  letter-spacing:.04em;
}
.ke-step-arrow{color:var(--tx-3);font-size:.72rem}

/* ── Expand/Collapse btn ────────────────────────────────────────── */
.btn-expand{
  background:transparent;border:1px solid var(--bdr-subtle);
  color:var(--tx-3);font-size:.7rem;font-weight:650;
  font-family:var(--font-ui);padding:.3rem .7rem;
  border-radius:6px;cursor:pointer;display:inline-flex;align-items:center;gap:.3rem;
  transition:all .18s var(--ease);
}
.btn-expand:hover{border-color:var(--bdr-default);color:var(--tx-2)}
.btn-expand svg{width:14px;height:14px}

/* ── Accordion (Round Steps) ────────────────────────────────────── */
.accordion{display:flex;flex-direction:column;gap:.6rem}

.acc-group{
  background:var(--bg-input);border:1px solid var(--bdr-subtle);
  border-radius:var(--radius-md);overflow:hidden;
  transition:border-color .2s var(--ease);
}
.acc-group:hover{border-color:var(--bdr-default)}

.acc-hdr{
  display:flex;align-items:center;justify-content:space-between;
  padding:.7rem 1rem;cursor:pointer;user-select:none;
  transition:background .18s var(--ease);
}
.acc-hdr:hover{background:rgba(255,255,255,.025)}
.acc-hdr-left{display:flex;align-items:center;gap:.7rem}

/* Step number badge */
.step-num{
  font-size:.58rem;font-weight:750;font-family:var(--font-mono);
  padding:.2rem .5rem;border-radius:5px;
  text-transform:uppercase;letter-spacing:.04em;
  white-space:nowrap;
}
.step-num-init{background:var(--g-violet);color:var(--tx-inv)}
.step-num-r1{background:var(--g-primary);color:var(--tx-inv)}
.step-num-r2{background:var(--g-success);color:var(--tx-inv)}
.step-num-final{background:var(--g-warm);color:var(--tx-inv)}

.acc-title{font-size:.8rem;font-weight:600;color:var(--tx-1)}
.acc-chev{color:var(--tx-3);transition:transform .25s var(--ease);flex-shrink:0}
.acc-chev svg{width:15px;height:15px}
.acc-group.open .acc-chev{transform:rotate(180deg)}
.acc-body{max-height:0;overflow:hidden;transition:max-height .4s var(--ease)}
.acc-group.open .acc-body{max-height:600px}
.acc-inner{padding:.6rem 1rem 1rem}

/* Step description */
.step-desc{
  font-size:.78rem;color:var(--tx-2);margin-bottom:.75rem;
  line-height:1.5;
}

/* ── State Matrix 2×2 ───────────────────────────────────────────── */
.state-matrix-wrap{
  display:flex;align-items:center;gap:1.2rem;flex-wrap:wrap;
}
.state-matrix{
  display:inline-grid;grid-template-columns:repeat(2,1fr);
  gap:2px;font-family:var(--font-mono);font-size:.88rem;font-weight:600;
  background:var(--bdr-subtle);border-radius:8px;overflow:hidden;
}
.state-cell{
  background:var(--bg-base);
  padding:.55rem .85rem;text-align:center;
  color:var(--tx-1);
  min-width:60px;
  transition:background .18s var(--ease);
}
.state-matrix:hover .state-cell{background:rgba(13,21,41,.9)}

.state-info{
  display:flex;flex-direction:column;gap:.3rem;
}
.state-info-row{
  font-size:.72rem;color:var(--tx-3);
  display:flex;align-items:baseline;gap:.4rem;
}
.state-info-label{font-weight:600;min-width:35px}
.state-info-val{font-family:var(--font-mono);color:var(--tx-2);letter-spacing:.04em}

/* ── Reference Tables Section ───────────────────────────────────── */
.ref-tabs{
  display:flex;gap:2px;background:var(--bg-input);
  border-radius:var(--radius-sm);padding:3px;
  border:1px solid var(--bdr-subtle);
  margin-bottom:1.2rem;
}
.ref-tab{
  flex:1;padding:.5rem .8rem;font-size:.76rem;font-weight:650;
  font-family:var(--font-ui);color:var(--tx-3);
  background:transparent;border:none;border-radius:6px;
  cursor:pointer;transition:all .18s var(--ease);
  text-align:center;
}
.ref-tab:hover{color:var(--tx-2)}
.ref-tab.on{
  background:var(--g-primary);color:var(--tx-inv);
  box-shadow:0 2px 10px rgba(56,189,248,.25);
}

.ref-content{display:none}
.ref-content.active{display:block;animation:fadeIn .25s var(--ease)}
@keyframes fadeIn{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:translateY(0)}}

.ref-desc{
  font-size:.78rem;color:var(--tx-2);margin-bottom:.85rem;line-height:1.5;
}
.ref-desc strong{color:var(--cyan)}

/* Reference table */
.ref-table{
  width:100%;border-collapse:collapse;font-family:var(--font-mono);
  font-size:.78rem;
}
.ref-table th,.ref-table td{
  padding:.5rem .55rem;text-align:center;
  border:1px solid var(--bdr-subtle);
}
.ref-table thead th{
  background:rgba(56,189,248,.06);color:var(--cyan);
  font-weight:700;font-size:.68rem;text-transform:uppercase;
  letter-spacing:.06em;
}
.ref-table tbody th{
  background:rgba(129,140,248,.06);color:var(--indigo);
  font-weight:700;font-size:.68rem;text-transform:uppercase;
}
.ref-table tbody td{
  color:var(--tx-1);font-weight:500;
  transition:background .15s var(--ease);
}
.ref-table tbody td:hover{
  background:rgba(56,189,248,.08);color:var(--cyan);
}
.ref-table-sm{max-width:400px}

/* Matrix pair (MixColumns) */
.matrix-pair{
  display:flex;gap:2rem;flex-wrap:wrap;justify-content:center;
}
.matrix-card{text-align:center}
.matrix-label{
  font-size:.72rem;font-weight:700;color:var(--tx-2);
  margin-bottom:.55rem;text-transform:uppercase;letter-spacing:.08em;
}
.matrix-table{
  margin:0 auto;border-collapse:collapse;
  font-family:var(--font-mono);font-size:1rem;font-weight:600;
}
.matrix-table td{
  padding:.65rem 1.2rem;text-align:center;
  border:2px solid var(--bdr-default);color:var(--cyan);
  background:var(--bg-input);
  transition:background .15s var(--ease);
}
.matrix-table td:hover{background:rgba(56,189,248,.08)}

/* ── Footer ─────────────────────────────────────────────────────── */
.footer{
  position:relative;z-index:1;text-align:center;
  padding:2rem 1.5rem;color:var(--tx-3);font-size:.75rem;
  border-top:1px solid var(--bdr-subtle);
}
.footer strong{color:var(--tx-2)}
.footer-sub{margin-top:.2rem;font-size:.65rem;opacity:.6}

/* ── Utility ────────────────────────────────────────────────────── */
.hidden{display:none !important}
.mono{font-family:var(--font-mono)}

/* ── Responsive ─────────────────────────────────────────────────── */
@media(max-width:768px){
  .navbar{padding:.65rem 1rem}
  .nav-badges{display:none}
  .nav-title{font-size:1.05rem}
  .main{padding:1.3rem 1rem 2rem;gap:1.3rem}
  .card{padding:1.3rem;border-radius:var(--radius-lg)}
  .btn-row{flex-direction:column}
  .btn{justify-content:center}
  .result-row{grid-template-columns:1fr}
  .result-value{font-size:.95rem}
  .mode-row{flex-direction:column}
  .ke-grid{grid-template-columns:1fr}
  .ref-tabs{flex-wrap:wrap}
  .ref-table{font-size:.7rem}
  .ref-table th,.ref-table td{padding:.35rem .3rem}
  .matrix-pair{gap:1.2rem}
  .bg-glow-1{width:350px;height:350px}
  .bg-glow-2{width:280px;height:280px}
  .bg-glow-3{width:200px;height:200px}
}
@media(max-width:480px){
  .card{padding:1rem}
  .card-hdr h2{font-size:.95rem}
  .result-value{font-size:.82rem;letter-spacing:.03em}
  .state-cell{padding:.4rem .6rem;font-size:.78rem;min-width:48px}
  .ref-tab{font-size:.68rem;padding:.4rem .5rem}
}