:root{
    --bg:#ffffff;
    --ink:#000000;
    --muted: rgba(0,0,0,.72);
    --soft: rgba(0,0,0,.10);
    --line: rgba(0,0,0,.18);
    --line2: rgba(0,0,0,.28);
    --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono","Courier New", monospace;
    --sans: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
    --shadow: 0 20px 60px rgba(0,0,0,.08);
    --shadow2: 0 26px 70px rgba(0,0,0,.10);
    --ir: rgba(255,0,0,.10); /* subtle infrared tint */
}

*{box-sizing:border-box}
html,body{height:100%}
body{
    margin:0;
    background:var(--bg);
    color:var(--ink);
    font-family:var(--sans);
    overflow-x:hidden;
}

#bg{
    position:fixed;
    inset:0;
    width:100%;
    height:100%;
    z-index:0;
}

.top-nav{
    position:fixed; top:0; left:0; right:0;
    z-index:20;
    display:flex; align-items:center; gap:10px;
    padding:14px 16px;
    background:rgba(255,255,255,.85);
    backdrop-filter: blur(8px);
    border-bottom:1px solid var(--line);
}

.nav-right{ margin-left:auto; display:flex; gap:8px; align-items:center; }

.nav-btn{
    display:inline-flex; align-items:center; justify-content:center;
    padding:10px 12px;
    border:2px solid var(--ink);
    background:rgba(255,255,255,.65);
    color:var(--ink);
    text-decoration:none;
    font-family:var(--mono);
    font-size:12px;
    letter-spacing:.04em;
    text-transform:uppercase;
    box-shadow: 0 8px 24px rgba(0,0,0,.06);
}
.nav-btn:hover{ background:#fff; transform:translateY(-1px); }
.nav-btn:active{ transform:translateY(0); }

.pill{
    display:inline-flex; align-items:center; justify-content:center;
    padding:6px 10px;
    border:1px solid var(--ink);
    background:rgba(255,255,255,.5);
    font-family:var(--mono);
    font-size:11px;
    letter-spacing:.06em;
    text-transform:uppercase;
}

.page{
    position:relative; z-index:5;
    max-width:1200px;
    margin:0 auto;
    padding:92px 18px 64px;
}

.hero{
    position:relative;
    padding:30px 22px;
    border:2px solid var(--ink);
    background:rgba(255,255,255,.78);
    box-shadow: var(--shadow);
    overflow:hidden;
}

.kicker{ font-family:var(--mono); letter-spacing:.12em; text-transform:uppercase; font-size:12px; opacity:.75; }

.title{
    margin:8px 0 12px;
    font-size:44px;
    letter-spacing:-.02em;
    line-height:1.05;
    position:relative;
}
.title-ghost{
    position:absolute;
    left:0; top:0;
    transform:translate(2px,2px);
    opacity:.12;
    pointer-events:none;
    user-select:none;
}

.lead{
    margin:0 0 16px;
    max-width:900px;
    color:var(--muted);
    line-height:1.55;
}

.meta{ display:flex; flex-wrap:wrap; gap:8px; }

.scanline{
    position:absolute;
    left:-20%;
    top:0;
    width:140%;
    height:60px;
    background:linear-gradient(to bottom, transparent, rgba(0,0,0,.10), transparent);
    transform:translateY(-40px);
    opacity:.6;
    pointer-events:none;
}

.grid{
    margin-top:18px;
    display:grid;
    grid-template-columns: 1fr 1fr;
    gap:16px;
}
@media (max-width: 980px){
    .grid{ grid-template-columns: 1fr; }
    .title{ font-size:38px; }
}

.panel{
    border:2px solid var(--ink);
    background:rgba(255,255,255,.78);
    box-shadow: var(--shadow);
    overflow:hidden;
}
.panel-bar{
    display:flex; align-items:center; justify-content:space-between;
    padding:12px 14px;
    border-bottom:1px solid var(--line);
    background:rgba(0,0,0,.04);
}
.panel-title{
    font-family:var(--mono);
    font-size:12px;
    letter-spacing:.12em;
    text-transform:uppercase;
}
.panel-tags{ display:flex; gap:8px; flex-wrap:wrap; }
.panel-body{ padding:14px; }

.copy{ margin:0 0 14px; color:var(--muted); line-height:1.6; }

.mono{ font-family:var(--mono); }

.form{ display:flex; flex-direction:column; gap:12px; }

.field{ display:flex; flex-direction:column; gap:6px; }
.label{
    font-size:11px;
    letter-spacing:.12em;
    text-transform:uppercase;
    opacity:.8;
}

.input{
    height:44px;
    padding:10px 12px;
    border:2px solid var(--ink);
    background:rgba(255,255,255,.7);
    font-family:var(--mono);
    font-size:13px;
    outline:none;
}
.input:focus{
    background:#fff;
    box-shadow: 0 0 0 3px rgba(0,0,0,.12);
}

.row{
    display:grid;
    grid-template-columns: 1fr 180px;
    gap:12px;
}
@media (max-width: 520px){
    .row{ grid-template-columns: 1fr; }
}

.gate{
    border:1px solid var(--line2);
    background:rgba(0,0,0,.03);
    padding:12px;
}
.gate-head{
    letter-spacing:.12em;
    text-transform:uppercase;
    font-size:11px;
    opacity:.75;
    margin-bottom:10px;
}
.gate-steps{
    display:grid;
    grid-template-columns: repeat(3, 1fr);
    gap:10px;
}
.gate-step{
    display:flex; flex-direction:column; gap:6px;
    padding:12px 10px;
    border:2px solid var(--ink);
    background:rgba(255,255,255,.65);
    cursor:pointer;
    font-family:var(--mono);
    text-transform:uppercase;
    letter-spacing:.06em;
    font-size:12px;
    transition: transform .15s ease, background .15s ease;
}
.gate-step:hover{ transform:translateY(-1px); background:#fff; }
.gate-step.active{
    background:rgba(0,0,0,.06);
    box-shadow: inset 0 0 0 2px rgba(0,0,0,.25);
}
.gate-status{
    margin-top:10px;
    font-size:11px;
    letter-spacing:.12em;
    opacity:.7;
}

.sig{
    border:1px solid var(--line2);
    background:rgba(0,0,0,.02);
    padding:12px;
}
.sig-head{
    letter-spacing:.12em;
    text-transform:uppercase;
    font-size:11px;
    opacity:.75;
    margin-bottom:10px;
}
.sig-canvas{
    width:100%;
    height:auto;
    display:block;
    border:2px solid var(--ink);
    background:rgba(255,255,255,.72);
}
.sig-hint{
    margin-top:8px;
    font-size:11px;
    letter-spacing:.1em;
    opacity:.7;
}

.actions{ display:flex; gap:10px; flex-wrap:wrap; }

.btn{
    display:inline-flex; align-items:center; justify-content:center;
    padding:12px 14px;
    border:2px solid var(--ink);
    background:rgba(255,255,255,.72);
    font-family:var(--mono);
    font-size:12px;
    letter-spacing:.08em;
    text-transform:uppercase;
    cursor:pointer;
    transition: transform .15s ease, background .15s ease, opacity .15s ease;
}
.btn:hover{ transform:translateY(-1px); background:#fff; }
.btn:active{ transform:translateY(0); }
.btn:disabled{ opacity:.4; cursor:not-allowed; transform:none; }
.btn.ghost{ background:rgba(0,0,0,.03); }

.fine{
    font-size:11px;
    letter-spacing:.06em;
    opacity:.7;
    line-height:1.55;
    margin-top:6px;
}

/* exam */
.exam{ display:flex; flex-direction:column; gap:12px; }
.exam-top{
    display:flex; align-items:center; justify-content:space-between; gap:12px;
}

.progress{
    flex:1;
    height:10px;
    border:1px solid var(--ink);
    background:rgba(0,0,0,.03);
    overflow:hidden;
}
.progress-bar{
    height:100%;
    width:0%;
    background:rgba(0,0,0,.20);
    transition: width .25s ease;
}

/* dossier stage */
.dossier{
    position:relative;
    border:1px solid var(--line2);
    background:rgba(0,0,0,.02);
    padding:12px;
    overflow:hidden;
}

/* vault door = big animation */
.vault{
    position:absolute;
    inset:0;
    pointer-events:none;
    z-index:2;
}
.vault-door{
    position:absolute;
    top:0; bottom:0;
    width:52%;
    background:rgba(0,0,0,.06);
    border:2px solid rgba(0,0,0,.55);
    box-shadow: inset 0 0 0 1px rgba(255,255,255,.35);
    backdrop-filter: blur(2px);
}
.vault-door.left{ left:-2%; }
.vault-door.right{ right:-2%; }
.vault-scan{
    position:absolute;
    left:-10%;
    top:0;
    width:120%;
    height:50px;
    background:linear-gradient(to bottom, transparent, rgba(0,0,0,.14), transparent);
    transform:translateY(-60px);
    opacity:.0;
}

/* state classes controlled by JS */
.dossier.vault-open .vault-door.left{ transform:translateX(-112%); transition: transform 900ms cubic-bezier(.2,.9,.2,1); }
.dossier.vault-open .vault-door.right{ transform:translateX(112%); transition: transform 900ms cubic-bezier(.2,.9,.2,1); }
.dossier.vault-open .vault-scan{ opacity:.65; transition: opacity 260ms ease; animation: vaultScan 1400ms ease-in-out 1; }

@keyframes vaultScan{
    0%{ transform:translateY(-60px); }
    55%{ transform:translateY(220px); }
    100%{ transform:translateY(520px); }
}

/* blueprint = stroke draw overlay */
.blueprint{
    position:absolute;
    inset:10px;
    z-index:3;
    opacity:0;
    pointer-events:none;
}
.bp{
    fill:none;
    stroke:rgba(0,0,0,.35);
    stroke-width:2;
    stroke-dasharray: 1800;
    stroke-dashoffset: 1800;
}
.dossier.bp-on .blueprint{ opacity:1; }

/* book wrap */
.book-wrap{ position:relative; z-index:4; }
.book-head{
    display:flex;
    align-items:center;
    justify-content:space-between;
    margin-bottom:10px;
    letter-spacing:.12em;
    text-transform:uppercase;
    font-size:11px;
    opacity:.85;
}

.book{
    position:relative;
    height:380px;
    border:2px solid var(--ink);
    background:rgba(255,255,255,.86);
    box-shadow: var(--shadow2);
    perspective:1600px;
    transform-style:preserve-3d;
    overflow:hidden;
}

@media (max-width:520px){
    .book{ height:460px; }
}

/* paper edge */
.book-edge{
    position:absolute;
    top:0; bottom:0;
    right:0;
    width:26px;
    background:
            repeating-linear-gradient(
                    to bottom,
                    rgba(0,0,0,.10) 0px,
                    rgba(0,0,0,.10) 1px,
                    rgba(255,255,255,.0) 6px
            ),
            linear-gradient(to left, rgba(0,0,0,.22), rgba(0,0,0,0));
    opacity:.55;
    transform: translateZ(2px);
    pointer-events:none;
}

/* sheet (page) */
.sheet{
    position:absolute;
    inset:0;
    transform-style:preserve-3d;
    transform-origin:left center;
    /* JS sets --a (angle), --shade */
    transform: rotateY(var(--a, 0deg));
    transition: transform 420ms cubic-bezier(.2,.9,.2,1);
    will-change: transform;
}

.sheet.dragging{
    transition:none;
}

.sheet::after{
    /* thickness illusion */
    content:"";
    position:absolute;
    top:0; bottom:0;
    right:0;
    width:10px;
    background:linear-gradient(to left, rgba(0,0,0,.14), rgba(0,0,0,0));
    opacity: calc(var(--edge, .0));
    transform: translateZ(1px);
    pointer-events:none;
}

.face{
    position:absolute;
    inset:0;
    padding:16px;
    backface-visibility:hidden;
    background:rgba(255,255,255,.94);
}

.face.back{
    transform: rotateY(180deg);
    background:rgba(255,255,255,.92);
}

.page-top{
    display:flex; justify-content:space-between; align-items:center; gap:10px;
    border-bottom:1px solid var(--line);
    padding-bottom:10px;
}
.page-title{
    font-family:var(--mono);
    letter-spacing:.12em;
    text-transform:uppercase;
    font-size:12px;
}

.q{
    font-size:18px;
    line-height:1.4;
    margin:12px 0 0;
}

.opts{
    display:grid;
    gap:10px;
    margin-top:12px;
}

.opt{
    display:flex;
    gap:10px;
    align-items:flex-start;
    padding:12px 10px;
    border:2px solid var(--ink);
    background:rgba(255,255,255,.65);
    cursor:pointer;
    font-family:var(--mono);
    font-size:12px;
    letter-spacing:.06em;
    text-transform:uppercase;
}
.opt:hover{ background:#fff; }
.opt.selected{
    background:rgba(0,0,0,.06);
}
.opt .tag{
    min-width:28px;
    height:28px;
    border:1px solid var(--ink);
    display:flex;
    align-items:center;
    justify-content:center;
}

.corner{
    position:absolute;
    right:0;
    top:0;
    width:120px;
    height:120px;
    background:
            linear-gradient(135deg, rgba(0,0,0,0) 55%, rgba(0,0,0,.10) 56%, rgba(0,0,0,.0) 72%),
            radial-gradient(circle at 78% 22%, rgba(0,0,0,.12), rgba(0,0,0,0) 56%);
    pointer-events:none;
    opacity: .7;
}

.turn-hint{
    position:absolute;
    right:10px;
    bottom:10px;
    font-family:var(--mono);
    font-size:11px;
    letter-spacing:.12em;
    text-transform:uppercase;
    opacity:.55;
}

/* back face minimal seal text */
.back .back-note{
    border:1px solid var(--line2);
    padding:12px;
    background:rgba(0,0,0,.03);
    font-family:var(--mono);
    font-size:12px;
    letter-spacing:.08em;
    line-height:1.6;
}
.back .back-note .small{
    display:block;
    margin-top:10px;
    opacity:.7;
    font-size:11px;
}

/* hint */
.dossier-hint{
    margin-top:10px;
    font-size:11px;
    letter-spacing:.1em;
    opacity:.7;
}

/* actions */
.exam-actions{
    display:flex; gap:10px; flex-wrap:wrap;
}

.footer{
    margin-top:18px;
    border:2px solid var(--ink);
    background:rgba(255,255,255,.78);
    box-shadow: var(--shadow);
    padding:14px;
}
.footer-line{ height:1px; background:var(--line2); margin-bottom:12px; }
.footer-row{ display:flex; align-items:center; justify-content:space-between; gap:12px; }
.logo{ width:44px; height:44px; object-fit:contain; }

/* Seal overlay */
.seal-overlay{
    position:fixed;
    inset:0;
    display:none;
    align-items:center;
    justify-content:center;
    z-index:50;
    background:rgba(255,255,255,.65);
    backdrop-filter: blur(10px);
}
.seal-overlay.on{ display:flex; }

.seal-fx{
    position:absolute;
    inset:0;
    width:100%;
    height:100%;
    pointer-events:none;
}

.seal-card{
    width:min(560px, 92vw);
    border:2px solid var(--ink);
    background:rgba(255,255,255,.92);
    box-shadow: var(--shadow2);
    padding:22px 18px;
    position:relative;
    overflow:hidden;
    z-index:2;
}

.seal-title{
    font-size:11px;
    letter-spacing:.18em;
    text-transform:uppercase;
    opacity:.75;
}
.seal-text{
    margin-top:8px;
    font-size:14px;
    letter-spacing:.18em;
    text-transform:uppercase;
}
.seal-sub{
    margin-top:8px;
    font-size:11px;
    letter-spacing:.12em;
    opacity:.7;
}
.seal-footer{
    margin-top:14px;
    display:flex;
    justify-content:space-between;
    gap:10px;
    font-size:11px;
    letter-spacing:.12em;
    opacity:.8;
    text-transform:uppercase;
}

.toast{
    position:fixed;
    left:16px;
    bottom:16px;
    z-index:60;
    max-width:min(520px, calc(100vw - 32px));
    padding:12px 14px;
    border:2px solid var(--ink);
    background:rgba(255,255,255,.92);
    box-shadow: var(--shadow);
    font-family:var(--mono);
    font-size:12px;
    letter-spacing:.08em;
    text-transform:uppercase;
    display:none;
}
.toast.on{ display:block; }

/* reduced motion */
@media (prefers-reduced-motion: reduce){
    .nav-btn:hover, .btn:hover, .gate-step:hover{ transform:none; }
    .progress-bar{ transition:none; }
    .sheet{ transition:none; }
}