:root {
    --bg: #0b1220;
    --panel: #121a2b;
    --accent: #f7931a;
    /* Bitcoin orange */
    --accent-2: #39d98a;
    /* success green */
    --text: #e6edf7;
    --muted: #9fb0d1;
    --warn: #ffd166;
    --border: #203252;
    --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    --sans: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
}

* {
    box-sizing: border-box;
}

html,
body {
    height: 100%;
}

body {
    margin: 0;
    background: radial-gradient(1200px 600px at 60% -10%, #17233b 0%, var(--bg) 60%);
    color: var(--text);
    font-family: var(--sans);
    display: grid;
    grid-template-rows: auto 1fr auto;
    min-height: 100vh;
}

header {
    padding: 20px clamp(16px, 3vw, 32px);
    border-bottom: 1px solid var(--border);
    background: #0d1628cc;
    backdrop-filter: blur(6px);
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
}

.logo {
    width: 36px;
    height: 36px;
    display: grid;
    place-items: center;
    border-radius: 10px;
    background: conic-gradient(from 30deg, #f7931a, #ffb347, #f7931a);
    color: #111;
    font-weight: 800;
}

h1 {
    font-size: clamp(34px, 3vw, 24px);
    margin: 0;
    letter-spacing: 0.2px;
}

header p {
    margin: 0;
    color: var(--muted);
    font-size: 14px;
}

main {
    padding: 24px clamp(16px, 3vw, 32px);
    display: grid;
    gap: 20px;
}

.grid {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 16px;
    align-items: start;
}

.card {
    background: linear-gradient(180deg, #121c31, #0f1627);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 16px;
    box-shadow: 0 10px 30px #00000040;
}

.card h2 {
    margin: 0 0 8px;
    font-size: 18px;
}

.card p {
    color: var(--muted);
    margin: 8px 0;
}

.muted {
    color: var(--muted);
}

.mono {
    font-family: var(--mono);
    font-size: 13px;
}

.explainer {
    grid-column: span 12;
}

.block {
    grid-column: span 7;
}

.stats {
    grid-column: span 5;
}

@media (max-width: 960px) {

    .block,
    .stats {
        grid-column: span 12;
    }
}

.row {
    display: grid;
    grid-template-columns: 160px 1fr;
    gap: 10px;
    align-items: center;
    margin: 10px 0;
}

.row label {
    color: var(--muted);
    font-size: 14px;
}

input[type="text"],
input[type="number"],
input[type='range'],
textarea {
    width: 100%;
    background: #0a1120;
    border: 1px solid var(--border);
    color: var(--text);
    padding: 10px 12px;
    border-radius: 10px;
    font-family: var(--mono);
}

textarea {
    resize: vertical;
    min-height: 80px;
}

.btns {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 8px;
}

button {
    background: var(--panel);
    color: var(--text);
    border: 1px solid var(--border);
    padding: 10px 14px;
    border-radius: 12px;
    cursor: pointer;
    transition: transform .05s ease, background .2s;
}

button:hover {
    background: #13213a;
}

button:active {
    transform: translateY(1px);
}

.primary {
    background: linear-gradient(180deg, #f7931a, #d37603);
    border-color: #d37603;
    color: #111;
    font-weight: 700;
}

.danger {
    background: #2a1320;
    border-color: #61243f;
}

.success {
    background: #0e2a1f;
    border-color: #235a45;
}

.hashbox {
    background: #0a1120;
    border: 1px dashed #28406f;
    padding: 12px;
    border-radius: 12px;
    font-family: var(--mono);
    word-break: break-all;
    overflow-wrap: anywhere;
    font-size: 13px;
}

.keep-space {
    visibility: hidden;
    /* hides it but keeps the space */
    min-height: 160px;
    /* adjust to match your old quiz height */
}

.statgrid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.tile {
    background: #0b1529;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 12px;
}

.tile .big {
    font-size: 22px;
    font-weight: 800;
}

.progress {
    height: 10px;
    background: #0a1120;
    border: 1px solid var(--border);
    border-radius: 999px;
    overflow: hidden;
}

.bar {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, #f7931a, #ffbf69);
}

.quiz {
    grid-column: span 12;
}

.choices {
    display: grid;
    gap: 8px;
    margin-top: 8px;
}

.choice {
    display: flex;
    gap: 8px;
    align-items: center;
    background: #0b1529;
    border: 1px solid var(--border);
    padding: 10px 12px;
    border-radius: 12px;
    cursor: pointer;
}

footer {
    padding: 18px clamp(16px, 3vw, 32px);
    border-top: 1px solid var(--border);
    color: var(--muted);
    font-size: 13px;
}

a {
    color: var(--warn);
    text-decoration: none;
}