/* ===== Sanfoundry Java MCQ Quiz — styles ===== */

:root {
  --bg: #f5f6f8;
  --panel: #ffffff;
  --panel-2: #fafbfc;
  --text: #16191d;
  --muted: #5c6570;
  --faint: #8b95a1;
  --border: #dfe3e8;
  --accent: #d4741a;
  --accent-soft: #fdf1e3;
  --ok: #1a7f4b;
  --ok-soft: #e6f4ec;
  --bad: #c02a37;
  --bad-soft: #fdecee;
  --code-bg: #1e2430;
  --code-text: #e6e9ef;
  --shadow: 0 1px 2px rgba(16, 20, 26, .06), 0 4px 16px rgba(16, 20, 26, .05);
  --radius: 12px;
  --mono: "JetBrains Mono", "Cascadia Code", Consolas, "SF Mono", Menlo, monospace;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

html[data-theme="dark"] {
  --bg: #0e1116;
  --panel: #161b22;
  --panel-2: #1b212a;
  --text: #e6e9ef;
  --muted: #9aa4b1;
  --faint: #6e7884;
  --border: #2a313c;
  --accent: #e8973d;
  --accent-soft: #2a2115;
  --ok: #4ac27f;
  --ok-soft: #13291d;
  --bad: #f2606d;
  --bad-soft: #2c1418;
  --code-bg: #0b0e13;
  --code-text: #e6e9ef;
  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 4px 16px rgba(0, 0, 0, .25);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

button, input, select { font: inherit; color: inherit; }
button { cursor: pointer; }

.wrap { max-width: 900px; margin: 0 auto; padding: 24px 20px 80px; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.topbar-in {
  max-width: 900px; margin: 0 auto; padding: 12px 20px;
  display: flex; align-items: center; gap: 12px;
}
.brand { font-weight: 700; letter-spacing: -.02em; font-size: 1.05rem; }
.brand span { color: var(--accent); }
.spacer { flex: 1; }

.nav-tabs { display: flex; gap: 3px; background: var(--panel-2); border: 1px solid var(--border);
  border-radius: 9px; padding: 3px; margin-left: 6px; }
.tab { background: none; border: none; color: var(--muted); border-radius: 6px;
  padding: 5px 14px; font-size: .87rem; font-weight: 600; transition: .15s; }
.tab:hover { color: var(--accent); }
.tab.on { background: var(--accent); color: #fff; }

/* ---------- theory ---------- */
.qcard.th .qtext { font-size: 1.04rem; }
.th-ans { margin-top: 12px; border-left: 3px solid var(--accent); background: var(--panel-2);
  border-radius: 0 9px 9px 0; padding: 12px 16px; }
.th-ans p { margin: 0 0 9px; }
.th-ans p:last-of-type { margin-bottom: 0; }
.th-ans ul { margin: 6px 0 0; padding-left: 20px; }
.th-ans li { margin-bottom: 5px; }
.th-toggle { padding: 8px 16px; font-size: .87rem; }
.th-prompt { margin-top: 10px; border-left: 3px solid var(--faint); background: var(--panel-2);
  border-radius: 0 9px 9px 0; padding: 10px 14px; color: var(--muted); font-size: .9rem; }
.th-prompt b { color: var(--accent); }

.keyblock { border-top: 1px solid var(--border); padding: 13px 0 4px; }
.keyblock:first-child { border-top: none; padding-top: 0; }
.keyblock .lbl { font-size: .74rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: .07em; color: var(--accent); margin-bottom: 7px; }
.keyblock ul { margin: 0; padding-left: 20px; }
.keyblock li { margin-bottom: 6px; font-size: .93rem; }

.warnbox { background: var(--bad-soft); border-left: 3px solid var(--bad);
  border-radius: 0 9px 9px 0; padding: 12px 16px; font-size: .93rem; }
.warnbox b { color: var(--bad); display: block; margin-bottom: 3px; }

ol.opts.th-opts { list-style: none; margin: 0 0 12px; padding: 0; }
ol.opts.th-opts li { display: flex; align-items: flex-start; gap: 11px; padding: 10px 13px;
  border: 1.5px solid var(--border); border-radius: 10px; background: var(--panel-2);
  margin-bottom: 7px; }
ol.opts.th-opts li.right { border-color: var(--ok); background: var(--ok-soft); }
ol.opts.th-opts .lk { flex: none; width: 24px; height: 24px; border-radius: 6px;
  background: var(--panel); border: 1px solid var(--border); display: grid; place-items: center;
  font-size: .78rem; font-weight: 700; text-transform: uppercase; }
ol.opts.th-opts li.right .lk { background: var(--ok); color: #fff; border-color: var(--ok); }
ol.opts.th-opts .lt { flex: 1; }
ol.opts.th-opts .tick { color: var(--ok); font-weight: 700; margin-left: auto; }

.icon-btn {
  background: var(--panel); border: 1px solid var(--border); color: var(--muted);
  border-radius: 8px; padding: 7px 12px; font-size: .85rem; font-weight: 500;
  transition: .15s;
}
.icon-btn:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- cards ---------- */
.card {
  background: var(--panel); border: 1px solid var(--border);
  border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 24px; margin-bottom: 18px;
}

h1 { font-size: 1.9rem; letter-spacing: -.03em; margin: 0 0 6px; }
h2 { font-size: 1.15rem; letter-spacing: -.01em; margin: 0 0 14px; }
.sub { color: var(--muted); margin: 0 0 22px; }

/* ---------- start screen ---------- */
.stats { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 22px; }
.stat {
  flex: 1; min-width: 110px; background: var(--panel-2);
  border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px;
}
.stat b { display: block; font-size: 1.5rem; letter-spacing: -.02em; line-height: 1.2; }
.stat span { font-size: .78rem; color: var(--faint); text-transform: uppercase; letter-spacing: .05em; }

.field { margin-bottom: 20px; }
.field > label {
  display: block; font-size: .8rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: .05em; color: var(--faint); margin-bottom: 9px;
}

.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  background: var(--panel-2); border: 1px solid var(--border);
  border-radius: 999px; padding: 7px 15px; font-size: .88rem; transition: .15s;
}
.chip:hover { border-color: var(--accent); }
.chip.on { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 500; }
.chip:disabled { opacity: .38; cursor: not-allowed; }
.chip:disabled:hover { border-color: var(--border); }
.chip.primary { border-color: var(--accent); color: var(--accent); font-weight: 600; }
.chip.primary.on { color: #fff; }
.chip .n { opacity: .65; font-size: .8em; margin-left: 5px; }

select, input[type="search"] {
  width: 100%; background: var(--panel-2); border: 1px solid var(--border);
  border-radius: 9px; padding: 10px 12px; outline: none;
}
select:focus, input:focus { border-color: var(--accent); }

.topic-box {
  max-height: 230px; overflow-y: auto; border: 1px solid var(--border);
  border-radius: 9px; padding: 10px; background: var(--panel-2); margin-top: 9px;
}
.topic-row { display: flex; align-items: center; gap: 9px; padding: 5px 6px; border-radius: 6px; font-size: .9rem; }
.topic-row:hover { background: var(--bg); }
.topic-row input { accent-color: var(--accent); width: 15px; height: 15px; }
.topic-row .n { margin-left: auto; color: var(--faint); font-size: .8rem; font-variant-numeric: tabular-nums; }
.topic-cat { font-size: .72rem; text-transform: uppercase; letter-spacing: .06em; color: var(--faint);
  padding: 10px 6px 4px; font-weight: 600; }

.switches { display: flex; flex-direction: column; gap: 11px; }
.switch { display: flex; align-items: center; gap: 10px; font-size: .93rem; }
.switch input { accent-color: var(--accent); width: 16px; height: 16px; }

.btn {
  background: var(--accent); color: #fff; border: none; border-radius: 10px;
  padding: 13px 26px; font-weight: 600; font-size: .97rem; transition: .15s;
}
.btn:hover { filter: brightness(1.07); }
.btn:disabled { opacity: .45; cursor: not-allowed; filter: none; }
.btn.ghost { background: transparent; color: var(--muted); border: 1px solid var(--border); }
.btn.ghost:hover { border-color: var(--accent); color: var(--accent); filter: none; }
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }

/* ---------- quiz (scrolling list) ---------- */
.quizbar {
  position: sticky; top: 53px; z-index: 40;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  margin: -24px -20px 18px; padding: 10px 20px 0;
}
.quizbar-in { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; }

.qcard { scroll-margin-top: 110px; }
.qn {
  flex: none; min-width: 26px; height: 26px; padding: 0 7px; border-radius: 7px;
  background: var(--text); color: var(--panel);
  display: grid; place-items: center; font-size: .8rem; font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.pagenav { margin-top: 4px; }
.lbl-hint {
  text-transform: none; letter-spacing: 0; font-weight: 400;
  color: var(--faint); font-size: .9em; margin-left: 6px;
}

.qhead { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; }
.badge {
  background: var(--accent-soft); color: var(--accent); border-radius: 999px;
  padding: 4px 12px; font-size: .78rem; font-weight: 600;
}
.badge.plain { background: var(--panel-2); color: var(--muted); }
.counter { color: var(--faint); font-size: .85rem; font-variant-numeric: tabular-nums; }

.progress { height: 5px; background: var(--border); border-radius: 999px; overflow: hidden; margin-bottom: 18px; }
.progress > i { display: block; height: 100%; background: var(--accent); transition: width .25s ease; }

.qtext { font-size: 1.1rem; font-weight: 500; margin: 0 0 16px; white-space: pre-wrap; }

pre.code {
  background: var(--code-bg); color: var(--code-text); border-radius: 10px;
  padding: 15px 17px; overflow-x: auto; margin: 0 0 16px;
  font-family: var(--mono); font-size: .855rem; line-height: 1.65;
  tab-size: 4; white-space: pre;
}
pre.code .kw { color: #ff9d5c; }
pre.code .str { color: #9ae87f; }
pre.code .cmt { color: #6b7686; font-style: italic; }
pre.code .num { color: #7fd0ff; }

.opts { display: flex; flex-direction: column; gap: 9px; margin-bottom: 18px; }
.opt {
  display: flex; align-items: flex-start; gap: 12px; width: 100%; text-align: left;
  background: var(--panel-2); border: 1.5px solid var(--border);
  border-radius: 10px; padding: 13px 15px; transition: .12s;
}
.opt:hover:not(:disabled) { border-color: var(--accent); background: var(--accent-soft); }
.opt .key {
  flex: none; width: 25px; height: 25px; border-radius: 6px; background: var(--panel);
  border: 1px solid var(--border); display: grid; place-items: center;
  font-size: .8rem; font-weight: 700; text-transform: uppercase;
}
.opt .txt { flex: 1; white-space: pre-wrap; }
.opt.sel { border-color: var(--accent); background: var(--accent-soft); }
.opt.sel .key { background: var(--accent); color: #fff; border-color: var(--accent); }
.opt.correct { border-color: var(--ok); background: var(--ok-soft); }
.opt.correct .key { background: var(--ok); color: #fff; border-color: var(--ok); }
.opt.wrong { border-color: var(--bad); background: var(--bad-soft); }
.opt.wrong .key { background: var(--bad); color: #fff; border-color: var(--bad); }
.opt:disabled { cursor: default; }
.opt .mark { margin-left: auto; font-weight: 700; font-size: .95rem; }
.opt.correct .mark { color: var(--ok); }
.opt.wrong .mark { color: var(--bad); }

.explain {
  border-left: 3px solid var(--accent); background: var(--panel-2);
  border-radius: 0 9px 9px 0; padding: 13px 16px; margin-bottom: 18px;
}
.explain .lbl {
  font-size: .74rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: .07em; color: var(--faint); margin-bottom: 5px;
}
.explain p { margin: 0 0 8px; white-space: pre-wrap; }
.explain p:last-child { margin-bottom: 0; }
.explain pre.code { margin-top: 10px; margin-bottom: 0; font-size: .8rem; }
.verdict { font-weight: 700; margin-bottom: 8px; }
.verdict.ok { color: var(--ok); }
.verdict.bad { color: var(--bad); }

.nav { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.hint { color: var(--faint); font-size: .8rem; margin-left: auto; }

/* ---------- results ---------- */
.score-ring { display: flex; align-items: center; gap: 26px; flex-wrap: wrap; margin-bottom: 22px; }
.ring { --p: 0; --c: var(--accent); flex: none;
  width: 132px; height: 132px; border-radius: 50%; display: grid; place-items: center;
  background: conic-gradient(var(--c) calc(var(--p) * 1%), var(--border) 0);
}
.ring > div {
  width: 106px; height: 106px; border-radius: 50%; background: var(--panel);
  display: grid; place-items: center; text-align: center;
}
.ring b { font-size: 1.85rem; letter-spacing: -.03em; line-height: 1; }
.ring span { font-size: .74rem; color: var(--faint); text-transform: uppercase; letter-spacing: .06em; }

.tally { display: flex; gap: 10px; flex-wrap: wrap; flex: 1; min-width: 220px; }
.tally .stat b.ok { color: var(--ok); }
.tally .stat b.bad { color: var(--bad); }

.bars { display: flex; flex-direction: column; gap: 9px; }
.bar-row { display: grid; grid-template-columns: 1fr 90px 52px; gap: 11px; align-items: center; font-size: .87rem; }
.bar-row .nm { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.bar { height: 7px; background: var(--border); border-radius: 999px; overflow: hidden; }
.bar > i { display: block; height: 100%; background: var(--ok); }
.bar-row .pc { text-align: right; color: var(--muted); font-variant-numeric: tabular-nums; font-size: .82rem; }

.review-item { border-top: 1px solid var(--border); padding: 18px 0; }
.review-item:first-of-type { border-top: none; padding-top: 4px; }
.rv-head { display: flex; gap: 10px; align-items: baseline; margin-bottom: 9px; }
.rv-n { color: var(--faint); font-size: .82rem; font-variant-numeric: tabular-nums; flex: none; }
.rv-tag { font-size: .72rem; font-weight: 700; padding: 2px 9px; border-radius: 999px; flex: none; }
.rv-tag.ok { background: var(--ok-soft); color: var(--ok); }
.rv-tag.bad { background: var(--bad-soft); color: var(--bad); }
.rv-tag.skip { background: var(--panel-2); color: var(--faint); }

.src { font-size: .78rem; color: var(--faint); margin-top: 10px; }
.src a { color: var(--faint); }

.hide { display: none !important; }

.footer { text-align: center; color: var(--faint); font-size: .8rem; padding: 30px 20px; }
.footer a { color: var(--faint); }

@media (max-width: 640px) {
  .wrap { padding: 16px 14px 60px; }
  .card { padding: 18px 16px; }
  h1 { font-size: 1.5rem; }
  .bar-row { grid-template-columns: 1fr 60px 46px; }
  .hint { display: none; }
}