/* =========================================================
   Robinson Tuition - free maths tools
   Layered on top of styles.css: uses the same tokens, fonts
   and buttons as the marketing site so the tools feel native.
   ========================================================= */

.tool-main { padding-block: clamp(1.5rem, 4vw, 2.75rem) clamp(4rem, 8vw, 6rem); }
.tool-wrap { width: 100%; max-width: 860px; margin-inline: auto; padding-inline: clamp(1rem, 4vw, 1.5rem); }
.tool-wrap--wide { max-width: 1040px; }

/* ---------- tool header ---------- */
.tool-head { display: flex; align-items: flex-start; gap: 1rem; flex-wrap: wrap; margin-bottom: 1.5rem; }
.tool-head h1 { font-size: clamp(1.9rem, 4vw, 2.7rem); }
.tool-head .lead { margin-top: 0.35rem; font-size: 1rem; color: var(--text-soft); max-width: 54ch; }
.tool-head__aside { margin-left: auto; display: flex; gap: 0.6rem; align-items: center; flex-wrap: wrap; }

/* ---------- streak pill ---------- */
.streak-pill {
  display: inline-flex; align-items: center; gap: 0.55rem;
  background: var(--ink); color: #fff; border-radius: var(--r-pill);
  padding: 0.55rem 1.05rem; font-weight: 700; font-size: 0.95rem; white-space: nowrap;
}
.streak-pill .n { font-size: 1.25rem; font-variant-numeric: tabular-nums; }
.streak-pill--quiet { background: var(--cream-2); color: var(--ink); }

/* ---------- week strip ---------- */
.week-strip { display: flex; gap: 0.5rem; align-items: flex-end; }
.week-day { display: flex; flex-direction: column; align-items: center; gap: 0.35rem; flex: 1; min-width: 0; }
.week-day .dot {
  width: 100%; max-width: 44px; aspect-ratio: 1; border-radius: var(--r-sm);
  background: var(--cream-2); border: 1.5px solid var(--line);
  display: grid; place-items: center;
  font-weight: 700; font-size: 0.85rem; color: var(--text-soft);
  font-variant-numeric: tabular-nums; transition: transform 0.15s ease;
}
.week-day .dot.done { background: var(--accent); border-color: var(--accent); color: #fff; }
.week-day .dot.full { background: #1e9e5a; border-color: #1e9e5a; }
.week-day.today .dot { box-shadow: 0 0 0 3px var(--accent-soft); }
.week-day .lbl { font-size: 0.7rem; font-weight: 600; color: var(--text-soft); text-transform: uppercase; letter-spacing: 0.04em; }

/* ---------- cards ---------- */
.tool-card {
  background: var(--paper); border: 1px solid var(--line); border-radius: var(--r);
  box-shadow: var(--shadow-sm); padding: clamp(1.1rem, 3vw, 1.6rem); margin-bottom: 1.25rem;
}
.tool-card--flush { padding: 0; overflow: hidden; }
.tool-card h2 { font-size: 1.25rem; }
.tool-card h3 { font-size: 1.05rem; }

/* ---------- grade chips ---------- */
.chips { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.chip-btn {
  border: 1.5px solid var(--line); background: var(--paper); color: var(--text-soft);
  padding: 0.55rem 1rem; border-radius: var(--r-pill); font-weight: 700; font-size: 0.92rem;
  font-family: var(--font-sans); cursor: pointer; transition: 0.14s;
}
.chip-btn:hover { border-color: var(--accent); color: var(--accent); }
.chip-btn.on { background: var(--accent); border-color: var(--accent); color: #fff; }
.chip-btn:focus-visible { outline: 3px solid var(--ring); outline-offset: 2px; }

/* ---------- question ---------- */
.q-meta { display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap; margin-bottom: 0.9rem; }
.q-meta .qno { font-weight: 800; color: var(--ink); font-size: 1.05rem; }
.tag {
  font-size: 0.7rem; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase;
  border-radius: var(--r-pill); padding: 0.22rem 0.6rem; white-space: nowrap;
}
.tag--topic { background: var(--accent-soft); color: var(--accent); text-transform: none; letter-spacing: 0; font-size: 0.78rem; }
.tag--calc { background: #fbf1de; color: #b9750e; }
.tag--nocalc { background: var(--cream-2); color: var(--text-soft); }
.tag--stretch { background: #f3ecfb; color: #5b3e8c; }
.tag--secure { background: #e3f6ec; color: #1a7a48; }
.tag--working { background: #fbf1de; color: #b9750e; }
.q-meta .marks { margin-left: auto; font-weight: 700; color: var(--text-soft); font-size: 0.92rem; white-space: nowrap; }

.q-text { font-family: var(--font-display); font-size: 1.12rem; line-height: 1.7; }
.q-text p { margin: 0 0 0.65rem; }
.q-text ol, .q-text ul { margin: 0 0 0.65rem; padding-left: 1.4rem; }
.q-text li { margin-bottom: 0.35rem; }
.q-text table { border-collapse: collapse; margin: 0.6rem 0; font-family: var(--font-sans); }
.q-text th, .q-text td { border: 1px solid var(--line); padding: 0.4rem 0.85rem; text-align: center; font-size: 0.95rem; }
.q-text th { background: var(--cream); font-weight: 700; }
.q-scroll { overflow-x: auto; }

/* stacked fractions, exam-print style */
.frac {
  display: inline-flex; flex-direction: column; align-items: center;
  vertical-align: -0.65em; margin: 0 2px; line-height: 1.15; text-align: center; font-size: 0.92em;
}
.frac .fr-n { padding: 0 4px; }
.frac .fr-d { padding: 0 4px; border-top: 1.4px solid currentColor; }
sup .frac { font-size: 0.9em; vertical-align: -0.45em; line-height: 1.05; }
sup .frac .fr-n, sup .frac .fr-d { padding: 0 2px; }

/* ---------- answering ---------- */
.answer-row { display: flex; gap: 0.6rem; flex-wrap: wrap; align-items: center; margin-top: 1.1rem; }
.answer-row input[type="text"] {
  font: inherit; font-family: var(--font-sans); padding: 0.7rem 0.9rem;
  border: 1.5px solid var(--line); border-radius: var(--r-sm); background: var(--paper);
  color: var(--text); flex: 1 1 180px; max-width: 300px; min-width: 0;
}
.answer-row input[type="text"]:focus { outline: 3px solid var(--ring); outline-offset: 1px; border-color: var(--accent); }
.answer-row .hint { font-size: 0.9rem; color: var(--text-soft); }

.verdict { margin-top: 1rem; border-radius: var(--r-sm); padding: 0.8rem 1.1rem; font-weight: 600; display: none; }
.verdict.right { display: block; background: #e3f6ec; color: #1a7a48; }
.verdict.wrong { display: block; background: #fbf1de; color: #b9750e; }

.solution { margin-top: 1rem; display: none; }
.solution.show { display: block; }
.solution__box {
  background: var(--cream); border: 1px solid var(--line); border-left: 3px solid #1e9e5a;
  border-radius: var(--r-sm); padding: 0.95rem 1.2rem;
}
.solution__box h4 {
  margin: 0 0 0.5rem; font-family: var(--font-sans); font-size: 0.75rem;
  letter-spacing: 0.09em; text-transform: uppercase; color: #1a7a48;
}
.solution__box ol { margin: 0; padding-left: 1.25rem; display: grid; gap: 0.35rem; font-size: 0.98rem; }
.solution__final { margin-top: 0.7rem; font-weight: 800; color: var(--ink); }
.selfmark { display: none; gap: 0.6rem; margin-top: 0.9rem; flex-wrap: wrap; align-items: center; }
.selfmark.show { display: flex; }
.selfmark span { font-weight: 700; font-size: 0.92rem; color: var(--text-soft); }

/* ---------- progress dots for a set ---------- */
.setdots { display: flex; gap: 0.45rem; align-items: center; margin-bottom: 1rem; }
.setdots .d { width: 13px; height: 13px; border-radius: 50%; background: var(--paper); border: 2px solid var(--line); }
.setdots .d.now { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.setdots .d.right { background: #1e9e5a; border-color: #1e9e5a; }
.setdots .d.wrong { background: #e8a33d; border-color: #e8a33d; }
.setdots .lbl { margin-left: auto; font-size: 0.82rem; font-weight: 700; color: var(--text-soft); }

/* ---------- results ---------- */
.result { text-align: center; padding: clamp(1.5rem, 5vw, 2.75rem) 1rem; }
.result__score { font-family: var(--font-display); font-size: clamp(2.6rem, 8vw, 3.6rem); font-weight: 600; color: var(--ink); font-variant-numeric: tabular-nums; line-height: 1; }
.result__streak { font-size: 1.1rem; font-weight: 700; margin-top: 0.5rem; color: #b9750e; }
.result__msg { max-width: 46ch; margin: 0.85rem auto 0; color: var(--text-soft); }
.result__actions { display: flex; gap: 0.65rem; justify-content: center; flex-wrap: wrap; margin-top: 1.5rem; }

/* ---------- progress ring ---------- */
.ring { --pct: 0; width: 46px; height: 46px; flex: none; display: grid; place-items: center; position: relative; }
.ring svg { transform: rotate(-90deg); width: 100%; height: 100%; }
.ring circle { fill: none; stroke-width: 5; }
.ring .bg { stroke: var(--cream-2); }
.ring .fg { stroke: #1e9e5a; stroke-linecap: round; transition: stroke-dashoffset 0.5s ease; }
.ring span { position: absolute; font-size: 0.68rem; font-weight: 800; color: var(--ink); font-variant-numeric: tabular-nums; }

/* ---------- topic list ---------- */
.grade-block { border: 1px solid var(--line); border-radius: var(--r); overflow: hidden; margin-bottom: 0.9rem; background: var(--paper); }
.grade-block > summary {
  list-style: none; cursor: pointer; padding: 0.9rem 1.1rem; background: var(--cream);
  display: flex; align-items: center; gap: 0.85rem; font-weight: 800; color: var(--ink);
}
.grade-block > summary::-webkit-details-marker { display: none; }
.grade-block > summary:focus-visible { outline: 3px solid var(--ring); outline-offset: -3px; }
.grade-block .caret { color: var(--text-soft); transition: transform 0.15s; font-size: 0.8rem; }
.grade-block[open] .caret { transform: rotate(90deg); }
.grade-block .count { margin-left: auto; font-size: 0.82rem; font-weight: 700; color: var(--text-soft); }

.topic-row {
  display: flex; align-items: center; gap: 0.75rem; width: 100%; text-align: left;
  padding: 0.75rem 1.1rem; border: 0; border-top: 1px solid var(--line);
  background: var(--paper); font-family: var(--font-sans); font-size: 0.98rem; cursor: pointer; transition: background 0.12s;
}
.topic-row:hover { background: var(--cream); }
.topic-row:focus-visible { outline: 3px solid var(--ring); outline-offset: -3px; }
.topic-row__name { flex: 1; font-weight: 600; color: var(--text); min-width: 0; }
.topic-row__go { color: var(--accent); font-weight: 700; font-size: 0.88rem; white-space: nowrap; }
.topic-row.is-secure .topic-row__name { color: var(--text-soft); }
.topic-tick { width: 22px; height: 22px; flex: none; border-radius: 50%; border: 2px solid var(--line); display: grid; place-items: center; font-size: 0.7rem; color: #fff; }
.topic-tick.secure { background: #1e9e5a; border-color: #1e9e5a; }
.topic-tick.working { background: #e8a33d; border-color: #e8a33d; }

/* ---------- account bar ---------- */
.acct-bar { display: flex; align-items: center; gap: 0.6rem; flex-wrap: wrap; font-size: 0.9rem; color: var(--text-soft); }
.acct-bar strong { color: var(--ink); }
.acct-bar button { font-size: 0.88rem; }

/* ---------- modal ---------- */
.rt-modal {
  position: fixed; inset: 0; z-index: 200; display: none;
  align-items: center; justify-content: center; padding: 1rem;
  background: rgba(12, 29, 64, 0.55);
}
.rt-modal.show { display: flex; }
.rt-modal__panel {
  background: var(--paper); border-radius: var(--r-lg); box-shadow: var(--shadow-lg);
  max-width: 460px; width: 100%; padding: clamp(1.3rem, 4vw, 2rem); position: relative;
  max-height: 90vh; overflow-y: auto;
}
.rt-modal__panel h2 { font-size: 1.4rem; margin-bottom: 0.5rem; }
.rt-modal__panel p { color: var(--text-soft); font-size: 0.96rem; margin-bottom: 1rem; }
.rt-modal__close {
  position: absolute; top: 0.7rem; right: 0.8rem; border: 0; background: none;
  font-size: 1.4rem; line-height: 1; color: var(--text-soft); cursor: pointer; padding: 0.25rem 0.4rem;
}
.rt-modal__close:hover { color: var(--ink); }
.rt-field { display: flex; flex-direction: column; gap: 0.35rem; margin-bottom: 0.9rem; }
.rt-field label { font-size: 0.85rem; font-weight: 700; color: var(--text-soft); }
.rt-field input[type="email"] {
  font: inherit; font-family: var(--font-sans); padding: 0.7rem 0.9rem;
  border: 1.5px solid var(--line); border-radius: var(--r-sm); background: var(--paper); color: var(--text);
}
.rt-field input[type="email"]:focus { outline: 3px solid var(--ring); outline-offset: 1px; border-color: var(--accent); }
.rt-check { display: flex; gap: 0.6rem; align-items: flex-start; font-size: 0.88rem; color: var(--text-soft); margin-bottom: 1rem; line-height: 1.5; }
.rt-check input { margin-top: 0.22rem; width: 18px; height: 18px; flex: none; }
.rt-fineprint { font-size: 0.78rem; color: var(--text-soft); margin-top: 0.9rem; line-height: 1.5; }
.rt-fineprint a { color: var(--accent); }

/* ---------- sticky book-a-session ---------- */
.rt-cta-float {
  position: fixed; right: clamp(0.75rem, 3vw, 1.5rem); bottom: clamp(0.75rem, 3vw, 1.5rem);
  z-index: 150; display: inline-flex; align-items: center; gap: 0.5rem;
  background: var(--accent); color: #fff; text-decoration: none;
  padding: 0.75rem 1.15rem; border-radius: var(--r-pill); font-weight: 700; font-size: 0.94rem;
  box-shadow: 0 10px 26px -8px rgba(12, 29, 64, 0.5); transition: transform 0.15s, box-shadow 0.15s;
}
.rt-cta-float:hover { transform: translateY(-2px); box-shadow: 0 16px 32px -10px rgba(12, 29, 64, 0.55); color: #fff; }
.rt-cta-float:focus-visible { outline: 3px solid var(--ring); outline-offset: 3px; }
.rt-cta-float svg { width: 17px; height: 17px; flex: none; }
@media (max-width: 560px) { .rt-cta-float .lbl-long { display: none; } }

/* ---------- toast ---------- */
.rt-toast {
  position: fixed; left: 50%; bottom: 1.4rem; transform: translateX(-50%) translateY(20px);
  background: var(--ink); color: #fff; padding: 0.65rem 1.15rem; border-radius: var(--r-pill);
  font-size: 0.92rem; font-weight: 600; opacity: 0; transition: 0.25s; pointer-events: none; z-index: 300;
  max-width: calc(100vw - 2rem); text-align: center;
}
.rt-toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- share card preview ---------- */
.share-preview { width: 100%; border-radius: var(--r); border: 1px solid var(--line); display: block; margin-bottom: 1rem; }

/* ---------- small print / empty states ---------- */
.tool-note { font-size: 0.9rem; color: var(--text-soft); }
.tool-note a { color: var(--accent); }

@media (prefers-reduced-motion: reduce) {
  .rt-toast, .ring .fg, .week-day .dot, .rt-cta-float { transition: none; }
}

@media print {
  .site-header, .site-footer, .rt-cta-float, .rt-toast, .rt-modal, .answer-row, .selfmark { display: none !important; }
  .tool-card { box-shadow: none; border-color: #999; break-inside: avoid; }
}