:root {
  --ink: #1f252d;
  --muted: #6f7782;
  --canvas: #f7f7f3;
  --paper: #ffffff;
  --line: #e4e7e5;
  --lime: #c9fa57;
  --lime-deep: #a7d733;
  --blue: #2964e8;
  --navy: #1a2446;
  --coral: #f66f5e;
  --shadow: 0 18px 45px rgba(25, 36, 70, .09);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  background: var(--canvas);
  font-family: "Noto Sans TC", Arial, sans-serif;
}

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

.ambient { position: fixed; z-index: -1; border-radius: 999px; filter: blur(1px); opacity: .6; pointer-events: none; }
.ambient-one { width: 440px; height: 440px; top: -260px; left: 12%; background: #e9ffc1; }
.ambient-two { width: 370px; height: 370px; right: -190px; bottom: -170px; background: #d5e5ff; }

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1240px;
  margin: 0 auto;
  padding: 24px 28px;
}

.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 800; letter-spacing: -.04em; font-size: 1.08rem; }
.brand-mark { display: grid; width: 37px; height: 37px; place-items: center; color: var(--navy); background: var(--lime); border: 2px solid var(--navy); border-radius: 10px; font-family: "DM Mono", monospace; font-weight: 500; letter-spacing: -.1em; box-shadow: 3px 3px 0 var(--navy); }
.header-meta { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: .82rem; font-weight: 600; }
.online-dot { width: 8px; height: 8px; background: #54b356; border-radius: 50%; box-shadow: 0 0 0 4px #ddf3dc; }

.page-shell { max-width: 1240px; margin: 0 auto; padding: 48px 28px 34px; }
.intro { display: flex; justify-content: space-between; align-items: flex-end; gap: 48px; margin-bottom: 47px; }
.eyebrow { margin: 0 0 10px; color: var(--blue); font-family: "DM Mono", monospace; font-size: .71rem; font-weight: 500; letter-spacing: .12em; }
h1, h2, p { margin-top: 0; }
h1 { max-width: 720px; margin-bottom: 0; font-size: clamp(2.25rem, 4.8vw, 4.5rem); line-height: 1.13; letter-spacing: -.075em; }
h1 em { color: var(--blue); font-style: normal; }
.intro-copy { max-width: 350px; margin: 0 0 7px; color: var(--muted); line-height: 1.85; font-size: .95rem; }

.quiz-layout { display: grid; grid-template-columns: 245px minmax(0, 1fr); min-height: 570px; overflow: hidden; background: var(--paper); border: 1px solid var(--line); border-radius: 22px; box-shadow: var(--shadow); }
.quiz-sidebar { display: flex; flex-direction: column; padding: 32px 26px 25px; background: var(--navy); color: white; }
.session-label { color: var(--lime); font-family: "DM Mono", monospace; font-size: .72rem; letter-spacing: .08em; }
.question-count { display: flex; align-items: baseline; gap: 7px; margin: 9px 0 14px; }
.question-count strong { font-size: 2.3rem; letter-spacing: -.08em; }
.question-count span { color: #aeb9d9; font-size: .8rem; }
.progress-track { height: 5px; overflow: hidden; background: rgba(255,255,255,.16); border-radius: 9px; }
.progress-track span { display: block; width: 0; height: 100%; background: var(--lime); border-radius: inherit; transition: width .25s ease; }
.question-nav { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; margin-top: 34px; }
.nav-question { display: grid; width: 31px; aspect-ratio: 1; place-items: center; color: #dce3fb; background: transparent; border: 1px solid #485474; border-radius: 8px; font-family: "DM Mono", monospace; font-size: .77rem; transition: .2s; }
.nav-question:hover { border-color: var(--lime); }
.nav-question.is-active { color: var(--navy); background: var(--lime); border-color: var(--lime); font-weight: 700; }
.nav-question.is-answered:not(.is-active) { border-color: #92a1c5; color: white; }
.time-card { margin-top: auto; padding: 14px 15px; border: 1px solid #3b476a; border-radius: 10px; }
.time-card span { display: block; color: #aeb9d9; font-size: .72rem; }
.time-card strong { display: block; margin-top: 2px; font-family: "DM Mono", monospace; font-size: 1.27rem; font-weight: 500; }
.text-button { width: fit-content; margin-top: 20px; padding: 0; color: #dce3fb; background: none; border: 0; font-size: .8rem; text-align: left; }
.text-button:hover { color: var(--lime); }

.quiz-panel { position: relative; padding: 40px 48px; }
.panel-topline { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin-bottom: 36px; }
.category-pill { display: inline-block; margin-right: 11px; padding: 5px 9px; color: var(--blue); background: #edf2ff; border-radius: 5px; font-size: .74rem; font-weight: 700; }
.question-type { color: var(--muted); font-size: .78rem; }
.question-position { color: var(--muted); font-family: "DM Mono", monospace; font-size: .82rem; }
.question-card { min-height: 315px; }
.question-prompt { max-width: 760px; margin-bottom: 25px; font-size: clamp(1.25rem, 2vw, 1.68rem); font-weight: 700; line-height: 1.63; letter-spacing: -.035em; }
.code-context { max-width: 690px; margin: -6px 0 22px; padding: 18px 20px; overflow-x: auto; color: #e9f0ff; background: #202a48; border-radius: 10px; font-family: "DM Mono", monospace; font-size: .88rem; line-height: 1.7; white-space: pre-wrap; }
.answer-area { display: grid; max-width: 720px; gap: 11px; }
.option { display: flex; align-items: center; gap: 14px; min-height: 62px; padding: 13px 17px; border: 1px solid var(--line); border-radius: 10px; cursor: pointer; transition: border .18s, background .18s, transform .18s; }
.option:hover { border-color: #acb8d6; background: #fafbff; transform: translateY(-1px); }
.option:has(input:checked) { border-color: var(--blue); background: #f1f5ff; }
.option input { position: absolute; opacity: 0; }
.option-key { display: grid; width: 29px; aspect-ratio: 1; place-items: center; color: #68738d; background: white; border: 1px solid #cfd5e1; border-radius: 7px; font-family: "DM Mono", monospace; font-size: .75rem; }
.option:has(input:checked) .option-key { color: white; background: var(--blue); border-color: var(--blue); }
.option-text { font-size: .95rem; font-weight: 600; }
.code-input-wrap { position: relative; max-width: 640px; }
.code-input-wrap::before { content: ">_"; position: absolute; top: 15px; left: 16px; color: var(--blue); font-family: "DM Mono", monospace; font-weight: 700; }
.code-input { width: 100%; padding: 14px 17px 14px 47px; color: var(--ink); background: #fbfbfa; border: 1px solid #cfd5e1; border-radius: 9px; font-family: "DM Mono", monospace; font-size: .98rem; outline: none; transition: border .2s, box-shadow .2s; }
.code-input:focus { border-color: var(--blue); box-shadow: 0 0 0 4px #e7eeff; }
.input-hint { margin: 2px 0 0; color: var(--muted); font-size: .79rem; }
.validation-message { min-height: 22px; margin: 18px 0 0; color: var(--coral); font-size: .84rem; font-weight: 600; }
.quiz-actions { display: flex; justify-content: flex-end; gap: 11px; padding-top: 25px; border-top: 1px solid var(--line); }
.primary-button, .secondary-button { min-height: 46px; padding: 0 19px; border-radius: 8px; font-size: .88rem; font-weight: 700; transition: transform .18s, box-shadow .18s, background .18s; }
.primary-button { color: var(--navy); background: var(--lime); border: 1px solid var(--navy); box-shadow: 3px 3px 0 var(--navy); }
.primary-button:hover { background: #d8ff82; transform: translate(-1px, -1px); box-shadow: 5px 5px 0 var(--navy); }
.primary-button:active { transform: translate(2px, 2px); box-shadow: 1px 1px 0 var(--navy); }
.secondary-button { color: var(--ink); background: white; border: 1px solid #cfd5e1; }
.secondary-button:hover { border-color: #8692ad; background: #fafbfc; }
.submit-button { display: none; }
.quiz-panel.is-final-question #next-button { display: none; }
.quiz-panel.is-final-question .submit-button { display: inline-block; }

.result-panel { margin-top: 35px; padding-top: 35px; border-top: 1px solid var(--line); }
.result-summary { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 24px; padding: 25px; background: #f7f9ff; border-radius: 15px; }
.score-ring { --score: 0%; display: grid; width: 100px; aspect-ratio: 1; place-content: center; background: radial-gradient(closest-side, #f7f9ff 77%, transparent 78% 100%), conic-gradient(var(--blue) var(--score), #dfe6f8 0); border-radius: 50%; text-align: center; }
.score-ring strong { font-family: "DM Mono", monospace; font-size: 1.15rem; }
.score-ring span { color: var(--muted); font-size: .68rem; }
.result-summary h2 { margin-bottom: 6px; font-size: 1.4rem; letter-spacing: -.04em; }
.result-summary p:not(.eyebrow) { margin-bottom: 0; color: var(--muted); font-size: .88rem; line-height: 1.6; }
.answer-review { display: grid; gap: 12px; margin-top: 18px; }
.review-card { padding: 19px 20px; border: 1px solid var(--line); border-left: 4px solid #b9c3d9; border-radius: 9px; }
.review-card.is-correct { border-left-color: #52ae5b; }
.review-card.is-wrong { border-left-color: var(--coral); }
.review-head { display: flex; justify-content: space-between; gap: 15px; margin-bottom: 8px; }
.review-number { color: var(--muted); font-family: "DM Mono", monospace; font-size: .75rem; }
.review-status { font-size: .78rem; font-weight: 800; }
.is-correct .review-status { color: #278b31; }
.is-wrong .review-status { color: #d64f3f; }
.review-card h3 { margin: 0 0 7px; font-size: .96rem; line-height: 1.5; }
.review-card p { margin: 0; color: var(--muted); font-size: .83rem; line-height: 1.7; }
.review-card code { padding: 1px 4px; color: #24365e; background: #edf1fb; border-radius: 3px; font-family: "DM Mono", monospace; }

footer { max-width: 1240px; margin: 0 auto; padding: 14px 28px 28px; color: var(--muted); font-size: .75rem; }

@media (max-width: 780px) {
  .site-header { padding: 18px 20px; }
  .header-meta { display: none; }
  .page-shell { padding: 27px 17px 24px; }
  .intro { display: block; margin-bottom: 30px; }
  h1 { font-size: clamp(2rem, 10vw, 3rem); }
  .intro-copy { margin-top: 18px; }
  .quiz-layout { display: block; border-radius: 15px; }
  .quiz-sidebar { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 0 20px; padding: 19px; }
  .session-label { grid-column: 1; grid-row: 1; }
  .question-count { grid-column: 1; grid-row: 2; margin: 3px 0 0; }
  .question-count strong { font-size: 1.6rem; }
  .progress-track { grid-column: 2 / 4; grid-row: 2; }
  .question-nav { grid-column: 1 / 4; margin: 18px 0 0; }
  .nav-question { width: 100%; }
  .time-card { grid-column: 3; grid-row: 1; margin: 0; padding: 0; border: 0; text-align: right; }
  .time-card span { font-size: .65rem; }
  .time-card strong { font-size: .92rem; }
  .text-button { display: none; }
  .quiz-panel { padding: 27px 20px; }
  .panel-topline { margin-bottom: 25px; }
  .question-card { min-height: 300px; }
  .result-summary { grid-template-columns: auto 1fr; gap: 17px; }
  .result-summary .secondary-button { grid-column: 1 / 3; }
  footer { padding: 14px 20px 24px; }
}

@media (max-width: 450px) {
  .category-pill { margin-right: 3px; }
  .question-type { display: none; }
  .quiz-actions { justify-content: space-between; }
  .primary-button, .secondary-button { padding: 0 12px; font-size: .8rem; }
  .option { gap: 10px; padding: 12px; }
  .option-text { font-size: .88rem; }
}