:root {
  color-scheme: light;
  font-family: -apple-system, BlinkMacSystemFont, 'Apple SD Gothic Neo', 'Noto Sans KR', system-ui, sans-serif;
  color: #1d1d1f;
  background: #f5f5f7;
  font-weight: 400;
  line-height: 1.55;
  --canvas: #f5f5f7;
  --paper: #fff;
  --pearl: #fafafc;
  --ink: #1d1d1f;
  --muted: #5d5d64;
  --line: #e0e0e4;
  --control-line: #c7c7ce;
  --accent: #0066cc;
  --accent-hover: #0059b3;
  --accent-soft: #eaf3fe;
  --success: #14683d;
  --success-soft: #e8f6ee;
  --warning: #834100;
  --warning-soft: #fff1e1;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; }
button, input, select { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: wait; opacity: .58; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; }

.shell { width: min(100% - 32px, 664px); margin-inline: auto; }
.masthead { background: var(--pearl); border-bottom: 1px solid var(--line); }
.masthead-inner { min-height: 54px; display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.academy { font-size: .95rem; font-weight: 650; letter-spacing: -.025em; }
.student-nav { display: flex; flex-wrap: wrap; justify-content: end; }
.student-nav .quiet { padding-inline: 7px; font-size: .9rem; }
.student-nav a { display: inline-flex; align-items: center; text-decoration: none; }
main { padding-block: clamp(28px, 7vw, 56px) max(56px, calc(env(safe-area-inset-bottom, 0px) + 24px)); }
.exam-heading { margin-block-end: clamp(20px, 5vw, 32px); }
h1, h2, h3, h4, h5, p { margin: 0; }
h1, h2, h3, h4, h5 { word-break: keep-all; overflow-wrap: anywhere; }
h1 { font-size: clamp(1.875rem, 6.5vw, 2.75rem); font-weight: 720; line-height: 1.15; letter-spacing: -.048em; }
h2 { font-size: clamp(1.28rem, 4vw, 1.55rem); font-weight: 690; line-height: 1.25; letter-spacing: -.035em; }
h3 { font-size: 1.15rem; font-weight: 680; line-height: 1.3; letter-spacing: -.028em; }
h4 { font-size: 1.03rem; font-weight: 650; letter-spacing: -.02em; }
h5 { font-size: .88rem; font-weight: 650; }
p { color: var(--muted); word-break: keep-all; overflow-wrap: anywhere; }
.exam-heading p, .panel > p:not(.score), .corrections > p, .correct-review > p { margin-top: 8px; }
.practice-badge { display: inline-block; padding: 4px 10px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); font-size: .82rem; font-weight: 650; }
.panel { margin-top: 16px; padding: clamp(18px, 5vw, 32px); border: 1px solid var(--line); border-radius: 22px; background: var(--paper); }
.notice, .inline-status { padding: 10px 12px; border-radius: 12px; background: var(--canvas); color: var(--ink); }
.notice[data-kind='error'], .inline-status[data-kind='error'], .inline-status[data-kind='incorrect'] { background: var(--warning-soft); color: var(--warning); }
.inline-status[data-kind='correct'] { background: var(--success-soft); color: var(--success); }
.inline-status:empty { display: none; }
#reload { margin-top: 10px; }
#login-form, #alias-form { margin-top: 22px; display: grid; gap: 9px; }
#login-form label, #alias-form label { font-size: .92rem; font-weight: 650; }
#login-form .primary, #alias-form .primary { margin-top: 5px; }
#alias-help { font-size: .875rem; }
input[type='text'], select { min-width: 0; min-height: 48px; padding: 9px 13px; border: 1px solid var(--control-line); border-radius: 12px; background: var(--pearl); color: var(--ink); font-size: 1rem; }
input[type='text'] { width: 100%; }
input::placeholder { color: var(--muted); }
#student-code { letter-spacing: .045em; }
#student-code::placeholder { letter-spacing: 0; }
.primary, .secondary, .quiet { min-height: 44px; border-radius: 999px; padding: 8px 16px; font-weight: 630; line-height: 1.3; }
.primary { background: var(--accent); color: var(--paper); border: 1px solid var(--accent); }
.secondary { background: var(--paper); color: var(--accent); border: 1px solid var(--accent); }
.quiet { background: transparent; color: var(--accent); border: 1px solid transparent; }
#login-form .primary, #alias-form .primary { min-height: 48px; }
.scan-actions { display: flex; gap: 8px; margin-block: 18px 10px; flex-wrap: wrap; }
.scan-actions .primary { flex: 1 1 auto; }
.entry-link { display: inline-flex; align-items: center; justify-content: center; text-decoration: none; }
#scan-help { margin-top: 0; font-size: .875rem; }
#scan-status:not([hidden]) { margin-top: 12px; }
.review { display: grid; gap: 12px; border-top: 1px solid var(--line); margin-top: 20px; padding-top: 18px; }
.review-items { display: grid; gap: 8px; }
.review-row { display: flex; gap: 10px; align-items: center; justify-content: space-between; border-radius: 12px; padding: 9px 11px; background: var(--warning-soft); }
.manual-answers .review-row { background: var(--canvas); }
.manual-answers select { min-width: 7rem; }
@media (min-width: 570px) { .manual-answers .review-items { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.review-row label { font-weight: 650; }
.review-row small { display: block; color: var(--warning); }
.review-row select { flex-shrink: 0; }
details { border: 1px solid var(--line); padding: 0 12px; border-radius: 12px; }
details[open] { padding-bottom: 12px; }
summary { cursor: pointer; color: var(--accent); font-weight: 650; min-height: 44px; padding-block: 9px; }
.answers-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(65px, 1fr)); list-style: none; padding: 0; margin: 6px 0 0; gap: 6px; }
.answers-list li { font-size: .88rem; padding: 5px 7px; border-radius: 7px; background: var(--canvas); }
.score { display: flex; flex-wrap: wrap; align-items: baseline; column-gap: 8px; margin-block: 5px 12px; }
.score strong { color: var(--ink); font-size: clamp(2.6rem, 12vw, 4rem); font-weight: 720; line-height: 1.12; letter-spacing: -.055em; font-variant-numeric: tabular-nums; }
.score span { color: var(--muted); font-variant-numeric: tabular-nums; }
.corrections, .correct-review { margin-top: 22px; border-top: 1px solid var(--line); padding-top: 20px; }
.wrong-items, .choices, .answer-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.choices:empty, .wrong-items:empty { display: none; }
.answer-list { list-style: none; padding: 0; }
.question, .choice { background: var(--paper); color: var(--ink); border: 1px solid var(--control-line); border-radius: 12px; min-height: 44px; min-width: 48px; padding: 6px 10px; font-weight: 630; line-height: 1.2; }
.question[aria-pressed='true'] { background: var(--accent-soft); border-color: var(--accent); color: var(--accent); }
.question[data-corrected]:not([aria-pressed='true']) { color: var(--success); }
.retry, .explanation-detail { margin-top: 14px; padding: clamp(13px, 4vw, 18px); background: var(--canvas); border-radius: 16px; }
.retry .inline-status:not(:empty) { margin-top: 12px; }
.explanation { margin-top: 12px; padding: clamp(12px, 4vw, 16px); border: 1px solid var(--line); border-radius: 12px; background: var(--paper); }
.explanation-body { color: var(--ink); margin-top: 7px; line-height: 1.7; white-space: pre-wrap; overflow-wrap: anywhere; }
.rank-list { list-style: none; padding: 0; margin: 13px 0 0; }
.rank-list li { display: grid; grid-template-columns: minmax(2.6rem, 3.3rem) minmax(0, 1fr) auto; gap: 8px; align-items: baseline; padding: 9px; border-bottom: 1px solid var(--line); font-variant-numeric: tabular-nums; }
.rank-list li[data-you] { border-radius: 9px; border-bottom-color: transparent; background: var(--accent-soft); color: var(--accent); }
.rank-list li strong { overflow-wrap: anywhere; }
.rank-list small { font-size: .75rem; color: var(--muted); }
.history-list { list-style: none; margin: 12px 0 0; padding: 0; }
.history-list li + li { border-top: 1px solid var(--line); }
.history-list a { display: flex; align-items: center; gap: 12px; min-height: 56px; padding: 12px 4px; color: var(--ink); text-decoration: none; }
.history-entry { flex: 1; min-width: 0; }
.history-entry strong { display: block; word-break: keep-all; overflow-wrap: anywhere; }
.history-entry small { display: block; color: var(--muted); margin-top: 2px; font-variant-numeric: tabular-nums; }
.history-arrow { color: var(--accent); font-size: 1.4rem; }
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; clip: rect(0, 0, 0, 0); white-space: nowrap; overflow: hidden; border: 0; }

@media (hover: hover) {
  .primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
  .quiet:hover, .secondary:hover, .question:hover, .choice:hover { background: var(--accent-soft); color: var(--accent); }
  .history-list a:hover { color: var(--accent); }
}