:root { --ink: #17212b; --muted: #607080; --paper: #f7f8f5; --line: #dce2dc; --accent: #167a61; --accent-soft: #dff3e9; --danger: #a43b3b; }
* { box-sizing: border-box; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: "Pretendard", "Noto Sans KR", Arial, sans-serif; line-height: 1.6; }
a { color: inherit; text-decoration: none; }
.site-header, main, footer { max-width: 1060px; margin: auto; padding-left: 24px; padding-right: 24px; }
.site-header { height: 76px; display: flex; align-items: center; justify-content: space-between; }
.brand { font-weight: 800; letter-spacing: .08em; }
.site-header nav a { color: var(--muted); font-size: .92rem; }
.site-nav { display: flex; gap: 20px; }
.hero { padding: 84px 0 70px; max-width: 720px; }
.eyebrow { color: var(--accent); font-weight: 700; font-size: .87rem; letter-spacing: .05em; margin: 0 0 8px; }
h1 { font-size: clamp(2.1rem, 6vw, 4.2rem); letter-spacing: -.06em; line-height: 1.13; margin: 0 0 22px; }
h2 { letter-spacing: -.04em; }
.hero > p:not(.eyebrow), .quiz-intro > p:not(.eyebrow), .result-summary > p:not(.eyebrow) { color: var(--muted); font-size: 1.08rem; max-width: 620px; }
.button { display: inline-block; border: 0; border-radius: 8px; cursor: pointer; font: inherit; font-weight: 700; padding: 13px 20px; margin: 12px 8px 0 0; }
.primary { background: var(--accent); color: white; }
.secondary { background: #e7ece9; }
.section-heading { display: flex; justify-content: space-between; align-items: baseline; }
.section-heading span { color: var(--muted); font-size: .9rem; }
.category-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; padding-bottom: 72px; }
.category-card { position: relative; min-height: 155px; padding: 24px; background: white; border: 1px solid var(--line); border-radius: 12px; transition: transform .15s; }
.category-card:hover { transform: translateY(-3px); border-color: var(--accent); }
.category-card.empty-category { opacity: .65; }.category-card.empty-category:hover { transform: none; border-color: var(--line); }
.category-card h3 { font-size: 1.25rem; margin: 12px 0 0; }
.count { color: var(--muted); font-size: .84rem; }.arrow { position: absolute; right: 22px; bottom: 18px; color: var(--accent); font-size: 1.5rem; }
.quiz-intro, .result-summary { padding: 44px 0 28px; }.back { color: var(--muted); font-size: .9rem; display: inline-block; margin-bottom: 24px; }
.quiz-form { padding-bottom: 64px; }.question-card, .answer-card, .builder-form { background: white; border: 1px solid var(--line); border-radius: 12px; padding: 26px; margin: 0 0 18px; }.question-card { min-width: 0; }
.question-card legend { float: left; width: 100%; font-size: 1.16rem; font-weight: 700; padding: 0; margin: 0 0 20px; }.question-card legend span { color: var(--accent); margin-right: 10px; }.question-image { clear: both; display: block; width: auto; max-width: 100%; max-height: 520px; margin: 0 0 20px; border: 1px solid var(--line); border-radius: 8px; object-fit: contain; }
.choices { clear: both; display: grid; gap: 10px; }.choices label { border: 1px solid var(--line); border-radius: 7px; padding: 12px; cursor: pointer; }.choices label:has(input:checked) { border-color: var(--accent); background: var(--accent-soft); }.choice-option { display: grid; gap: 10px; }.choice-image { display: block; width: auto; max-width: 100%; max-height: 320px; border-radius: 6px; object-fit: contain; }.answer-hint { color: var(--accent); font-weight: 700; margin: 0 0 2px; }.short-answer-field { clear: both; display: grid; gap: 7px; }.short-answer-field label { font-weight: 700; }.short-answer-field input { width: 100%; padding: 12px; border: 1px solid #bfc9c1; border-radius: 7px; font: inherit; }
.result-list { padding: 12px 0 64px; }.answer-card { border-left: 5px solid var(--danger); }.answer-card.correct { border-left-color: var(--accent); }.status { color: var(--danger); font-weight: 800; margin: 0; }.correct .status { color: var(--accent); }.answer-card h2 { font-size: 1.15rem; }.explanation { padding: 14px; background: #f0f4f1; border-radius: 7px; }
.builder-form { display: grid; gap: 16px; margin-bottom: 64px; }.builder-form label { display: grid; gap: 7px; font-weight: 700; }.builder-form input, .builder-form select, .builder-form textarea { width: 100%; font: inherit; font-weight: 400; border: 1px solid #bfc9c1; border-radius: 6px; padding: 10px; }.builder-form textarea { min-height: 100px; resize: vertical; }.question-type-fields { display: grid; gap: 16px; }.choice-editor { display: grid; gap: 12px; padding: 16px; border: 1px solid var(--line); border-radius: 8px; }.choice-image-file-controls { display: flex; align-items: center; gap: 8px; }.choice-image-file-controls button { flex: 0 0 auto; padding: 9px 12px; color: var(--danger); background: white; border: 1px solid var(--line); border-radius: 6px; cursor: pointer; font: inherit; font-weight: 700; }.choice-image-file-controls button:disabled { color: var(--muted); background: #eef2ef; cursor: not-allowed; }.choice-image-file-controls input { min-width: 0; }.math-editor { display: grid; gap: 10px; }.math-assistant { display: grid; gap: 8px; }.math-toolbar { display: flex; flex-wrap: wrap; gap: 6px; }.builder-form .math-toolbar button { width: auto; padding: 6px 10px; color: var(--ink); background: #eef2ef; border: 1px solid var(--line); border-radius: 6px; cursor: pointer; font: inherit; font-size: .84rem; font-weight: 700; }.builder-form .math-toolbar button:hover, .builder-form .math-toolbar button:focus-visible { border-color: var(--accent); background: var(--accent-soft); }.math-preview { min-height: 76px; padding: 10px 12px; border: 1px dashed #bfc9c1; border-radius: 7px; background: #fafcfb; overflow-x: auto; }.math-preview small { display: block; margin-bottom: 4px; }.math-preview [data-math-preview] { min-height: 28px; }.math-preview [data-math-preview].empty { color: var(--muted); }.math-preview [data-math-preview].error { color: var(--danger); }.answer-options { display: flex; flex-wrap: wrap; gap: 10px 18px; border: 1px solid var(--line); border-radius: 8px; padding: 16px; }.answer-options legend { font-weight: 700; padding: 0 6px; }.answer-options small { flex-basis: 100%; }.answer-options label { display: flex; grid-template-columns: auto 1fr; align-items: center; gap: 6px; }.answer-options input { width: auto; }.admin-image-preview, .admin-choice-image-preview { display: grid; justify-items: start; gap: 10px; }.admin-image-preview img { max-width: 100%; max-height: 360px; border: 1px solid var(--line); border-radius: 8px; }.admin-choice-image-preview img { max-width: 100%; max-height: 240px; border: 1px solid var(--line); border-radius: 8px; }.builder-form .inline-check { display: flex; align-items: center; gap: 7px; }.builder-form .inline-check input { width: auto; }.admin-question-image { display: block; max-width: 240px; max-height: 150px; margin-top: 12px; border: 1px solid var(--line); border-radius: 7px; object-fit: contain; } code { background: #e9eeea; padding: 2px 5px; border-radius: 4px; }
footer { color: var(--muted); font-size: .8rem; padding-top: 24px; padding-bottom: 24px; border-top: 1px solid var(--line); }
.db-practice-intro { max-width: 780px; padding: 46px 0 38px; }
.db-practice-intro h1 { font-size: clamp(2.5rem, 6vw, 4.5rem); margin-bottom: 18px; }
.db-practice-intro > p:last-child { max-width: 700px; color: var(--muted); font-size: 1.05rem; }
.db-practice-layout { display: grid; grid-template-columns: 230px minmax(0, 1fr); gap: 24px; align-items: start; padding-bottom: 80px; }
.db-practice-sidebar, .db-workspace { background: white; border: 1px solid var(--line); border-radius: 12px; }
.db-practice-sidebar { position: sticky; top: 20px; padding: 20px; }
.db-progress-heading { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; font-size: .9rem; }
.db-progress-heading strong { color: var(--accent); }
.db-progress-track { height: 6px; overflow: hidden; margin-bottom: 20px; background: #e7ece9; border-radius: 999px; }
.db-progress-track span { display: block; width: 0; height: 100%; background: var(--accent); border-radius: inherit; transition: width .2s ease; }
.db-step-list { display: grid; gap: 5px; margin: 0; padding: 0; list-style: none; }
.db-step-list button { width: 100%; padding: 10px; color: var(--muted); background: transparent; border: 0; border-radius: 7px; cursor: pointer; font: inherit; text-align: left; }
.db-step-list button:hover, .db-step-list button[aria-current="step"] { color: var(--ink); background: var(--accent-soft); }
.db-step-list button span { display: inline-block; width: 32px; color: #91a096; font-size: .8rem; font-weight: 800; }
.db-step-list button.completed span { color: var(--accent); }
.db-step-list button.completed span::after { content: "✓"; margin-left: 3px; }
.db-reset { margin-top: 18px; padding: 0; color: var(--muted); background: transparent; border: 0; cursor: pointer; font: inherit; font-size: .78rem; text-decoration: underline; }
.db-workspace { min-width: 0; padding: 30px; }
.db-question[hidden] { display: none; }
.db-question-meta { display: flex; justify-content: space-between; gap: 12px; color: var(--muted); font-size: .8rem; font-weight: 700; }
.db-question-meta span:first-child { color: var(--accent); letter-spacing: .05em; }
.db-question h2 { margin: 12px 0 8px; font-size: 1.75rem; }
.db-question > p { margin-top: 0; color: var(--muted); }
.db-schema { display: flex; flex-wrap: wrap; gap: 7px; align-items: center; margin: 8px 0; padding: 10px 12px; background: #f0f4f1; border-radius: 7px; font-family: Consolas, monospace; font-size: .82rem; }
.db-schema span { margin-right: 5px; color: var(--accent); font-weight: 800; }
.db-schema code { background: white; border: 1px solid var(--line); }
.db-editor-label { display: block; margin: 24px 0 8px; font-size: .9rem; font-weight: 800; }
.db-editor { width: 100%; min-height: 210px; padding: 20px; color: #d9e7df; background: #17212b; border: 2px solid #17212b; border-radius: 9px; outline: none; resize: vertical; font: 500 .95rem/1.7 Consolas, "Courier New", monospace; tab-size: 2; }
.db-editor:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(22, 122, 97, .14); }
.db-editor::placeholder { color: #74818b; }
.db-answer-actions { display: flex; flex-wrap: wrap; }
.db-feedback { margin-top: 14px; padding: 12px 14px; border-radius: 7px; font-weight: 700; }
.db-feedback.success { color: #0d644e; background: var(--accent-soft); }
.db-feedback.error { color: #7b2424; background: #f9e3e3; }
.db-model-answer { overflow-x: auto; margin: 14px 0 0; padding: 18px; color: #d9e7df; background: #17212b; border-radius: 8px; white-space: pre; }
.db-model-answer code { padding: 0; background: transparent; }
.db-question-footer { display: flex; justify-content: space-between; align-items: center; margin-top: 20px; padding-top: 16px; border-top: 1px solid var(--line); }
.db-question-footer .button { margin: 0; }
.db-question-footer button:disabled { opacity: .45; cursor: not-allowed; }
.choice-line { display: flex; align-items: flex-start; gap: 6px; }.choice-line > input { flex: 0 0 auto; margin-top: .35em; }.choice-document { min-width: 0; flex: 1; }.choice-document .ql-container { border: 0; font: inherit; }.choice-document .ql-editor { min-height: 0; padding: 0; font: inherit; line-height: 1.5; }.choice-document .ql-editor p { margin: 0; }.choice-rich-editor { display: grid; gap: 7px; }.choice-rich-editor > label { font-weight: 700; }.choice-rich-editor .ql-editor { min-height: 90px; font-size: 1rem; line-height: 1.5; }
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }.question-prompt, .question-document { clear: both; margin-bottom: 18px; font-size: 1.16rem; font-weight: 700; }.question-prompt, .question-document-fallback { white-space: pre-wrap; }.question-document .ql-editor { padding: 0; font: inherit; line-height: 1.6; }.question-document .ql-container { border: 0; font: inherit; }.question-image-embed { margin: 16px 0; }.question-image-embed img { display: block; width: auto; max-width: 100%; max-height: 520px; border: 1px solid var(--line); border-radius: 8px; object-fit: contain; }.question-image-embed.ql-align-center img { margin-left: auto; margin-right: auto; }.question-image-embed.ql-align-right img { margin-left: auto; }.rich-question-editor { display: grid; gap: 10px; }.rich-question-editor > label { font-weight: 700; }.rich-question-editor .ql-editor { min-height: 220px; font-size: 1rem; }.rich-question-editor .question-image-embed { position: relative; }.rich-editor-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 10px; }.rich-editor-actions .button { margin: 0; }.content-image-manager { display: flex; flex-wrap: wrap; gap: 8px; }.content-image-item { display: flex; align-items: center; gap: 8px; padding: 7px 9px; border: 1px solid var(--line); border-radius: 7px; background: #f5f7f5; }.content-image-item button, .rich-math-toolbar button { padding: 5px 8px; border: 1px solid var(--line); border-radius: 5px; background: white; color: var(--ink); cursor: pointer; font: inherit; font-size: .82rem; }.content-image-item button { color: var(--danger); }.rich-math-toolbar { display: flex; flex-wrap: wrap; gap: 6px; }.rich-question-preview { margin-top: 2px; }
.admin-form-actions { display: flex; align-items: center; flex-wrap: wrap; }.question-preview-dialog { width: min(900px, calc(100% - 32px)); max-height: calc(100vh - 40px); padding: 0; color: var(--ink); background: var(--paper); border: 0; border-radius: 14px; box-shadow: 0 22px 70px rgba(23, 33, 43, .28); }.question-preview-dialog::backdrop { background: rgba(23, 33, 43, .58); }.question-preview-header { position: sticky; top: 0; z-index: 2; display: flex; justify-content: space-between; align-items: flex-start; gap: 20px; padding: 22px 26px 14px; background: var(--paper); border-bottom: 1px solid var(--line); }.question-preview-header h2 { margin: 0; }.preview-close { padding: 0 8px; color: var(--muted); background: transparent; border: 0; cursor: pointer; font-size: 2rem; line-height: 1; }.question-preview-card { margin: 22px 26px 18px; }.preview-question-document { min-height: 40px; }.preview-explanation { margin: 0 26px; white-space: pre-wrap; }.preview-explanation > div { margin-top: 5px; }.preview-footer { padding: 10px 26px 24px; text-align: right; }
.admin-auth { max-width: 520px; margin: 70px auto; padding: 34px; background: white; border: 1px solid var(--line); border-radius: 12px; }.admin-auth h1 { font-size: 2.5rem; }.admin-login-form { display: grid; gap: 14px; margin-top: 24px; }.admin-login-form label { display: grid; gap: 7px; font-weight: 700; }.admin-login-form input { font: inherit; border: 1px solid #bfc9c1; border-radius: 6px; padding: 11px; }
.notice { padding: 14px 16px; margin: 0 0 20px; border-radius: 8px; background: var(--accent-soft); }.notice.error { color: #7b2424; background: #f9e3e3; border: 1px solid #efb9b9; }.notice ul { margin: 0; padding-left: 20px; }
.admin-heading { display: flex; justify-content: space-between; align-items: end; gap: 24px; padding: 48px 0 28px; }.admin-heading h1 { font-size: 3.2rem; margin-bottom: 8px; }.admin-heading p:last-child { color: var(--muted); }.admin-heading-actions { display: flex; align-items: center; }.admin-heading-actions form { margin: 0; }
.admin-question-list { display: grid; gap: 14px; padding-bottom: 64px; }.admin-question-card { background: white; border: 1px solid var(--line); border-radius: 12px; padding: 22px; }.admin-question-card h2 { font-size: 1.1rem; margin: 10px 0; }.admin-question-card > p { color: var(--muted); margin: 0; }.admin-question-meta { display: flex; align-items: center; gap: 10px; color: var(--accent); font-size: .85rem; font-weight: 700; }.admin-question-actions { display: flex; margin-top: 12px; }.danger { color: white; background: var(--danger); }.empty-state { padding: 40px; text-align: center; color: var(--muted); background: white; border: 1px solid var(--line); border-radius: 12px; }
.admin-category-section { margin-bottom: 28px; }.admin-category-list { display: flex; flex-wrap: wrap; gap: 10px; }.admin-category-item { display: inline-flex; align-items: center; gap: 8px; padding: 9px 12px; background: white; border: 1px solid var(--line); border-radius: 8px; }.admin-category-item small { color: var(--muted); }
.admin-list-controls { display: flex; align-items: end; justify-content: space-between; gap: 20px; margin-bottom: 18px; }.admin-list-controls form { display: flex; align-items: end; gap: 10px; }.admin-list-controls label { display: grid; gap: 5px; font-weight: 700; }.admin-list-controls select { min-width: 210px; padding: 10px; border: 1px solid #bfc9c1; border-radius: 6px; background: white; font: inherit; }.admin-list-controls .button { margin: 0; }.admin-list-controls p { color: var(--muted); margin: 0; font-size: .9rem; }.pagination { display: flex; justify-content: center; align-items: center; flex-wrap: wrap; gap: 7px; padding: 0 0 64px; }.pagination a { min-width: 40px; padding: 8px 11px; text-align: center; background: white; border: 1px solid var(--line); border-radius: 7px; }.pagination a[aria-current="page"] { color: white; background: var(--accent); border-color: var(--accent); }
.admin-form-heading { padding-bottom: 10px; }.admin-question-form small { color: var(--muted); font-weight: 400; }.delete-confirmation { max-width: 760px; padding: 54px 0 72px; }.delete-confirmation h1 { font-size: 2.8rem; }.delete-warning { color: var(--danger); font-weight: 700; }
.category-delete-link { color: var(--danger); font-size: .8rem; font-weight: 700; }.word-bank { clear: both; display: flex; align-items: flex-start; gap: 12px; margin-bottom: 18px; padding: 12px 14px; background: var(--accent-soft); border: 1px solid #b8ddcc; border-radius: 8px; }.word-bank > b { flex: 0 0 auto; color: var(--accent); }.word-bank > div { display: flex; flex-wrap: wrap; gap: 7px; }.word-bank span { padding: 3px 9px; background: white; border: 1px solid #b8ddcc; border-radius: 999px; }.fill-blank-list { display: grid; gap: 14px; margin: 0; padding-left: 28px; }.fill-blank-list li { padding-left: 5px; }.fill-blank-list label { display: block; line-height: 2.8; }.fill-blank-list input { width: min(180px, 45vw); margin: 0 7px; padding: 7px 9px; border: 1px solid #9eaaa2; border-radius: 6px; font: inherit; }.fill-blank-builder-heading { display: flex; align-items: end; justify-content: space-between; gap: 16px; }.fill-blank-builder-heading > div { display: grid; gap: 5px; }.fill-blank-builder-heading .button { flex: 0 0 auto; margin: 0; }.fill-blank-item-list { display: grid; gap: 10px; }.fill-blank-builder-item { display: grid; grid-template-columns: auto minmax(0, 2fr) minmax(140px, 1fr) auto; align-items: end; gap: 10px; padding: 13px; border: 1px solid var(--line); border-radius: 8px; }.fill-blank-item-number { align-self: center; color: var(--accent); font-weight: 800; }.fill-blank-remove { padding: 10px; color: var(--danger); background: white; border: 1px solid var(--line); border-radius: 6px; cursor: pointer; font: inherit; font-weight: 700; }.fill-blank-result ol { display: grid; gap: 10px; padding-left: 24px; }.fill-blank-result li { padding: 10px 12px; border-left: 4px solid var(--danger); background: #f8eeee; border-radius: 5px; }.fill-blank-result li.correct { border-left-color: var(--accent); background: #edf7f2; }.fill-blank-result p { margin: 0 0 5px; white-space: pre-wrap; }
@media (max-width: 760px) { .db-practice-layout { grid-template-columns: 1fr; }.db-practice-sidebar { position: static; }.db-step-list { grid-template-columns: repeat(5, 1fr); }.db-step-list button { padding: 8px 4px; text-align: center; font-size: 0; }.db-step-list button span { width: auto; font-size: .82rem; }.db-workspace { padding: 22px; } }
@media (max-width: 620px) { .category-grid { grid-template-columns: 1fr; }.site-header, main, footer { padding-left: 18px; padding-right: 18px; }.site-nav { gap: 12px; }.hero { padding-top: 54px; }.admin-heading { align-items: flex-start; flex-direction: column; }.admin-heading h1 { font-size: 2.5rem; }.admin-heading-actions { flex-wrap: wrap; }.admin-list-controls, .admin-list-controls form { align-items: stretch; flex-direction: column; }.admin-list-controls select { width: 100%; }.admin-list-controls p { margin-top: 6px; }.fill-blank-builder-item { grid-template-columns: auto 1fr; }.fill-blank-builder-item label { grid-column: 2; }.fill-blank-builder-item .fill-blank-remove { grid-column: 2; justify-self: start; }.word-bank { flex-direction: column; }.db-practice-intro { padding-top: 30px; }.db-workspace { padding: 18px; }.db-question h2 { font-size: 1.45rem; }.db-editor { min-height: 180px; padding: 15px; } }
.question-type-fields[hidden] { display: none; }
.question-type-selection, .category-selection fieldset { display: flex; flex-wrap: wrap; gap: 10px 18px; border: 1px solid var(--line); border-radius: 8px; padding: 16px; }
.question-type-selection legend, .category-selection legend { font-weight: 700; padding: 0 6px; }
.builder-form .question-type-selection label, .category-selection label { display: inline-flex; align-items: center; gap: 6px; }
.builder-form .question-type-selection input, .category-selection input[type="checkbox"] { width: auto; }
.category-selection { display: grid; justify-items: start; gap: 12px; margin: 22px 0; }
.category-selection fieldset { margin: 0; }
.choice-editor-list { display: grid; gap: 16px; }
.choice-actions { display: flex; flex-wrap: wrap; gap: 8px; }
.choice-actions .button { margin: 0; }
.choice-actions .button:disabled { opacity: .5; cursor: not-allowed; }
[data-preview-choices][hidden], [data-preview-short-answer][hidden], [data-preview-fill-blank][hidden] { display: none; }