:root {
    --bg: #f4faff;
    --bg-deep: #e9f5ff;
    --surface: rgba(255, 255, 255, 0.94);
    --surface-soft: #f8fcff;
    --blue-50: #eff8ff;
    --blue-100: #dcefff;
    --blue-200: #bddfff;
    --blue-300: #91c9f8;
    --blue-500: #559edc;
    --blue-600: #3d82bd;
    --blue-700: #2d668f;
    --ink: #29435a;
    --ink-soft: #637c91;
    --lavender: #8f8ed8;
    --pink: #d989a8;
    --pink-soft: #fff0f6;
    --danger: #bd5d70;
    --danger-soft: #fff0f2;
    --success: #4f917f;
    --border: #cfe4f5;
    --shadow: 0 16px 45px rgba(88, 139, 178, 0.13);
    --shadow-soft: 0 7px 24px rgba(88, 139, 178, 0.1);
    --radius-xl: 28px;
    --radius-lg: 20px;
    --radius-md: 14px;
    --radius-sm: 10px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    min-height: 100vh;
    color: var(--ink);
    background: linear-gradient(160deg, #f9fcff 0%, var(--bg) 42%, #eef7ff 100%);
    font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", system-ui, sans-serif;
    line-height: 1.65;
}

a { color: var(--blue-700); text-decoration: none; }
a:hover { color: var(--lavender); }
img { max-width: 100%; }
button, input, select, textarea { font: inherit; }

.page-bg { position: fixed; inset: 0; overflow: hidden; pointer-events: none; z-index: -1; }
.bubble { position: absolute; border: 2px solid rgba(145, 201, 248, .22); border-radius: 999px; }
.bubble-one { width: 260px; height: 260px; right: -80px; top: 12%; }
.bubble-two { width: 150px; height: 150px; left: -45px; bottom: 12%; }
.sparkle { position: absolute; color: rgba(143, 142, 216, .25); font-size: 40px; }
.sparkle-one { left: 7%; top: 20%; }
.sparkle-two { right: 8%; bottom: 18%; }
.chem-doodle { position: absolute; color: rgba(85, 158, 220, .10); line-height: 1; }
.chem-doodle-one { left: 2.5%; top: 48%; font-size: 92px; transform: rotate(-14deg); }
.chem-doodle-two { right: 3%; bottom: 3%; font-size: 70px; transform: rotate(12deg); }

.site-header { padding: 18px 24px 0; }
.nav-shell {
    width: min(1180px, 100%);
    margin: 0 auto;
    min-height: 72px;
    padding: 10px 12px 10px 16px;
    display: flex;
    align-items: center;
    gap: 18px;
    border: 1px solid rgba(189, 223, 255, .9);
    border-radius: 24px;
    background: rgba(255, 255, 255, .88);
    box-shadow: var(--shadow-soft);
    backdrop-filter: blur(16px);
}
.brand { display: flex; align-items: center; gap: 10px; min-width: 220px; color: var(--ink); }
.brand:hover { color: var(--ink); }
.brand-mark {
    width: 45px; height: 45px; display: grid; place-items: center;
    color: white; background: linear-gradient(145deg, var(--blue-300), var(--lavender));
    border-radius: 15px; font-size: 25px; box-shadow: 0 7px 18px rgba(85, 158, 220, .24);
}
.brand strong, .brand small { display: block; }
.brand strong { font-size: 16px; letter-spacing: .03em; }
.brand small { color: var(--ink-soft); font-size: 11px; margin-top: -2px; }
.main-nav { display: flex; align-items: center; justify-content: center; gap: 5px; flex: 1; }
.main-nav a, .nav-button {
    padding: 8px 13px; border: 0; border-radius: 12px; color: var(--ink-soft);
    background: transparent; cursor: pointer; white-space: nowrap;
}
.main-nav a:hover, .main-nav a.active, .nav-button:hover {
    color: var(--blue-700); background: var(--blue-50);
}
.main-nav a.active { font-weight: 700; box-shadow: inset 0 0 0 1px var(--blue-100); }
.account-area { display: flex; align-items: center; gap: 5px; }
.account-area form { margin: 0; }
.user-chip { padding: 7px 10px; color: var(--blue-700); background: #f2f9ff; border-radius: 12px; font-size: 13px; }

.page-shell { width: min(1120px, calc(100% - 40px)); margin: 34px auto 56px; }
.site-footer {
    width: min(1120px, calc(100% - 40px)); margin: 0 auto 28px; padding: 14px 20px;
    display: flex; justify-content: space-between; color: var(--ink-soft); font-size: 13px;
}

h1, h2, h3 { line-height: 1.3; color: #294f6d; }
h1 { margin: 0 0 20px; font-size: clamp(27px, 4vw, 40px); letter-spacing: .02em; }
h2 { font-size: 20px; }
h3 { font-size: 16px; }
.page-title-row { display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; margin-bottom: 20px; }
.page-title-row h1 { margin-bottom: 5px; }
.eyebrow { margin: 0 0 7px; color: var(--blue-600); font-size: 12px; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; }
.lead { margin: 0; color: var(--ink-soft); font-size: 15px; }

.hero {
    min-height: 420px; display: grid; grid-template-columns: minmax(0, .9fr) minmax(420px, 1.1fr);
    align-items: center; overflow: hidden; border: 1px solid var(--blue-100);
    border-radius: var(--radius-xl); background: var(--surface); box-shadow: var(--shadow);
}
.hero-copy { padding: clamp(28px, 5vw, 58px); z-index: 1; }
.hero-copy h1 { font-size: clamp(34px, 5vw, 54px); margin-bottom: 14px; }
.hero-copy h1 span { color: var(--blue-600); }
.hero-actions, .button-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-top: 22px; }
.hero-art { height: 100%; min-height: 420px; overflow: hidden; background: var(--blue-50); }
.hero-art img { width: 100%; height: 100%; object-fit: cover; display: block; }

.dashboard-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 22px; }
.quick-card, .stat-card, .form-card, .question-item, .panel, .login-card, .empty-state {
    border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--surface); box-shadow: var(--shadow-soft);
}
.quick-card { min-height: 165px; padding: 22px; transition: transform .2s ease, box-shadow .2s ease; }
.quick-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); color: var(--ink); }
.quick-icon { width: 42px; height: 42px; display: grid; place-items: center; border-radius: 14px; background: var(--blue-50); font-size: 22px; }
.quick-card h2 { margin: 16px 0 5px; }
.quick-card p { margin: 0; color: var(--ink-soft); }
.stats-strip { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 16px; }
.stat-card { padding: 16px 18px; display: flex; justify-content: space-between; align-items: center; }
.stat-card strong { font-size: 25px; color: var(--blue-600); }
.stat-card span { color: var(--ink-soft); font-size: 13px; }
.companion-ribbon {
    position: relative; min-height: 190px; margin-top: 18px; padding: 30px 38px 30px 270px;
    display: flex; align-items: center; overflow: hidden; border: 1px solid var(--blue-100);
    border-radius: var(--radius-xl); background: linear-gradient(110deg, rgba(255,255,255,.96), rgba(236,247,255,.92)); box-shadow: var(--shadow-soft);
}
.companion-ribbon h2 { margin: 0 0 8px; font-size: 23px; }
.companion-art { position: absolute; inset: 0 auto 0 0; width: 245px; overflow: hidden; }
.companion-art::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, transparent 58%, #f7fbff 100%); }
.companion-art img { width: 100%; height: 100%; object-fit: cover; object-position: 55% 72%; display: block; }
.ribbon-molecule { position: absolute; right: 30px; top: 16px; color: rgba(143,142,216,.12); font-size: 64px; transform: rotate(16deg); }

.button, button:not(.nav-button) {
    display: inline-flex; align-items: center; justify-content: center; gap: 6px;
    width: auto; min-height: 42px; padding: 9px 17px; margin: 0;
    border: 1px solid var(--blue-500); border-radius: 13px; color: white;
    background: linear-gradient(145deg, #6cb4ec, #578fd1); box-shadow: 0 7px 16px rgba(85, 158, 220, .2);
    cursor: pointer; text-decoration: none; transition: transform .18s ease, box-shadow .18s ease;
}
.button:hover, button:not(.nav-button):hover { color: white; transform: translateY(-2px); box-shadow: 0 10px 20px rgba(85, 158, 220, .25); }
.button.secondary, button.secondary {
    color: var(--blue-700); border-color: var(--blue-200); background: white; box-shadow: none;
}
.button.secondary:hover, button.secondary:hover { color: var(--blue-700); background: var(--blue-50); }
.button.danger, button.danger { color: white; border-color: var(--danger); background: var(--danger); }
button:disabled { opacity: .55; cursor: not-allowed; transform: none !important; }

label { display: block; margin: 0 0 6px; color: #385b76; font-size: 14px; font-weight: 700; }
input, select, textarea {
    width: 100%; padding: 11px 13px; color: var(--ink); border: 1px solid var(--border);
    border-radius: 12px; outline: 0; background: white; transition: border-color .18s ease, box-shadow .18s ease;
}
input:focus, select:focus, textarea:focus, .visual-editor:focus {
    border-color: var(--blue-300); box-shadow: 0 0 0 4px rgba(145, 201, 248, .2);
}
input[type="checkbox"] { width: auto; accent-color: var(--blue-500); }
.form-row { margin-top: 16px; }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px 20px; }
.form-card, .panel { margin-top: 18px; padding: 22px; }
.form-card h2, .panel h2 { margin-top: 0; }
.search-form { padding: 20px; border: 1px solid var(--border); border-radius: var(--radius-lg); background: rgba(255,255,255,.82); box-shadow: var(--shadow-soft); }
.search-companion { position: relative; padding-top: 74px; }
.search-companion .search-form { position: relative; z-index: 2; }
.search-companion > img {
    position: absolute; z-index: 1; top: 0; right: 24px; width: 260px; height: 150px;
    object-fit: cover; object-position: 63% 35%; border-radius: 34px 34px 0 0; filter: drop-shadow(0 8px 15px rgba(85,158,220,.12));
}
.filter-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }
.filter-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.meta, .help-text, .formula-note { color: var(--ink-soft); font-size: 13px; }
.formula-note { padding: 12px 14px; border-radius: 12px; background: var(--blue-50); }

.question-list { display: grid; gap: 15px; margin-top: 20px; }
.question-item { padding: 22px; transition: transform .18s ease, border-color .18s ease; }
.question-item:hover { transform: translateY(-2px); border-color: var(--blue-300); }
.question-item h2 { margin: 0 0 10px; }
.question-item p { margin: 9px 0 0; }
.tag-row { display: flex; flex-wrap: wrap; gap: 7px; align-items: center; }
.tag {
    display: inline-flex; padding: 4px 9px; color: var(--blue-700); border: 1px solid var(--blue-100);
    border-radius: 999px; background: var(--blue-50); font-size: 12px;
}
.tag.pink { color: #985671; border-color: #f4ccda; background: var(--pink-soft); }
.tag.lavender { color: #6766a6; border-color: #deddf7; background: #f4f3ff; }
.question-meta-stack { display: grid; gap: 8px; margin: 8px 0 2px; }
.meta-primary-row { gap: 8px; }
.topic-tag-row { gap: 6px; }
.question-meta-stack .tag {
    font-weight: 700;
    letter-spacing: .01em;
    border-width: 1px;
    box-shadow: 0 5px 14px rgba(67, 132, 196, .08);
}
.difficulty-tag { min-width: 78px; justify-content: center; }
.difficulty-easy { color: #147254; border-color: #b7ead4; background: #eafbf4; }
.difficulty-relatively_easy { color: #32712a; border-color: #cceaa3; background: #f3fbdf; }
.difficulty-medium { color: #8a5b00; border-color: #f4d179; background: #fff6d8; }
.difficulty-relatively_hard { color: #a64b18; border-color: #f0b083; background: #fff0e7; }
.difficulty-hard { color: #9b2142; border-color: #ef9bb0; background: #fff0f4; }
.round-tag { color: #5c5ea8; border-color: #d8d7fb; background: #f3f2ff; }
.stage-tag { color: #0f5f68; border-color: #9bdce2; background: #e8fbfd; }
.source-tag { color: #8d4860; border-color: #f3c5d4; background: #fff0f6; }
.topic-tag { color: #24577f; border-color: #c6dff3; background: #eef8ff; }
.topic-tag::before {
    content: "";
    width: 7px;
    height: 7px;
    margin-right: 3px;
    border-radius: 999px;
    background: currentColor;
    opacity: .82;
}
.topic-tag[data-category="无机化学"] { color: #2563a6; border-color: #bcd8f5; background: #edf7ff; }
.topic-tag[data-category="元素化学"] { color: #0f766e; border-color: #a9e5dc; background: #e8fbf8; }
.topic-tag[data-category="结构化学"] { color: #7c3aed; border-color: #d8c7ff; background: #f5f0ff; }
.topic-tag[data-category="晶体推断"] { color: #b45309; border-color: #f2ce8f; background: #fff6e7; }
.topic-tag[data-category="计算"] { color: #b91c1c; border-color: #f4b6b6; background: #fff1f1; }
.topic-tag[data-category="物理化学"] { color: #0369a1; border-color: #a8d8f0; background: #eef9ff; }
.topic-tag[data-category="有机化学"] { color: #15803d; border-color: #b9e6c8; background: #effbf1; }
.topic-tag[data-category="高级化学模块"] { color: #9333ea; border-color: #e3c4fb; background: #fbf2ff; }
.topic-tag[data-category="综合"] { color: #475569; border-color: #cbd5e1; background: #f8fafc; }
.empty-topic { color: #64748b; border-color: #dbe3ee; background: #f8fbff; }
.similar-source-card { margin-bottom: 14px; }
.similar-filter-card { margin: 14px 0 18px; }
.similar-filter-form { display: flex; flex-wrap: wrap; gap: 10px; align-items: end; }
.similar-filter-form label { font-weight: 800; color: var(--ink); }
.similar-filter-form select { min-width: 210px; }
.similar-question-item {
    display: grid;
    grid-template-columns: 112px minmax(0, 1fr);
    gap: 18px;
    align-items: start;
}
.similar-rank {
    display: grid;
    gap: 4px;
    justify-items: center;
    padding: 14px 10px;
    border: 1px solid #b9dcf6;
    border-radius: 18px;
    background: linear-gradient(180deg, #eef8ff, #f8fcff);
    color: var(--blue-700);
    box-shadow: 0 8px 18px rgba(63, 144, 214, .10);
}
.similar-rank span,
.similar-rank small { color: var(--ink-soft); font-size: 12px; }
.similar-rank strong { font-size: 28px; line-height: 1; }
.similar-question-body { min-width: 0; }

.upload-layout, .status-hero { display: grid; grid-template-columns: minmax(0, 1fr) 330px; gap: 22px; align-items: stretch; }
.upload-card { padding: 28px; border: 2px dashed var(--blue-200); border-radius: var(--radius-xl); background: rgba(255,255,255,.9); }
.upload-card input[type="file"] { padding: 18px; background: var(--blue-50); }
.upload-field-block { margin-top: 16px; }
.ai-model-panel {
    margin-top: 20px; padding: 18px; border: 1px solid #9fcdf4; border-radius: 18px;
    background: linear-gradient(180deg, #f1f9ff, #ffffff);
    box-shadow: 0 12px 26px rgba(83, 151, 210, .12);
}
.ai-model-head { display: flex; justify-content: space-between; gap: 16px; align-items: flex-start; }
.ai-model-panel h3 { margin: 0 0 6px; font-size: 18px; }
.ai-model-presets { display: flex; flex-wrap: wrap; gap: 8px; justify-content: flex-end; }
.ai-model-presets button { min-height: 36px; padding: 7px 12px; border-radius: 999px; font-size: 13px; }
.ai-model-grid { display: grid; gap: 10px; margin-top: 12px; }
.ai-model-row { display: grid; grid-template-columns: minmax(170px, .9fr) minmax(220px, 1fr); gap: 12px; align-items: center; padding: 10px 12px; border: 1px solid #d9ebf8; border-radius: 13px; background: white; }
.ai-model-row > span { color: #385b76; font-size: 13px; font-weight: 800; }
.ai-model-row ul { display: flex; flex-wrap: wrap; gap: 8px; margin: 0; padding: 0; list-style: none; }
.ai-model-row li { margin: 0; }
.ai-model-row label { display: inline-flex; align-items: center; gap: 6px; min-height: 34px; margin: 0; padding: 6px 12px; border: 1px solid var(--blue-200); border-radius: 999px; background: var(--blue-50); color: var(--blue-700); cursor: pointer; }
.ai-model-row input[type="radio"] { width: auto; margin: 0; accent-color: var(--blue-500); }
.ai-model-row label:has(input[type="radio"]:checked) {
    color: white; border-color: var(--blue-500); background: linear-gradient(145deg, #66afe9, #578fd1);
    box-shadow: 0 6px 14px rgba(85, 158, 220, .20);
}
.retry-model-details { width: 100%; max-width: 360px; padding: 9px 11px; border: 1px solid var(--blue-100); border-radius: 12px; background: #f8fcff; color: var(--ink-soft); font-size: 12px; }
.retry-model-details summary { cursor: pointer; color: var(--blue-700); font-weight: 800; }
.retry-model-details label { display: grid; grid-template-columns: 42px 1fr; gap: 8px; align-items: center; margin-top: 8px; font-size: 12px; }
.retry-model-details select { min-height: 34px; padding: 6px 8px; border-radius: 10px; font-size: 12px; }
.mascot-card { overflow: hidden; border: 1px solid var(--blue-100); border-radius: var(--radius-xl); background: var(--blue-50); box-shadow: var(--shadow-soft); }
.mascot-card img { width: 100%; height: 100%; min-height: 280px; object-fit: cover; display: block; }
.mascot-small { width: 92px; height: 92px; object-fit: cover; border-radius: 24px; border: 1px solid var(--blue-100); }

.progress-shell { position: relative; height: 30px; overflow: hidden; border: 1px solid var(--blue-200); border-radius: 999px; background: var(--blue-50); }
.progress-bar {
    min-width: 42px; height: 100%; display: flex; align-items: center; justify-content: center;
    color: white; background: linear-gradient(90deg, var(--blue-300), var(--lavender)); transition: width .35s ease;
}
.progress-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px 18px; }
.progress-details { margin-top: 16px; padding: 14px; border-radius: 14px; background: var(--surface-soft); }
.progress-details summary { cursor: pointer; color: var(--blue-700); font-weight: 700; }
#progress-events { max-height: 280px; overflow: auto; padding-left: 24px; color: var(--ink-soft); font-size: 13px; line-height: 1.65; }

.status-grid, .image-page-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.result-summary p:first-child { margin-top: 0; }
.result-celebration { position: relative; min-height: 128px; padding-right: 235px; overflow: hidden; display: flex; align-items: center; }
.result-celebration > div { position: relative; z-index: 1; min-width: 0; }
.result-celebration > img { position: absolute; right: 0; top: 0; width: 220px; height: 100%; object-fit: cover; object-position: 50% 42%; mask-image: linear-gradient(90deg, transparent 0%, black 28%); }
.result-question { display: flow-root; margin-top: 22px; overflow: hidden; }
.page-title-row.compact { align-items: center; }
.page-title-row.compact h2 { margin: 0; }
.actions-inline { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; }
.actions-inline form { margin: 0; }
.upload-history { margin-top: 24px; }
.history-list { display: grid; gap: 12px; }
.history-item { display: flex; justify-content: space-between; gap: 18px; align-items: center; padding: 16px 18px; border: 1px solid var(--blue-200); border-radius: 18px; background: rgba(255, 255, 255, .78); }
.history-main { min-width: 0; }
.history-main > strong { display: block; overflow-wrap: anywhere; margin-bottom: 9px; color: var(--blue-800); }
.history-status-lines { display: grid; gap: 7px; }
.history-status-row { display: flex; flex-wrap: wrap; gap: 7px; align-items: center; }
.history-status-row .tag { color: var(--blue-700); border-color: var(--blue-200); background: var(--blue-50); }
.history-status-lines + .meta { margin-top: 10px; }
@media (max-width: 760px) { .history-item { align-items: stretch; flex-direction: column; } }
.page-actions { margin-top: 22px; }
.inline-action-form { display: inline-flex; margin: 0; }
pre { max-width: 100%; margin: 12px 0 0; padding: 16px; overflow: auto; white-space: pre-wrap; overflow-wrap: anywhere; line-height: 1.65; border: 1px solid var(--border); border-radius: 14px; background: #fbfdff; }

.rich-content { white-space: pre-wrap; overflow-wrap: anywhere; line-height: 1.8; }
.rich-content img { display: block; max-width: 100%; height: auto; margin: 14px 0; border-radius: 12px; }
.rich-content [style*="text-align: center"] > img,
.rich-content [style*="text-align:center"] > img {
    margin-left: auto;
    margin-right: auto;
}
.rich-content .structure-option-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
    gap: 18px 20px;
    margin: 16px 0;
    white-space: normal;
}
.rich-content .structure-option-card {
    overflow: hidden;
    border: 1px solid var(--blue-200);
    border-radius: 16px;
    background: #fff;
    box-shadow: 0 8px 18px rgba(80, 150, 210, .08);
}
.rich-content .structure-option-label {
    padding: 10px 14px;
    color: var(--blue-800);
    border-bottom: 1px solid var(--blue-100);
    background: var(--blue-50);
    font-size: 18px;
    font-weight: 900;
    line-height: 1.2;
}
.rich-content .structure-option-card p {
    margin: 0;
    padding: 12px;
}
.rich-content .structure-option-card img {
    max-height: 260px;
    width: auto;
    max-width: 100%;
    margin: 0 auto;
    object-fit: contain;
}
.rich-content strong, .rich-content b { font-weight: 800; }
.rich-content .reaction-arrow {
    display: inline-grid; grid-template-rows: auto auto; align-items: end; justify-items: center;
    min-width: 3.2em; margin: 0 .2em; vertical-align: middle; line-height: 1;
}
.rich-content .reaction-arrow-label { padding: 0 .25em .08em; font-size: .78em; white-space: nowrap; }
.rich-content .reaction-arrow-glyph { font-size: 1.25em; line-height: .8; }
.rich-content .inline-fraction {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    vertical-align: middle;
    line-height: 1.05;
    margin: 0 .12em;
    white-space: nowrap;
}
.rich-content .inline-fraction-num { display: block; padding: 0 .22em .08em; border-bottom: 1px solid currentColor; }
.rich-content .inline-fraction-den { display: block; padding: .08em .22em 0; }
.rich-content .answer-key-table {
    width: 100%; margin: 12px 0 !important; overflow: hidden; border: 1px solid var(--blue-200);
    border-collapse: separate; border-spacing: 0; border-radius: 12px; background: #fff;
    table-layout: auto; white-space: normal;
}
.rich-content .answer-key-table td { padding: 12px 14px; border: 0; border-bottom: 1px solid var(--blue-100); vertical-align: top; }
.rich-content .answer-key-table tr:last-child td { border-bottom: 0; }
.rich-content .answer-key-table .answer-key-label {
    width: 88px; min-width: 88px; max-width: 120px; white-space: nowrap !important;
    word-break: keep-all !important; overflow-wrap: normal !important; text-align: left !important;
    color: var(--blue-800); background: var(--blue-50); font-weight: 800; font-variant-numeric: tabular-nums;
}
.rich-content .answer-key-table .answer-key-content { min-width: 0; text-align: left !important; overflow-wrap: anywhere; }
.rich-content .answer-key-table .answer-key-content > :first-child { margin-top: 0; }
.rich-content .answer-key-table .answer-key-content > :last-child { margin-bottom: 0; }
.rich-content .answer-subquestion-list { display: grid; gap: 14px; margin: 12px 0; white-space: normal; }
.rich-content .answer-subquestion-card {
    display: grid; grid-template-columns: minmax(76px, auto) minmax(0, 1fr); overflow: hidden;
    width: 100%; max-width: 100%; min-width: 0;
    border: 1px solid var(--blue-200); border-radius: 14px; background: #fff;
    box-shadow: 0 8px 24px rgba(91, 153, 213, .08);
}
.rich-content .answer-subquestion-label {
    display: flex; align-items: flex-start; justify-content: center; min-width: 76px; padding: 14px 16px;
    color: var(--blue-800); background: var(--blue-50); border-right: 1px solid var(--blue-100);
    font-weight: 800; font-variant-numeric: tabular-nums; white-space: nowrap;
}
.rich-content .answer-subquestion-content { min-width: 0; max-width: 100%; padding: 14px 16px; text-align: left; overflow-x: auto; overflow-wrap: anywhere; white-space: pre-wrap; }
.rich-content .answer-subquestion-content mjx-container { max-width: 100%; overflow-x: auto; overflow-y: hidden; }
.rich-content .answer-subquestion-content > :first-child { margin-top: 0; }
.rich-content .answer-subquestion-content > :last-child { margin-bottom: 0; }
.rich-content .answer-subquestion-empty { color: var(--muted); font-size: .94rem; }
.rich-content .question-subquestion-preamble { margin: 0 0 14px; white-space: pre-wrap; }
.rich-content .question-subquestion-list { display: grid; gap: 14px; margin: 12px 0; white-space: normal; }
.rich-content .question-subquestion-card {
    display: grid; grid-template-columns: minmax(76px, auto) minmax(0, 1fr); overflow: hidden;
    width: 100%; max-width: 100%; min-width: 0;
    border: 1px solid var(--border); border-radius: 14px; background: rgba(255, 255, 255, .92);
    box-shadow: 0 8px 24px rgba(91, 153, 213, .06);
}
.rich-content .question-subquestion-label {
    display: flex; align-items: flex-start; justify-content: center; min-width: 76px; padding: 14px 16px;
    color: var(--blue-800); background: rgba(231, 244, 255, .72); border-right: 1px solid var(--blue-100);
    font-weight: 800; font-variant-numeric: tabular-nums; white-space: nowrap;
}
.rich-content .question-subquestion-content { min-width: 0; max-width: 100%; padding: 14px 16px; text-align: left; overflow-x: auto; overflow-wrap: anywhere; white-space: pre-wrap; }
.rich-content .question-subquestion-content mjx-container { max-width: 100%; overflow-x: auto; overflow-y: hidden; }
.rich-content .question-subquestion-content > :first-child { margin-top: 0; }
.rich-content .question-subquestion-content > :last-child { margin-bottom: 0; }
.rich-content .question-subquestion-empty { color: var(--muted); font-size: .94rem; }
.rich-content .answer-letter-structure-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 14px;
    margin: 10px 0 18px;
    white-space: normal;
}
.rich-content .answer-letter-structure-item {
    overflow: hidden;
    border: 1px solid var(--blue-100);
    border-radius: 16px;
    background: rgba(255, 255, 255, .86);
}
.rich-content .answer-letter-structure-label {
    padding: 7px 12px;
    color: var(--blue-700);
    font-weight: 800;
    background: var(--blue-50);
    border-bottom: 1px solid var(--blue-100);
}
.rich-content .answer-letter-structure-visual { padding: 10px; text-align: center; }
.rich-content .answer-letter-structure-visual img { display: block; width: 100%; height: auto; margin: 0 auto; object-fit: contain; }
.rich-content .question-subquestion-line { margin: .55em 0; text-align: left !important; }
.rich-content .question-heading-line { margin: .8em 0 .55em; text-align: left; font-size: 1.08em; color: var(--ink); }
.rich-content .answer-source-crop { width: 100%; overflow: hidden; border-radius: 10px; background: #fff; }
.rich-content .answer-source-crop img { width: 100%; max-width: 100%; margin: 0; object-fit: contain; border-radius: 8px; }
@media (max-width: 560px) {
    .rich-content .question-subquestion-card { grid-template-columns: 1fr; }
    .rich-content .question-subquestion-label { justify-content: flex-start; border-right: 0; border-bottom: 1px solid var(--blue-100); }
    .rich-content .answer-subquestion-card { grid-template-columns: 1fr; }
    .rich-content .answer-subquestion-label { justify-content: flex-start; border-right: 0; border-bottom: 1px solid var(--blue-100); }
}
.detail-section { margin-top: 16px; padding: 20px; border: 1px solid var(--border); border-radius: var(--radius-lg); background: white; }
.detail-section h2 { margin-top: 0; }

.empty-state { padding: 28px; display: grid; grid-template-columns: 230px 1fr; gap: 24px; align-items: center; }
.empty-state img { width: 230px; border-radius: 20px; }
.empty-state h2 { margin-top: 0; }
.login-shell { min-height: 60vh; display: grid; place-items: center; }
.login-card { width: min(430px, 100%); padding: 30px; }
.login-card h1 { text-align: center; }
.login-intro { text-align: center; }
.login-mascot { display: block; width: 140px; height: 105px; margin: -5px auto 14px; object-fit: cover; object-position: center 20%; border-radius: 28px; }

.messages { margin: 0 0 18px; padding: 0; list-style: none; }
.messages li { padding: 12px 15px; color: #346e61; border: 1px solid #bfe2d8; border-radius: 13px; background: #effbf7; }
.errorlist, .form-errors { color: var(--danger); }
.errorlist { padding-left: 22px; }
.danger-panel { border-color: #efc2cb; background: var(--danger-soft); }

.proofread-layout { display: grid; grid-template-columns: minmax(380px, 1fr) minmax(420px, 1.08fr); gap: 20px; align-items: start; }
.proofread-editor, .proofread-original { min-width: 0; }
.proofread-original { position: sticky; top: 18px; max-height: calc(100vh - 36px); overflow: auto; padding: 18px; border: 1px solid var(--border); border-radius: var(--radius-lg); background: white; }
.hidden-proofread-source { display: none; }
.editor-toolbar { display: flex; flex-wrap: wrap; gap: 6px; margin: 8px 0; padding: 8px; border: 1px solid var(--border); border-radius: 12px; background: var(--blue-50); }
.editor-toolbar button { min-width: 36px; min-height: 34px; padding: 5px 9px; color: var(--blue-700); border-color: var(--blue-200); background: white; box-shadow: none; }
.visual-editor { min-height: 260px; padding: 13px; overflow: auto; border: 1px solid var(--border); border-radius: 12px; background: white; outline: 0; }
.visual-editor img.selected-proofread-image { outline: 3px solid var(--pink); outline-offset: 2px; }
.proofread-crop img { display: block; width: 100%; height: auto; border: 1px solid var(--border); border-radius: 12px; background: white; }
.crop-panel { margin-top: 18px; padding: 14px; border: 1px solid var(--border); border-radius: 14px; background: white; }
#crop-canvas { display: block; max-width: 100%; border: 1px solid var(--border); border-radius: 10px; background: #fafcff; cursor: crosshair; }
.crop-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.topic-checkbox-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
.checkbox-row { margin-top: 18px; }
.checkbox-row label { display: inline; margin-left: 6px; font-weight: 400; }
.hidden-topic-tags { display: none; }
.topic-picker { margin-top: 12px; padding: 16px; border: 1px solid var(--border); border-radius: 14px; background: var(--blue-50); }
.topic-picker-controls { display: grid; grid-template-columns: 1fr 1fr auto; gap: 8px; align-items: end; }
.topic-picker-message { min-height: 20px; margin-top: 8px; color: var(--danger); font-size: 13px; }
.selected-topic-list { display: flex; flex-wrap: wrap; gap: 7px; min-height: 44px; margin-top: 8px; padding: 10px; border: 1px dashed var(--blue-200); border-radius: 12px; background: white; }
.selected-topic-item { padding: 6px 10px; border-radius: 999px; background: var(--blue-50); color: var(--blue-700); }
.topic-pill { display: inline-flex; align-items: center; gap: 7px; padding: 6px 10px; border-radius: 999px; background: #eaf5ff; color: var(--blue-700); font-size: 13px; }
.topic-pill button { min-height: auto; padding: 0 3px; color: var(--blue-700); border: 0; background: transparent; box-shadow: none; }
.empty-selected-topics { color: var(--ink-soft); font-size: 13px; }
.proofread-heading-actions { display: flex; align-items: center; gap: 10px; }
.topic-score-details { margin-top: 14px; padding: 12px 14px; border: 1px solid var(--border); border-radius: 14px; background: var(--surface-soft); }
.topic-score-details summary { cursor: pointer; color: var(--blue-700); font-weight: 700; }
.topic-score-list { display: grid; gap: 8px; margin-top: 12px; }
.topic-score-row { display: grid; grid-template-columns: minmax(180px, 1fr) minmax(120px, 2fr) 52px; gap: 12px; align-items: center; font-size: 13px; }
.topic-score-row strong { text-align: right; font-variant-numeric: tabular-nums; }
.topic-vector-section { margin-top: 14px; }
.topic-vector-section > h4 { margin: 0 0 4px; color: var(--blue-800); }
.subquestion-vector-section { padding-top: 14px; border-top: 1px dashed var(--border); }
.subquestion-topic-vector { margin-top: 9px; padding: 10px 12px; border: 1px solid rgba(184, 220, 244, .9); border-radius: 12px; background: rgba(255, 255, 255, .78); }
.subquestion-topic-vector > summary { display: flex; align-items: center; gap: 10px; }
.subquestion-label { display: inline-flex; align-items: center; min-height: 25px; padding: 2px 10px; color: var(--blue-800); border-radius: 999px; background: #e4f4ff; font-weight: 800; }
.score-track { height: 9px; overflow: hidden; border-radius: 999px; background: var(--blue-100); }
.score-track i { display: block; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--blue-300), var(--lavender)); }
.evaluation-fields { margin: 0 0 18px; }

@keyframes mascot-float { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-6px); } }
@keyframes soft-pulse { 0%,100% { box-shadow: 0 0 0 0 rgba(145,201,248,.18); } 50% { box-shadow: 0 0 0 10px rgba(145,201,248,0); } }
.hero-art img, .mascot-card.processing img { animation: mascot-float 4.8s ease-in-out infinite; }
.progress-bar { animation: soft-pulse 2.4s ease-in-out infinite; }

@media (max-width: 900px) {
    .nav-shell { flex-wrap: wrap; }
    .brand { flex: 1; }
    .main-nav { order: 3; width: 100%; justify-content: flex-start; overflow-x: auto; }
    .hero { grid-template-columns: 1fr; }
    .hero-art { min-height: 320px; order: -1; }
    .dashboard-grid, .stats-strip { grid-template-columns: 1fr; }
    .companion-ribbon { padding-left: 220px; }
    .companion-art { width: 195px; }
    .filter-grid { grid-template-columns: repeat(2, 1fr); }
    .upload-layout, .status-hero { grid-template-columns: 1fr; }
    .mascot-card { max-height: 360px; }
    .proofread-layout { grid-template-columns: 1fr; }
    .proofread-original { position: static; max-height: none; }
}

@media (max-width: 620px) {
    .site-header { padding: 10px 10px 0; }
    .page-shell, .site-footer { width: min(100% - 20px, 1120px); }
    .page-shell { margin-top: 22px; }
    .brand small, .user-chip { display: none; }
    .main-nav a { padding: 7px 10px; }
    .account-area { margin-left: auto; }
    .hero-copy { padding: 25px 20px 30px; }
    .hero-art { min-height: 240px; }
    .companion-ribbon { min-height: 0; padding: 22px; }
    .companion-art { position: relative; width: 120px; height: 110px; margin: -10px auto 10px; border-radius: 28px; }
    .companion-art::after { display: none; }
    .companion-ribbon { display: block; text-align: center; }
    .search-companion { padding-top: 54px; }
    .search-companion > img { right: 10px; width: 190px; height: 110px; }
    .result-celebration { padding-right: 120px; }
    .result-celebration > img { width: 130px; }
    .filter-grid, .form-grid, .progress-grid, .topic-checkbox-list, .status-grid, .image-page-grid { grid-template-columns: 1fr; }
    .page-title-row { flex-direction: column; }
    .empty-state { grid-template-columns: 1fr; text-align: center; }
    .empty-state img { width: min(230px, 100%); margin: auto; }
    .topic-picker-controls { grid-template-columns: 1fr; }
    .proofread-heading-actions { width: 100%; justify-content: space-between; }
    .topic-score-row { grid-template-columns: 1fr 48px; }
    .topic-score-row .score-track { grid-column: 1 / -1; grid-row: 2; }
    .site-footer { flex-direction: column; gap: 4px; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}

.paper-list, .paper-builder { display: grid; gap: 16px; }
.paper-summary, .paper-basket-bar, .paper-item-head { display: flex; align-items: center; justify-content: space-between; gap: 18px; }
.paper-summary h2, .paper-item h2, .export-panel h2 { margin: 0 0 6px; }
.paper-settings, .export-panel { margin-bottom: 16px; }
.paper-settings > summary, .paper-item > details > summary { cursor: pointer; color: var(--blue-700); font-weight: 800; }
.paper-settings form { margin-top: 16px; }
.paper-settings-form, .paper-settings form { max-width: 820px; }
.paper-settings-form input[type="text"], .paper-settings-form input[type="date"], .paper-settings-form input[type="number"], .paper-settings-form textarea,
.paper-settings input[type="text"], .paper-settings input[type="date"], .paper-settings input[type="number"], .paper-settings textarea { width: 100%; }
.export-options { display: flex; flex-wrap: wrap; gap: 16px; align-items: center; }
.export-options label { display: inline-flex; align-items: center; gap: 6px; font-weight: 600; }
.export-warning, .export-ready, .export-note { margin: 12px 0 16px; padding: 12px 14px; border-radius: 12px; }
.export-warning { color: #8a4b08; border: 1px solid #f2c879; background: #fff8e7; }
.export-ready { color: #2f6d5f; border: 1px solid #bfe2d8; background: #effbf7; }
.export-note { color: #315f86; border: 1px solid #c7dff3; background: #f1f8fe; }
.export-options button:disabled { cursor: not-allowed; opacity: .5; box-shadow: none; }
.paper-item { padding: 20px; }
.paper-subquestion-list { display: grid; gap: 16px; margin: 16px 0; }
.paper-common-stem, .paper-parent-stem { margin: 16px 0; padding: 15px 17px; border-radius: 14px; }
.paper-common-stem { border: 1px solid #9fcbed; background: #edf7ff; }
.paper-parent-stem { margin-bottom: 0; border: 1px solid #c9dced; border-left: 5px solid #75add8; background: #f7fbfe; }
.paper-parent-stem strong { display: block; margin-bottom: 8px; color: var(--blue-700); }
.paper-subquestion-card { overflow: hidden; border: 1px solid #cfe3f5; border-radius: 15px; background: #fff; }
.paper-subquestion-title { padding: 10px 14px; color: var(--blue-700); border-bottom: 1px solid #dcebf7; background: #f2f8fe; }
.paper-subquestion-content-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
.paper-preview-block { min-width: 0; padding: 14px; }
.paper-preview-block + .paper-preview-block { border-left: 1px solid #e1edf7; }
.paper-preview-block.answer-block { background: #fffafb; }
.field-caption { display: block; margin-bottom: 8px; color: #668099; font-size: .84rem; font-weight: 800; }
.paper-subquestion-settings { display: grid; grid-template-columns: minmax(120px, .7fr) minmax(190px, 1.2fr) minmax(140px, .8fr); gap: 12px; padding: 12px 14px; border-top: 1px solid #dcebf7; background: #f8fbfe; }
.paper-subquestion-settings label { display: grid; gap: 6px; font-weight: 700; }
.paper-subquestion-settings input, .paper-subquestion-settings select { width: 100%; }
.raw-snapshot { margin: 16px 0; }
@media (max-width: 760px) {
  .paper-subquestion-content-grid, .paper-subquestion-settings { grid-template-columns: 1fr; }
  .paper-preview-block + .paper-preview-block { border-left: 0; border-top: 1px solid #e1edf7; }
}
.paper-item-head { align-items: flex-start; }
.drag-handle { cursor: grab; color: var(--blue-500); font-size: 28px; user-select: none; }
.paper-item details { margin: 14px 0; padding: 12px; border: 1px solid var(--border); border-radius: 12px; background: var(--surface-soft); }
.subquestion-config { margin: 14px 0; padding: 14px; border: 1px solid var(--border); border-radius: 14px; background: var(--blue-50); }
.subquestion-grid { display: grid; grid-template-columns: minmax(80px,.7fr) minmax(100px,.8fr) minmax(160px,1.2fr) minmax(90px,.6fr); gap: 10px; align-items: center; margin-bottom: 8px; }
.subquestion-grid.header { color: var(--ink-soft); font-size: 13px; font-weight: 700; }
.paper-order-save, .paper-basket-submit { position: sticky; bottom: 12px; z-index: 4; display: flex; justify-content: flex-end; margin: 14px 0; }
.paper-order-save button, .paper-basket-submit button { box-shadow: 0 8px 25px rgba(68,137,197,.22); }
.paper-basket-submit.bottom { margin-top: 18px; }
.question-pick { display: inline-flex; align-items: center; gap: 6px; margin-bottom: 8px; color: var(--blue-700); }
.question-pick:has(input:disabled) { color: #7890a6; }
.paper-basket-feedback { position: sticky; bottom: 76px; z-index: 5; margin: 10px 0; padding: 11px 15px; border: 1px solid #b8d9f3; border-radius: 13px; background: #eef8ff; color: #315f86; font-weight: 700; }
.paper-basket-feedback.success { border-color: #a9ddce; background: #edfbf6; color: #28705f; }
.paper-basket-feedback.error { border-color: #efbdc8; background: #fff1f4; color: #9d3f58; }

@media (max-width: 720px) {
    .paper-summary, .paper-basket-bar, .paper-item-head { align-items: stretch; flex-direction: column; }
    .subquestion-grid { grid-template-columns: 1fr 1fr; }
    .subquestion-grid.header { display: none; }
}