:root {
    --page-bg: #eef5fb;
    --panel-bg: #ffffff;
    --line: #d6e3f0;
    --line-strong: #b8cde2;
    --text-main: #18344e;
    --text-soft: #5d7287;
    --text-muted: #7f93a6;
    --brand: #2d74b6;
    --brand-deep: #1b4f88;
    --brand-soft: #e7f1fb;
    --success: #198754;
    --success-soft: #e7f6ee;
    --danger: #c94b4b;
    --danger-soft: #fdecec;
    --warn: #c27b12;
    --warn-soft: #fff6df;
    --shadow: 0 18px 40px rgba(22, 56, 87, 0.08);
    --radius-lg: 22px;
    --radius-md: 16px;
    --radius-sm: 12px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
    background:
        radial-gradient(circle at top left, rgba(94, 167, 255, 0.16), transparent 26%),
        radial-gradient(circle at top right, rgba(79, 188, 143, 0.12), transparent 22%),
        linear-gradient(180deg, #f4f9fd 0%, var(--page-bg) 100%);
    color: var(--text-main);
}

button,
input,
textarea,
select {
    font: inherit;
}

a {
    color: var(--brand);
    text-decoration: none;
}

.hidden {
    display: none !important;
}

.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 32px 18px;
}

.auth-card {
    width: min(1120px, 100%);
    background: rgba(255, 255, 255, 0.96);
    border: 1px solid rgba(184, 205, 226, 0.7);
    border-radius: 28px;
    box-shadow: var(--shadow);
    padding: 28px;
    backdrop-filter: blur(8px);
}

.auth-heading {
    margin: 0;
    font-size: 2rem;
    font-weight: 800;
    color: var(--brand-deep);
}

.auth-subheading {
    margin: 10px 0 0;
    color: var(--text-soft);
    line-height: 1.7;
}

.auth-seat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 18px;
    margin-top: 24px;
}

.seat-card {
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 18px;
    background: linear-gradient(180deg, #ffffff 0%, #f8fbfe 100%);
    display: flex;
    flex-direction: column;
    gap: 14px;
    min-height: 180px;
}

.seat-card h3 {
    margin: 0;
    font-size: 1.1rem;
}

.seat-card p {
    margin: 0;
    color: var(--text-soft);
    line-height: 1.6;
}

.badge-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    border-radius: 999px;
    padding: 6px 12px;
    font-size: 0.82rem;
    font-weight: 700;
    background: #eef4fa;
    color: var(--text-soft);
}

.badge.success {
    background: var(--success-soft);
    color: var(--success);
}

.badge.warn {
    background: var(--warn-soft);
    color: var(--warn);
}

.badge.danger {
    background: var(--danger-soft);
    color: var(--danger);
}

.badge.brand {
    background: var(--brand-soft);
    color: var(--brand-deep);
}

.auth-input {
    width: 100%;
    border: 1px solid var(--line-strong);
    border-radius: 14px;
    padding: 12px 14px;
    background: #fff;
    color: var(--text-main);
    outline: none;
}

.auth-input:focus,
.textarea-field:focus {
    border-color: var(--brand);
    box-shadow: 0 0 0 4px rgba(45, 116, 182, 0.12);
}

.auth-actions,
.toolbar-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.auth-btn,
.app-topbar-btn,
.action-btn {
    border: none;
    border-radius: 999px;
    padding: 10px 18px;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.18s ease, filter 0.18s ease, box-shadow 0.18s ease;
}

.auth-btn:hover,
.app-topbar-btn:hover,
.action-btn:hover {
    transform: translateY(-1px);
    filter: brightness(1.02);
}

.auth-btn.primary,
.app-topbar-btn.primary,
.action-btn.primary {
    background: linear-gradient(135deg, #2d74b6 0%, #1a548f 100%);
    color: #fff;
    box-shadow: 0 10px 18px rgba(45, 116, 182, 0.2);
}

.auth-btn.secondary,
.app-topbar-btn.secondary,
.action-btn.secondary {
    background: #edf4fb;
    color: var(--brand-deep);
    border: 1px solid #cfe0f2;
}

.auth-btn.danger,
.app-topbar-btn.danger,
.action-btn.danger {
    background: #fff1f1;
    color: var(--danger);
    border: 1px solid #f3c3c3;
}

.error-msg {
    color: var(--danger);
    min-height: 1.4rem;
    margin-top: 10px;
}

.app-shell {
    min-height: 100vh;
}

.app-topbar {
    position: sticky;
    top: 0;
    z-index: 20;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 18px;
    padding: 16px 22px;
    background: rgba(255, 255, 255, 0.92);
    border-bottom: 1px solid rgba(184, 205, 226, 0.8);
    backdrop-filter: blur(10px);
}

.app-topbar-title {
    font-size: 1.12rem;
    font-weight: 800;
    color: var(--brand-deep);
}

.page-body {
    max-width: 1400px;
    margin: 0 auto;
    padding: 24px 18px 30px;
}

.page-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.55fr) minmax(320px, 0.78fr);
    gap: 20px;
}

.panel {
    background: var(--panel-bg);
    border: 1px solid rgba(184, 205, 226, 0.7);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    padding: 20px;
}

.panel + .panel {
    margin-top: 18px;
}

.panel-title {
    margin: 0;
    font-size: 1.15rem;
    color: var(--brand-deep);
}

.panel-subtitle {
    margin: 8px 0 0;
    color: var(--text-soft);
    line-height: 1.7;
}

.meta-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
    gap: 12px;
    margin-top: 16px;
}

.meta-item {
    border-radius: var(--radius-sm);
    background: #f6fafe;
    border: 1px solid #dbe8f4;
    padding: 14px;
}

.meta-label {
    color: var(--text-muted);
    font-size: 0.82rem;
}

.meta-value {
    margin-top: 8px;
    font-weight: 800;
    font-size: 1rem;
    color: var(--text-main);
}

.section-block {
    margin-top: 22px;
}

.section-heading {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.section-heading h2,
.section-heading h3 {
    margin: 0;
    font-size: 1.12rem;
    color: var(--brand-deep);
}

.question-card {
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 18px;
    background: linear-gradient(180deg, #ffffff 0%, #f9fbfd 100%);
}

.question-card + .question-card {
    margin-top: 14px;
}

.question-title {
    margin: 0;
    font-size: 1.02rem;
    line-height: 1.7;
}

.question-label {
    color: var(--text-soft);
    font-size: 0.84rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.option-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 12px;
    margin-top: 14px;
}

.option-btn {
    width: 100%;
    text-align: left;
    padding: 14px 14px;
    border-radius: 14px;
    border: 1px solid var(--line);
    background: #fff;
    color: var(--text-main);
    cursor: pointer;
    transition: all 0.18s ease;
}

.option-btn:hover {
    border-color: #a9c4df;
    background: #f6fbff;
}

.option-btn.is-selected {
    border-color: var(--brand);
    background: var(--brand-soft);
}

.option-btn.is-correct {
    border-color: #9fd0b5;
    background: #ebf8f1;
}

.option-btn.is-wrong {
    border-color: #efb4b4;
    background: #fff3f3;
}

.feedback-box {
    margin-top: 14px;
    border-radius: 14px;
    padding: 12px 14px;
    line-height: 1.7;
    font-size: 0.92rem;
}

.feedback-box.info {
    background: #edf5fe;
    border: 1px solid #cfe0f2;
    color: var(--brand-deep);
}

.feedback-box.success {
    background: var(--success-soft);
    border: 1px solid #b7dfc7;
    color: var(--success);
}

.feedback-box.error {
    background: var(--danger-soft);
    border: 1px solid #f2c8c8;
    color: var(--danger);
}

.textarea-field {
    width: 100%;
    min-height: 140px;
    resize: vertical;
    border: 1px solid var(--line-strong);
    border-radius: 16px;
    padding: 14px;
    outline: none;
    background: #fff;
    color: var(--text-main);
    line-height: 1.8;
}

.save-hint {
    margin-top: 10px;
    color: var(--text-muted);
    font-size: 0.85rem;
}

.iframe-shell {
    margin-top: 14px;
    border-radius: 18px;
    overflow: hidden;
    border: 1px solid var(--line);
    background: #fff;
}

.deepseek-frame {
    width: 100%;
    height: 620px;
    border: none;
    display: block;
}

.student-list {
    display: grid;
    gap: 14px;
}

.student-row {
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 16px;
    background: #fff;
}

.student-row-head {
    display: flex;
    justify-content: space-between;
    gap: 14px;
    flex-wrap: wrap;
}

.student-row-title {
    margin: 0;
    font-size: 1rem;
}

.student-row-meta {
    margin-top: 8px;
    color: var(--text-soft);
    line-height: 1.7;
}

.progress-bar {
    width: 100%;
    height: 10px;
    border-radius: 999px;
    background: #edf3f8;
    overflow: hidden;
    margin-top: 10px;
}

.progress-bar > span {
    display: block;
    height: 100%;
    background: linear-gradient(90deg, #3a8dde 0%, #2fbe89 100%);
}

.view-tabs {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 16px;
}

.view-tab {
    padding: 10px 18px;
    border-radius: 999px;
    border: 1px solid #cfe0f2;
    background: #edf4fb;
    color: var(--brand-deep);
    font-weight: 700;
    cursor: pointer;
}

.view-tab.active {
    background: linear-gradient(135deg, #2d74b6 0%, #1a548f 100%);
    color: #fff;
    border-color: transparent;
}

.view-section {
    display: none;
}

.view-section.active {
    display: block;
}

.matrix-scroll {
    overflow: auto;
    border-radius: 18px;
    border: 1px solid var(--line);
    background: #fff;
}

.matrix-table {
    width: 100%;
    min-width: 780px;
    border-collapse: collapse;
}

.matrix-table th,
.matrix-table td {
    padding: 12px;
    border: 1px solid #dde7f0;
    vertical-align: top;
    text-align: left;
}

.matrix-table th {
    background: #eef5fb;
    color: var(--brand-deep);
}

.matrix-answer.good {
    color: var(--success);
    font-weight: 700;
}

.matrix-answer.bad {
    color: var(--danger);
    font-weight: 700;
}

.monitor-wall {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
}

.monitor-card {
    border: 1px solid var(--line);
    border-radius: 18px;
    overflow: hidden;
    background: #fff;
}

.monitor-card-head {
    padding: 14px 16px;
    border-bottom: 1px solid var(--line);
    background: #f7fbff;
}

.monitor-card-head h3 {
    margin: 0;
    font-size: 1rem;
}

.monitor-card-head p {
    margin: 8px 0 0;
    color: var(--text-soft);
    line-height: 1.6;
}

.monitor-iframe {
    width: 100%;
    height: 600px;
    border: none;
    display: block;
    background: #fff;
}

.mini-stat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 12px;
    margin-top: 14px;
}

.mini-stat {
    padding: 12px;
    border-radius: 14px;
    border: 1px solid var(--line);
    background: #fbfdff;
}

.mini-stat strong {
    display: block;
    margin-top: 6px;
    color: var(--brand-deep);
}

.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(12, 29, 46, 0.5);
    display: none;
    align-items: center;
    justify-content: center;
    padding: 18px;
    z-index: 50;
}

.modal-overlay.open {
    display: flex;
}

.modal-card {
    width: min(900px, 100%);
    max-height: 88vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    background: #fff;
    border-radius: 24px;
    box-shadow: 0 24px 54px rgba(13, 35, 57, 0.24);
}

.modal-head {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    padding: 18px 22px;
    border-bottom: 1px solid var(--line);
}

.modal-head h3 {
    margin: 0;
}

.modal-body {
    padding: 18px 22px;
    overflow: auto;
}

.close-btn {
    border: none;
    background: none;
    color: var(--text-soft);
    font-size: 1.6rem;
    cursor: pointer;
}

.readonly-mask {
    color: var(--text-muted);
    font-size: 0.86rem;
}

.answer-detail {
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 14px;
    background: #fcfdff;
}

.answer-detail + .answer-detail {
    margin-top: 14px;
}

.inline-list {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 12px;
}

@media (max-width: 1200px) {
    .page-grid {
        grid-template-columns: 1fr;
    }

    .monitor-wall {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .auth-card,
    .panel {
        padding: 18px;
        border-radius: 20px;
    }

    .app-topbar {
        flex-direction: column;
        align-items: stretch;
        padding: 14px 16px;
    }

    .deepseek-frame,
    .monitor-iframe {
        height: 520px;
    }

    .option-grid {
        grid-template-columns: 1fr;
    }
}