:root {
    --bg: #f4f7fb;
    --surface: #ffffff;
    --surface-soft: #f8fafc;
    --text: #172033;
    --muted: #6a7486;
    --line: #e5ebf3;
    --primary: #4061ff;
    --primary-dark: #2648e0;
    --green: #22a06b;
    --orange: #e88c22;
    --purple: #7a5af8;
    --danger: #d64545;
    --blue-soft: #eef3ff;
    --green-soft: #eefbf5;
    --orange-soft: #fff6ea;
    --purple-soft: #f4efff;
    --danger-soft: #fff1f1;
    --shadow: 0 18px 45px rgba(31, 52, 97, 0.08);
    --radius-lg: 24px;
    --radius-md: 18px;
    --radius-sm: 12px;
}

* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    min-height: 100%;
    font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    color: var(--text);
    background: radial-gradient(circle at top left, #eef4ff 0, #f4f7fb 42%, #f7f8fc 100%);
}

button,
input {
    font: inherit;
}

select,
textarea {
    font: inherit;
}

button {
    cursor: pointer;
}

a {
    color: inherit;
    text-decoration: none;
}

#app {
    min-height: 100vh;
}

.surface-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
}

.button {
    border: none;
    border-radius: 999px;
    padding: 12px 20px;
    background: var(--primary);
    color: #fff;
    font-weight: 600;
    transition: transform 0.15s ease, background 0.15s ease;
}

.button:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.button:disabled {
    opacity: 0.62;
    cursor: not-allowed;
    transform: none;
}

.button-secondary {
    background: #fff;
    color: var(--primary);
    border: 1px solid rgba(64, 97, 255, 0.18);
}

.button-secondary:hover {
    background: var(--blue-soft);
}

.button-ghost {
    background: transparent;
    color: var(--muted);
    border: 1px solid var(--line);
}

.button-ghost:hover {
    background: var(--surface-soft);
    color: var(--text);
}

.button-block {
    width: 100%;
}

.eyebrow {
    margin: 0 0 8px;
    font-size: 12px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--muted);
}

.toolbar-inline {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.marketing-page {
    padding: 28px;
}

.marketing-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 28px;
}

.brand-inline,
.brand-block {
    display: flex;
    align-items: center;
    gap: 14px;
}

.brand-mark {
    width: 42px;
    height: 42px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 14px;
    background: linear-gradient(135deg, var(--primary), #7f9cff);
    color: #fff;
    font-size: 20px;
    font-weight: 700;
}

.hero-section {
    display: grid;
    grid-template-columns: minmax(0, 1.3fr) minmax(300px, 0.9fr);
    gap: 24px;
    align-items: center;
    margin-bottom: 24px;
}

.hero-copy,
.hero-panel,
.feature-card {
    padding: 28px;
}

.hero-copy h1 {
    margin: 0 0 16px;
    font-size: clamp(34px, 5vw, 58px);
    line-height: 1.08;
}

.hero-text,
.page-subtitle,
.auth-text,
.feature-card p,
.insight-card p,
.metric-hint,
.section-note,
.simple-list-item p {
    color: var(--muted);
    line-height: 1.65;
}

.feature-list,
.checklist-list {
    margin: 0;
    padding-left: 18px;
    display: grid;
    gap: 10px;
    color: var(--text);
}

.marketing-grid,
.split-grid {
    display: grid;
    gap: 20px;
}

.marketing-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.auth-page {
    min-height: 100vh;
    padding: 28px;
    display: grid;
    grid-template-columns: minmax(320px, 520px) minmax(280px, 420px);
    justify-content: center;
    gap: 24px;
    align-items: center;
}

.auth-panel,
.auth-side .surface-card {
    padding: 28px;
}

.auth-form {
    display: grid;
    gap: 16px;
    margin: 24px 0 16px;
}

.auth-form label {
    display: grid;
    gap: 8px;
    font-weight: 600;
}

.auth-form input {
    border: 1px solid var(--line);
    border-radius: 16px;
    background: #fff;
    padding: 14px 16px;
    outline: none;
}

.auth-form input:focus {
    border-color: rgba(64, 97, 255, 0.35);
    box-shadow: 0 0 0 4px rgba(64, 97, 255, 0.08);
}

.auth-actions {
    display: grid;
    gap: 12px;
}

.inline-message {
    border-radius: 14px;
    padding: 12px 14px;
    font-size: 14px;
}

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

.dialog-overlay {
    position: fixed;
    inset: 0;
    z-index: 50;
    padding: 24px;
    background: rgba(15, 23, 42, 0.42);
    display: grid;
    place-items: center;
}

.dialog-window {
    width: min(760px, 100%);
    max-height: calc(100vh - 48px);
    overflow: auto;
    padding: 24px;
    display: grid;
    gap: 20px;
}

.dialog-head {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    align-items: flex-start;
}

.dialog-close {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--line);
    background: var(--surface-soft);
    color: var(--muted);
    font-size: 24px;
    line-height: 1;
}

.dialog-form,
.dialog-section {
    display: grid;
    gap: 16px;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
}

.form-field {
    display: grid;
    gap: 8px;
    font-weight: 600;
}

.form-field input,
.form-field select,
.form-field textarea {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 16px;
    background: #fff;
    padding: 14px 16px;
    outline: none;
}

.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
    border-color: rgba(64, 97, 255, 0.35);
    box-shadow: 0 0 0 4px rgba(64, 97, 255, 0.08);
}

.form-field textarea {
    resize: vertical;
}

.form-tip {
    margin: 0;
    color: var(--muted);
    font-size: 13px;
    line-height: 1.6;
}

.dialog-footer {
    display: flex;
    justify-content: flex-end;
    flex-wrap: wrap;
    gap: 12px;
}

.checkbox-list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
    max-height: 280px;
    overflow: auto;
}

.checkbox-row {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 14px;
    border-radius: 16px;
    background: var(--surface-soft);
    border: 1px solid var(--line);
    font-weight: 500;
}

.checkbox-row input {
    margin: 0;
}

.checkbox-row strong {
    margin-left: auto;
}

.dialog-summary-list {
    display: grid;
    gap: 12px;
}

.dialog-summary-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 14px;
    padding: 14px 16px;
    border-radius: 16px;
    background: var(--surface-soft);
    border: 1px solid var(--line);
}

.dialog-summary-item p {
    margin: 4px 0 0;
    color: var(--muted);
}

.app-shell {
    min-height: 100vh;
    display: grid;
    grid-template-columns: 300px minmax(0, 1fr);
}

.sidebar {
    padding: 28px 20px;
    border-right: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.82);
    backdrop-filter: blur(8px);
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.sidebar h1 {
    margin: 0;
    font-size: 24px;
}

.main-nav,
.sidebar-class-list {
    display: grid;
    gap: 10px;
}

.nav-item,
.class-link {
    width: 100%;
    text-align: left;
    padding: 14px 16px;
    border-radius: 16px;
    border: 1px solid transparent;
    background: transparent;
    color: var(--muted);
    transition: background 0.15s ease, color 0.15s ease, border 0.15s ease;
}

.nav-item:hover,
.class-link:hover {
    background: var(--surface-soft);
    color: var(--text);
    border-color: var(--line);
}

.nav-item.active,
.class-link.active {
    color: var(--primary);
    background: var(--blue-soft);
    border-color: rgba(64, 97, 255, 0.2);
}

.class-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.class-link small {
    color: inherit;
}

.sidebar-section {
    display: grid;
    gap: 12px;
}

.sidebar-plan {
    margin-top: auto;
    padding: 18px;
    border-radius: 18px;
    background: linear-gradient(180deg, #ffffff, #f6f8ff);
    border: 1px solid var(--line);
}

.sidebar-plan p {
    margin: 0;
    color: var(--muted);
}

.shell-main {
    padding: 28px;
}

.topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
    margin-bottom: 22px;
}

.topbar h2 {
    margin: 0;
    font-size: clamp(24px, 3vw, 34px);
}

.topbar-actions {
    display: flex;
    align-items: center;
    gap: 14px;
}

.profile-chip {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    border-radius: 999px;
    background: #fff;
    border: 1px solid var(--line);
}

.profile-avatar {
    width: 36px;
    height: 36px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--blue-soft);
    color: var(--primary);
    font-weight: 700;
}

.content-area {
    display: grid;
    gap: 20px;
}

.banner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    border-radius: 18px;
    padding: 14px 18px;
    border: 1px solid transparent;
}

.banner-info {
    background: var(--blue-soft);
    color: var(--primary-dark);
    border-color: rgba(64, 97, 255, 0.14);
}

.banner-danger {
    background: var(--danger-soft);
    color: var(--danger);
    border-color: rgba(214, 69, 69, 0.14);
}

.banner-close {
    border: none;
    background: transparent;
    color: inherit;
    font-weight: 600;
}

.page-head,
.section-head,
.card-head {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 16px;
}

.page-head h2,
.section-head h3,
.surface-card h3,
.surface-card h4 {
    margin: 0;
}

.section-block {
    display: grid;
    gap: 14px;
}

.metric-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
}

.compact-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.metric-card,
.mini-metric {
    padding: 22px;
}

.mini-metric {
    background: var(--surface-soft);
    border-radius: 18px;
    display: grid;
    gap: 10px;
}

.metric-label,
.mini-metric span {
    margin: 0;
    color: var(--muted);
    font-size: 14px;
}

.metric-value,
.mini-metric strong {
    margin: 0;
    font-size: clamp(24px, 3vw, 34px);
    font-weight: 700;
}

.tone-blue {
    background: linear-gradient(180deg, #ffffff, #f5f8ff);
}

.tone-green {
    background: linear-gradient(180deg, #ffffff, #f3fcf7);
}

.tone-orange {
    background: linear-gradient(180deg, #ffffff, #fff8ef);
}

.tone-purple {
    background: linear-gradient(180deg, #ffffff, #f7f3ff);
}

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

.class-card {
    padding: 22px;
    display: grid;
    gap: 18px;
}

.card-metrics {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
}

.card-metrics span {
    display: block;
    margin-bottom: 6px;
    color: var(--muted);
    font-size: 13px;
}

.card-metrics strong {
    font-size: 20px;
}

.pill,
.tag {
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    padding: 6px 12px;
    font-size: 12px;
    font-weight: 600;
}

.pill {
    background: var(--surface-soft);
    color: var(--muted);
}

.pill-warning {
    background: var(--orange-soft);
    color: var(--orange);
}

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

.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.tag {
    background: var(--blue-soft);
    color: var(--primary);
}

.timeline-card,
.checklist-card,
.tree-card,
.rewards-card,
.surface-card {
    padding: 22px;
}

.checklist-item {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text);
}

.check-icon {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--green-soft);
    color: var(--green);
    font-size: 12px;
    font-weight: 700;
}

.subsection {
    margin-top: 18px;
    display: grid;
    gap: 12px;
}

.empty-card {
    padding: 28px;
}

.empty-title {
    margin: 0 0 8px;
    font-size: 18px;
    font-weight: 700;
}

.empty-text {
    margin: 0;
    color: var(--muted);
    line-height: 1.65;
}

.timeline-list,
.simple-list {
    display: grid;
    gap: 14px;
}

.timeline-item,
.simple-list-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 14px;
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
}

.timeline-item:last-child,
.simple-list-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.timeline-item:first-child,
.simple-list-item:first-child {
    padding-top: 0;
}

.timeline-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--primary);
    flex-shrink: 0;
    margin-top: 6px;
}

.timeline-title,
.simple-list-item strong {
    margin: 0 0 4px;
}

.timeline-subtitle,
.timeline-time,
.simple-list-item time,
.simple-list-item span,
.section-note {
    color: var(--muted);
    font-size: 14px;
}

.split-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.split-grid-wide {
    align-items: start;
}

.insight-card {
    padding: 22px;
}

.progress-track {
    height: 10px;
    background: var(--surface-soft);
    border-radius: 999px;
    overflow: hidden;
    margin: 18px 0 14px;
}

.progress-fill {
    height: 100%;
    border-radius: inherit;
    background: linear-gradient(90deg, var(--primary), #8ea6ff);
}

.tree-highlight {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
}

.quick-action-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
}

.quick-action {
    text-align: left;
    border: 1px solid var(--line);
    background: var(--surface-soft);
    border-radius: 18px;
    padding: 18px;
    display: grid;
    gap: 10px;
}

.quick-action strong {
    font-size: 16px;
}

.quick-action span {
    color: var(--muted);
    line-height: 1.5;
}

.table-wrap {
    overflow-x: auto;
}

.student-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 880px;
}

.student-table th,
.student-table td {
    text-align: left;
    padding: 14px 10px;
    border-bottom: 1px solid var(--line);
    vertical-align: middle;
}

.student-table th {
    color: var(--muted);
    font-size: 13px;
    font-weight: 600;
}

.student-name-cell {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
}

.avatar-badge {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--blue-soft);
    color: var(--primary);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 700;
}

.text-success {
    color: var(--green);
}

.text-danger {
    color: var(--danger);
}

.loading-state,
.empty-state {
    min-height: 360px;
    display: grid;
    place-items: center;
    text-align: center;
    border: 1px dashed var(--line);
    border-radius: var(--radius-lg);
    background: rgba(255, 255, 255, 0.72);
    padding: 24px;
}

.loading-spinner {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    border: 4px solid rgba(64, 97, 255, 0.16);
    border-top-color: var(--primary);
    animation: spin 0.85s linear infinite;
    margin-bottom: 12px;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

@media (max-width: 1280px) {
    .metric-grid,
    .quick-action-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .class-grid,
    .split-grid,
    .marketing-grid,
    .hero-section {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 980px) {
    .app-shell {
        grid-template-columns: 1fr;
    }

    .sidebar {
        border-right: none;
        border-bottom: 1px solid var(--line);
    }

    .topbar,
    .page-head,
    .section-head,
    .card-head {
        flex-direction: column;
    }

    .auth-page {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 680px) {
    .marketing-page,
    .shell-main,
    .sidebar,
    .auth-page {
        padding: 18px;
    }

    .metric-grid,
    .compact-grid,
    .form-grid,
    .quick-action-grid,
    .card-metrics,
    .tree-highlight,
    .checkbox-list {
        grid-template-columns: 1fr;
    }

    .profile-chip {
        width: 100%;
        justify-content: center;
    }

    .topbar-actions {
        width: 100%;
        flex-direction: column;
        align-items: stretch;
    }
}