:root {
    --bg: #f4f7f6;
    --surface: #ffffff;
    --surface-alt: #ecf0f1;
    --text: #2c3e50;
    --muted: #7f8c8d;
    --primary: #2c3e50;
    --primary-strong: #1f2d3a;
    --accent: #34495e;
    --success: #27ae60;
    --danger: #c0392b;
    --border: #dcdcdc;
    --shadow: none;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    overflow-x: hidden;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
    line-height: 1.5;
    background: var(--bg);
    color: var(--text);
}

a {
    color: var(--primary);
}

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

.container {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
}

.site-header {
    border-bottom: 1px solid var(--border);
    background: var(--surface);
    position: sticky;
    top: 0;
    z-index: 20;
}

.topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 24px;
    padding: 16px 0;
}

.topbar h1 {
    overflow-wrap: anywhere;
}

.nav-list {
    list-style: none;
    display: flex;
    gap: 16px;
    align-items: center;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.nav-list a {
    text-decoration: none;
    color: inherit;
    padding: 8px 12px;
    border-radius: 2px;
    transition: background-color 0.2s;
}

.nav-list a:hover {
    background-color: var(--hover, rgba(0, 0, 0, 0.05));
}

.nav-account {
    list-style: none;
    position: relative;
}

.nav-account .user-menu {
    cursor: pointer;
}

.nav-account summary {
    padding: 8px 12px;
    border-radius: 2px;
    transition: background-color 0.2s;
    list-style: none;
}

.nav-account summary:hover {
    background-color: var(--hover, rgba(0, 0, 0, 0.05));
}

.nav-account .user-menu-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 2px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    margin-top: 8px;
    min-width: 180px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    z-index: 30;
}

.nav-account .user-menu-dropdown a {
    padding: 10px 16px;
    text-decoration: none;
    color: inherit;
    border-bottom: 1px solid var(--border);
    transition: background-color 0.2s;
}

.nav-account .user-menu-dropdown a:last-child {
    border-bottom: none;
}

.nav-account .user-menu-dropdown a:hover {
    background-color: var(--hover, rgba(0, 0, 0, 0.05));
}

.page-shell,
.auth-shell {
    padding: 32px 0 48px;
}

.hero {
    background: var(--primary);
    color: #fff;
    padding: 24px;
    margin-bottom: 24px;
}

.panel,
.auth-card,
.stat-card,
.action-card {
    background: var(--surface);
    border: 1px solid var(--border);
    padding: 20px;
}

.panel {
    overflow-x: auto;
}

.stats-grid,
.link-grid,
.admin-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}

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

.stat-card strong {
    display: block;
    font-size: 2rem;
    margin-top: 8px;
}

.assignment-card {
    border: 1px solid var(--border);
    padding: 16px;
    display: flex;
    justify-content: space-between;
    gap: 16px;
    background: var(--surface-alt);
    margin-bottom: 16px;
}

.assignment-main {
    min-width: 0;
    overflow-wrap: anywhere;
}

.assignment-side {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 12px;
    margin-top: 12px;
}

.assignment-meta,
.action-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
}

.single-action-form {
    display: inline-flex;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
}

.form-group-full {
    grid-column: 1 / -1;
}

.compact-form {
    grid-template-columns: 1fr;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.filter-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: flex-end;
    margin-bottom: 24px;
}

.filter-field {
    width: min(320px, 100%);
}

.section-stack {
    margin-bottom: 24px;
}

.stack {
    display: grid;
    gap: 16px;
}

.pill,
.badge {
    display: inline-block;
    padding: 4px 10px;
    background: #e1e5e7;
    font-size: 0.85rem;
}

.badge.success {
    background: #d4efdf;
    color: var(--success);
}

input,
select,
textarea {
    width: 100%;
    border: 1px solid var(--border);
    padding: 10px 12px;
    background: #fff;
}

.btn {
    border: 1px solid var(--primary);
    padding: 10px 16px;
    background: var(--primary);
    color: #fff;
    cursor: pointer;
    font-weight: 600;
    margin-top: 20px;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.btn:hover {
    background: var(--primary-strong);
}

.action-row .btn,
.single-action-form .btn {
    margin-top: 0;
}

.btn-secondary {
    background: var(--accent);
    border-color: var(--accent);
}

.btn-danger {
    background: var(--danger);
    border-color: var(--danger);
}

.btn-google {
    width: 100%;
    background: #fff;
    color: var(--text);
    border-color: var(--border);
}

.btn-google:hover {
    background: var(--surface-alt);
}

.auth-divider {
    margin: 20px 0 0;
    color: var(--muted);
    text-align: center;
}

.alert {
    padding: 12px 16px;
    margin-bottom: 16px;
    border: 1px solid var(--border);
    background: var(--surface);
}

.alert-success {
    border-color: var(--success);
    background: #eafaf1;
}

.alert-error {
    border-color: var(--danger);
    background: #fdecea;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 640px;
}

.data-table th,
.data-table td {
    text-align: left;
    padding: 10px;
    border-bottom: 1px solid var(--border);
    vertical-align: top;
    overflow-wrap: anywhere;
}

.site-footer {
    padding: 24px 0 32px;
    color: var(--muted);
}

.site-footer a:hover{
    text-decoration: none;
}


.section-tabs {
    display: flex;
    gap: 24px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 24px;
    overflow-x: auto;
    padding-bottom: 1px;
}

.section-tab {
    text-decoration: none;
    padding: 10px 0;
    color: var(--muted);
    font-weight: 600;
    border-bottom: 2px solid transparent;
    flex: 0 0 auto;
    white-space: nowrap;
}

.section-tab:hover {
    color: var(--primary);
}

.section-tab.active {
    color: var(--primary);
    border-bottom: 2px solid var(--primary);
}

@media (max-width: 900px) {
    .topbar {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .topbar nav,
    .nav-list {
        width: 100%;
    }

    .nav-list {
        justify-content: flex-start;
        gap: 8px;
    }

    .stats-grid,
    .link-grid,
    .admin-grid {
        grid-template-columns: 1fr;
    }

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

    .assignment-card {
        flex-direction: column;
        margin-bottom: 16px;
    }

    .assignment-side {
        align-items: flex-start;
    }

    .panel,
    .auth-card,
    .stat-card,
    .action-card {
        padding: 16px;
    }
}

@media (max-width: 640px) {
    .container {
        width: min(100% - 20px, 1120px);
    }

    .page-shell,
    .auth-shell {
        padding: 20px 0 36px;
    }

    .hero {
        padding: 18px;
        margin-bottom: 16px;
    }

    .nav-list a,
    .nav-account summary {
        padding: 7px 8px;
    }

    .nav-account .user-menu-dropdown {
        left: 0;
        right: auto;
    }

    .section-tabs {
        gap: 18px;
        margin-bottom: 18px;
    }

    .data-table {
        min-width: 560px;
    }

    .btn,
    .action-row .btn,
    .single-action-form,
    .single-action-form .btn {
        width: 100%;
    }

    .action-row {
        width: 100%;
    }

    .action-row .btn,
    .action-row form .btn {
        margin-top: 0;
    }

    .assignment-card {
        gap: 12px;
    }

    input,
    select,
    textarea {
        font-size: 16px;
    }
}