:root {
    --bg: #f5f5f7;
    --card: rgba(255, 255, 255, 0.78);
    --card-solid: #ffffff;
    --text: #1d1d1f;
    --muted: #6e6e73;
    --line: rgba(0, 0, 0, 0.08);
    --primary: #007aff;
    --primary-dark: #005fd1;
    --green: #34c759;
    --orange: #ff9500;
    --red: #ff3b30;
    --purple: #af52de;
    --shadow: 0 20px 60px rgba(0, 0, 0, 0.08);
    --radius: 24px;
}

[data-theme="dark"] {
    --bg: #0b0b0f;
    --card: rgba(28, 28, 30, 0.78);
    --card-solid: #1c1c1e;
    --text: #f5f5f7;
    --muted: #a1a1a6;
    --line: rgba(255, 255, 255, 0.1);
    --shadow: 0 20px 70px rgba(0, 0, 0, 0.45);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Tahoma, sans-serif;
    background:
        radial-gradient(circle at top left, rgba(0, 122, 255, 0.16), transparent 34%),
        radial-gradient(circle at bottom right, rgba(175, 82, 222, 0.14), transparent 30%),
        var(--bg);
    color: var(--text);
    min-height: 100vh;
}

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

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

.sidebar {
    width: 290px;
    padding: 22px;
    border-right: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.35);
    backdrop-filter: blur(24px);
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 20;
}

[data-theme="dark"] .sidebar {
    background: rgba(20, 20, 24, 0.55);
}

.brand {
    display: flex;
    gap: 14px;
    align-items: center;
    margin-bottom: 28px;
}

.brand-icon {
    width: 52px;
    height: 52px;
    border-radius: 18px;
    background: linear-gradient(135deg, var(--primary), var(--purple));
    display: grid;
    place-items: center;
    color: white;
    font-weight: 800;
    box-shadow: var(--shadow);
}

.brand h1 {
    font-size: 20px;
    margin: 0;
}

.brand p {
    margin: 4px 0 0;
    color: var(--muted);
    font-size: 13px;
}

.side-nav {
    display: grid;
    gap: 8px;
}

.side-nav a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 13px 14px;
    border-radius: 18px;
    color: var(--muted);
    font-weight: 650;
    transition: 0.2s;
}

.side-nav a:hover,
.side-nav a.active {
    background: var(--card-solid);
    color: var(--text);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.06);
}

.sidebar-footer {
    position: absolute;
    left: 22px;
    right: 22px;
    bottom: 22px;
}

.user-mini {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 20px;
}

.avatar {
    width: 42px;
    height: 42px;
    border-radius: 15px;
    background: var(--primary);
    color: white;
    display: grid;
    place-items: center;
    font-weight: 800;
}

.user-mini strong {
    display: block;
    font-size: 14px;
}

.user-mini a {
    color: var(--primary);
    font-size: 13px;
}

.main {
    flex: 1;
    margin-left: 290px;
    padding: 22px;
}

.topbar {
    height: 86px;
    background: var(--card);
    backdrop-filter: blur(24px);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 22px;
    position: sticky;
    top: 18px;
    z-index: 10;
}

.topbar h2 {
    margin: 0;
    font-size: 24px;
}

.topbar p {
    margin: 5px 0 0;
    color: var(--muted);
    font-size: 14px;
}

.topbar-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.menu-btn,
.theme-toggle {
    border: 0;
    border-radius: 16px;
    background: var(--card-solid);
    color: var(--text);
    width: 44px;
    height: 44px;
    cursor: pointer;
    box-shadow: 0 8px 18px rgba(0, 0, 0, 0.06);
}

.menu-btn {
    display: none;
}

.content {
    padding-top: 24px;
}

.grid {
    display: grid;
    gap: 18px;
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

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

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

.card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 22px;
    backdrop-filter: blur(24px);
}

.stat-card h3 {
    color: var(--muted);
    font-size: 14px;
    margin: 0 0 10px;
}

.stat-card strong {
    font-size: 34px;
}

.btn {
    border: 0;
    border-radius: 16px;
    padding: 12px 16px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 750;
    cursor: pointer;
    transition: 0.2s;
    gap: 8px;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

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

.btn-soft {
    background: var(--card-solid);
    color: var(--text);
    border: 1px solid var(--line);
}

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

.form-card {
    max-width: 980px;
}

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

.form-group {
    display: grid;
    gap: 8px;
}

label {
    font-weight: 700;
    color: var(--text);
}

input,
select,
textarea {
    width: 100%;
    border: 1px solid var(--line);
    background: var(--card-solid);
    color: var(--text);
    border-radius: 16px;
    padding: 13px 14px;
    outline: none;
    font-size: 15px;
}

textarea {
    resize: vertical;
    min-height: 120px;
}

input:focus,
select:focus,
textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.12);
}

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

.alert {
    padding: 14px 16px;
    border-radius: 18px;
    margin-bottom: 16px;
    font-weight: 650;
}

.alert-error {
    background: rgba(255, 59, 48, 0.12);
    color: var(--red);
}

.alert-success {
    background: rgba(52, 199, 89, 0.14);
    color: var(--green);
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
}

.project-card {
    overflow: hidden;
    padding: 0;
}

.project-cover {
    height: 190px;
    background: #ddd;
    overflow: hidden;
}

.project-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.project-body {
    padding: 18px;
}

.project-body h3 {
    margin: 0 0 8px;
    font-size: 20px;
}

.project-body p {
    color: var(--muted);
    margin: 0 0 14px;
    line-height: 1.6;
}

.badge-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 14px;
}

.badge {
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    padding: 6px 10px;
    font-size: 12px;
    font-weight: 800;
}

.status-completed {
    background: rgba(52, 199, 89, 0.14);
    color: var(--green);
}

.status-progress {
    background: rgba(0, 122, 255, 0.14);
    color: var(--primary);
}

.status-planning {
    background: rgba(175, 82, 222, 0.14);
    color: var(--purple);
}

.status-hold {
    background: rgba(255, 149, 0, 0.14);
    color: var(--orange);
}

.status-cancelled,
.status-overdue {
    background: rgba(255, 59, 48, 0.14);
    color: var(--red);
}

.status-todo,
.status-default {
    background: rgba(142, 142, 147, 0.16);
    color: var(--muted);
}

.priority-high {
    background: rgba(255, 59, 48, 0.14);
    color: var(--red);
}

.priority-medium {
    background: rgba(255, 149, 0, 0.14);
    color: var(--orange);
}

.priority-low {
    background: rgba(52, 199, 89, 0.14);
    color: var(--green);
}

.progress {
    height: 10px;
    background: rgba(142, 142, 147, 0.18);
    border-radius: 999px;
    overflow: hidden;
}

.progress span {
    height: 100%;
    display: block;
    background: linear-gradient(90deg, var(--primary), var(--purple));
    border-radius: inherit;
}

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

.table {
    width: 100%;
    border-collapse: collapse;
}

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

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

.auth-page {
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 24px;
}

.auth-card {
    width: 100%;
    max-width: 460px;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 30px;
    box-shadow: var(--shadow);
    padding: 28px;
    backdrop-filter: blur(24px);
}

.auth-logo {
    width: 64px;
    height: 64px;
    border-radius: 22px;
    background: linear-gradient(135deg, var(--primary), var(--purple));
    color: white;
    display: grid;
    place-items: center;
    font-weight: 900;
    margin-bottom: 18px;
}

.auth-card h1 {
    margin: 0 0 6px;
}

.auth-card p {
    color: var(--muted);
    margin: 0 0 20px;
}

.auth-links {
    text-align: center;
    margin-top: 18px;
    color: var(--muted);
}

.auth-links a {
    color: var(--primary);
    font-weight: 800;
}

.topic-box {
    border: 1px solid var(--line);
    border-radius: 22px;
    padding: 16px;
    background: var(--card-solid);
    margin-bottom: 14px;
}

.topic-box h3 {
    margin: 0 0 8px;
}

.task-list {
    display: grid;
    gap: 10px;
    margin-top: 12px;
}

.task-item {
    padding: 12px;
    border-radius: 16px;
    border: 1px solid var(--line);
    display: flex;
    justify-content: space-between;
    gap: 12px;
}

.empty {
    text-align: center;
    color: var(--muted);
    padding: 40px 20px;
}

@media (max-width: 1100px) {
    .grid-4,
    .grid-3,
    .project-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 760px) {
    .sidebar {
        transform: translateX(-105%);
        transition: 0.25s;
    }

    .sidebar.show {
        transform: translateX(0);
    }

    .main {
        margin-left: 0;
        padding: 14px;
    }

    .menu-btn {
        display: inline-grid;
        place-items: center;
    }

    .topbar {
        height: auto;
        align-items: flex-start;
        gap: 14px;
        flex-wrap: wrap;
    }

    .topbar-actions {
        width: 100%;
        justify-content: space-between;
    }

    .grid-4,
    .grid-3,
    .grid-2,
    .project-grid,
    .form-grid {
        grid-template-columns: 1fr;
    }

    .project-cover {
        height: 210px;
    }
}
.topic-with-image {
    overflow: hidden;
}

.topic-image-wrap {
    width: 100%;
    height: 260px;
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid var(--line);
    margin-bottom: 16px;
    background: var(--card-solid);
}

.topic-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}