/* =====================================================================
   Course Dashboard - Main Stylesheet
   Notion-style personal workspace, light & dark theme support
   ===================================================================== */

:root {
    --bg: #f7f7f5;
    --bg-secondary: #ffffff;
    --bg-sidebar: #ffffff;
    --bg-hover: #f1f1ef;
    --text: #1f1f1f;
    --text-secondary: #6b6b6b;
    --border: #e9e9e7;
    --accent: #5b6cf0;
    --accent-hover: #4756c9;
    --accent-soft: #eef0fe;
    --success: #2e9e5b;
    --warning: #d9a300;
    --danger: #e25555;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --sidebar-width: 250px;
}

[data-theme="dark"] {
    --bg: #191919;
    --bg-secondary: #232323;
    --bg-sidebar: #1f1f1f;
    --bg-hover: #2a2a2a;
    --text: #e8e8e6;
    --text-secondary: #9b9b99;
    --border: #2f2f2f;
    --accent: #7c8cff;
    --accent-hover: #98a4ff;
    --accent-soft: #262a45;
    --success: #4cbf81;
    --warning: #e6bd4d;
    --danger: #f08080;
    --shadow: 0 1px 3px rgba(0,0,0,0.4);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.5);
}

* { box-sizing: border-box; }

body {
    background-color: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
    font-size: 15px;
    transition: background-color .2s ease, color .2s ease;
}

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

h1, h2, h3, h4, h5, h6 { font-weight: 700; letter-spacing: -0.01em; }

/* ===================== LAYOUT ===================== */
.app-wrapper {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-sidebar);
    border-right: 1px solid var(--border);
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 1030;
    display: flex;
    flex-direction: column;
    transition: transform .25s ease;
    overflow-y: auto;
}

.sidebar-brand {
    padding: 1.25rem 1.25rem 0.75rem;
    font-weight: 800;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.sidebar-brand .brand-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background: linear-gradient(135deg, var(--accent), #8fa1ff);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 800;
    font-size: 0.95rem;
}

.sidebar-nav {
    padding: 0.5rem 0.75rem;
    flex: 1;
}

.sidebar-nav .nav-link {
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    padding: 0.55rem 0.75rem;
    margin-bottom: 2px;
    font-weight: 500;
    font-size: 0.92rem;
    display: flex;
    align-items: center;
    gap: 0.65rem;
    transition: background-color .15s ease, color .15s ease;
}

.sidebar-nav .nav-link i { width: 18px; text-align: center; font-size: 1rem; }

.sidebar-nav .nav-link:hover {
    background-color: var(--bg-hover);
    color: var(--text);
}

.sidebar-nav .nav-link.active {
    background-color: var(--accent-soft);
    color: var(--accent);
    font-weight: 600;
}

.sidebar-section-title {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
    padding: 1rem 0.85rem 0.35rem;
    font-weight: 700;
}

.sidebar-footer {
    padding: 0.85rem 1.25rem;
    border-top: 1px solid var(--border);
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.main-content {
    margin-left: var(--sidebar-width);
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
}

.topbar {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 1.5rem;
    position: sticky;
    top: 0;
    z-index: 1020;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.topbar .search-box {
    flex: 1;
    max-width: 420px;
    position: relative;
}

.topbar .search-box input {
    background-color: var(--bg);
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: var(--radius-sm);
    padding: 0.45rem 0.85rem 0.45rem 2.25rem;
    width: 100%;
    font-size: 0.9rem;
}

.topbar .search-box i {
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

#searchResults {
    position: absolute;
    top: calc(100% + 6px);
    left: 0;
    right: 0;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
    max-height: 360px;
    overflow-y: auto;
    z-index: 1050;
    display: none;
}

#searchResults a {
    display: block;
    padding: 0.55rem 0.85rem;
    color: var(--text);
    border-bottom: 1px solid var(--border);
    font-size: 0.85rem;
}

#searchResults a:last-child { border-bottom: none; }
#searchResults a:hover { background-color: var(--bg-hover); }
#searchResults .result-type {
    font-size: 0.7rem;
    text-transform: uppercase;
    color: var(--accent);
    font-weight: 700;
    letter-spacing: 0.05em;
    margin-right: 0.4rem;
}

.content-area {
    padding: 1.5rem;
    flex: 1;
}

.theme-toggle, .sidebar-toggle {
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text);
    width: 38px;
    height: 38px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background-color .15s ease;
}

.theme-toggle:hover, .sidebar-toggle:hover { background-color: var(--bg-hover); }

.sidebar-toggle { display: none; }

/* ===================== CARDS ===================== */
.card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.card-header {
    background-color: transparent;
    border-bottom: 1px solid var(--border);
    font-weight: 700;
}

.stat-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.1rem 1.25rem;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    height: 100%;
}

.stat-card .stat-icon {
    width: 38px;
    height: 38px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    margin-bottom: 0.35rem;
}

.stat-card .stat-value {
    font-size: 1.6rem;
    font-weight: 800;
}

.stat-card .stat-label {
    color: var(--text-secondary);
    font-size: 0.82rem;
}

.bg-icon-accent { background-color: var(--accent-soft); color: var(--accent); }
.bg-icon-success { background-color: rgba(46,158,91,0.12); color: var(--success); }
.bg-icon-warning { background-color: rgba(217,163,0,0.12); color: var(--warning); }
.bg-icon-danger { background-color: rgba(226,85,85,0.12); color: var(--danger); }

/* ===================== PROGRESS BARS ===================== */
.progress {
    background-color: var(--bg-hover);
    border-radius: 999px;
    height: 10px;
    overflow: hidden;
}

.progress-bar {
    background: linear-gradient(90deg, var(--accent), #8fa1ff);
    border-radius: 999px;
}

.progress-thin { height: 6px; }

/* ===================== BADGES ===================== */
.badge-status-notstarted { background-color: rgba(155,155,153,0.18); color: var(--text-secondary); }
.badge-status-draft { background-color: rgba(217,163,0,0.15); color: var(--warning); }
.badge-status-progress { background-color: var(--accent-soft); color: var(--accent); }
.badge-status-review { background-color: rgba(226,85,85,0.12); color: var(--danger); }
.badge-status-completed { background-color: rgba(46,158,91,0.14); color: var(--success); }

.badge-priority-high { background-color: rgba(226,85,85,0.12); color: var(--danger); }
.badge-priority-medium { background-color: rgba(217,163,0,0.15); color: var(--warning); }
.badge-priority-low { background-color: rgba(46,158,91,0.14); color: var(--success); }

.badge {
    font-weight: 600;
    font-size: 0.72rem;
    padding: 0.32em 0.65em;
    border-radius: 6px;
}

/* ===================== BUTTONS ===================== */
.btn {
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.88rem;
}

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

.btn-primary:hover, .btn-primary:focus {
    background-color: var(--accent-hover);
    border-color: var(--accent-hover);
}

.btn-outline-secondary {
    border-color: var(--border);
    color: var(--text);
}

.btn-outline-secondary:hover {
    background-color: var(--bg-hover);
    color: var(--text);
    border-color: var(--border);
}

.btn-light-icon {
    background-color: var(--bg-hover);
    border: none;
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    width: 34px;
    height: 34px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.btn-light-icon:hover { color: var(--text); }

/* ===================== FORMS ===================== */
.form-control, .form-select {
    background-color: var(--bg);
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: var(--radius-sm);
}

.form-control:focus, .form-select:focus {
    background-color: var(--bg);
    color: var(--text);
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

.form-label { font-weight: 600; font-size: 0.85rem; }

textarea.form-control { min-height: 100px; }

/* ===================== MODALS ===================== */
.modal-content {
    background-color: var(--bg-secondary);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.modal-header, .modal-footer { border-color: var(--border); }
.btn-close { filter: var(--btn-close-filter, none); }
[data-theme="dark"] .btn-close { filter: invert(1) grayscale(100%) brightness(200%); }

/* ===================== MODULE / LESSON LISTS ===================== */
.module-card {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background-color: var(--bg-secondary);
    margin-bottom: 0.85rem;
    overflow: hidden;
}

.module-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.25rem;
    cursor: pointer;
}

.module-header:hover { background-color: var(--bg-hover); }

.module-header .drag-handle { color: var(--text-secondary); cursor: grab; }

.module-title { font-weight: 700; flex: 1; }
.module-meta { font-size: 0.8rem; color: var(--text-secondary); }

.module-body {
    border-top: 1px solid var(--border);
    padding: 0.75rem 1.25rem 1.1rem;
    display: none;
}

.module-body.show { display: block; }

.lesson-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.65rem 0.75rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    margin-bottom: 0.5rem;
    background-color: var(--bg);
}

.lesson-row:hover { border-color: var(--accent); }
.lesson-row .lesson-title { font-weight: 600; flex: 1; }
.lesson-row .lesson-meta { font-size: 0.78rem; color: var(--text-secondary); }

.chevron { transition: transform .2s ease; }
.chevron.rotated { transform: rotate(90deg); }

/* ===================== CHECKLIST ===================== */
.checklist-item {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.4rem 0;
    border-bottom: 1px solid var(--border);
}

.checklist-item:last-child { border-bottom: none; }
.checklist-item label { cursor: pointer; flex: 1; }
.checklist-item.checked label { text-decoration: line-through; color: var(--text-secondary); }

/* ===================== EDITOR ===================== */
.editor-toolbar {
    background-color: var(--bg);
    border: 1px solid var(--border);
    border-bottom: none;
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
    padding: 0.4rem 0.5rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
}

.editor-toolbar button {
    background: none;
    border: 1px solid transparent;
    border-radius: 6px;
    color: var(--text-secondary);
    width: 32px;
    height: 32px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
}

.editor-toolbar button:hover { background-color: var(--bg-hover); color: var(--text); }
.editor-toolbar button.active { background-color: var(--accent-soft); color: var(--accent); }

.editor-content {
    border: 1px solid var(--border);
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    min-height: 320px;
    padding: 1rem;
    background-color: var(--bg-secondary);
    outline: none;
    line-height: 1.6;
}

.editor-content:focus { border-color: var(--accent); }
.editor-content pre {
    background-color: var(--bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 0.75rem;
    overflow-x: auto;
}

.editor-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    font-size: 0.78rem;
    color: var(--text-secondary);
    margin-top: 0.6rem;
}

#autosaveStatus { font-size: 0.78rem; color: var(--text-secondary); transition: opacity .3s ease; }
#autosaveStatus.saving { color: var(--warning); }
#autosaveStatus.saved { color: var(--success); }

/* ===================== TREE VIEW ===================== */
.tree { list-style: none; padding-left: 0; }
.tree ul { list-style: none; padding-left: 1.4rem; }
.tree li { margin: 0.2rem 0; }
.tree .tree-toggle { cursor: pointer; color: var(--text-secondary); width: 16px; display: inline-block; }
.tree .tree-label { font-weight: 600; }
.tree .tree-children { display: none; }
.tree .tree-children.show { display: block; }

/* ===================== ACTIVITY LIST ===================== */
.activity-item {
    display: flex;
    gap: 0.75rem;
    padding: 0.6rem 0;
    border-bottom: 1px solid var(--border);
    font-size: 0.86rem;
}

.activity-item:last-child { border-bottom: none; }
.activity-item .activity-icon {
    width: 32px; height: 32px;
    border-radius: 50%;
    background-color: var(--accent-soft);
    color: var(--accent);
    display: flex; align-items: center; justify-content: center;
    flex-shrink: 0;
    font-size: 0.85rem;
}

/* ===================== FILE MANAGER ===================== */
.file-card {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background-color: var(--bg-secondary);
    padding: 0.85rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    height: 100%;
}

.file-card .file-preview {
    height: 110px;
    border-radius: var(--radius-sm);
    background-color: var(--bg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--text-secondary);
    overflow: hidden;
}

.file-card .file-preview img { width: 100%; height: 100%; object-fit: cover; }
.file-card .file-name { font-weight: 600; font-size: 0.85rem; word-break: break-word; }
.file-card .file-meta { font-size: 0.75rem; color: var(--text-secondary); }

/* ===================== AUTH PAGES ===================== */
.auth-wrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--accent-soft), var(--bg));
}

.auth-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    padding: 2.25rem;
    width: 100%;
    max-width: 400px;
}

.auth-card .brand-icon {
    width: 46px;
    height: 46px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--accent), #8fa1ff);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 800;
    font-size: 1.3rem;
    margin-bottom: 1rem;
}

/* ===================== UTILITIES ===================== */
.text-muted-soft { color: var(--text-secondary); }
.fade-in { animation: fadeIn .25s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: translateY(0); } }

/* ===================== DARK MODE CONTRAST FIXES ===================== */
[data-theme="dark"] {
    --bg: #151515;
    --bg-secondary: #222222;
    --bg-sidebar: #1d1d1d;
    --bg-hover: #303030;
    --text: #f2f2ee;
    --text-secondary: #c2c2bc;
    --border: #3a3a3a;
    color-scheme: dark;
}

[data-theme="dark"] body,
[data-theme="dark"] .content-area,
[data-theme="dark"] .card,
[data-theme="dark"] .module-card,
[data-theme="dark"] .module-header,
[data-theme="dark"] .module-body,
[data-theme="dark"] .tree,
[data-theme="dark"] .tree li,
[data-theme="dark"] .tree .tree-label,
[data-theme="dark"] .lesson-title,
[data-theme="dark"] .lesson-meta,
[data-theme="dark"] .form-label,
[data-theme="dark"] .dropdown-menu,
[data-theme="dark"] .dropdown-item,
[data-theme="dark"] .dropdown-item-text {
    color: var(--text) !important;
}

[data-theme="dark"] .text-muted,
[data-theme="dark"] .text-muted-soft,
[data-theme="dark"] .module-meta,
[data-theme="dark"] .lesson-meta,
[data-theme="dark"] .form-text,
[data-theme="dark"] .tree .tree-toggle {
    color: var(--text-secondary) !important;
}

[data-theme="dark"] a,
[data-theme="dark"] .lesson-title a,
[data-theme="dark"] .tree a {
    color: #aeb8ff;
}

[data-theme="dark"] a:hover,
[data-theme="dark"] .lesson-title a:hover,
[data-theme="dark"] .tree a:hover {
    color: #c8d0ff;
}

[data-theme="dark"] .form-control,
[data-theme="dark"] .form-select,
[data-theme="dark"] textarea,
[data-theme="dark"] input {
    background-color: #181818;
    border-color: var(--border);
    color: var(--text);
}

[data-theme="dark"] .form-control::placeholder,
[data-theme="dark"] .topbar .search-box input::placeholder {
    color: #8f8f89;
}

[data-theme="dark"] .dropdown-menu,
[data-theme="dark"] #searchResults {
    background-color: var(--bg-secondary);
    border-color: var(--border);
}

[data-theme="dark"] .dropdown-item:hover,
[data-theme="dark"] .dropdown-item:focus {
    background-color: var(--bg-hover);
    color: var(--text) !important;
}

[data-theme="dark"] .progress {
    background-color: #383838;
}

[data-theme="dark"] .badge.bg-secondary {
    background-color: #69717d !important;
    color: #fff;
}

.empty-state {
    text-align: center;
    padding: 2.5rem 1rem;
    color: var(--text-secondary);
}

.empty-state i { font-size: 2.5rem; margin-bottom: 0.75rem; display: block; }

/* ===================== RESPONSIVE ===================== */
@media (max-width: 991px) {
    .sidebar { transform: translateX(-100%); }
    .sidebar.show { transform: translateX(0); box-shadow: var(--shadow-md); }
    .main-content { margin-left: 0; }
    .sidebar-toggle { display: flex; }
    .topbar .search-box { max-width: none; }
}

@media (max-width: 575px) {
    .content-area { padding: 1rem; }
    .stat-card .stat-value { font-size: 1.3rem; }
}