:root {
    --color-background: #121212; 
    --color-surface: #1e1e1e;   
    --color-surface-hover: #2a2a2a; 
    --color-border: #333333;     
    --color-text-primary: #e0e0e0; 
    --color-text-secondary: #a0a0a0; 
    --color-accent: #8A2BE2; 
    --color-accent-hover: #7B1FA2; 
    --color-glow: rgba(138, 43, 226, 0.4); 
    --color-error: #ff4d4d;
    --color-success: #4dff4d;
    --color-danger: #dc3545; 
    --color-danger-hover: #c82333; 
    --color-task-completed-text: #666; 
    --font-family-main: 'Kanit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --border-radius-sm: 3px; 
    --border-radius-md: 6px; 
    --border-radius-lg: 10px; 
    --shadow-color: rgba(0, 0, 0, 0.5);
    --glow-shadow: 0 0 12px var(--color-glow), 0 0 4px var(--color-accent); 
    --card-shadow: 0 3px 10px var(--shadow-color); 
    --transition-speed-fast: 0.2s;
    --transition-speed-normal: 0.3s;
}

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

body {
    font-family: var(--font-family-main);
    background-color: var(--color-background);
    color: var(--color-text-primary);
    line-height: 1.5; 
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    padding: 15px; 
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 750px; 
    margin: 0 auto;
}

.app-header {
    text-align: center;
    margin-bottom: 25px; 
    padding: 15px 20px; 
    background-color: var(--color-surface);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--card-shadow), 0 0 0 1px var(--color-border);
    border-top: 3px solid var(--color-accent); 
}

.app-header h1 { 
    font-size: 2.2rem; 
    font-weight: 700; 
    color: var(--color-text-primary);
    text-shadow: 0 0 8px var(--color-glow); 
    margin-bottom: 0.2em;
}

.app-header p {
    font-size: 0.95rem; 
    font-weight: 400; 
    color: var(--color-text-secondary);
}

.page-section {
    margin-bottom: 25px; 
}

.card {
    background-color: var(--color-surface);
    padding: 20px 25px; 
    border-radius: var(--border-radius-lg);
    box-shadow: var(--card-shadow);
    border: 1px solid var(--color-border);
    transition: box-shadow var(--transition-speed-normal) ease, transform var(--transition-speed-normal) ease;
}
.card:hover {
    box-shadow: var(--card-shadow), var(--glow-shadow);
}

.page-section h2, .card h2 { 
    text-align: center;
    margin-bottom: 20px; 
    font-size: 1.6rem; 
    font-weight: 600; 
    color: var(--color-text-primary);
}
.page-section h3, .card h3 { 
    margin-bottom: 15px; 
    font-size: 1.3rem; 
    font-weight: 500;
    color: var(--color-text-primary);
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 8px; 
    text-align: left; 
}
.card h4 { 
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--color-text-secondary); 
    margin-bottom: 10px;
    text-align: left;
}

.form-group {
    margin-bottom: 12px; 
}
.form-group label {
    display: block;
    margin-bottom: 6px; 
    font-weight: 500; 
    font-size: 0.9rem; 
    color: var(--color-text-secondary);
}
.sr-only { 
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

.form-group input[type="text"],
.form-group textarea {
    width: 100%;
    padding: 8px 10px; 
    background-color: var(--color-background); 
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    color: var(--color-text-primary);
    font-family: var(--font-family-main); 
    font-size: 0.9rem; 
    font-weight: 400;
    transition: border-color var(--transition-speed-fast) ease, box-shadow var(--transition-speed-fast) ease;
}
.form-group textarea {
    resize: vertical; 
    min-height: 50px; 
}
.form-group input[type="text"]:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 2px var(--color-glow); 
}
.form-group .char-count-info {
    font-size: 0.75rem; 
    font-weight: 300; 
    color: var(--color-text-secondary);
    margin-top: 4px;
}

.form-actions {
    display: flex;
    gap: 10px; 
    margin-top: 20px; 
    justify-content: flex-end; 
}
.form-actions button {
    min-width: 100px; 
}

.btn {
    display: inline-block;
    padding: 8px 16px; 
    border: none;
    border-radius: var(--border-radius-md);
    font-family: var(--font-family-main); 
    font-size: 0.9rem; 
    font-weight: 500; 
    cursor: pointer;
    text-align: center;
    transition: background-color var(--transition-speed-fast) ease, transform var(--transition-speed-fast) ease, box-shadow var(--transition-speed-fast) ease;
    text-decoration: none;
    letter-spacing: 0.25px; 
}
.btn-primary {
    background-color: var(--color-accent);
    color: #ffffff; 
    box-shadow: 0 1px 4px rgba(0,0,0,0.2), 0 0 6px var(--color-glow); 
}
.btn-primary:hover {
    background-color: var(--color-accent-hover);
    transform: translateY(-1px); 
    box-shadow: 0 2px 8px rgba(0,0,0,0.3), 0 0 10px var(--color-glow);
}
.btn-secondary {
    background-color: var(--color-surface-hover);
    color: var(--color-text-primary);
    border: 1px solid var(--color-border);
}
.btn-secondary:hover {
    background-color: var(--color-border); 
    border-color: var(--color-surface-hover);
    transform: translateY(-1px);
}
.btn-danger { 
    background-color: var(--color-danger);
    color: #ffffff;
    box-shadow: 0 1px 4px rgba(0,0,0,0.2);
}
.btn-danger:hover {
    background-color: var(--color-danger-hover);
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0,0,0,0.3);
}
.btn-small {
    padding: 6px 12px; 
    font-size: 0.8rem; 
}
.btn-icon { 
    background: none;
    border: none;
    color: var(--color-text-secondary);
    font-size: 1.1rem; 
    padding: 4px; 
    cursor: pointer;
    line-height: 1;
    transition: color var(--transition-speed-fast) ease, transform var(--transition-speed-fast) ease;
}
.btn-icon:hover {
    color: var(--color-accent);
    transform: scale(1.05); 
}
.delete-task-btn:hover, .delete-folder-btn:hover {
    color: var(--color-error) !important;
}


#auth-form { display: flex; flex-direction: column; }
#auth-form button[type="submit"] { width: 100%; }

.dashboard-header { margin-bottom: 25px; }
.dashboard-header h2 { text-align: left; margin-bottom: 8px; }
.dashboard-controls { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 10px; }
.dashboard-controls p { margin-bottom: 0; font-size: 1rem; }
#projects-list-container h3 { text-align: left; }

.projects-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); 
    gap: 15px; 
    margin-top: 8px;
}
.project-card {
    background-color: var(--color-surface-hover); 
    padding: 15px; 
    border-radius: var(--border-radius-md);
    border: 1px solid var(--color-border);
    box-shadow: 0 2px 6px rgba(0,0,0,0.3); 
    transition: transform var(--transition-speed-normal) ease, box-shadow var(--transition-speed-normal) ease;
    display: flex;
    flex-direction: column;
    justify-content: space-between; 
}
.project-card:hover {
    transform: translateY(-2px) scale(1.01); 
    box-shadow: 0 4px 12px var(--shadow-color), var(--glow-shadow);
}
.project-card h4 {
    font-size: 1.15rem; 
    font-weight: 600;
    color: var(--color-accent); 
    margin-bottom: 8px;
}
.project-card p { 
    font-size: 0.85rem; 
    color: var(--color-text-secondary);
    margin-bottom: 10px; 
    flex-grow: 1; 
    line-height: 1.4;
    overflow: hidden; 
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2; 
    -webkit-box-orient: vertical;
}
.project-card-actions { display: flex; justify-content: space-between; align-items: center; margin-top: auto; gap: 8px; }
.project-card-actions > div { display: flex; gap: 8px; }
.task-count { font-size: 0.75rem; color: var(--color-text-secondary); font-style: italic; }
.project-card .btn { width: auto; }

.project-detail-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; padding-bottom: 12px; border-bottom: 1px solid var(--color-border); }
.project-detail-header h2 { text-align: left; margin-bottom: 0; color: var(--color-accent); }
.project-description-text {
    font-size: 0.95rem; 
    color: var(--color-text-secondary);
    margin-bottom: 20px; 
    padding: 12px; 
    background-color: var(--color-background); 
    border-radius: var(--border-radius-sm);
    border-left: 3px solid var(--color-accent);
    white-space: pre-wrap; 
}

.project-tools-card h3 { 
    text-align: center; 
}
.tools-forms-container {
    display: flex;
    flex-direction: column; 
    gap: 20px; 
}
#folder-creation-subsection, #task-creation-subsection {
    padding: 10px;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    background-color: var(--color-background); 
}
.tools-divider { display: none; }

.add-folder-form { 
    display: flex;
    gap: 10px;
}
.add-folder-form .form-group { flex-grow: 1; margin-bottom: 0; }
.add-folder-form button[type="submit"] { flex-shrink: 0; }

.add-task-form {
    display: flex;
    flex-wrap: wrap; 
    gap: 8px; 
    align-items: flex-start; 
}
.add-task-form .task-name-group { flex-grow: 1; min-width: 180px; }
.add-task-form .task-description-group { flex-basis: 100%; }
.add-task-form .form-group { margin-bottom: 0; }
.add-task-form input[type="text"] { font-size: 0.9rem; padding: 8px 10px; }
.add-task-form textarea { font-size: 0.85rem; padding: 6px 10px; }
.add-task-form button[type="submit"] { flex-shrink: 0; align-self: center; }
@media (max-width: 500px) {
    .add-task-form button[type="submit"] { width: 100%; margin-top: 8px; }
}

.tasks-display-card h3 { 
    text-align: center; 
}
#folders-tasks-container { margin-top: 15px; }
.folder-container.card { 
    padding: 15px 20px; 
    margin-bottom: 15px; 
    background-color: var(--color-surface-hover); 
    border: 2px dashed transparent; 
    transition: border-color var(--transition-speed-fast) ease, opacity var(--transition-speed-normal) ease;
}
.folder-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
    padding-bottom: 5px;
    border-bottom: 1px solid var(--color-border);
}
.folder-title { 
    font-size: 1.1rem !important; 
    font-weight: 500 !important;
    color: var(--color-accent) !important;
    margin-bottom: 0 !important;
    padding-bottom: 0 !important;
    border-bottom: none !important;
    text-align: left;
    transition: text-decoration var(--transition-speed-fast) ease, color var(--transition-speed-fast) ease;
}
.folder-container.folder-completed .folder-title {
    text-decoration: line-through;
    color: var(--color-task-completed-text) !important;
}
.folder-container.folder-completed {
    opacity: 0.7;
}

.folder-container.uncategorized-tasks {
    border-top: 2px dashed var(--color-border); 
    margin-top: 20px;
}

.task-list { list-style: none; padding: 0; margin-top: 8px; min-height: 30px; }
.task-item {
    display: flex;
    justify-content: space-between;
    align-items: flex-start; 
    padding: 10px 12px; 
    background-color: var(--color-background); 
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    margin-bottom: 8px; 
    transition: background-color var(--transition-speed-fast) ease, border-color var(--transition-speed-fast) ease, opacity var(--transition-speed-fast) ease;
    cursor: grab; 
}
.task-item:hover { border-color: var(--color-accent); background-color: var(--color-surface-hover); }
.task-item.is-dragging { 
    opacity: 0.5;
    border-style: dashed;
}
.folder-container.drag-over-target { 
    border-color: var(--color-accent);
    background-color: rgba(138, 43, 226, 0.1); 
}

.task-item-main-content { flex-grow: 1; margin-right: 10px; }
.task-item .task-text {
    font-size: 0.9rem; 
    font-weight: 500; 
    display: block; 
    margin-bottom: 3px; 
    transition: color var(--transition-speed-fast) ease, text-decoration var(--transition-speed-fast) ease;
}
.task-item-description {
    font-size: 0.8rem; 
    color: var(--color-text-secondary);
    line-height: 1.3;
    white-space: pre-wrap; 
    word-break: break-word; 
}
.task-item.completed .task-text { text-decoration: line-through; color: var(--color-task-completed-text); }
.task-item.completed .task-item-description { color: var(--color-task-completed-text); text-decoration: line-through; }
.task-item .task-actions { display: flex; align-items: center; gap: 6px; flex-shrink: 0; }
.task-item .toggle-complete-btn { font-weight: bold; }
.task-item.completed .toggle-complete-btn { color: var(--color-success); }

.form-message { text-align: center; margin-top: 10px; font-weight: 500; min-height: 1.3em; font-size: 0.85rem; transition: opacity var(--transition-speed-fast) ease; }
.form-message.success { color: var(--color-success); }
.form-message.error { color: var(--color-error); }
.empty-state-message { color: var(--color-text-secondary); text-align: center; padding: 20px 15px; font-style: italic; background-color: var(--color-background); border-radius: var(--border-radius-md); border: 1px dashed var(--color-border); margin-top: 8px; font-size: 0.85rem; }
.empty-state-message.small { padding: 10px 15px; font-size: 0.8rem; }

footer { text-align: center; margin-top: 30px; padding-top: 15px; border-top: 1px solid var(--color-border); color: var(--color-text-secondary); font-size: 0.85rem; font-weight: 400; }