/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary: #4f6ef7;
    --primary-hover: #3b5de7;
    --danger: #e74c3c;
    --danger-hover: #c0392b;
    --success: #2ecc71;
    --bg: #f5f6fa;
    --card-bg: #ffffff;
    --text: #2c3e50;
    --text-light: #95a5a6;
    --border: #e0e3eb;
    --shadow: 0 2px 12px rgba(0,0,0,0.08);
    --radius: 10px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
}

/* Header */
.header {
    background: var(--primary);
    color: #fff;
    padding: 18px 24px;
    text-align: center;
    font-size: 20px;
    font-weight: 600;
    letter-spacing: 1px;
    box-shadow: 0 2px 8px rgba(79,110,247,0.3);
}

/* Container */
.container {
    max-width: 780px;
    margin: 0 auto;
    padding: 20px 16px 80px;
}

/* List Section */
.list-section {
    margin-bottom: 20px;
}

.list-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    background: var(--card-bg);
    border-radius: var(--radius) var(--radius) 0 0;
    border-bottom: 2px solid var(--border);
    cursor: pointer;
    user-select: none;
}

.list-header .list-name {
    font-size: 16px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
}

.list-header .list-name .count {
    font-size: 12px;
    color: var(--text-light);
    font-weight: 400;
}

.list-header .list-actions {
    display: flex;
    gap: 6px;
}

.list-header .btn-icon {
    background: none;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    padding: 4px 8px;
    font-size: 14px;
    border-radius: 6px;
    transition: all 0.2s;
}

.list-header .btn-icon:hover {
    background: var(--bg);
    color: var(--danger);
}

/* Task Cards */
.task-list {
    background: var(--card-bg);
    border-radius: 0 0 var(--radius) var(--radius);
    overflow: hidden;
}

.task-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 16px;
    border-bottom: 1px solid var(--border);
    transition: background 0.15s;
}

.task-item:last-child {
    border-bottom: none;
}

.task-item:hover {
    background: #f8f9fd;
}

.task-checkbox {
    flex-shrink: 0;
    width: 22px;
    height: 22px;
    margin-top: 2px;
    border: 2px solid var(--border);
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    background: #fff;
}

.task-checkbox:hover {
    border-color: var(--primary);
}

.task-checkbox.checked {
    background: var(--success);
    border-color: var(--success);
    color: #fff;
}

.task-checkbox.checked::after {
    content: '✓';
    font-size: 14px;
    font-weight: bold;
}

.task-body {
    flex: 1;
    min-width: 0;
}

.task-title {
    font-size: 15px;
    line-height: 1.4;
    word-break: break-word;
}

.task-title.completed {
    text-decoration: line-through;
    color: var(--text-light);
}

.task-meta {
    display: flex;
    gap: 12px;
    margin-top: 4px;
    font-size: 12px;
    color: var(--text-light);
}

.task-meta .priority-high { color: var(--danger); }
.task-meta .priority-medium { color: #f39c12; }
.task-meta .priority-low { color: var(--success); }

.task-desc {
    font-size: 13px;
    color: var(--text-light);
    margin-top: 4px;
    line-height: 1.4;
}

.task-actions {
    flex-shrink: 0;
    display: flex;
    gap: 4px;
    opacity: 0;
    transition: opacity 0.2s;
}

.task-item:hover .task-actions {
    opacity: 1;
}

.task-actions .btn-icon {
    background: none;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    padding: 4px 6px;
    font-size: 14px;
    border-radius: 6px;
    transition: all 0.15s;
}

.task-actions .btn-icon:hover {
    background: var(--bg);
}

.task-actions .btn-delete:hover {
    color: var(--danger);
}

/* Quick Add */
.quick-add {
    display: flex;
    gap: 10px;
    margin-bottom: 24px;
}

.quick-add input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    font-size: 15px;
    outline: none;
    transition: border-color 0.2s;
}

.quick-add input:focus {
    border-color: var(--primary);
}

.quick-add select {
    padding: 12px;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    outline: none;
    background: #fff;
    color: var(--text);
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    border: none;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s;
    white-space: nowrap;
}

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

/* Add List */
.add-list-area {
    text-align: center;
    margin-top: 16px;
}

.btn-add-list {
    background: none;
    border: 2px dashed var(--border);
    color: var(--text-light);
    padding: 12px 24px;
    border-radius: var(--radius);
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
    width: 100%;
}

.btn-add-list:hover {
    border-color: var(--primary);
    color: var(--primary);
}

/* Modal */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.4);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.modal-overlay.active {
    display: flex;
}

.modal {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 24px;
    width: 90%;
    max-width: 480px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.15);
}

.modal h3 {
    margin-bottom: 16px;
    font-size: 18px;
}

.modal .form-group {
    margin-bottom: 14px;
}

.modal .form-group label {
    display: block;
    font-size: 13px;
    color: var(--text-light);
    margin-bottom: 4px;
}

.modal .form-group input,
.modal .form-group textarea,
.modal .form-group select {
    width: 100%;
    padding: 10px 12px;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 14px;
    outline: none;
    transition: border-color 0.2s;
}

.modal .form-group input:focus,
.modal .form-group textarea:focus,
.modal .form-group select:focus {
    border-color: var(--primary);
}

.modal .form-group textarea {
    min-height: 80px;
    resize: vertical;
}

.modal .modal-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    margin-top: 20px;
}

.btn-cancel {
    background: var(--bg);
    color: var(--text);
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.2s;
}

.btn-cancel:hover {
    background: var(--border);
}

.btn-save {
    background: var(--primary);
    color: #fff;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.2s;
}

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

/* Empty state */
.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-light);
}

.empty-state .icon {
    font-size: 48px;
    margin-bottom: 12px;
}

.empty-state p {
    font-size: 14px;
}

/* Toasts */
.toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--text);
    color: #fff;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 14px;
    z-index: 2000;
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
}

.toast.show {
    opacity: 1;
}

/* Priority tags inline */
.priority-tag {
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    margin-right: 6px;
}

.priority-tag.p1 { background: var(--danger); }
.priority-tag.p2 { background: #f39c12; }
.priority-tag.p3 { background: var(--success); }

/* Responsive */
@media (max-width: 600px) {
    .container { padding: 12px 10px 80px; }
    .quick-add { flex-direction: column; }
    .quick-add select { width: 100%; }
    .btn-primary { width: 100%; }
    .task-actions { opacity: 1; }
}