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

body {
    font-family: -apple-system, BlinkMacSystemFont, Microsoft YaHei, sans-serif;
    background: linear-gradient(135deg, #e0f2fe 0%, #bae6fd 25%, #7dd3fc 50%, #38bdf8 75%, #0ea5e9 100%);
    min-height: 100vh;
    padding: 40px 20px;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.98);
    border-radius: 24px;
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.25);
    overflow: hidden;
}

.header {
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    color: white;
    padding: 50px 30px;
    text-align: center;
}

.header h1 {
    font-size: 2.2em;
    font-weight: 700;
    margin-bottom: 10px;
}

.header p {
    opacity: 0.95;
}

.stats {
    display: flex;
    justify-content: space-around;
    padding: 25px;
    background: linear-gradient(to bottom, #f8f9ff, #ffffff);
    border-bottom: 1px solid #e8ecff;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 2.5em;
    font-weight: 700;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.stat-label {
    font-size: 0.9em;
    color: #8892b0;
    margin-top: 8px;
}

.add-task {
    padding: 30px;
    background: white;
}

.add-task form {
    display: flex;
    gap: 12px;
}

.add-task input {
    flex: 1;
    padding: 16px 24px;
    border: 2px solid #e8ecff;
    border-radius: 14px;
    font-size: 1em;
    transition: all 0.3s;
    background: #fafbff;
}

.add-task input:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.12);
    background: white;
}

.add-task button {
    padding: 16px 35px;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    color: white;
    border: none;
    border-radius: 14px;
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.3);
}

.add-task button:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(59, 130, 246, 0.4);
}

.filter-tabs {
    display: flex;
    gap: 10px;
    padding: 20px 30px;
    background: white;
    border-bottom: 1px solid #e8ecff;
    flex-wrap: wrap;
    justify-content: center;
}

.import-export-btn {
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
    text-decoration: none;
}

.import-export-btn:hover {
    background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
    box-shadow: 0 6px 16px rgba(59, 130, 246, 0.4);
}

.filter-tab {
    padding: 12px 24px;
    border: none;
    background: #f8f9ff;
    border-radius: 10px;
    cursor: pointer;
    font-size: 0.95em;
    color: #8892b0;
    transition: all 0.2s;
    font-weight: 500;
}

.filter-tab.active {
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.task-list {
    padding: 0 30px 30px;
    background: white;
    min-height: 300px;
}

.task-item {
    display: flex;
    align-items: center;
    padding: 22px;
    margin: 12px 0;
    background: linear-gradient(to right, #eff6ff, #ffffff);
    border-radius: 14px;
    border-left: 5px solid #3b82f6;
    transition: all 0.3s;
    animation: slideIn 0.3s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
    position: relative;
}

.task-item.selected {
    border-left-color: #ef4444;
    background: linear-gradient(to right, #fef2f2, #ffffff);
}

.task-item:hover {
    transform: translateX(8px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.15);
}

.task-item.completed {
    opacity: 0.65;
    border-left-color: #48bb78;
    background: linear-gradient(to right, #f0fff4, #ffffff);
}

.task-item.completed .task-text {
    text-decoration: line-through;
    color: #8892b0;
}

.task-number {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    color: white;
    font-weight: 700;
    font-size: 1.1em;
    border-radius: 12px;
    margin-right: 18px;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.25);
}

.task-checkbox {
    width: 24px;
    height: 24px;
    margin-right: 18px;
    cursor: pointer;
    accent-color: #3b82f6;
}

.task-select-checkbox {
    width: 20px;
    height: 20px;
    margin-right: 15px;
    cursor: pointer;
    accent-color: #3b82f6;
}

.task-content {
    flex: 1;
}

.task-text {
    font-size: 1.08em;
    color: #2d3748;
    margin-bottom: 6px;
}

.task-date {
    font-size: 0.85em;
    color: #8892b0;
}

.task-actions {
    display: flex;
    gap: 10px;
}

.task-btn {
    padding: 10px 18px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-size: 0.88em;
    font-weight: 500;
    transition: all 0.2s;
}

.edit-btn {
    background: #3b82f6;
    color: white;
}

.edit-btn:hover {
    background: #2563eb;
    transform: translateY(-2px);
}

.delete-btn {
    background: #fc8181;
    color: white;
}

.delete-btn:hover {
    background: #f56565;
    transform: translateY(-2px);
}

.empty-state {
    text-align: center;
    padding: 80px 20px;
    color: #8892b0;
}

.empty-state svg {
    width: 100px;
    height: 100px;
    margin-bottom: 25px;
    opacity: 0.4;
}

.batch-actions {
    padding: 15px 30px;
    background: white;
    border-top: 1px solid #e5e7eb;
    border-bottom: 1px solid #e5e7eb;
}

.batch-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
}

.select-all-wrapper {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    user-select: none;
    font-size: 0.95em;
    color: #374151;
}

.select-all-wrapper input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: #3b82f6;
}

.btn-batch-delete {
    padding: 12px 24px;
    background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 0.95em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 4px 15px rgba(239, 68, 68, 0.3);
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-batch-delete:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(239, 68, 68, 0.4);
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@media (max-width: 600px) {
    body {
        padding: 20px 10px;
    }

    .header {
        padding: 40px 20px;
    }

    .header h1 {
        font-size: 1.6em;
    }

    .add-task form {
        flex-direction: column;
    }

    .task-item {
        flex-wrap: wrap;
    }

    .task-actions {
        width: 100%;
        margin-top: 12px;
        justify-content: flex-end;
    }
}

.beian-info {
    padding: 20px;
    text-align: center;
    font-size: 0.85em;
    color: #8892b0;
    background: linear-gradient(to top, #f8fafc, #ffffff);
    border-top: 1px solid #e5e7eb;
}

.beian-info a {
    color: inherit;
    text-decoration: none;
    margin: 0 8px;
    display: inline-flex;
    align-items: center;
    transition: color 0.2s;
}

.beian-info a:hover {
    color: #3b82f6;
}

.beian-info img {
    vertical-align: middle;
    height: 20px;
    margin-right: 5px;
}