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

:root {
    --primary-color: #4CAF50;
    --secondary-color: #45a049;
    --danger-color: #f44336;
    --bg-color: #f5f5f5;
    --card-bg: #ffffff;
    --text-color: #333;
    --border-color: #ddd;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    text-align: center;
    color: white;
    padding: 30px 0;
    animation: fadeInDown 0.6s ease-out;
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1.1em;
    opacity: 0.9;
}

main {
    flex: 1;
    animation: fadeInUp 0.6s ease-out;
}

.card {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
    animation: slideIn 0.4s ease-out;
}

.card h2 {
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 1.5em;
}

.card h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.3em;
}

.input-group {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

input[type="text"] {
    flex: 1;
    padding: 12px 15px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s ease;
}

input[type="text"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.1);
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

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

.btn-primary:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(76, 175, 80, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: linear-gradient(135deg, #9E9E9E 0%, #757575 100%);
    color: white;
}

.btn-secondary:hover {
    background: linear-gradient(135deg, #757575 0%, #616161 100%);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.btn-install {
    width: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    margin-top: 15px;
    font-size: 1.1em;
}

.btn-install:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

.todo-list {
    list-style: none;
}

.todo-item {
    background: var(--bg-color);
    padding: 15px;
    margin-bottom: 10px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: all 0.3s ease;
    animation: slideIn 0.3s ease-out;
}

.todo-item:hover {
    transform: translateX(5px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.todo-item.completed {
    opacity: 0.6;
}

.todo-item.completed .todo-text {
    text-decoration: line-through;
}

.todo-content {
    display: flex;
    align-items: center;
    flex: 1;
    gap: 12px;
}

.todo-checkbox {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.todo-text {
    flex: 1;
    font-size: 16px;
}

.delete-btn {
    background: var(--danger-color);
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
}

.delete-btn:hover {
    background: #da190b;
    transform: scale(1.05);
}

.info-card {
    background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
}

.install-info {
    font-size: 0.95em;
    line-height: 1.8;
}

.install-info ul {
    margin: 10px 0;
    padding-left: 20px;
}

.install-info li {
    margin: 5px 0;
}

.install-info p strong {
    color: var(--primary-color);
}

.status-card {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 20px;
    text-align: center;
    box-shadow: var(--shadow);
}

.status {
    font-size: 1.2em;
    font-weight: 600;
    margin-bottom: 5px;
}

.status-text {
    color: #666;
    font-size: 0.9em;
}

footer {
    text-align: center;
    padding: 20px 0;
    color: white;
    opacity: 0.8;
    font-size: 0.9em;
}

/* 动画 */
@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

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

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

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

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

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

/* 响应式设计 */
@media (max-width: 600px) {
    .container {
        padding: 10px;
    }

    header h1 {
        font-size: 2em;
    }

    .card {
        padding: 20px;
    }

    .input-group {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}

/* PWA安装提示样式 */
.pwa-install-prompt {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: white;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    z-index: 1000;
    max-width: 90%;
    animation: slideUp 0.4s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Toast 提示消息 */
.toast {
    position: fixed;
    bottom: 80px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: rgba(0, 0, 0, 0.85);
    color: white;
    padding: 16px 24px;
    border-radius: 50px;
    font-size: 15px;
    font-weight: 500;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    z-index: 9999;
    opacity: 0;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    max-width: 90%;
    text-align: center;
    backdrop-filter: blur(10px);
}

.toast-show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

.toast-success {
    background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
}

.toast-error {
    background: linear-gradient(135deg, #f44336 0%, #da190b 100%);
}

.toast-info {
    background: linear-gradient(135deg, #2196F3 0%, #1976D2 100%);
}

/* 按钮禁用状态 */
.btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    transform: none !important;
}

.btn-install:disabled {
    background: linear-gradient(135deg, #999 0%, #777 100%);
}

/* 响应式 Toast */
@media (max-width: 600px) {
    .toast {
        bottom: 60px;
        font-size: 14px;
        padding: 14px 20px;
    }
}