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

:root {
    --primary-color: #4a90d9;
    --primary-hover: #357abd;
    --danger-color: #e74c3c;
    --danger-hover: #c0392b;
    --success-color: #27ae60;
    --bg-color: #f5f5f5;
    --card-bg: #ffffff;
    --text-color: #333333;
    --text-muted: #888888;
    --border-color: #e0e0e0;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #1a1a2e;
        --card-bg: #16213e;
        --text-color: #eaeaea;
        --text-muted: #a0a0a0;
        --border-color: #2a2a4a;
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    margin-bottom: 24px;
    font-size: 2rem;
    color: var(--primary-color);
}

.notification-permission {
    background-color: rgba(74, 144, 217, 0.1);
    border: 1px solid var(--primary-color);
    border-radius: 8px;
    padding: 16px;
    margin-bottom: 20px;
    text-align: center;
}

.notification-permission.hidden {
    display: none;
}

.notification-permission p {
    margin-bottom: 12px;
    font-size: 0.9rem;
}

.notification-permission button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 8px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background-color 0.2s;
}

.notification-permission button:hover {
    background-color: var(--primary-hover);
}

.todo-form {
    margin-bottom: 24px;
}

.form-group {
    margin-bottom: 12px;
}

.form-group label {
    display: block;
    margin-bottom: 4px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.todo-form input[type="text"] {
    width: 100%;
    padding: 12px 16px;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--card-bg);
    color: var(--text-color);
    transition: border-color 0.2s;
}

.todo-form input[type="text"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

.todo-form input[type="datetime-local"] {
    width: 100%;
    padding: 10px 12px;
    font-size: 0.9rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--card-bg);
    color: var(--text-color);
}

.todo-form button[type="submit"] {
    width: 100%;
    padding: 12px;
    font-size: 1rem;
    font-weight: 600;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.todo-form button[type="submit"]:hover {
    background-color: var(--primary-hover);
}

.filters {
    display: flex;
    gap: 8px;
    margin-bottom: 20px;
}

.filter-btn {
    flex: 1;
    padding: 10px;
    font-size: 0.9rem;
    background-color: transparent;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.2s;
}

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

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

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

.todo-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 10px;
    transition: all 0.2s;
}

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

.todo-item.completed .todo-text {
    text-decoration: line-through;
    color: var(--text-muted);
}

.todo-checkbox {
    width: 22px;
    height: 22px;
    cursor: pointer;
    accent-color: var(--success-color);
}

.todo-content {
    flex: 1;
    min-width: 0;
}

.todo-text {
    font-size: 1rem;
    word-break: break-word;
}

.todo-reminder {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 4px;
    display: flex;
    align-items: center;
    gap: 4px;
}

.todo-reminder::before {
    content: "\1F514";
    font-size: 0.9rem;
}

.todo-delete {
    padding: 8px 12px;
    font-size: 0.85rem;
    background-color: var(--danger-color);
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.todo-delete:hover {
    background-color: var(--danger-hover);
}

.empty-message {
    text-align: center;
    color: var(--text-muted);
    padding: 40px 20px;
    font-size: 1rem;
}

/* User bar */
.user-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.9rem;
    color: var(--text-muted);
}

.user-bar button {
    padding: 6px 14px;
    font-size: 0.85rem;
    background-color: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.2s;
}

.user-bar button:hover {
    border-color: var(--danger-color);
    color: var(--danger-color);
}

/* Auth forms */
.auth-title {
    text-align: center;
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: var(--text-color);
}

.auth-form {
    margin-bottom: 24px;
}

.auth-form .form-group {
    margin-bottom: 16px;
}

.auth-form .form-group label {
    display: block;
    margin-bottom: 6px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.auth-form input[type="email"],
.auth-form input[type="password"] {
    width: 100%;
    padding: 12px 16px;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--card-bg);
    color: var(--text-color);
    transition: border-color 0.2s;
}

.auth-form input[type="email"]:focus,
.auth-form input[type="password"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

.auth-form button[type="submit"] {
    width: 100%;
    padding: 12px;
    font-size: 1rem;
    font-weight: 600;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.auth-form button[type="submit"]:hover {
    background-color: var(--primary-hover);
}

.auth-link {
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.auth-link a {
    color: var(--primary-color);
    text-decoration: none;
}

.auth-link a:hover {
    text-decoration: underline;
}

/* Error message */
.error-message {
    background-color: rgba(231, 76, 60, 0.1);
    border: 1px solid var(--danger-color);
    color: var(--danger-color);
    border-radius: 8px;
    padding: 12px 16px;
    margin-bottom: 16px;
    font-size: 0.9rem;
}

.error-message.hidden {
    display: none;
}

@media (max-width: 480px) {
    .container {
        padding: 20px;
    }

    h1 {
        font-size: 1.5rem;
    }

    .filters {
        flex-direction: column;
    }

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

    .todo-content {
        flex-basis: calc(100% - 46px);
    }

    .todo-delete {
        margin-left: auto;
    }
}