diff --git a/.config/nvim/init.lua b/.config/nvim/init.lua
index ee63e88..4d8d311 100644
--- a/.config/nvim/init.lua
+++ b/.config/nvim/init.lua
@@ -28,8 +28,10 @@ opt("inccommand", "split")
 opt("updatetime", 100)
 opt("mouse", "a")
 
+vim.g.mapleader = " "
+
 require("plugins")
 require("mappings")
 require("treesitter")
-require("lsp")
 require("completion")
+require("lsp")
diff --git a/.config/nvim/lua/completion.lua b/.config/nvim/lua/completion.lua
index 2bc4326..9455cb7 100644
--- a/.config/nvim/lua/completion.lua
+++ b/.config/nvim/lua/completion.lua
@@ -1,31 +1,3 @@
--- nvim-cmp
-local cmp = require("cmp")
-
-cmp.setup {
-    completion = {
-        autocomplete = false
-    },
-    snippet = {
-        expand = function(args)
-            require("luasnip").lsp_expand(args.body)
-        end,
-    },
-    mapping = {
-        ['<C-b>'] = cmp.mapping(cmp.mapping.scroll_docs(-4), { 'i', 'c' }),
-        ['<C-f>'] = cmp.mapping(cmp.mapping.scroll_docs(4), { 'i', 'c' }),
-        ['<C-Space>'] = cmp.mapping(cmp.mapping.complete(), { 'i', 'c' }),
-        ['<C-y>'] = cmp.config.disable, -- Specify `cmp.config.disable` if you want to remove the default `<C-y>` mapping.
-        ['<C-e>'] = cmp.mapping({
-            i = cmp.mapping.abort(),
-            c = cmp.mapping.close(),
-        }),
-        ['<CR>'] = cmp.mapping.confirm({ select = true }), -- Accept currently selected item. Set `select` to `false` to only confirm explicitly selected items.
-    },
-    sources = cmp.config.sources {
-        { name = "nvim_lsp" },
-        { name = "nvim_lua" },
-        { name = "luasnip" },
-        { name = "buffer" },
-        { name = "path" }
-    }
-}
+vim.g.coq_settings = {auto_start = true}
+local coq = require('coq')
+vim.cmd('COQnow')
diff --git a/.config/nvim/lua/lsp.lua b/.config/nvim/lua/lsp.lua
index e172ecd..3852f92 100644
--- a/.config/nvim/lua/lsp.lua
+++ b/.config/nvim/lua/lsp.lua
@@ -1,30 +1,40 @@
 local lspconfig = require('lspconfig')
 
-local opts = { noremap = true, silent = true }
 
 local on_attach = function(client, bufnr)
+    local opts = { noremap = true, silent = true }
+
+    local function key(mode, keys, cmd)
+        vim.api.nvim_buf_set_keymap(bufnr, mode, keys, cmd, opts)
+    end
+
+    local function opt(...)
+        vim.api.nvim_buf_set_option(bufnr, ...)
+    end
+
     -- Enable completion
-    vim.api.nvim_buf_set_option(bufnr, 'omnifunc')
+    opt('omnifunc', 'v:lua.vim.lsp.omnifunc')
 
     -- Mappings
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gd', '<cmd>lua vim.lsp.buf.definition()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'K', '<cmd>lua vim.lsp.buf.hover()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<C-k>', '<cmd>lua vim.lsp.buf.signature_help()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<space>wa', '<cmd>lua vim.lsp.buf.add_workspace_folder()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<space>wr', '<cmd>lua vim.lsp.buf.remove_workspace_folder()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<space>wl', '<cmd>lua print(vim.inspect(vim.lsp.buf.list_workspace_folders()))<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<space>D', '<cmd>lua vim.lsp.buf.type_definition()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<space>rn', '<cmd>lua vim.lsp.buf.rename()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<space>ca', '<cmd>lua vim.lsp.buf.code_action()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gr', '<cmd>lua vim.lsp.buf.references()<CR>', opts)
-    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<space>f', '<cmd>lua vim.lsp.buf.formatting()<CR>', opts)
+    key('n', '<leader>cD', '<cmd>lua vim.lsp.buf.declaration()<CR>')
+    key('n', '<leader>cd', '<cmd>lua vim.lsp.buf.definition()<CR>')
+    key('n', '<leader>ch', '<cmd>lua vim.lsp.buf.hover()<CR>')
+    key('n', '<leader>ci', '<cmd>lua vim.lsp.buf.implementation()<CR>')
+    key('n', '<leader>sh', '<cmd>lua vim.lsp.buf.signature_help()<CR>')
+    key('n', '<leader>wa', '<cmd>lua vim.lsp.buf.add_workspace_folder()<CR>')
+    key('n', '<leader>wr', '<cmd>lua vim.lsp.buf.remove_workspace_folder()<CR>')
+    key('n', '<leader>wl', '<cmd>lua print(vim.inspect(vim.lsp.buf.list_workspace_folders()))<CR>')
+    key('n', '<leader>D', '<cmd>lua vim.lsp.buf.type_definition()<CR>')
+    key('n', '<leader>rn', '<cmd>lua vim.lsp.buf.rename()<CR>')
+    key('n', '<leader>ca', '<cmd>lua vim.lsp.buf.code_action()<CR>')
+    key('n', '<leader>cr', '<cmd>lua vim.lsp.buf.references()<CR>')
+    key('n', '<space>f', '<cmd>lua vim.lsp.buf.formatting()<CR>')
+    key('n', '<leader>cs', '<cmd>lua vim.diagnostic.open_float()<CR>')
 end
 
-local capabilities = require("cmp_nvim_lsp").update_capabilities(vim.lsp.protocol.make_client_capabilities())
+local coq = require('coq')
 
-lspconfig.ccls.setup {
+lspconfig.ccls.setup(coq.lsp_ensure_capabilities{
     on_attach = on_attach,
     capabilities = capabilities,
     init_options = {
@@ -32,9 +42,9 @@ lspconfig.ccls.setup {
             directory = vim.fn.expand("$HOME/.cache/ccls/")
         }
     }
-}
+})
 
-lspconfig.rust_analyzer.setup {
+lspconfig.rust_analyzer.setup(coq.lsp_ensure_capabilities{
     on_attach = on_attach,
     capabilities = capabilities,
     settings = {
@@ -49,22 +59,24 @@ lspconfig.rust_analyzer.setup {
             }
         }
     }
-}
+})
 
 lspconfig.tsserver.setup {
     on_attach = on_attach,
     capabilities = capabilities
 }
+lspconfig.tsserver.setup(coq.lsp_ensure_capabilities())
 
-lspconfig.java_language_server.setup {
+lspconfig.java_language_server.setup(coq.lsp_ensure_capabilities{
     on_attach = on_attach,
     capabilities = capabilities,
     cmd = { "/usr/share/java/java-language-server/lang_server_linux.sh" }
-}
+})
 
 lspconfig.vuels.setup {
     on_attach = on_attach,
     capabilities = capabilities
 }
+lspconfig.vuels.setup(coq.lsp_ensure_capabilities())
 
 lspconfig.racket_langserver.setup {}
diff --git a/.config/nvim/lua/mappings.lua b/.config/nvim/lua/mappings.lua
index 442bf47..daaf791 100644
--- a/.config/nvim/lua/mappings.lua
+++ b/.config/nvim/lua/mappings.lua
@@ -1 +1,22 @@
-vim.g.mapleader = "<Space>"
+--  map the key (sequence) to a command
+local function map(mode, lhs, rhs, opts)
+    local options = { noremap = true }
+    if opts then
+        options = vim.tbl_extend("force", options, opts)
+    end
+    vim.api.nvim_set_keymap(mode, lhs, rhs, options)
+end
+
+-- open terminal
+map("n", "<leader>ot", ":ToggleTerm<CR>")
+
+-- exit terminal mode
+map("t", "<esc>", "<C-\\><C-n>")
+
+-- open tree
+map("n", "<leader>op", ":NvimTreeToggle<CR>")
+
+-- telescope
+map("n", "<leader>to", ":Telescope<CR>")
+map("n", "<leader>tf", ":Telescope find_files<CR>")
+map("n", "<leader>tg", ":Telescope live_grep<CR>")
diff --git a/.config/nvim/lua/plugins.lua b/.config/nvim/lua/plugins.lua
index 777dd51..18fee27 100644
--- a/.config/nvim/lua/plugins.lua
+++ b/.config/nvim/lua/plugins.lua
@@ -12,6 +12,7 @@ packer.startup(function()
     use("nvim-treesitter/nvim-treesitter")
     use("neovim/nvim-lspconfig")
     use("j-hui/fidget.nvim")
+    use("onsails/lspkind-nvim")
 
     -- ui
     use("ayu-theme/ayu-vim")
@@ -24,13 +25,11 @@ packer.startup(function()
     use("akinsho/toggleterm.nvim")
 
     -- completion
-    use("hrsh7th/nvim-cmp")
-    use("hrsh7th/cmp-path")
-    use("hrsh7th/cmp-buffer")
-    use("hrsh7th/cmp-nvim-lsp")
-    use("hrsh7th/cmp-nvim-lua")
-    use("L3MON4D3/LuaSnip")
-    use("saadparwaiz1/cmp_luasnip")
+    use{"ms-jpq/coq_nvim",branch='coq'}
+    
+    -- misc
+    use("davidgranstrom/nvim-markdown-preview")
+    use("folke/todo-comments.nvim")
 
     if packer_bootstrap then
       require('packer').sync()
@@ -84,7 +83,7 @@ require('nvim-web-devicons').setup {}
 -- nvim-tree
 require('nvim-tree').setup {
     view = {
-        width = 25,
+        width = 35,
         signcolumn = "no",
     },
     diagnostics = {
@@ -106,5 +105,13 @@ require('lualine').setup {
 
 -- toggleterm
 require('toggleterm').setup {
-    open_mapping = [[<leader>ot]]
+    open_mapping = nil
 }
+
+-- markdown preview
+vim.cmd[[
+    let g:mkdp_browser = 'surf'
+]]
+
+-- todo-comments
+require('todo-comments').setup {}