diff --git a/.github/workflows/atcoder.yaml b/.github/workflows/atcoder.yaml
new file mode 100644
index 0000000..570e761
--- /dev/null
+++ b/.github/workflows/atcoder.yaml
@@ -0,0 +1,45 @@
+name: Test (atcoder)
+
+on:
+  push:
+    branches: ['**']
+    tags-ignore: ['*']
+    paths: ['atcoder/*']
+
+  workflow_dispatch:
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest 
+
+    steps:
+      - name: Set up Go 1.15
+        uses: actions/setup-go@v2
+        with:
+          go-version: 1.15
+
+      - name: Checkout Project
+        uses: actions/checkout@v2
+      
+      - name: Cache Dependencies
+        uses: actions/cache@v2
+        with:
+          path: ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: ${{ runner.os }}-go-
+
+      - name: Run Tests
+        run: go test -v -coverprofile=c.out ./atcoder
+        env:
+          BROWSER_HEADLESS:
+          BROWSER_BINARY: google-chrome
+
+          ATCODER_USERNAME: cptools
+          ATCODER_PASSWORD: ${{ secrets.ATCODER_PASSWORD }}
+
+      - name: Upload Coverage
+        uses: shogo82148/actions-goveralls@v1
+        with:
+          path-to-profile: c.out
+
diff --git a/.gitignore b/.gitignore
index 839a56d..81a8163 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,3 +13,5 @@
 
 # Dependency directories (remove the comment below to include it)
 vendor/
+
+.env
\ No newline at end of file
diff --git a/atcoder/atcoder.go b/atcoder/atcoder.go
new file mode 100644
index 0000000..7b931e3
--- /dev/null
+++ b/atcoder/atcoder.go
@@ -0,0 +1,88 @@
+package atcoder
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/cp-tools/cpt-lib/util"
+
+	"github.com/go-rod/rod"
+)
+
+type (
+	// Args holds specifier details parsed by
+	// Parse() function. All methods use this
+	// at the core.
+	Args struct {
+		Contest string
+		Problem string
+	}
+
+	page struct {
+		*rod.Page
+	}
+)
+
+// Errors returned by library.
+var (
+	ErrInvalidSpecifier = fmt.Errorf("invalid specifier data")
+)
+
+var (
+	hostURL = "https://atcoder.jp"
+
+	// Browser is the headless browser to use.
+	Browser *rod.Browser
+)
+
+// Start initiates the automated browser to use.
+func Start(headless bool, userDataDir, bin string) error {
+	bs, err := util.NewBrowser(headless, userDataDir, bin)
+	Browser = bs
+
+	return err
+}
+
+// Parse passed in specifier string to new Args struct.
+// Validates parsed args and returns error if any.
+func Parse(str string) (Args, error) {
+	var (
+		rxCont = `(?P<cont>[A-Za-z0-9-]+)`
+		rxProb = `(?P<prob>[A-Za-z0-9_]+)`
+
+		valRx = []string{
+			`atcoder.jp\/contests\/` + rxCont + `$`,
+			`atcoder.jp\/contests\/` + rxCont + `\/tasks\/` + rxProb + `$`,
+
+			`^` + rxCont + `$`,
+			`^` + rxCont + `\s+` + rxProb + `$`,
+		}
+	)
+
+	str = strings.TrimSpace(util.StrClean(str))
+	if str == "" {
+		return Args{}, nil
+	}
+
+	for _, rgx := range valRx {
+		re := regexp.MustCompile(rgx)
+		if re.MatchString(str) {
+			// https://stackoverflow.com/a/46202939/9606036
+			match := re.FindStringSubmatch(str)
+			result := map[string]string{}
+			for i, name := range re.SubexpNames() {
+				if i != 0 && name != "" {
+					result[name] = match[i]
+				}
+			}
+
+			arg := Args{
+				Contest: result["cont"],
+				Problem: result["prob"],
+			}
+			return arg, nil
+		}
+	}
+	return Args{}, ErrInvalidSpecifier
+}
diff --git a/atcoder/atcoder_test.go b/atcoder/atcoder_test.go
new file mode 100644
index 0000000..dd8a787
--- /dev/null
+++ b/atcoder/atcoder_test.go
@@ -0,0 +1,139 @@
+package atcoder
+
+import (
+	"fmt"
+	"os"
+	"reflect"
+	"testing"
+
+	"github.com/go-rod/rod"
+	"github.com/joho/godotenv"
+)
+
+func login(usr, passwd string) (string, error) {
+	p, err := loadPage(fmt.Sprintf("%v/login", hostURL))
+	if err != nil {
+		return "", err
+	}
+	defer p.Close()
+
+	if _, err := p.Race().Element(`alert`).Handle(handleErrMsg).
+		Element(`footer.footer`).Do(); err != nil {
+		return "", err
+	}
+
+	// Check if current user is logged in.
+	if handle := p.MustEval(`userScreenName`).String(); handle != "" {
+		return handle, nil
+	}
+	// Otherwise, login.
+	p.MustElement("#username").Input(usr)
+	p.MustElement("#password").Input(passwd)
+	p.MustElement("#submit").MustClick().WaitInvisible()
+
+	if _, err := p.Race().ElementR(`.alert`, `Username or Password is incorrect`).
+		Handle(func(e *rod.Element) error { return fmt.Errorf(e.MustText()) }).
+		Element(`.navbar-right>li:last-child>a[class]`).Do(); err != nil {
+		return "", err
+	}
+
+	handle := p.MustEval(`userScreenName`).String()
+	return handle, nil
+}
+
+func getLoginCredentials() (string, string) {
+	// setup login access to use
+	usr := os.Getenv("ATCODER_USERNAME")
+	passwd := os.Getenv("ATCODER_PASSWORD")
+	return usr, passwd
+}
+
+func TestMain(m *testing.M) {
+	// Load local .env file.
+	godotenv.Load()
+
+	_, browserHeadless := os.LookupEnv("BROWSER_HEADLESS")
+	browserBin := os.Getenv("BROWSER_BINARY")
+	if err := Start(browserHeadless, "", browserBin); err != nil {
+		fmt.Println("Failed to start browser:", err)
+		os.Exit(1)
+	}
+
+	if _, err := login(getLoginCredentials()); err != nil {
+		fmt.Println("Login failed:", err)
+		Browser.Close()
+		os.Exit(1)
+	}
+
+	exitCode := m.Run()
+
+	Browser.Close()
+	os.Exit(exitCode)
+}
+
+func TestParse(t *testing.T) {
+	type args struct {
+		str string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    Args
+		wantErr bool
+	}{
+		{
+			name:    "Test #1",
+			args:    args{"https://atcoder.jp/contests/acl1"},
+			want:    Args{"acl1", ""},
+			wantErr: false,
+		},
+		{
+			name:    "Test #2",
+			args:    args{"https://atcoder.jp/contests/m-solutions2020/tasks/m_solutions2020_a"},
+			want:    Args{"m-solutions2020", "m_solutions2020_a"},
+			wantErr: false,
+		},
+		{
+			name:    "Test #3",
+			args:    args{"arc107"},
+			want:    Args{"arc107", ""},
+			wantErr: false,
+		},
+		{
+			name:    "Test #4", // Problem id need not match contest id.
+			args:    args{"arc9999 aproblem"},
+			want:    Args{"arc9999", "aproblem"},
+			wantErr: false,
+		},
+		{
+			name:    "Test #5",
+			args:    args{"in_valid"},
+			want:    Args{},
+			wantErr: true,
+		},
+		{
+			name:    "Test #6",
+			args:    args{"in-valid in-valid"},
+			want:    Args{},
+			wantErr: true,
+		},
+		{
+			name:    "Test #7",
+			args:    args{""},
+			want:    Args{},
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := Parse(tt.args.str)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Parse() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("Parse() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
diff --git a/atcoder/contests.go b/atcoder/contests.go
new file mode 100644
index 0000000..ff8c344
--- /dev/null
+++ b/atcoder/contests.go
@@ -0,0 +1,59 @@
+package atcoder
+
+import (
+	"regexp"
+	"time"
+)
+
+func (p *page) getCountdown() (time.Duration, error) {
+	// First check for virtual countdown.
+	if match := regexp.MustCompile(`var virtualStartTime = moment\("(.*)"\)`).
+		FindStringSubmatch(p.MustElement("html").MustHTML()); len(match) == 2 {
+		startTime, err := time.Parse(time.RFC3339Nano, match[1])
+		if err != nil {
+			return 0, err
+		}
+
+		dur := time.Until(startTime).Truncate(time.Second)
+		if dur < 0 { // Virtual already started; No countdown
+			dur = 0
+		}
+		return dur, nil
+	}
+
+	// Parse actual contest start time.
+	startTimeStr := p.MustEval("startTime._d.toISOString()").String()
+	startTime, err := time.Parse(time.RFC3339Nano, startTimeStr)
+	if err != nil {
+		return 0, err
+	}
+
+	dur := time.Until(startTime).Truncate(time.Second)
+	if dur < 0 { // Contest already started; No countdown
+		dur = 0
+	}
+	return dur, nil
+}
+
+// GetCountdown ...
+func (arg Args) GetCountdown() (time.Duration, error) {
+	link, err := arg.VirtualPage()
+	if err != nil {
+		return 0, err
+	}
+
+	p, err := loadPage(link)
+	if err != nil {
+		return 0, err
+	}
+	defer p.Close()
+
+	_, err = p.Race().Element(`.alert`).Handle(handleErrMsg).
+		Element(`footer.footer`).Do()
+
+	if err != nil {
+		return 0, err
+	}
+
+	return p.getCountdown()
+}
diff --git a/atcoder/contests_test.go b/atcoder/contests_test.go
new file mode 100644
index 0000000..ec7266a
--- /dev/null
+++ b/atcoder/contests_test.go
@@ -0,0 +1,40 @@
+package atcoder
+
+import (
+	"testing"
+	"time"
+)
+
+func TestArgs_GetCountdown(t *testing.T) {
+	tests := []struct {
+		name    string
+		arg     Args
+		want    time.Duration
+		wantErr bool
+	}{
+		{
+			name:    "Test #1",
+			arg:     Args{"abc180", ""},
+			want:    0,
+			wantErr: false,
+		},
+		{
+			name:    "Test #2",
+			arg:     Args{"InVaLiD123", ""},
+			want:    0,
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := tt.arg.GetCountdown()
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Args.GetCountdown() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("Args.GetCountdown() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
diff --git a/atcoder/pages.go b/atcoder/pages.go
new file mode 100644
index 0000000..4c9e5c4
--- /dev/null
+++ b/atcoder/pages.go
@@ -0,0 +1,24 @@
+package atcoder
+
+import "fmt"
+
+// DashboardPage returns link to dashboard of contest
+func (arg Args) DashboardPage() (link string, err error) {
+	if arg.Contest == "" {
+		return "", ErrInvalidSpecifier
+	}
+
+	link = fmt.Sprintf("%v/contests/%v", hostURL, arg.Contest)
+	return
+}
+
+// VirtualPage returns link to virtual contest tab.
+func (arg Args) VirtualPage() (link string, err error) {
+	if arg.Contest == "" {
+		return "", ErrInvalidSpecifier
+	}
+
+	dashboardLink, _ := arg.DashboardPage()
+	link = fmt.Sprintf("%v/virtual", dashboardLink)
+	return
+}
diff --git a/atcoder/pages_test.go b/atcoder/pages_test.go
new file mode 100644
index 0000000..af35abe
--- /dev/null
+++ b/atcoder/pages_test.go
@@ -0,0 +1,71 @@
+package atcoder
+
+import "testing"
+
+func TestArgs_DashboardPage(t *testing.T) {
+	tests := []struct {
+		name     string
+		arg      Args
+		wantLink string
+		wantErr  bool
+	}{
+		{
+			name:     "Test #1",
+			arg:      Args{"hhkb2020", ""},
+			wantLink: "https://atcoder.jp/contests/hhkb2020",
+			wantErr:  false,
+		},
+		{
+			name:     "Test #2",
+			arg:      Args{},
+			wantLink: "",
+			wantErr:  true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotLink, err := tt.arg.DashboardPage()
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Args.DashboardPage() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if gotLink != tt.wantLink {
+				t.Errorf("Args.DashboardPage() = %v, want %v", gotLink, tt.wantLink)
+			}
+		})
+	}
+}
+
+func TestArgs_VirtualPage(t *testing.T) {
+	tests := []struct {
+		name     string
+		arg      Args
+		wantLink string
+		wantErr  bool
+	}{
+		{
+			name:     "Test #1",
+			arg:      Args{"tokiomarine2020", ""},
+			wantLink: "https://atcoder.jp/contests/tokiomarine2020/virtual",
+			wantErr:  false,
+		},
+		{
+			name:     "Test #2",
+			arg:      Args{},
+			wantLink: "",
+			wantErr:  true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotLink, err := tt.arg.VirtualPage()
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Args.DashboardPage() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if gotLink != tt.wantLink {
+				t.Errorf("Args.DashboardPage() = %v, want %v", gotLink, tt.wantLink)
+			}
+		})
+	}
+}
diff --git a/atcoder/utils.go b/atcoder/utils.go
new file mode 100644
index 0000000..53d8988
--- /dev/null
+++ b/atcoder/utils.go
@@ -0,0 +1,27 @@
+package atcoder
+
+import (
+	"fmt"
+
+	"github.com/cp-tools/cpt-lib/util"
+	"github.com/go-rod/rod"
+	"github.com/go-rod/rod/lib/proto"
+)
+
+func loadPage(link string) (*page, error) {
+	// Blocking these files results in faster page loading.
+	resourcesToBlock := []proto.NetworkResourceType{
+		proto.NetworkResourceTypeFont,
+		proto.NetworkResourceTypeMedia,
+		proto.NetworkResourceTypeImage,
+		proto.NetworkResourceTypeStylesheet,
+	}
+
+	p, err := util.NewPage(Browser, link, resourcesToBlock)
+	return &page{p}, err
+}
+
+func handleErrMsg(e *rod.Element) error {
+	// There should be no notification.
+	return fmt.Errorf(e.MustText())
+}
diff --git a/go.mod b/go.mod
index fbd74d6..9ebd4d9 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,8 @@ module github.com/cp-tools/cpt-lib
 
 go 1.14
 
-require github.com/PuerkitoBio/goquery v1.5.1
+require (
+	github.com/PuerkitoBio/goquery v1.6.0
+	github.com/go-rod/rod v0.87.2
+	github.com/joho/godotenv v1.3.0
+)
diff --git a/go.sum b/go.sum
index 6b8db65..b2c07e0 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,21 @@
-github.com/PuerkitoBio/goquery v1.5.1 h1:PSPBGne8NIUWw+/7vFBV+kG2J/5MOjbzc7154OaKCSE=
-github.com/PuerkitoBio/goquery v1.5.1/go.mod h1:GsLWisAFVj4WgDibEWF4pvYnkVQBpKBKeU+7zCJoLcc=
+github.com/PuerkitoBio/goquery v1.6.0 h1:j7taAbelrdcsOlGeMenZxc2AWXD5fieT1/znArdnx94=
+github.com/PuerkitoBio/goquery v1.6.0/go.mod h1:GsLWisAFVj4WgDibEWF4pvYnkVQBpKBKeU+7zCJoLcc=
 github.com/andybalholm/cascadia v1.1.0 h1:BuuO6sSfQNFRu1LppgbD25Hr2vLYW25JvxHs5zzsLTo=
 github.com/andybalholm/cascadia v1.1.0/go.mod h1:GsXiBklL0woXo1j/WYWtSYYC4ouU9PqHO0sqidkEA4Y=
+github.com/go-rod/rod v0.87.2 h1:zlos09t7oV1kDxgz26oRvcYX0mQkjeJSNJugq9MUCno=
+github.com/go-rod/rod v0.87.2/go.mod h1:UEYVhPXlrtQIL1Nlnq/fPY7Q5pB708UIEy5IKtNVuFg=
+github.com/joho/godotenv v1.3.0 h1:Zjp+RcGpHhGlrMbJzXTrZZPrWj+1vfm90La1wgB6Bhc=
+github.com/joho/godotenv v1.3.0/go.mod h1:7hK45KPybAkOC6peb+G5yklZfMxEjkZhHbwpqxOKXbg=
+github.com/ysmood/goob v0.3.0 h1:XZ51cZJ4W3WCoCiUktixzMIQF86W7G5VFL4QQ/Q2uS0=
+github.com/ysmood/goob v0.3.0/go.mod h1:S3lq113Y91y1UBf1wj1pFOxeahvfKkCk6mTWTWbDdWs=
+github.com/ysmood/got v0.8.9 h1:fUbi0c03DSNdo82DWd4m6l63WswtJDqwBPTcrrKMUHU=
+github.com/ysmood/got v0.8.9/go.mod h1:pE1l4LOwOBhQg6A/8IAatkGp7uZjnalzrZolnlhhMgY=
+github.com/ysmood/gotrace v0.1.1 h1:1H9L1Rc0o/80+2Vtm3vn85rNVpNOo94/wf+G5qW0JY8=
+github.com/ysmood/gotrace v0.1.1/go.mod h1:TzhIG7nHDry5//eYZDYcTzuJLYQIkykJzCRIo4/dzQM=
+github.com/ysmood/gson v0.6.3 h1:4cU+5oOdsyundXHy00t99H0rLXLthuseD3x6W+xmCiU=
+github.com/ysmood/gson v0.6.3/go.mod h1:3Kzs5zDl21g5F/BlLTNcuAGAYLKt2lV5G8D1zF3RNmg=
+github.com/ysmood/leakless v0.6.11 h1:9y8/5v9FjHFXo81vZyh+VQTQCLs+aFjuJJqbpn33TLg=
+github.com/ysmood/leakless v0.6.11/go.mod h1:R8iAXPRaG97QJwqxs74RdwzcRHT1SWCGTNqY8q0JvMQ=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/net v0.0.0-20180218175443-cbe0f9307d01/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20200202094626-16171245cfb2 h1:CCH4IOTTfewWjGOlSp+zGcjutRKlBEZQ6wTn8ozI/nI=
diff --git a/util/browser.go b/util/browser.go
new file mode 100644
index 0000000..7bc1dec
--- /dev/null
+++ b/util/browser.go
@@ -0,0 +1,88 @@
+package util
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/go-rod/rod"
+	"github.com/go-rod/rod/lib/launcher"
+	"github.com/go-rod/rod/lib/proto"
+)
+
+// NewBrowser initiates the automated browser to use.
+func NewBrowser(headless bool, userDataDir, bin string) (*rod.Browser, error) {
+	// Launch browser.
+	launchBrowser := func(controlURL string) (*rod.Browser, error) {
+		b := rod.New().ControlURL(controlURL)
+		if err := b.Connect(); err != nil {
+			return nil, err
+		}
+		return b, nil
+	}
+
+	// Store data in cache (to reduce time).
+	cacheDir, _ := os.UserCacheDir()
+	cacheUserDataDir := filepath.Join(cacheDir, "cp-tools", "cpt-lib", bin)
+
+	// Initiate the browser to use.
+	l := launcher.New().
+		UserDataDir(cacheUserDataDir).
+		Headless(headless).
+		Bin(bin)
+
+	controlURL, err := l.Launch()
+	if err != nil {
+		return nil, err
+	}
+
+	Browser, err := launchBrowser(controlURL)
+	if err != nil {
+		return nil, err
+	}
+
+	// Load temporary browser to extract cookies only if path exists.
+	if file, err := os.Stat(userDataDir); err == nil && file.IsDir() {
+		// Initiate browser to extract cookies from.
+		cookiesl := launcher.NewUserMode().
+			UserDataDir(userDataDir).
+			Headless(true).
+			Bin(bin)
+
+		cookiesControlURL, err := cookiesl.Launch()
+		if err != nil {
+			return nil, err
+		}
+
+		cookiesBrowser, err := launchBrowser(cookiesControlURL)
+		if err != nil {
+			return nil, err
+		}
+		defer cookiesBrowser.Close()
+		// Copy cookies of user.
+		Browser.MustSetCookies(cookiesBrowser.MustGetCookies())
+	}
+
+	return Browser, nil
+}
+
+// NewPage loads the given link in a new browser tab.
+func NewPage(browser *rod.Browser, link string, block []proto.NetworkResourceType) (*rod.Page, error) {
+	page, err := browser.Page(proto.TargetCreateTarget{URL: link})
+	if err != nil {
+		return nil, err
+	}
+
+	router := page.HijackRequests()
+	router.MustAdd("*", func(h *rod.Hijack) {
+		for _, b := range block {
+			if h.Request.Type() == b {
+				h.Response.Fail(proto.NetworkErrorReasonBlockedByClient)
+				return
+			}
+		}
+		h.ContinueRequest(&proto.FetchContinueRequest{})
+	})
+	go router.Run()
+
+	return page, nil
+}
diff --git a/util/strings.go b/util/strings.go
new file mode 100644
index 0000000..9468eef
--- /dev/null
+++ b/util/strings.go
@@ -0,0 +1,29 @@
+package util
+
+import (
+	"math/rand"
+	"regexp"
+)
+
+// StrClean replaces all unicode space
+// characters in the string with ascii space.
+func StrClean(str string) string {
+	re := regexp.MustCompile(`\p{Z}`)
+	return re.ReplaceAllString(str, " ")
+}
+
+// StrRandom generates a random string of length n.
+// The returned string is strictly alpha-numeric.
+// Attrib: https://stackoverflow.com/a/31832326/9606036.
+func StrRandom(n int) string {
+	const charBytes = "abcdefghijklmnopqrstuvwxyz" +
+		"ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
+		"0123456789"
+
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = charBytes[rand.Intn(len(charBytes))]
+	}
+
+	return string(b)
+}