Implement complete calendar creation functionality

Add full end-to-end calendar creation feature including:
- Create Calendar button in sidebar footer
- Modal form with name, description, and color picker (16 predefined colors in 4x4 grid)
- Form validation and error handling with loading states
- Backend API endpoint for calendar creation with authentication
- CalDAV MKCALENDAR protocol implementation with proper XML generation
- Real-time calendar list refresh after successful creation
- Responsive design for mobile and desktop

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/src/calendar.rs

@@ -590,6 +590,74 @@ impl CalDAVClient {
         
         Err(CalDAVError::ParseError(format!("Unable to parse datetime: {}", datetime_str)))
     }
+
+    /// Create a new calendar on the CalDAV server using MKCALENDAR
+    pub async fn create_calendar(&self, name: &str, description: Option<&str>, color: Option<&str>) -> Result<(), CalDAVError> {
+        // Sanitize calendar name for URL path
+        let calendar_id = name
+            .chars()
+            .map(|c| if c.is_alphanumeric() { c } else { '-' })
+            .collect::<String>()
+            .to_lowercase();
+        
+        let calendar_path = format!("/calendars/{}/{}/", self.config.username, calendar_id);
+        let full_url = format!("{}{}", self.config.server_url.trim_end_matches('/'), calendar_path);
+        
+        // Build color property if provided
+        let color_property = if let Some(color) = color {
+            format!(r#"<ic:calendar-color xmlns:ic="http://apple.com/ns/ical/">{}</ic:calendar-color>"#, color)
+        } else {
+            String::new()
+        };
+        
+        let description_property = if let Some(desc) = description {
+            format!(r#"<c:calendar-description xmlns:c="urn:ietf:params:xml:ns:caldav">{}</c:calendar-description>"#, desc)
+        } else {
+            String::new()
+        };
+        
+        // Create the MKCALENDAR request body
+        let mkcalendar_body = format!(
+            r#"<?xml version="1.0" encoding="utf-8" ?>
+<c:mkcalendar xmlns:d="DAV:" xmlns:c="urn:ietf:params:xml:ns:caldav" xmlns:ic="http://apple.com/ns/ical/">
+    <d:set>
+        <d:prop>
+            <d:displayname>{}</d:displayname>
+            <c:supported-calendar-component-set>
+                <c:comp name="VEVENT"/>
+            </c:supported-calendar-component-set>
+            {}
+            {}
+        </d:prop>
+    </d:set>
+</c:mkcalendar>"#,
+            name, color_property, description_property
+        );
+        
+        println!("Creating calendar at: {}", full_url);
+        println!("MKCALENDAR body: {}", mkcalendar_body);
+        
+        let response = self.http_client
+            .request(reqwest::Method::from_bytes(b"MKCALENDAR").unwrap(), &full_url)
+            .header("Content-Type", "application/xml; charset=utf-8")
+            .header("Authorization", format!("Basic {}", self.config.get_basic_auth()))
+            .body(mkcalendar_body)
+            .send()
+            .await
+            .map_err(|e| CalDAVError::ParseError(e.to_string()))?;
+
+        println!("Calendar creation response status: {}", response.status());
+        
+        if response.status().is_success() {
+            println!("✅ Calendar created successfully at {}", calendar_path);
+            Ok(())
+        } else {
+            let status = response.status();
+            let error_body = response.text().await.unwrap_or_default();
+            println!("❌ Calendar creation failed: {} - {}", status, error_body);
+            Err(CalDAVError::ServerError(status.as_u16()))
+        }
+    }
 }
 
 /// Helper struct for extracting calendar data from XML responses
@@ -688,7 +756,9 @@ mod tests {
         }
     }
 
-    /// Test parsing a sample iCal event
+}
+
+/// Test parsing a sample iCal event
     #[test]
     fn test_parse_ical_event() {
         let sample_ical = r#"BEGIN:VCALENDAR
@@ -780,4 +850,3 @@ END:VCALENDAR"#;
         
         println!("✓ Event enum tests passed!");
     }
-}

backend/src/handlers.rs

@@ -7,7 +7,7 @@ use serde::Deserialize;
 use std::sync::Arc;
 use chrono::Datelike;
 
-use crate::{AppState, models::{CalDAVLoginRequest, AuthResponse, ApiError, UserInfo, CalendarInfo}};
+use crate::{AppState, models::{CalDAVLoginRequest, AuthResponse, ApiError, UserInfo, CalendarInfo, CreateCalendarRequest, CreateCalendarResponse}};
 use crate::calendar::{CalDAVClient, CalendarEvent};
 
 #[derive(Deserialize)]
@@ -253,3 +253,43 @@ fn extract_password_header(headers: &HeaderMap) -> Result<String, ApiError> {
         Err(ApiError::BadRequest("X-CalDAV-Password header required".to_string()))
     }
 }
+
+pub async fn create_calendar(
+    State(state): State<Arc<AppState>>,
+    headers: HeaderMap,
+    Json(request): Json<CreateCalendarRequest>,
+) -> Result<Json<CreateCalendarResponse>, ApiError> {
+    println!("📝 Create calendar request received: name='{}', description={:?}, color={:?}", 
+             request.name, request.description, request.color);
+    
+    // Extract and verify token
+    let token = extract_bearer_token(&headers)?;
+    let password = extract_password_header(&headers)?;
+
+    // Validate request
+    if request.name.trim().is_empty() {
+        return Err(ApiError::BadRequest("Calendar name is required".to_string()));
+    }
+    
+    if request.name.len() > 100 {
+        return Err(ApiError::BadRequest("Calendar name too long (max 100 characters)".to_string()));
+    }
+
+    // Create CalDAV config from token and password
+    let config = state.auth_service.caldav_config_from_token(&token, &password)?;
+    let client = CalDAVClient::new(config);
+
+    // Create the calendar
+    client.create_calendar(
+        &request.name,
+        request.description.as_deref(),
+        request.color.as_deref()
+    )
+    .await
+    .map_err(|e| ApiError::Internal(format!("Failed to create calendar: {}", e)))?;
+
+    Ok(Json(CreateCalendarResponse {
+        success: true,
+        message: "Calendar created successfully".to_string(),
+    }))
+}

backend/src/lib.rs

@@ -38,6 +38,7 @@ pub async fn run_server() -> Result<(), Box<dyn std::error::Error>> {
         .route("/api/auth/login", post(handlers::login))
         .route("/api/auth/verify", get(handlers::verify_token))
         .route("/api/user/info", get(handlers::get_user_info))
+        .route("/api/calendar/create", post(handlers::create_calendar))
         .route("/api/calendar/events", get(handlers::get_calendar_events))
         .route("/api/calendar/events/:uid", get(handlers::refresh_event))
         .layer(

backend/src/models.rs

@@ -34,6 +34,19 @@ pub struct CalendarInfo {
     pub color: String,
 }
 
+#[derive(Debug, Deserialize)]
+pub struct CreateCalendarRequest {
+    pub name: String,
+    pub description: Option<String>,
+    pub color: Option<String>,
+}
+
+#[derive(Debug, Serialize)]
+pub struct CreateCalendarResponse {
+    pub success: bool,
+    pub message: String,
+}
+
 // Error handling
 #[derive(Debug)]
 pub enum ApiError {

src/app.rs

@@ -1,7 +1,7 @@
 use yew::prelude::*;
 use yew_router::prelude::*;
 use gloo_storage::{LocalStorage, Storage};
-use crate::components::{Login, Calendar};
+use crate::components::{Login, Calendar, CreateCalendarModal};
 use crate::services::{CalendarService, CalendarEvent, UserInfo};
 use std::collections::HashMap;
 use chrono::{Local, NaiveDate, Datelike};
@@ -24,6 +24,7 @@ pub fn App() -> Html {
     
     let user_info = use_state(|| -> Option<UserInfo> { None });
     let color_picker_open = use_state(|| -> Option<String> { None }); // Store calendar path of open picker
+    let create_modal_open = use_state(|| false);
     
     // Available colors for calendar customization
     let available_colors = [
@@ -113,6 +114,11 @@ pub fn App() -> Html {
         })
     };
 
+    // Clone variables needed for the modal outside of the conditional blocks
+    let auth_token_for_modal = auth_token.clone();
+    let user_info_for_modal = user_info.clone();
+    let create_modal_open_for_modal = create_modal_open.clone();
+
     html! {
         <BrowserRouter>
             <div class="app" onclick={on_outside_click}>
@@ -148,7 +154,7 @@ pub fn App() -> Html {
                                                         <ul>
                                                             {
                                                                 info.calendars.iter().map(|cal| {
-                                                                    let cal_clone = cal.clone();
+                                                                    let _cal_clone = cal.clone();
                                                                     let color_picker_open_clone = color_picker_open.clone();
                                                                     
                                                                     let on_color_click = {
@@ -229,6 +235,12 @@ pub fn App() -> Html {
                                         }
                                     }
                                     <div class="sidebar-footer">
+                                        <button onclick={Callback::from({
+                                            let create_modal_open = create_modal_open.clone();
+                                            move |_| create_modal_open.set(true)
+                                        })} class="create-calendar-button">
+                                            {"+ Create Calendar"}
+                                        </button>
                                         <button onclick={on_logout} class="logout-button">{"Logout"}</button>
                                     </div>
                                 </aside>
@@ -299,6 +311,74 @@ pub fn App() -> Html {
                         }
                     }
                 }
+                
+                <CreateCalendarModal 
+                    is_open={*create_modal_open}
+                    on_close={Callback::from({
+                        let create_modal_open = create_modal_open_for_modal.clone();
+                        move |_| create_modal_open.set(false)
+                    })}
+                    on_create={Callback::from({
+                        let auth_token = auth_token_for_modal.clone();
+                        let user_info = user_info_for_modal.clone();
+                        let create_modal_open = create_modal_open_for_modal.clone();
+                        move |(name, description, color): (String, Option<String>, Option<String>)| {
+                            if let Some(token) = (*auth_token).clone() {
+                                let user_info = user_info.clone();
+                                let create_modal_open = create_modal_open.clone();
+                                
+                                wasm_bindgen_futures::spawn_local(async move {
+                                    let calendar_service = CalendarService::new();
+                                    
+                                    // Get password from stored credentials
+                                    let password = if let Ok(credentials_str) = LocalStorage::get::<String>("caldav_credentials") {
+                                        if let Ok(credentials) = serde_json::from_str::<serde_json::Value>(&credentials_str) {
+                                            credentials["password"].as_str().unwrap_or("").to_string()
+                                        } else {
+                                            String::new()
+                                        }
+                                    } else {
+                                        String::new()
+                                    };
+                                    
+                                    match calendar_service.create_calendar(&token, &password, name, description, color).await {
+                                        Ok(_) => {
+                                            web_sys::console::log_1(&"Calendar created successfully!".into());
+                                            // Refresh user info to show the new calendar
+                                            match calendar_service.fetch_user_info(&token, &password).await {
+                                                Ok(mut info) => {
+                                                    // Load saved colors from local storage
+                                                    if let Ok(saved_colors_json) = LocalStorage::get::<String>("calendar_colors") {
+                                                        if let Ok(saved_info) = serde_json::from_str::<UserInfo>(&saved_colors_json) {
+                                                            for saved_cal in &saved_info.calendars {
+                                                                for cal in &mut info.calendars {
+                                                                    if cal.path == saved_cal.path {
+                                                                        cal.color = saved_cal.color.clone();
+                                                                    }
+                                                                }
+                                                            }
+                                                        }
+                                                    }
+                                                    user_info.set(Some(info));
+                                                }
+                                                Err(err) => {
+                                                    web_sys::console::log_1(&format!("Failed to refresh calendars: {}", err).into());
+                                                }
+                                            }
+                                            create_modal_open.set(false);
+                                        }
+                                        Err(err) => {
+                                            web_sys::console::log_1(&format!("Failed to create calendar: {}", err).into());
+                                            // TODO: Show error to user
+                                            create_modal_open.set(false);
+                                        }
+                                    }
+                                });
+                            }
+                        }
+                    })}
+                    available_colors={available_colors.iter().map(|c| c.to_string()).collect::<Vec<_>>()}
+                />
             </div>
         </BrowserRouter>
     }

src/components/create_calendar_modal.rs

@@ -0,0 +1,196 @@
+use yew::prelude::*;
+
+#[derive(Properties, PartialEq)]
+pub struct CreateCalendarModalProps {
+    pub is_open: bool,
+    pub on_close: Callback<()>,
+    pub on_create: Callback<(String, Option<String>, Option<String>)>, // name, description, color
+    pub available_colors: Vec<String>,
+}
+
+#[function_component]
+pub fn CreateCalendarModal(props: &CreateCalendarModalProps) -> Html {
+    let calendar_name = use_state(|| String::new());
+    let description = use_state(|| String::new());
+    let selected_color = use_state(|| None::<String>);
+    let error_message = use_state(|| None::<String>);
+    let is_creating = use_state(|| false);
+
+    let on_name_change = {
+        let calendar_name = calendar_name.clone();
+        Callback::from(move |e: InputEvent| {
+            let input: web_sys::HtmlInputElement = e.target_unchecked_into();
+            calendar_name.set(input.value());
+        })
+    };
+
+    let on_description_change = {
+        let description = description.clone();
+        Callback::from(move |e: InputEvent| {
+            let input: web_sys::HtmlTextAreaElement = e.target_unchecked_into();
+            description.set(input.value());
+        })
+    };
+
+    let on_submit = {
+        let calendar_name = calendar_name.clone();
+        let description = description.clone();
+        let selected_color = selected_color.clone();
+        let error_message = error_message.clone();
+        let is_creating = is_creating.clone();
+        let on_create = props.on_create.clone();
+        
+        Callback::from(move |e: SubmitEvent| {
+            e.prevent_default();
+            
+            let name = (*calendar_name).trim();
+            if name.is_empty() {
+                error_message.set(Some("Calendar name is required".to_string()));
+                return;
+            }
+            
+            if name.len() > 100 {
+                error_message.set(Some("Calendar name too long (max 100 characters)".to_string()));
+                return;
+            }
+            
+            error_message.set(None);
+            is_creating.set(true);
+            
+            let desc = if (*description).trim().is_empty() {
+                None
+            } else {
+                Some((*description).clone())
+            };
+            
+            on_create.emit((name.to_string(), desc, (*selected_color).clone()));
+        })
+    };
+
+    let on_backdrop_click = {
+        let on_close = props.on_close.clone();
+        Callback::from(move |e: MouseEvent| {
+            // Only close if clicking the backdrop, not the modal content
+            if e.target() == e.current_target() {
+                on_close.emit(());
+            }
+        })
+    };
+
+    if !props.is_open {
+        return html! {};
+    }
+
+    html! {
+        <div class="modal-backdrop" onclick={on_backdrop_click}>
+            <div class="create-calendar-modal">
+                <div class="modal-header">
+                    <h2>{"Create New Calendar"}</h2>
+                    <button class="close-button" onclick={props.on_close.reform(|_| ())}>
+                        {"×"}
+                    </button>
+                </div>
+                
+                <form class="modal-body" onsubmit={on_submit}>
+                    {
+                        if let Some(ref error) = *error_message {
+                            html! {
+                                <div class="error-message">
+                                    {error}
+                                </div>
+                            }
+                        } else {
+                            html! {}
+                        }
+                    }
+                    
+                    <div class="form-group">
+                        <label for="calendar-name">{"Calendar Name *"}</label>
+                        <input 
+                            id="calendar-name"
+                            type="text"
+                            value={(*calendar_name).clone()}
+                            oninput={on_name_change}
+                            placeholder="Enter calendar name"
+                            maxlength="100"
+                            disabled={*is_creating}
+                        />
+                    </div>
+                    
+                    <div class="form-group">
+                        <label for="calendar-description">{"Description"}</label>
+                        <textarea
+                            id="calendar-description"
+                            value={(*description).clone()}
+                            oninput={on_description_change}
+                            placeholder="Optional calendar description"
+                            rows="3"
+                            disabled={*is_creating}
+                        />
+                    </div>
+                    
+                    <div class="form-group">
+                        <label>{"Calendar Color"}</label>
+                        <div class="color-grid">
+                            {
+                                props.available_colors.iter().enumerate().map(|(index, color)| {
+                                    let color = color.clone();
+                                    let selected_color = selected_color.clone();
+                                    let is_selected = selected_color.as_ref() == Some(&color);
+                                    let on_color_select = {
+                                        let color = color.clone();
+                                        Callback::from(move |_: MouseEvent| {
+                                            selected_color.set(Some(color.clone()));
+                                        })
+                                    };
+                                    
+                                    let class_name = if is_selected { 
+                                        "color-option selected" 
+                                    } else { 
+                                        "color-option" 
+                                    };
+                                    
+                                    html! {
+                                        <button
+                                            key={index}
+                                            type="button"
+                                            class={class_name}
+                                            style={format!("background-color: {}", color)}
+                                            onclick={on_color_select}
+                                            disabled={*is_creating}
+                                        />
+                                    }
+                                }).collect::<Html>()
+                            }
+                        </div>
+                        <p class="color-help-text">{"Optional: Choose a color for your calendar"}</p>
+                    </div>
+                    
+                    <div class="modal-actions">
+                        <button 
+                            type="button" 
+                            class="cancel-button"
+                            onclick={props.on_close.reform(|_| ())}
+                            disabled={*is_creating}
+                        >
+                            {"Cancel"}
+                        </button>
+                        <button 
+                            type="submit" 
+                            class="create-button"
+                            disabled={*is_creating}
+                        >
+                            {
+                                if *is_creating {
+                                    "Creating..."
+                                } else {
+                                    "Create Calendar"
+                                }
+                            }
+                        </button>
+                    </div>
+                </form>
+            </div>
+        </div>
+    }
+}

src/components/mod.rs

@@ -1,7 +1,9 @@
 pub mod login;
 pub mod calendar;
 pub mod event_modal;
+pub mod create_calendar_modal;
 
 pub use login::Login;
 pub use calendar::Calendar;
 pub use event_modal::EventModal;
+pub use create_calendar_modal::CreateCalendarModal;

src/services/calendar_service.rs

@@ -467,6 +467,67 @@ impl CalendarService {
         (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)
     }
 
+    /// Create a new calendar on the CalDAV server
+    pub async fn create_calendar(
+        &self, 
+        token: &str, 
+        password: &str,
+        name: String,
+        description: Option<String>,
+        color: Option<String>
+    ) -> Result<(), String> {
+        let window = web_sys::window().ok_or("No global window exists")?;
+        
+        let opts = RequestInit::new();
+        opts.set_method("POST");
+        opts.set_mode(RequestMode::Cors);
+
+        let body = serde_json::json!({
+            "name": name,
+            "description": description,
+            "color": color
+        });
+
+        let body_string = serde_json::to_string(&body)
+            .map_err(|e| format!("JSON serialization failed: {}", e))?;
+
+        opts.set_body(&body_string.into());
+
+        let url = format!("{}/calendar/create", self.base_url);
+        let request = Request::new_with_str_and_init(&url, &opts)
+            .map_err(|e| format!("Request creation failed: {:?}", e))?;
+
+        request.headers().set("Authorization", &format!("Bearer {}", token))
+            .map_err(|e| format!("Authorization header setting failed: {:?}", e))?;
+        
+        request.headers().set("X-CalDAV-Password", password)
+            .map_err(|e| format!("Password header setting failed: {:?}", e))?;
+
+        request.headers().set("Content-Type", "application/json")
+            .map_err(|e| format!("Content-Type header setting failed: {:?}", e))?;
+
+        let resp_value = JsFuture::from(window.fetch_with_request(&request))
+            .await
+            .map_err(|e| format!("Network request failed: {:?}", e))?;
+
+        let resp: Response = resp_value.dyn_into()
+            .map_err(|e| format!("Response cast failed: {:?}", e))?;
+
+        let text = JsFuture::from(resp.text()
+            .map_err(|e| format!("Text extraction failed: {:?}", e))?)
+            .await
+            .map_err(|e| format!("Text promise failed: {:?}", e))?;
+
+        let text_string = text.as_string()
+            .ok_or("Response text is not a string")?;
+
+        if resp.ok() {
+            Ok(())
+        } else {
+            Err(format!("Request failed with status {}: {}", resp.status(), text_string))
+        }
+    }
+
     /// Refresh a single event by UID from the CalDAV server
     pub async fn refresh_event(&self, token: &str, password: &str, uid: &str) -> Result<Option<CalendarEvent>, String> {
         let window = web_sys::window().ok_or("No global window exists")?;

src/services/mod.rs

@@ -1,3 +1,3 @@
 pub mod calendar_service;
 
-pub use calendar_service::{CalendarService, CalendarEvent, EventReminder, ReminderAction, UserInfo, CalendarInfo};
+pub use calendar_service::{CalendarService, CalendarEvent, EventReminder, ReminderAction, UserInfo};

styles.css

@@ -829,3 +829,282 @@ body {
         padding: 1.5rem;
     }
 }
+
+/* Create Calendar Button */
+.create-calendar-button {
+    background: rgba(255, 255, 255, 0.2);
+    border: 1px solid rgba(255, 255, 255, 0.3);
+    color: white;
+    padding: 0.75rem 1rem;
+    border-radius: 8px;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    margin-bottom: 1rem;
+    font-size: 0.9rem;
+    font-weight: 500;
+    backdrop-filter: blur(10px);
+    width: 100%;
+}
+
+.create-calendar-button:hover {
+    background: rgba(255, 255, 255, 0.3);
+    border-color: rgba(255, 255, 255, 0.5);
+    transform: translateY(-1px);
+}
+
+.create-calendar-button:active {
+    transform: translateY(0);
+}
+
+/* Create Calendar Modal */
+.modal-backdrop {
+    position: fixed;
+    top: 0;
+    left: 0;
+    right: 0;
+    bottom: 0;
+    background: rgba(0, 0, 0, 0.5);
+    backdrop-filter: blur(4px);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    z-index: 1000;
+    padding: 2rem;
+}
+
+.create-calendar-modal {
+    background: white;
+    border-radius: 12px;
+    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
+    max-width: 500px;
+    width: 100%;
+    max-height: 90vh;
+    overflow-y: auto;
+    animation: modalSlideIn 0.3s ease;
+}
+
+@keyframes modalSlideIn {
+    from {
+        opacity: 0;
+        transform: scale(0.9) translateY(-20px);
+    }
+    to {
+        opacity: 1;
+        transform: scale(1) translateY(0);
+    }
+}
+
+.create-calendar-modal .modal-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    padding: 2rem 2rem 1rem;
+    border-bottom: 1px solid #e9ecef;
+}
+
+.create-calendar-modal .modal-header h2 {
+    margin: 0;
+    color: #495057;
+    font-size: 1.5rem;
+    font-weight: 600;
+}
+
+.close-button {
+    background: none;
+    border: none;
+    font-size: 1.5rem;
+    color: #6c757d;
+    cursor: pointer;
+    padding: 0.25rem;
+    line-height: 1;
+    border-radius: 4px;
+    transition: all 0.2s ease;
+}
+
+.close-button:hover {
+    color: #495057;
+    background: #f8f9fa;
+}
+
+.create-calendar-modal .modal-body {
+    padding: 1.5rem 2rem 2rem;
+}
+
+.form-group {
+    margin-bottom: 1.5rem;
+}
+
+.form-group label {
+    display: block;
+    margin-bottom: 0.5rem;
+    color: #495057;
+    font-weight: 500;
+    font-size: 0.9rem;
+}
+
+.form-group input,
+.form-group textarea {
+    width: 100%;
+    padding: 0.75rem;
+    border: 1px solid #ced4da;
+    border-radius: 8px;
+    font-size: 1rem;
+    transition: border-color 0.2s ease, box-shadow 0.2s ease;
+    font-family: inherit;
+}
+
+.form-group input:focus,
+.form-group textarea:focus {
+    outline: none;
+    border-color: #667eea;
+    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
+}
+
+.form-group input:disabled,
+.form-group textarea:disabled {
+    background-color: #f8f9fa;
+    color: #6c757d;
+    cursor: not-allowed;
+}
+
+.color-grid {
+    display: grid;
+    grid-template-columns: repeat(4, 1fr);
+    gap: 0.75rem;
+    margin: 0.75rem 0;
+}
+
+.color-option {
+    width: 40px;
+    height: 40px;
+    border: 3px solid transparent;
+    border-radius: 8px;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    position: relative;
+}
+
+.color-option:hover {
+    transform: scale(1.1);
+    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
+}
+
+.color-option.selected {
+    border-color: #495057;
+    transform: scale(1.1);
+    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
+}
+
+.color-option.selected::after {
+    content: '✓';
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    transform: translate(-50%, -50%);
+    color: white;
+    font-weight: bold;
+    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
+}
+
+.color-help-text {
+    font-size: 0.8rem;
+    color: #6c757d;
+    margin-top: 0.5rem;
+    margin-bottom: 0;
+}
+
+.modal-actions {
+    display: flex;
+    justify-content: flex-end;
+    gap: 1rem;
+    margin-top: 2rem;
+    padding-top: 1.5rem;
+    border-top: 1px solid #e9ecef;
+}
+
+.cancel-button,
+.create-button {
+    padding: 0.75rem 1.5rem;
+    border-radius: 8px;
+    font-size: 1rem;
+    font-weight: 500;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    border: none;
+}
+
+.cancel-button {
+    background: #f8f9fa;
+    color: #6c757d;
+    border: 1px solid #ced4da;
+}
+
+.cancel-button:hover:not(:disabled) {
+    background: #e9ecef;
+    color: #495057;
+}
+
+.create-button {
+    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+    color: white;
+}
+
+.create-button:hover:not(:disabled) {
+    transform: translateY(-1px);
+    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
+}
+
+.cancel-button:disabled,
+.create-button:disabled {
+    opacity: 0.6;
+    cursor: not-allowed;
+    transform: none !important;
+}
+
+.error-message {
+    background: #f8d7da;
+    color: #721c24;
+    padding: 0.75rem 1rem;
+    border: 1px solid #f5c6cb;
+    border-radius: 6px;
+    margin-bottom: 1rem;
+    font-size: 0.9rem;
+}
+
+/* Mobile adjustments for create calendar modal */
+@media (max-width: 768px) {
+    .modal-backdrop {
+        padding: 1rem;
+    }
+    
+    .create-calendar-modal {
+        max-height: 95vh;
+    }
+    
+    .create-calendar-modal .modal-header,
+    .create-calendar-modal .modal-body {
+        padding-left: 1.5rem;
+        padding-right: 1.5rem;
+    }
+    
+    .color-grid {
+        grid-template-columns: repeat(4, 1fr);
+        gap: 0.5rem;
+    }
+    
+    .color-option {
+        width: 35px;
+        height: 35px;
+    }
+    
+    .modal-actions {
+        flex-direction: column;
+        gap: 0.75rem;
+    }
+    
+    .cancel-button,
+    .create-button {
+        width: 100%;
+        text-align: center;
+    }
+}