app.py

# -*- coding: utf-8 -*-
"""
YieldBridge — Fixed Income Analytics Platform
Entry point: navigation shell + global CSS injection.
Run with: streamlit run app.py
"""
import streamlit as st
from utils.styling import inject_css

st.set_page_config(
    page_title="YieldBridge | Fixed Income Analytics",
    page_icon="📈",
    layout="wide",
    initial_sidebar_state="expanded",
)

inject_css()

# ── Language initialisation (default: Chinese) ───────────────────────────────
if "lang" not in st.session_state:
    st.session_state.lang = "zh"

# ── Sidebar branding + language toggle ───────────────────────────────────────
with st.sidebar:
    st.markdown(
        """
        <div style="
            padding: 1.5rem 0 1.25rem;
            text-align: center;
            border-bottom: 1px solid #C9A84C;
            margin-bottom: 1.25rem;
        ">
          <div style="font-size: 1.8rem; margin-bottom: 0.25rem;">📈</div>
          <h2 style="
              color: #C9A84C;
              margin: 0;
              font-size: 1.5rem;
              font-weight: 800;
              letter-spacing: 0.04em;
              font-family: 'Segoe UI', Arial, sans-serif;
          ">YieldBridge</h2>
          <p id="subtitle" style="
              color: #9CA3AF;
              margin: 0.3rem 0 0;
              font-size: 0.7rem;
              text-transform: uppercase;
              letter-spacing: 0.14em;
              font-family: 'Segoe UI', Arial, sans-serif;
          ">Fixed Income Analytics</p>
        </div>
        """,
        unsafe_allow_html=True,
    )

    # Language toggle
    lang_choice = st.radio(
        "🌐",
        options=["中文", "EN"],
        index=0 if st.session_state.lang == "zh" else 1,
        horizontal=True,
        label_visibility="collapsed",
    )
    st.session_state.lang = "zh" if lang_choice == "中文" else "en"

    st.markdown(
        "<div style='margin-bottom:0.5rem; border-bottom:1px solid #1B3A6B;'></div>",
        unsafe_allow_html=True,
    )

# ── Multi-page navigation ─────────────────────────────────────────────────────
pg = st.navigation(
    [
        st.Page("pages/mortgage.py",     title="房贷计算机 / Mortgage", icon="🏠"),
        st.Page("pages/fixed_income.py", title="固定收益 / Fixed Income", icon="📊"),
        st.Page("pages/glossary.py",     title="CFA词汇表 / Glossary",  icon="📖"),
    ]
)
pg.run()