"""
Custom CSS styles for CSH2 Web Dashboard — Dark HUD / Brutalist Industrial Theme
Uses CSS variables for maintainability. Font pairing: JetBrains Mono (labels/data) + DM Sans (body/prose).
"""
import streamlit as st


def inject_custom_css():
    """Inject Dark HUD theme with CSS variables and dual-font typography"""
    st.markdown("""
    <style>
    /* ============================================================
       A. FONT IMPORTS
       ============================================================ */
    @import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@300;400;500;600;700&family=DM+Sans:ital,wght@0,400;0,500;0,600;1,400&display=swap');

    /* ============================================================
       B. DESIGN TOKENS (:root variables)
       ============================================================ */
    :root {
        /* Backgrounds */
        --bg-base:        #0C0A08;
        --bg-panel:       #12100E;
        --bg-elevated:    #1A1714;
        --bg-hover:       #201C18;

        /* Borders */
        --border:         #2A2520;
        --border-heavy:   #3A3530;

        /* Text */
        --text-primary:   #E8E0D4;
        --text-secondary: #B0A898;
        --text-muted:     #6B6358;
        --text-dim:       #2A2520;

        /* Accent — Amber */
        --accent:         #D4A04A;
        --accent-light:   #E8C47A;
        --accent-bg:      rgba(212, 160, 74, 0.1);
        --accent-bg-hover:rgba(212, 160, 74, 0.25);

        /* Semantic */
        --status-nominal: #5B9A6E;
        --status-warning: #CC8F00;
        --status-alarm:   #CC3030;
        --info:           #5BA3B5;
        --info-bg:        rgba(91, 163, 181, 0.1);

        /* Typography */
        --font-mono:      'JetBrains Mono', 'Fira Code', 'Source Code Pro', monospace;
        --font-body:      'DM Sans', 'Inter', system-ui, sans-serif;

        /* Spacing */
        --space-xs:       4px;
        --space-sm:       8px;
        --space-md:       12px;
        --space-lg:       16px;
        --space-xl:       24px;

        /* Radii */
        --radius:         2px;
    }

    /* ============================================================
       C. GLOBAL TYPOGRAPHY
       ============================================================ */
    /* Mono for UI chrome: labels, metrics, navigation, buttons */
    [data-testid="stMetric"] label,
    [data-testid="stMetric"] [data-testid="stMetricValue"],
    [data-testid="stSidebarNavLink"],
    .stButton > button,
    .stDownloadButton > button,
    .stTabs [data-baseweb="tab"],
    h1, h2, h3,
    .hud-subtitle,
    .brand-footer {
        font-family: var(--font-mono) !important;
    }

    /* Sans-serif for body: paragraphs, analysis prose, captions, tooltips */
    p, li, .stCaption, .stMarkdown,
    .analysis-card div,
    [data-testid="stExpander"] summary,
    .stTextInput > div > div > input,
    .stTextArea > div > div > textarea,
    .stSelectbox,
    .stMultiSelect {
        font-family: var(--font-body) !important;
    }

    /* Tabular numbers on all numeric data */
    [data-testid="stMetricValue"],
    .stDataFrame td,
    .stDataFrame th {
        font-variant-numeric: tabular-nums !important;
    }

    /* Restore Material Icons for Streamlit internal UI */
    [data-testid="stSidebarCollapseButton"],
    [data-testid="stSidebarCollapseButton"] *,
    [data-testid="stSidebarNavLink"] span[data-testid="stIconMaterial"],
    [data-testid="stSidebarNavLink"] span[data-testid="stIconMaterial"] *,
    .material-symbols-rounded,
    .material-icons {
        font-family: 'Material Symbols Rounded', 'Material Icons', sans-serif !important;
        font-variant-ligatures: normal !important;
    }

    /* ============================================================
       D. MAIN CONTAINER
       ============================================================ */
    .stApp {
        background-color: var(--bg-base);
    }

    .main .block-container {
        padding-top: 2rem;
        padding-bottom: 2rem;
        max-width: 1400px;
    }

    /* ============================================================
       E. HEADINGS
       ============================================================ */
    h1 {
        color: var(--accent) !important;
        font-weight: 700 !important;
        letter-spacing: 1px;
        text-transform: uppercase;
        font-size: 1.5rem !important;
    }

    h2 {
        color: var(--text-secondary) !important;
        font-weight: 600 !important;
        border-bottom: 1px solid var(--border);
        padding-bottom: 0.3rem;
        text-transform: uppercase;
        font-size: 1.1rem !important;
        letter-spacing: 0.5px;
    }

    h3 {
        color: var(--text-secondary) !important;
        font-weight: 500 !important;
        font-size: 0.95rem !important;
        letter-spacing: 0.3px;
    }

    /* ============================================================
       F. METRIC CARDS — HUD PANELS WITH CORNER BRACKETS
       ============================================================ */
    div[data-testid="stMetric"] {
        background-color: var(--bg-panel);
        border: 1px solid var(--border);
        border-radius: var(--radius);
        padding: var(--space-md) var(--space-lg);
        box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
        position: relative;
        transition: box-shadow 0.3s ease;
    }

    div[data-testid="stMetric"]:hover {
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
    }

    /* Corner bracket — top left */
    div[data-testid="stMetric"]::before {
        content: '';
        position: absolute;
        top: 0;
        left: 0;
        width: 12px;
        height: 12px;
        border-top: 2px solid var(--accent);
        border-left: 2px solid var(--accent);
        pointer-events: none;
    }

    /* Corner bracket — bottom right */
    div[data-testid="stMetric"]::after {
        content: '';
        position: absolute;
        bottom: 0;
        right: 0;
        width: 12px;
        height: 12px;
        border-bottom: 2px solid var(--accent);
        border-right: 2px solid var(--accent);
        pointer-events: none;
    }

    div[data-testid="stMetric"] label {
        color: var(--text-muted) !important;
        font-size: 0.7rem !important;
        text-transform: uppercase;
        letter-spacing: 1.5px;
    }

    div[data-testid="stMetric"] [data-testid="stMetricValue"] {
        color: #FFFFFF !important;
        font-size: 1.5rem !important;
        font-weight: 700 !important;
    }

    div[data-testid="stMetric"] [data-testid="stMetricDelta"] svg {
        fill: var(--status-nominal);
    }

    /* ============================================================
       G. SIDEBAR
       ============================================================ */
    section[data-testid="stSidebar"] {
        background-color: var(--bg-base);
        border-right: 1px solid var(--border);
    }

    section[data-testid="stSidebar"]::after {
        content: '';
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        height: 2px;
        background: linear-gradient(90deg, transparent, var(--accent), transparent);
        pointer-events: none;
    }

    section[data-testid="stSidebar"] h1,
    section[data-testid="stSidebar"] h2,
    section[data-testid="stSidebar"] h3 {
        color: var(--accent) !important;
        font-size: 1rem !important;
    }

    section[data-testid="stSidebar"] .stCaption {
        color: var(--text-muted) !important;
    }

    /* ============================================================
       H. BUTTONS — OUTLINE / HUD STYLE
       ============================================================ */
    .stButton > button {
        border-radius: var(--radius);
        border: 1px solid var(--accent);
        background-color: transparent;
        color: var(--accent) !important;
        font-weight: 600;
        text-transform: uppercase;
        letter-spacing: 1px;
        font-size: 0.8rem;
        transition: all 0.2s;
    }

    .stButton > button:hover {
        background-color: var(--accent-bg);
        border-color: var(--accent);
        box-shadow: 0 0 12px rgba(212, 160, 74, 0.2);
        color: var(--accent) !important;
    }

    .stButton > button:focus {
        color: var(--accent) !important;
    }

    /* Primary buttons */
    .stButton > button[kind="primary"],
    .stButton > button[data-testid="stBaseButton-primary"] {
        background-color: rgba(212, 160, 74, 0.15);
        border-color: var(--accent);
        color: var(--accent) !important;
    }

    .stButton > button[kind="primary"]:hover,
    .stButton > button[data-testid="stBaseButton-primary"]:hover {
        background-color: var(--accent-bg-hover);
    }

    /* Download button — info accent */
    .stDownloadButton > button {
        background-color: transparent !important;
        border: 1px solid var(--info) !important;
        color: var(--info) !important;
        border-radius: var(--radius);
        text-transform: uppercase;
        letter-spacing: 1px;
        font-size: 0.8rem;
    }

    .stDownloadButton > button:hover {
        background-color: var(--info-bg) !important;
        box-shadow: 0 0 12px rgba(91, 163, 181, 0.2) !important;
    }

    /* ============================================================
       I. ANALYSIS CARDS — TERMINAL OUTPUT AESTHETIC
       ============================================================ */
    .analysis-card {
        background-color: var(--bg-base);
        border: 1px solid var(--border);
        border-left: 3px solid var(--accent);
        border-radius: var(--radius);
        padding: 20px 24px;
        margin: var(--space-lg) 0;
        box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
        position: relative;
    }

    .analysis-card::before {
        content: '\25B8  ANALYSIS OUTPUT';
        display: block;
        color: var(--accent);
        font-family: var(--font-mono);
        font-size: 0.65rem;
        letter-spacing: 2px;
        text-transform: uppercase;
        margin-bottom: var(--space-md);
        padding-bottom: var(--space-sm);
        border-bottom: 1px solid var(--border);
        opacity: 0.7;
    }

    .analysis-card h4 {
        color: var(--accent) !important;
        font-family: var(--font-mono) !important;
        margin-top: 0;
        font-size: 0.9rem !important;
        text-transform: uppercase;
        letter-spacing: 1px;
    }

    .analysis-card div {
        color: var(--text-secondary) !important;
        font-family: var(--font-body) !important;
        line-height: 1.7;
        font-size: 0.85rem;
    }

    /* ============================================================
       J. TABS — UNDERLINE ACCENT
       ============================================================ */
    .stTabs [data-baseweb="tab-list"] {
        gap: 0px;
        border-bottom: 2px solid var(--border);
    }

    .stTabs [data-baseweb="tab"] {
        border-radius: 0;
        padding: var(--space-sm) 20px;
        color: var(--text-muted);
        border-bottom: 3px solid transparent;
        font-size: 0.8rem;
        letter-spacing: 0.5px;
        text-transform: uppercase;
    }

    .stTabs [data-baseweb="tab"][aria-selected="true"] {
        color: var(--accent) !important;
        border-bottom: 3px solid var(--accent) !important;
        background-color: rgba(212, 160, 74, 0.05);
    }

    /* ============================================================
       K. FORM ELEMENTS
       ============================================================ */
    .streamlit-expanderHeader {
        background-color: var(--bg-panel) !important;
        border-radius: var(--radius);
        border: 1px solid var(--border);
        color: var(--text-secondary) !important;
    }

    .stSelectbox > div > div {
        border-radius: var(--radius);
        border-color: var(--border);
    }

    hr {
        border-color: var(--border) !important;
    }

    .stDataFrame {
        border-radius: var(--radius);
        overflow: hidden;
        border: 1px solid var(--border);
    }

    .stTextInput > div > div > input,
    .stTextArea > div > div > textarea {
        border-color: var(--border);
        border-radius: var(--radius);
        color: var(--text-primary);
    }

    .stTextInput > div > div > input:focus,
    .stTextArea > div > div > textarea:focus {
        border-color: var(--accent);
        box-shadow: 0 0 6px rgba(212, 160, 74, 0.15);
    }

    .stMultiSelect > div > div {
        border-radius: var(--radius);
        border-color: var(--border);
    }

    .stDateInput > div > div > input {
        border-radius: var(--radius);
        border-color: var(--border);
    }

    /* ============================================================
       L. SPINNER
       ============================================================ */
    .stSpinner > div {
        border-color: var(--accent) !important;
    }

    /* ============================================================
       M. STATUS ANIMATIONS
       ============================================================ */
    @keyframes pulse-nominal {
        0%, 100% { box-shadow: 0 0 6px rgba(91, 154, 110, 0.1); }
        50% { box-shadow: 0 0 12px rgba(91, 154, 110, 0.2); }
    }

    @keyframes pulse-amber {
        0%, 100% { box-shadow: 0 0 6px rgba(204, 143, 0, 0.1); }
        50% { box-shadow: 0 0 12px rgba(204, 143, 0, 0.2); }
    }

    @keyframes pulse-red {
        0%, 100% { box-shadow: 0 0 6px rgba(204, 48, 48, 0.1); }
        50% { box-shadow: 0 0 12px rgba(204, 48, 48, 0.2); }
    }

    /* ============================================================
       N. STATUS CLASSES
       ============================================================ */
    .status-nominal {
        border-color: var(--status-nominal) !important;
    }
    .status-nominal .hud-indicator {
        background-color: var(--status-nominal);
        box-shadow: 0 0 6px var(--status-nominal);
    }

    .status-warning {
        border-color: var(--status-warning) !important;
        animation: pulse-amber 2s ease-in-out infinite;
    }
    .status-warning .hud-indicator {
        background-color: var(--status-warning);
        box-shadow: 0 0 6px var(--status-warning);
    }

    .status-alarm {
        border-color: var(--status-alarm) !important;
        animation: pulse-red 1.5s ease-in-out infinite;
    }
    .status-alarm .hud-indicator {
        background-color: var(--status-alarm);
        box-shadow: 0 0 6px var(--status-alarm);
    }

    .hud-indicator {
        display: inline-block;
        width: 6px;
        height: 6px;
        border-radius: 50%;
        margin-right: 6px;
        vertical-align: middle;
    }

    /* ============================================================
       O. HUD PAGE HEADER
       ============================================================ */
    .hud-page-header {
        margin-bottom: 1.5rem;
    }

    .hud-subtitle {
        color: var(--text-muted);
        font-size: 0.75rem;
        letter-spacing: 0.5px;
        margin-bottom: 0.5rem;
    }

    .hud-header-line {
        height: 1px;
        background: linear-gradient(90deg, var(--accent), var(--border) 60%, transparent);
    }

    /* ============================================================
       P. HIDE ERROR HELPER LINKS
       ============================================================ */
    [data-testid="stException"] a[href*="google"],
    [data-testid="stException"] a[href*="chatgpt"],
    [data-testid="stException"] a[href*="copy"],
    div[data-testid="stException"] div:last-child {
        display: none !important;
    }

    /* ============================================================
       Q. BRAND FOOTER
       ============================================================ */
    .brand-footer {
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        text-align: center;
        padding: 6px;
        background-color: var(--bg-base);
        color: var(--text-muted);
        font-size: 0.65rem;
        border-top: 1px solid var(--border);
        z-index: 999;
        letter-spacing: 1px;
        text-transform: uppercase;
    }

    /* ============================================================
       R. HIDE STREAMLIT BRANDING
       ============================================================ */
    #MainMenu { visibility: hidden; }
    footer { visibility: hidden; }

    </style>
    """, unsafe_allow_html=True)