:root {
    --spacing: 12px;
    --border-radius-large: 8px;
    --border-radius-small: 4px;
}

* {
    box-sizing: border-box;
}

body { /* wraps header and main */
    display: grid;
    grid-template-rows: auto 1fr;
    grid-row-gap: var(--spacing);
    height: 100vh;
    padding: var(--spacing);
    margin: 0;
    font-family: 'Roboto', sans-serif;
}

header img {
    display: block;
    margin: 4px auto;
    max-height: 40px;
}

main { /* wraps video-panel and chat-panel */
    display: grid;
    grid-template-columns: 4fr 7fr; /* video panel is 4/11 of the width, chat panel is 7/11 */
    grid-column-gap: var(--spacing);
    overflow: auto;
}

.video-panel {
    display: grid;
    grid-template-rows: 1fr 1fr;
    grid-row-gap: var(--spacing);
    overflow: auto;

    & section {
        overflow: auto;
        display: flex;
        justify-content: center;
        align-items: center;
        background: #f2f2f2;
        border-radius: var(--border-radius-large);

        & video {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        &.local video {
            transform: scaleX(-1);
        }
    }
}

.chat-panel {
    display: grid;
    grid-template-rows: 1fr auto;
    grid-row-gap: var(--spacing);
    padding: var(--spacing);
    background: #f2f2f2;
    border-radius: var(--border-radius-large);

    .chat-log {
        padding: var(--spacing);
        background: #fff;
        overflow-y: scroll;
        border-radius: var(--border-radius-small);
        line-height: 1.4;

        .message.local::before {
            font-weight: bold;
            color: blue;
            content: "You: ";
        }

        .message.remote::before {
            font-weight: bold;
            color: red;
            content: "Stranger: ";
        }

        .message.server {
            color: #999;
            font-style: italic;
        }
    }

    .chat-controls {
        display: flex;

        .messaging {
            display: flex;
            flex-grow: 1;

            & input {
                margin: 0 16px;
                width: 100%;
                height: 40px;
                padding: 16px;
                border: 0;
                border-radius: var(--border-radius-small);
                font-size: 16px;

                &:focus {
                    outline: none;
                }
            }
        }

        .pairing button {
            width: 120px;
        }
    }
}

button {
    background: #1e88e5;
    color: #fff;
    border: 0;
    border-radius: var(--border-radius-small);
    height: 40px;
    line-height: 1;
    padding: 0 16px;
    cursor: pointer;

    &:hover {
        background: #1976d2;
    }
}

/* Conditional styles for buttons */
.chat-controls .pairing button {
    display: none;
}

[data-state=NOT_CONNECTED] button#startPairing,
[data-state=DISCONNECTED_LOCAL] button#startPairing,
[data-state=DISCONNECTED_REMOTE] button#startPairing,
[data-state=CONNECTING] button#abortPairing,
[data-state=CONNECTED] button#leavePairing {
    display: block;
}

/* Conditional styles for spinner */
.spinner {
    display: none;
}

[data-state=CONNECTING] .spinner {
    display: block;
}

/* Conditional styles for remote video */
body:not([data-state=CONNECTED]) .remote video {
    display: none;
}

/* Conditional styles for chat */
body:not([data-state=CONNECTED]) .chat-controls .messaging {
    filter: grayscale(1);
    opacity: 0.6;
    pointer-events: none;
}

/* Mobile layout */
@media (max-width: 768px) {
    main { /* put video panel on top of chat panel */
        grid-template-columns: none;
        grid-template-rows: 1fr 2fr;
        grid-row-gap: var(--spacing);
    }

    .video-panel { /* put video side by side */
        grid-template-rows: none;
        grid-template-columns: 1fr 1fr;
        grid-column-gap: var(--spacing);
    }
}