:root {
    color-scheme: dark;
    font-family: Inter, ui-sans-serif, system-ui, sans-serif;
    background: #07111f;
    color: #e5eef9;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    min-height: 100vh;
    background: radial-gradient(circle at top, #15304b 0, #07111f 45rem);
}

main {
    width: min(68rem, calc(100% - 2rem));
    margin: 0 auto;
    padding: 3rem 0;
}

.chatroom,
.join-panel,
.conversation,
.presence {
    border: 1px solid #27435e;
    border-radius: 1rem;
    background: rgba(9, 24, 40, .92);
    box-shadow: 0 1.5rem 4rem rgba(0, 0, 0, .28);
}

.chatroom { overflow: hidden; }

.join-panel {
    max-width: 38rem;
    margin: 8vh auto;
    padding: 2.5rem;
}

.join-panel h1,
.room-header h1 { margin: .2rem 0 .75rem; }

.eyebrow {
    margin: 0;
    color: #67e8f9;
    font-size: .75rem;
    font-weight: 800;
    letter-spacing: .12em;
    text-transform: uppercase;
}

.join-form { margin-top: 2rem; }
.form-error { color: #fda4af; font-weight: 700; }

label { display: block; margin-bottom: .5rem; font-weight: 700; }

.input-row,
.composer { display: flex; gap: .75rem; }

input,
button { font: inherit; }

input {
    min-width: 0;
    flex: 1;
    padding: .8rem 1rem;
    border: 1px solid #365570;
    border-radius: .55rem;
    background: #07111f;
    color: inherit;
}

button {
    padding: .8rem 1.1rem;
    border: 0;
    border-radius: .55rem;
    background: #22d3ee;
    color: #083344;
    cursor: pointer;
    font-weight: 800;
}

.room-layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 15rem;
    min-height: 38rem;
}

.conversation,
.presence { border: 0; border-radius: 0; box-shadow: none; }

.conversation { display: grid; grid-template-rows: auto 1fr auto; }

.room-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid #27435e;
}

.quiet-button { background: #1b3349; color: #d8e8f6; }

.message-list {
    display: flex;
    flex-direction: column;
    gap: .75rem;
    margin: 0;
    padding: 1.5rem;
    list-style: none;
    overflow-wrap: anywhere;
}

.message-list li:not(.empty-message) {
    max-width: 80%;
    padding: .8rem 1rem;
    border-radius: .75rem;
    background: #142b40;
}

.message-list strong { color: #67e8f9; }
.message-list p { margin: .25rem 0 0; }
.empty-message { margin: auto; color: #8ca3b8; }

.composer { padding: 1rem 1.5rem 1.5rem; }

.presence {
    padding: 1.5rem;
    border-left: 1px solid #27435e;
    background: rgba(5, 17, 29, .72);
}

.presence ul { padding: 0; list-style: none; }
.presence li { padding: .45rem 0; }
.presence li::before { content: '●'; margin-right: .5rem; color: #4ade80; }
.presence .more-members { color: #8ca3b8; }
.presence .more-members::before { content: ''; margin: 0; }

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

@media (max-width: 42rem) {
    main { padding: 1rem 0; }
    .room-layout { grid-template-columns: 1fr; }
    .presence { border-top: 1px solid #27435e; border-left: 0; }
    .input-row { flex-direction: column; }
}