* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: #0f172a;
    color: #e2e8f0;
}

.hidden {
    display: none !important;
}

.shell {
    max-width: 960px;
    margin: 0 auto;
    padding: 24px;
}

.status-card,
.chat-app {
    background: rgba(15, 23, 42, 0.92);
    border: 1px solid rgba(148, 163, 184, 0.2);
    border-radius: 18px;
    box-shadow: 0 20px 60px rgba(15, 23, 42, 0.35);
}

.status-card {
    margin-top: 15vh;
    padding: 32px;
    text-align: center;
}

.status-card h1,
.topbar h1 {
    margin: 0 0 8px;
    font-size: 28px;
}

.topbar {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    align-items: center;
    padding: 20px 24px;
    border-bottom: 1px solid rgba(148, 163, 184, 0.18);
}

.topbar-main {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.topbar-actions {
    display: flex;
    gap: 10px;
    align-items: center;
}

.topbar p {
    margin: 0;
    color: #94a3b8;
}

.secondary-button,
.danger-button,
.composer button {
    border: 0;
    border-radius: 12px;
    padding: 12px 16px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
}

.secondary-button {
    background: #334155;
    color: #e2e8f0;
}

.secondary-button:hover {
    background: #475569;
}

.danger-button {
    background: #dc2626;
    color: white;
}

.danger-button:hover {
    background: #b91c1c;
}

.messages {
    height: 62vh;
    overflow-y: auto;
    padding: 20px 24px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    background: linear-gradient(180deg, rgba(15, 23, 42, 0.3), rgba(15, 23, 42, 0.65));
}

.message {
    max-width: 82%;
    padding: 12px 14px;
    border-radius: 14px;
    background: #1e293b;
    border: 1px solid rgba(148, 163, 184, 0.12);
}

.message.mine {
    align-self: flex-end;
    background: #1d4ed8;
}

.message .meta {
    font-size: 12px;
    color: #cbd5e1;
    margin-bottom: 6px;
}

.message .body {
    white-space: pre-wrap;
    word-break: break-word;
    line-height: 1.5;
}

.composer {
    display: flex;
    gap: 12px;
    padding: 20px 24px 24px;
    border-top: 1px solid rgba(148, 163, 184, 0.18);
}

.composer-fields {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.composer textarea {
    width: 100%;
    min-height: 96px;
    border-radius: 12px;
    border: 1px solid rgba(148, 163, 184, 0.2);
    padding: 12px 14px;
    font-size: 15px;
    background: #020617;
    color: #e2e8f0;
    resize: vertical;
    line-height: 1.5;
    font-family: inherit;
}

.composer-hint {
    font-size: 12px;
    color: #94a3b8;
}

.composer button {
    min-width: 92px;
    background: #22c55e;
    color: #052e16;
}

.composer button:hover {
    background: #16a34a;
}

@media (max-width: 700px) {
    .shell {
        padding: 12px;
    }

    .topbar,
    .composer {
        flex-direction: column;
        align-items: stretch;
    }

    .composer button {
        width: 100%;
    }

    .topbar-actions {
        width: 100%;
        flex-direction: column;
    }

    .message {
        max-width: 100%;
    }

    .messages {
        height: 58vh;
    }
}