* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: #212121;
    color: #ececec;
}

.login-body {
    min-height: 100vh;
    display: grid;
    place-items: center;
}

.login-box {
    width: 360px;
    background: #2f2f2f;
    padding: 32px;
    border-radius: 16px;
}

.login-box h1 {
    margin-top: 0;
}

.login-box label {
    display: block;
    margin-top: 16px;
    margin-bottom: 6px;
}

input,
textarea {
    width: 100%;
    border: 1px solid #555;
    border-radius: 10px;
    background: #1f1f1f;
    color: #fff;
    padding: 12px;
    font: inherit;
}

button {
    margin-top: 20px;
    border: 0;
    border-radius: 10px;
    padding: 12px 18px;
    background: #ececec;
    color: #111;
    cursor: pointer;
    font-weight: 600;
}

.error {
    background: #5a1f1f;
    color: #ffd0d0;
    padding: 10px;
    border-radius: 8px;
}

.lang a,
.sidebar a {
    color: #ececec;
}

.app-body {
    height: 100vh;
    display: flex;
}

.sidebar {
    width: 260px;
    background: #171717;
    padding: 18px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.brand {
    font-size: 22px;
    font-weight: 700;
}

.sidebar nav {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.logout {
    margin-top: auto;
}

.chat-main {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.messages {
    flex: 1;
    padding: 40px;
    overflow-y: auto;
}

.message {
    max-width: 760px;
    margin: 0 auto 20px auto;
    padding: 16px 20px;
    border-radius: 16px;
    line-height: 1.5;
}

.message.user {
    background: #303030;
}

.message.assistant {
    background: #262626;
}

.empty {
    text-align: center;
    color: #aaa;
    margin-top: 20vh;
}

.composer {
    max-width: 820px;
    width: 100%;
    margin: 0 auto 28px auto;
    display: flex;
    gap: 12px;
    padding: 0 20px;
}

.composer textarea {
    resize: none;
}

.composer button {
    margin-top: 0;
}