:root {
    --bg: #0b1020;
    --card: #0f172a;
    --elev: #111827;
    --text: #e5e7eb;
    --muted: #9ca3af;
    --border: #243147;
    --bubble: #111b34;
    --primary: #60a5fa;
    --primary-600: #3b82f6;
    --success: #22c55e;
    --danger: #ef4444;
    --focus: rgba(59, 130, 246, 0.5);
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

@media (prefers-color-scheme: light) {
    :root {
        --bg: #f1f5f9;
        --card: #ffffff;
        --elev: #ffffff;
        --text: #0f172a;
        --muted: #64748b;
        --border: #e2e8f0;
        --bubble: #f8fafc;
        --primary: #2563eb;
        --primary-600: #1d4ed8;
        --success: #16a34a;
        --danger: #dc2626;
        --focus: rgba(37, 99, 235, 0.3);
        --shadow: 0 10px 20px rgba(2, 8, 23, 0.08);
    }
}

html,
body {
    height: 100%;
}

body {
    font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto,
        "Helvetica Neue", Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji";
    background: radial-gradient(1200px 800px at 10% 10%,
            #1f2937 0%,
            transparent 60%) var(--bg);
    color: var(--text);
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 24px;
}

#layout {
    display: none;
    width: min(1100px, 96vw);
    background: linear-gradient(180deg, var(--card), var(--elev));
    border: 1px solid var(--border);
    border-radius: 18px;
    box-shadow: var(--shadow);
    padding: 22px;
    flex-direction: column;
    gap: 18px;
}

.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

h1 {
    font-size: clamp(18px, 2vw, 22px);
    font-weight: 700;
    margin: 0;
    letter-spacing: 0.2px;
}

.status {
    display: inline-flex;
    gap: 10px;
    align-items: center;
    padding: 8px 12px;
    background: var(--bubble);
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: 12px;
    color: var(--muted);
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--muted);
    box-shadow: 0 0 0 2px color-mix(in srgb, var(--muted), transparent 70%);
}

.dot.connected {
    background: var(--success);
}

.dot.disconnected {
    background: var(--danger);
}

#inner-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    grid-template-areas:
        "user form"
        "user messages";
    gap: 18px;
    align-items: start;
}

@media (max-width: 900px) {
    #inner-layout {
        grid-template-columns: 1fr;
        grid-template-areas:
            "user"
            "messages"
            "form";
    }
}

#username {
    grid-area: user;
    padding: 16px;
    background: var(--bubble);
    border: 1px solid var(--border);
    border-radius: 12px;
}

#username h2 {
    margin: 0 0 8px;
    font-size: 14px;
    color: var(--muted);
    font-weight: 600;
}

#currentUser {
    font-size: 16px;
    color: var(--text);
    margin: 0 0 15px;
    font-weight: 700;
}

/* Connected users list */
#userList {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

#userList li {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 10px;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 14px;
    color: var(--text);
    font-weight: 500;
    transition: background 0.2s ease;
}

#userList li:hover {
    background: color-mix(in srgb, var(--bubble), var(--primary) 15%);
}

#userList li .user-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--muted);
}

#userList li.me {
    background: var(--primary);
    color: white;
    font-weight: 600;
}

#userList li.me .user-dot {
    background: var(--success);
}

#chat-form {
    grid-area: form;
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 10px 12px;
    align-items: center;
    width: 100%;
}

#chat-form label {
    grid-column: 1 / -1;
    font-size: 12px;
    font-weight: 600;
    color: var(--muted);
    letter-spacing: 0.2px;
}

#chat-form input {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid var(--border);
    background: var(--card);
    color: var(--text);
    border-radius: 10px;
    font-size: 15px;
    outline: none;
    transition: border-color 0.15s, box-shadow 0.15s, background 0.15s;
}

#chat-form input::placeholder {
    color: color-mix(in srgb, var(--muted), transparent 10%);
}

#chat-form input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px var(--focus);
    background: color-mix(in srgb, var(--card), transparent 10%);
}

#chat-form button {
    height: 44px;
    padding: 0 16px;
    background: linear-gradient(180deg, var(--primary), var(--primary-600));
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 700;
    letter-spacing: 0.2px;
    transition: transform 0.05s ease, box-shadow 0.15s ease, filter 0.15s ease;
    box-shadow: 0 6px 16px color-mix(in srgb, var(--primary), transparent 70%);
}

#messages-container {
    grid-area: messages;
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 97%;
}

#messages-container span {
    font-size: 14px;
    font-weight: 700;
    color: var(--muted);
}

#messages {
    list-style-type: none;
    width: 100%;
    height: clamp(240px, 40vh, 520px);
    overflow-y: auto;
    margin: 0;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: linear-gradient(180deg,
            color-mix(in srgb, var(--bubble), transparent 20%),
            transparent 10%),
        var(--card);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.03);
    scroll-behavior: smooth;
    display: flex;
    flex-direction: column;
}

#messages li.my-message {
    align-self: flex-end;
    background: var(--primary);
    color: white;
}

#messages li.my-message .meta {
    color: color-mix(in srgb, white, transparent 30%);
}

#messages li {
    background: var(--bubble);
    border: 1px solid var(--border);
    padding: 10px 12px;
    border-radius: 12px;
    margin: 8px 0;
    line-height: 1.3;
    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.05);
}

#messages li .meta {
    display: block;
    font-size: 12px;
    color: var(--muted);
    margin-bottom: 4px;
    font-weight: 600;
}

#logout {
    height: 44px;
    padding: 0 16px;
    background: linear-gradient(180deg, var(--primary), var(--primary-600));
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 700;
    letter-spacing: 0.2px;
    transition: transform 0.05s ease, box-shadow 0.15s ease, filter 0.15s ease;
    box-shadow: 0 6px 16px color-mix(in srgb, var(--primary), transparent 70%);
}

#messages li.announcement {
    background: transparent;
    border: none;
    box-shadow: none;
    text-align: center;
    color: var(--muted);
    font-style: italic;
    font-size: 13px;
}

#login,
#register {
    display: none;
}

#login.active {
    display: block;
}

.auth-form-container {
    width: min(400px, 90vw);
    border: 1px solid var(--border);
    border-radius: 24px;
    padding: 40px 36px;
    display: flex;
    flex-direction: column;
    gap: 40px;
    position: relative;
    overflow: hidden;
}

.auth-form-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
}

.auth-form-container h2 {
    text-align: center;
    font-size: 28px;
    margin: 0;
    color: var(--text);
    font-weight: 800;
    letter-spacing: -0.5px;
}

.auth-form-container .subtitle {
    text-align: center;
    font-size: 14px;
    color: var(--muted);
    margin: -16px 0 8px;
}

.auth-form-container form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.auth-form-container .input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.auth-form-container .input-group label {
    font-size: 13px;
    font-weight: 600;
    color: var(--muted);
    letter-spacing: 0.3px;
    text-transform: uppercase;
}

.auth-form-container input {
    padding: 14px 16px;
    border: 2px solid var(--border);
    background: var(--bg);
    color: var(--text);
    border-radius: 12px;
    font-size: 15px;
    outline: none;
    transition: all 0.2s ease;
}

.auth-form-container input::placeholder {
    color: var(--muted);
    opacity: 0.7;
}

.auth-form-container input:hover {
    border-color: color-mix(in srgb, var(--border), var(--primary) 30%);
}

.auth-form-container input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px var(--focus);
    background: var(--card);
}

.auth-form-container .password-input-wrapper {
    position: relative;
}

.auth-form-container .password-input-wrapper input {
    width: 100%;
    box-sizing: border-box;
}

.auth-form-container .password-toggle {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--muted);
    cursor: pointer;
    padding: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color 0.2s ease;
}

.auth-form-container .password-toggle:hover {
    color: var(--primary);
}

.auth-form-container .submit-btn {
    height: 52px;
    background: #3b82f6;
    color: white;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    font-weight: 700;
    font-size: 16px;
    letter-spacing: 0.3px;
    transition: all 0.2s ease;
    margin-top: 8px;
}

.auth-form-container .submit-btn:hover {
    transform: translateY(-2px);
    filter: brightness(1.05);
}

.auth-form-container .submit-btn:active {
    transform: translateY(0);
}

.auth-form-container .submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.auth-form-container .divider {
    display: flex;
    align-items: center;
    gap: 26px;
    margin: 10px;
    color: var(--muted);
    font-size: 13px;
}

.auth-form-container .divider::before,
.auth-form-container .divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border);
}

.auth-form-container .switch-text {
    text-align: center;
    font-size: 14px;
    color: var(--muted);
    margin: 0;
}

.auth-form-container .switch-text a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s ease;
}

.auth-form-container .switch-text a:hover {
    text-decoration: underline;
    color: var(--primary-600);
}

.auth-form-container .error-message {
    background: color-mix(in srgb, var(--danger), transparent 85%);
    border: 1px solid color-mix(in srgb, var(--danger), transparent 50%);
    color: var(--danger);
    padding: 12px 16px;
    border-radius: 10px;
    font-size: 14px;
    display: none;
    align-items: center;
    gap: 10px;
}

.auth-form-container .error-message.visible {
    display: flex;
}

.auth-form-container .success-message {
    background: color-mix(in srgb, var(--success), transparent 85%);
    border: 1px solid color-mix(in srgb, var(--success), transparent 50%);
    color: var(--success);
    padding: 12px 16px;
    border-radius: 10px;
    font-size: 14px;
    display: none;
    align-items: center;
    gap: 10px;
}

.auth-form-container .success-message.visible {
    display: flex;
}

.auth-form-container .input-hint {
    font-size: 12px;
    color: var(--muted);
    margin: 1px 4px;
}

.auth-logo {
    display: flex;
    justify-content: center;
    margin-bottom: 8px;
}

.auth-logo svg {
    width: 56px;
    height: 56px;
    color: var(--primary);
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20%, 60% { transform: translateX(-8px); }
    40%, 80% { transform: translateX(8px); }
}

.auth-form-container.shake {
    animation: shake 0.4s ease-in-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.auth-form-container {
    animation: fadeIn 0.3s ease-out;
}