* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: 'Segoe UI', system-ui, sans-serif;
    background-color: #f0f2f5;
    color: #333;
    height: 100dvh; /* Изменено для мобилок */
    overflow: hidden;
}
.hidden { display: none !important; }

/* Авторизация и новые кнопки персонализации */
.auth-overlay {
    position: fixed; top: 0; left: 0; width: 100vw; height: 100dvh;
    background: #f0f2f5; display: flex; justify-content: center; align-items: center; z-index: 9999;
}
.auth-box {
    background: white; padding: 30px; border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05); width: 100%; max-width: 380px; text-align: center;
    max-height: 95dvh; overflow-y: auto; /* Защита для маленьких экранов */
}
.auth-logo img { width: 70px; border-radius: 16px; margin-bottom: 15px; }
#auth-title { margin-bottom: 20px; font-size: 22px; }
.auth-box input {
    width: 100%; padding: 14px; margin: 8px 0; border: 1px solid #ddd; border-radius: 12px;
    background: #fafafa; outline: none; font-size: 15px;
}
.auth-box input:focus { border-color: #1ABC9C; background: #fff; }

.primary-btn { width: 100%; padding: 14px; background: #1ABC9C; color: white; border: none; border-radius: 12px; font-size: 16px; font-weight: 600; cursor: pointer; margin-top: 15px; transition: 0.2s; }
.primary-btn:hover { background: #16a085; }
.secondary-btn { width: 100%; padding: 14px; background: #f0f2f5; color: #333; border: none; border-radius: 12px; font-size: 16px; font-weight: 600; cursor: pointer; margin-top: 10px; transition: 0.2s; }
.secondary-btn:hover { background: #e4e6e9; }

/* Настройки персонализации (Шаг 2) */
.pref-section { text-align: left; margin-bottom: 16px; }
.pref-section label { font-size: 13px; color: #666; font-weight: 600; margin-bottom: 8px; display: block; }
.pref-group { display: flex; flex-wrap: wrap; gap: 8px; }
.pref-btn { 
    padding: 8px 14px; background: #f0f2f5; border: 2px solid transparent; 
    border-radius: 20px; font-size: 13px; cursor: pointer; color: #555; transition: 0.2s; 
}
.pref-btn:hover { background: #e4e6e9; }
.pref-btn.active { background: #e0f2f1; border-color: #1ABC9C; color: #00796B; font-weight: bold; }

.forgot-link { font-size: 13px; color: #1ABC9C; cursor: pointer; margin: 5px 0 10px; text-align: right; }
.error-text { color: #e74c3c; font-size: 13px; margin-top: 15px; }

/* Общий каркас приложения */
.app-wrapper { display: flex; width: 100vw; height: 100dvh; overflow: hidden; }

/* Боковое меню */
.sidebar {
    width: 260px; background: #ffffff; border-right: 1px solid #e0e0e0;
    display: flex; flex-direction: column; z-index: 1000; transition: transform 0.3s;
}
.sidebar-header { padding: 20px; display: flex; align-items: center; gap: 12px; border-bottom: 1px solid #f0f0f0; }
.sidebar-logo { width: 32px; border-radius: 8px; }
.sidebar-title { font-weight: bold; font-size: 18px; }
.close-btn { background: none; border: none; font-size: 24px; cursor: pointer; margin-left: auto; }
.sidebar-content { padding: 20px; flex: 1; overflow-y: auto; display: flex; flex-direction: column; gap: 10px; }
.sidebar-btn { width: 100%; padding: 12px 15px; background: transparent; border: none; border-radius: 10px; text-align: left; font-size: 15px; cursor: pointer; display: flex; align-items: center; gap: 12px; color: #555; }
.sidebar-btn:hover { background: #f5f5f5; }
.sidebar-btn.primary-action { background: #1ABC9C; color: white; font-weight: 600; }
.sidebar-divider { height: 1px; background: #eee; margin: 10px 0; }
.streak-box { display: flex; align-items: center; gap: 10px; padding: 12px 15px; background: #fff5e6; border-radius: 10px; border: 1px solid #ffe0b2; margin-top: 10px; }
.streak-text { font-weight: 600; color: #e67e22; font-size: 14px;}
.sidebar-user-info { padding: 12px 15px; background: #fafafa; border-radius: 10px; border: 1px solid #eee; margin-top: 5px; }
.info-row { display: flex; justify-content: space-between; align-items: center; }
.info-row .label { font-size: 14px; color: #555; }
.tag { background: #eee; padding: 4px 8px; border-radius: 6px; font-size: 12px; font-weight: bold; color: #555; }
.lang-selector { position: relative; margin-top: 10px; }
.lang-dropdown { position: absolute; bottom: 100%; left: 0; width: 100%; background: white; border: 1px solid #eee; border-radius: 10px; box-shadow: 0 5px 15px rgba(0,0,0,0.1); margin-bottom: 5px; overflow: hidden; }
.lang-option { padding: 12px 15px; cursor: pointer; display: flex; align-items: center; gap: 10px; }
.lang-option:hover { background: #f5f5f5; }

/* Фикс автоскролла и исчезающего поля */
.main-content { flex: 1; display: flex; flex-direction: column; height: 100dvh; overflow: hidden; }
.top-bar { display: none; padding: 15px 20px; background: white; border-bottom: 1px solid #eee; align-items: center; flex-shrink: 0; }
.burger-btn { background: none; border: none; cursor: pointer; color: #333; display: flex; align-items: center; }

.chat-container { flex: 1; display: flex; flex-direction: column; background: #ffffff; max-width: 900px; margin: 0 auto; width: 100%; position: relative; overflow: hidden; }
.welcome-screen { flex: 1; display: flex; flex-direction: column; justify-content: center; align-items: center; text-align: center; padding: 20px; transition: 0.3s; overflow-y: auto; }
.welcome-screen.minimized { display: none; }
.welcome-logo { width: 80px; margin-bottom: 20px; border-radius: 20px; box-shadow: 0 10px 20px rgba(0,0,0,0.1); }
.welcome-screen h2 { font-size: 28px; margin-bottom: 10px; }
.welcome-screen p { color: #888; max-width: 400px; line-height: 1.5; }

/* Сам чат */
.chat-box { flex: 1; overflow-y: auto; padding: 20px; display: flex; flex-direction: column; gap: 20px; scroll-behavior: smooth; }
.msg { max-width: 85%; padding: 14px 18px; line-height: 1.5; font-size: 15px; position: relative; word-wrap: break-word; }
.user-msg { background: #1ABC9C; color: white; align-self: flex-end; border-radius: 18px 18px 0 18px; }
.user-msg::after { content: ""; position: absolute; bottom: 0; right: -8px; width: 8px; height: 16px; background-color: #1ABC9C; border-bottom-right-radius: 16px; z-index: 1; }
.user-msg::before { content: ""; position: absolute; bottom: 0; right: -10px; width: 10px; height: 20px; background-color: #ffffff; border-bottom-left-radius: 10px; z-index: 2; }
.ai-msg { background: #f0f2f5; color: #333; align-self: flex-start; border-radius: 18px 18px 18px 0; }
.ai-msg::after { content: ""; position: absolute; bottom: 0; left: -8px; width: 8px; height: 16px; background-color: #f0f2f5; border-bottom-left-radius: 16px; z-index: 1; }
.ai-msg::before { content: ""; position: absolute; bottom: 0; left: -10px; width: 10px; height: 20px; background-color: #ffffff; border-bottom-right-radius: 10px; z-index: 2; }
.ai-msg pre { background: #282c34 !important; color: #eee; padding: 15px; border-radius: 10px; overflow-x: auto; margin: 10px 0; font-family: monospace; }
.ai-msg code { font-family: monospace; }
.msg-actions { display: flex; gap: 10px; margin-top: 10px; }
.action-btn { background: #e0e0e0; border: none; padding: 5px 10px; border-radius: 5px; cursor: pointer; font-size: 12px; color: #333; transition: background 0.2s; }
.action-btn:hover { background: #d0d0d0; }

/* Панель ввода (теперь жестко зафиксирована внизу) */
.bottom-panel { flex-shrink: 0; padding: 15px 20px 20px; background: white; border-top: 1px solid #f0f0f0; }
#image-preview-container { margin-bottom: 10px; }
.preview-wrapper { position: relative; display: inline-block; }
#image-preview { max-height: 100px; border-radius: 10px; border: 2px solid #1ABC9C; }
#remove-image { position: absolute; top: -10px; right: -10px; background: #e74c3c; color: white; border: none; border-radius: 50%; width: 24px; height: 24px; cursor: pointer; display: flex; justify-content: center; align-items: center; font-size: 16px; }
.model-selector { display: flex; gap: 10px; overflow-x: auto; padding-bottom: 10px; margin-bottom: 5px; scrollbar-width: none; }
.model-selector::-webkit-scrollbar { display: none; }
.model-btn { padding: 8px 16px; background: #f0f0f0; border: 1px solid #e0e0e0; border-radius: 20px; font-size: 14px; cursor: pointer; white-space: nowrap; color: #666; transition: 0.2s; }
.model-btn.active { background: #1ABC9C; color: white; border-color: #1ABC9C; font-weight: 500; }
.input-area { display: flex; background: #f9f9f9; border-radius: 25px; border: 1px solid #e0e0e0; padding: 5px 5px 5px 15px; align-items: center; transition: 0.2s; }
.input-area:focus-within { border-color: #1ABC9C; background: #fff; box-shadow: 0 5px 15px rgba(26, 188, 156, 0.1); }
#user-input { flex: 1; padding: 12px 10px; border: none; background: transparent; font-size: 16px; outline: none; }
#attach-btn { background: none; border: none; cursor: pointer; color: #888; padding: 10px; border-radius: 50%; }
#attach-btn:hover { color: #1ABC9C; }
#send-btn { width: 40px; height: 40px; border-radius: 50%; background: #1ABC9C; border: none; color: white; cursor: pointer; flex-shrink: 0; margin-left: 5px; }

.modal { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); z-index: 5000; display: flex; justify-content: center; align-items: center; }
.modal-content { background: white; width: 320px; border-radius: 20px; padding: 30px; position: relative; text-align: center; }
.close-modal { position: absolute; top: 15px; right: 20px; font-size: 24px; cursor: pointer; color: #aaa; }
.avatar-circle { width: 70px; height: 70px; background: #e0f2f1; border-radius: 50%; margin: 0 auto 15px; }
.logout-btn-large { width: 100%; padding: 12px; margin-top: 25px; background: #fff5f5; color: #e74c3c; border: none; border-radius: 12px; cursor: pointer; font-weight: 600; }

.loading-dots::after { content: '...'; animation: dots 1.5s steps(4, end) infinite; }
@keyframes dots { 0%, 20% { content: ''; } 40% { content: '.'; } 60% { content: '..'; } 80%, 100% { content: '...'; } }

.mobile-only { display: none; }
@media (max-width: 768px) {
    .burger-btn { display: block; }
    .mobile-only { display: block; }
    .top-bar { display: flex; }
    .top-bar-title { flex: 1; text-align: center; font-weight: bold; font-size: 16px; margin-right: 26px; }
    .sidebar { position: fixed; left: 0; top: 0; bottom: 0; transform: translateX(-100%); width: 280px; }
    .sidebar.open { transform: translateX(0); }
    .sidebar-overlay { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.5); z-index: 999; }
    .chat-container { border-radius: 0; }
    .msg { max-width: 90%; }
}