:root{--bg: #000000;--card: #131b2a;--text: #ececf1;--muted: #8e96a3;--primary: #10a37f;--primary-contrast: #ffffff;--input-bg: #1a1f37;--input-border: #2d3748;--shadow: 0 10px 30px rgba(0, 0, 0, .3);--sidebar-bg: #111827}[data-theme=light]{--bg: #f6f7fb;--card: #ffffff;--text: #0f1724;--muted: #6b7280;--primary: #4f46e5;--primary-contrast: #ffffff;--input-bg: #ffffff;--input-border: #e6e9ef;--shadow: 0 8px 24px rgba(15, 23, 42, .06);--sidebar-bg: #f6f7fb}html,body,#root{height:100%}body{margin:0;background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Helvetica Neue,sans-serif}.container{max-width:1100px;margin:0 auto;padding:0 16px}.theme-toggle{display:inline-flex;align-items:center;gap:8px;padding:8px 10px;border-radius:999px;background:var(--card);color:var(--text);border:1px solid var(--input-border);cursor:pointer;box-shadow:var(--shadow);transition:background-color .2s ease}.theme-toggle:active{opacity:.8}.theme-toggle .dot{width:18px;height:18px;border-radius:50%;background:var(--primary)}*{margin:0;padding:0;box-sizing:border-box}html,body,#root{height:100%;width:100%}body{-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}.chat-container{display:flex;height:100vh;background:var(--bg)}.chat-main{flex:1;display:flex;flex-direction:column;background:var(--bg);width:100%;overflow:hidden}.welcome-container{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:40px 20px;text-align:center;gap:16px;overflow-y:auto}.welcome-label{font-size:12px;color:var(--muted);text-transform:uppercase;letter-spacing:.5px;font-weight:500}.welcome-title{font-size:36px;font-weight:500;margin:0;color:var(--text);letter-spacing:-.5px}.welcome-description{font-size:16px;color:var(--muted);max-width:500px;line-height:1.6;margin:0}@media(min-width:768px){.welcome-title{font-size:44px;margin-bottom:12px}.welcome-description{font-size:16px}}@media(min-width:1200px){.welcome-title{font-size:48px}.welcome-description{font-size:17px;max-width:600px}}.sidebar{width:260px;max-width:260px;height:100%;position:static;left:0;background:var(--sidebar-bg);border-right:1px solid var(--input-border);padding:16px;overflow-y:auto;display:flex;flex-direction:column;z-index:40}.sidebar.show{display:flex}.sidebar-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px;padding:0;border-bottom:none;position:relative}.sidebar-header h3{margin:0;font-size:16px;font-weight:600;color:var(--text);flex-grow:1}.sidebar-header:after{content:"NEW";font-size:11px;font-weight:700;color:var(--muted);letter-spacing:.5px;white-space:nowrap}.new-chat-btn{width:100%;padding:10px 12px;background:transparent;color:var(--text);border:1px solid var(--input-border);border-radius:8px;cursor:pointer;font-size:14px;font-weight:500;display:flex;align-items:center;justify-content:center;gap:8px;transition:all .2s ease;flex-shrink:0;margin-bottom:16px}.new-chat-btn:hover{background:var(--input-bg)}.new-chat-btn:active{opacity:.8;transform:scale(.98)}.sidebar-menu{display:none;flex-direction:column;gap:8px;margin:16px 0 20px;padding:0 0 12px;border-bottom:1px solid var(--input-border)}.menu-item{display:none;align-items:center;gap:12px;padding:10px 12px;border-radius:8px;cursor:pointer;color:var(--text);font-size:14px;transition:all .2s ease;-webkit-user-select:none;user-select:none}.menu-item:active{background:var(--input-bg);transform:translate(2px)}.menu-icon{display:none;font-size:16px;width:20px;text-align:center}.menu-label{display:none;flex:1}.sidebar-section-title{font-size:11px;font-weight:600;color:var(--muted);text-transform:uppercase;margin:20px 0 12px;padding:0;letter-spacing:.5px}.chats-list{display:flex;flex-direction:column;gap:8px;margin-top:8px}.previous-chat{padding:10px 12px;background:transparent;border:none;border-radius:8px;margin-bottom:0;cursor:pointer;color:var(--text);font-size:14px;transition:all .2s ease;text-align:left;word-break:break-word}.previous-chat:hover{background:var(--input-bg)}.previous-chat:active{background:var(--input-bg);transform:none}.previous-chat.active{background:var(--primary);color:var(--primary-contrast);border:none}.sidebar-toggle{display:none;align-items:center;justify-content:center;position:fixed;top:12px;left:12px;z-index:50;width:40px;height:40px;background:var(--card);border:1px solid var(--input-border);border-radius:8px;cursor:pointer;color:var(--text);font-size:20px;padding:0;transition:all .2s ease}.sidebar-toggle:active{opacity:.8;transform:scale(.95)}@media(min-width:768px){.sidebar{position:static;left:auto;width:260px;max-width:260px;height:100%;padding:16px;display:flex;transition:none;z-index:auto}.sidebar.show{left:auto}.sidebar-toggle{display:none}.sidebar-header{margin-bottom:20px}.menu-item:active,.previous-chat:active{transform:none}}@media(min-width:1200px){.sidebar{width:300px;max-width:300px}}.chat-messages{flex:1;overflow-y:auto;padding:12px;display:flex;flex-direction:column;gap:10px}.message{max-width:85%;padding:10px 12px;border-radius:12px;word-wrap:break-word;font-size:14px;line-height:1.5;animation:messageSlideIn .3s ease}@keyframes messageSlideIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.message.user{align-self:flex-end;background:var(--primary);color:var(--primary-contrast)}.message.ai{align-self:flex-start;background:var(--card);color:var(--text);border:1px solid var(--input-border)}@media(min-width:768px){.chat-messages{padding:16px;gap:12px}.message{max-width:70%;padding:12px 16px;font-size:15px}}@media(min-width:1200px){.message{max-width:60%}}.message-wrapper{display:flex;flex-direction:column}.message-wrapper.user{align-items:flex-end}.message-wrapper.ai{align-items:flex-start}.message-author{font-size:12px;margin-bottom:4px;color:#9ca3af}.chat-input-container{padding:12px;background:var(--card);border-top:1px solid var(--input-border);display:flex;gap:8px;align-items:flex-end}.chat-input{flex:1;padding:12px 14px;border:1px solid var(--input-border);border-radius:20px;background:var(--input-bg);color:var(--text);outline:none;font-size:14px;min-height:40px;resize:none;transition:all .2s ease;font-family:inherit}.chat-input:focus{border-color:var(--primary);background:var(--card)}.chat-input::placeholder{color:var(--muted)}.send-btn{min-width:44px;height:40px;padding:0 16px;background:var(--primary);color:var(--primary-contrast);border:none;border-radius:20px;cursor:pointer;font-size:14px;font-weight:600;transition:all .2s ease;flex-shrink:0}.send-btn:active:not(:disabled){opacity:.8;transform:scale(.95)}.send-btn:disabled{opacity:.5;cursor:not-allowed}@media(min-width:768px){.chat-input-container{padding:16px;gap:12px}.chat-input{padding:12px 16px;font-size:15px;min-height:44px}.send-btn{min-width:50px;height:44px;padding:0 20px;font-size:15px}}.auth-container{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:28px 16px}.auth-card{width:100%;max-width:420px;background:var(--card);border-radius:12px;box-shadow:var(--shadow);padding:20px;border:1px solid var(--input-border)}.auth-header{text-align:center;margin-bottom:14px}.auth-header h2{margin:0 0 6px;font-size:20px}.muted{color:var(--muted);font-size:14px;margin:0}.auth-form{display:flex;flex-direction:column;gap:12px;margin-top:8px}.auth-input{width:100%;padding:12px 14px;border-radius:10px;border:1px solid var(--input-border);background:var(--input-bg);color:var(--text);font-size:15px}.auth-button{width:100%;padding:12px 14px;border-radius:10px;border:none;background:var(--primary);color:var(--primary-contrast);font-weight:600;cursor:pointer;font-size:15px}.auth-foot{text-align:center;margin-top:12px;font-size:14px}.auth-link{color:var(--primary);text-decoration:none;font-weight:600}@media(min-width:768px){.auth-card{padding:28px}.auth-header h2{font-size:22px}}