:root {
    --bg-deep: #0b141a;
    --bg-panel: #111b21;
    --bg-header: #202c33;
    --bg-input: #2a3942;
    --bg-sent: #005c4b;
    --bg-received: #202c33;
    --bg-hover: #202c33;
    --bg-active: #2a3942;
    --text-primary: #e9edef;
    --text-secondary: #8696a0;
    --text-sent: #e9edef;
    --accent: #00a884;
    --accent-hover: #06cf9c;
    --border: #222d34;
    --tick-read: #53bdeb;
    --tick-default: #8696a0;
    --danger: #ea4335;
    --warning: #f59e0b;
    --success: #00a884;
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --sidebar-width: 380px;
    --header-height: 60px;
    --input-bar-height: 62px;
    --safe-top: env(safe-area-inset-top, 0px);
    --safe-bottom: env(safe-area-inset-bottom, 0px);
}
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html,body{height:100%;overflow:hidden;background:var(--bg-deep);color:var(--text-primary);font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;font-size:14px;line-height:1.5;-webkit-font-smoothing:antialiased;-webkit-tap-highlight-color:transparent;selection:background:rgba(0,168,132,0.3)}
::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:rgba(134,150,160,0.3);border-radius:3px}::-webkit-scrollbar-thumb:hover{background:rgba(134,150,160,0.5)}
button{cursor:pointer;border:none;background:none;color:inherit;font-family:inherit;font-size:inherit}input,textarea{border:none;outline:none;background:none;color:inherit;font-family:inherit;font-size:inherit}textarea{resize:vertical}

/* ===== SCREENS ===== */
.screen{position:fixed;inset:0;display:flex;align-items:center;justify-content:center;background:var(--bg-deep);background-image:radial-gradient(ellipse at 20% 50%,rgba(0,168,132,0.04) 0%,transparent 60%),radial-gradient(ellipse at 80% 20%,rgba(0,168,132,0.03) 0%,transparent 50%);z-index:100;padding:1rem}
.auth-container{width:100%;max-width:400px;animation:fadeUp .4s ease}
@keyframes fadeUp{from{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}

/* Brand */
.brand{text-align:center;margin-bottom:2rem}
.brand-icon{width:64px;height:64px;border-radius:50%;background:linear-gradient(135deg,#00a884,#00d4aa);display:inline-flex;align-items:center;justify-content:center;font-size:28px;color:#0b141a;margin-bottom:.75rem;box-shadow:0 0 40px rgba(0,168,132,0.2)}
.brand-icon.large{width:96px;height:96px;font-size:42px;box-shadow:0 0 60px rgba(0,168,132,0.25)}
.brand-name{font-size:1.75rem;font-weight:700;letter-spacing:-.5px}
.brand-slogan{color:var(--text-secondary);font-size:.85rem;margin-top:.25rem;font-style:italic}
.brand-slogan.big{font-size:1.05rem;margin-top:.75rem}
.encrypt-badge{display:inline-flex;align-items:center;gap:.5rem;margin-top:1.25rem;padding:.5rem 1rem;background:rgba(0,168,132,0.1);border:1px solid rgba(0,168,132,0.2);border-radius:999px;font-size:.8rem;color:var(--accent)}

/* Form */
.auth-form{display:flex;flex-direction:column;gap:1rem}
.input-group{display:flex;flex-direction:column;gap:.4rem}
.input-group label{font-size:.82rem;color:var(--text-secondary);font-weight:500}
.input-wrapper{display:flex;align-items:center;gap:.75rem;background:var(--bg-input);border-radius:var(--radius-md);padding:0 .85rem;height:48px;border:2px solid transparent;transition:border-color .2s}
.input-wrapper:focus-within{border-color:var(--accent)}
.input-wrapper i{color:var(--text-secondary);font-size:.9rem;flex-shrink:0}
.input-wrapper input{flex:1;height:100%;color:var(--text-primary);font-size:.95rem}
.input-wrapper input::placeholder{color:var(--text-secondary);opacity:.6}
.toggle-pw{color:var(--text-secondary)!important;font-size:.9rem!important;padding:4px;transition:color .2s}
.toggle-pw:hover{color:var(--text-primary)!important}
.pw-strength{display:flex;align-items:center;gap:.5rem;height:16px}
.pw-bar{flex:1;height:4px;background:var(--bg-header);border-radius:2px;overflow:hidden}
.pw-fill{height:100%;width:0%;border-radius:2px;transition:width .3s,background .3s}
.pw-strength span{font-size:.72rem;color:var(--text-secondary);white-space:nowrap}
.auth-warning{display:flex;align-items:flex-start;gap:.5rem;font-size:.78rem;color:var(--warning);background:rgba(245,158,11,0.08);padding:.6rem .75rem;border-radius:var(--radius-sm);line-height:1.4}
.auth-warning i{margin-top:2px;flex-shrink:0}

/* Buttons */
.btn-primary{width:100%;height:48px;background:var(--accent);color:#0b141a;font-weight:600;font-size:.95rem;border-radius:var(--radius-md);transition:background .2s,transform .1s,opacity .2s;display:flex;align-items:center;justify-content:center;gap:.5rem}
.btn-primary:hover:not(:disabled){background:var(--accent-hover)}.btn-primary:active:not(:disabled){transform:scale(.98)}.btn-primary:disabled{opacity:.4;cursor:not-allowed}
.btn-secondary{height:42px;padding:0 1.25rem;background:transparent;color:var(--accent);border:1.5px solid var(--accent);font-weight:600;font-size:.9rem;border-radius:var(--radius-md);transition:background .2s;display:inline-flex;align-items:center;gap:.5rem}
.btn-secondary:hover{background:rgba(0,168,132,0.1)}

/* ID Card */
.id-card{background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--radius-lg);padding:2rem;text-align:center}
.id-label{font-size:.85rem;color:var(--text-secondary);margin-bottom:1rem}
.id-value{font-family:'Courier New','Consolas',monospace;font-size:2.5rem;font-weight:700;letter-spacing:.45em;color:var(--accent);padding-left:.45em;margin-bottom:1rem;user-select:all}
.id-hint{font-size:.8rem;color:var(--text-secondary);margin-bottom:1.25rem;line-height:1.5}

/* ===== MAIN APP ===== */
#main-app{display:flex;height:100vh;height:100dvh;overflow:hidden}
#sidebar{width:var(--sidebar-width);min-width:var(--sidebar-width);background:var(--bg-panel);border-right:1px solid var(--border);display:flex;flex-direction:column;height:100%}
.sidebar-header{height:var(--header-height);padding:0 1rem;display:flex;align-items:center;justify-content:space-between;background:var(--bg-header);flex-shrink:0}
.user-info{display:flex;align-items:center;gap:.75rem;min-width:0}
.user-avatar,.contact-avatar{width:40px;height:40px;border-radius:50%;background:var(--bg-input);display:flex;align-items:center;justify-content:center;font-weight:700;font-size:1rem;color:var(--accent);flex-shrink:0;overflow:hidden}
.user-avatar img,.contact-avatar img{width:100%;height:100%;object-fit:cover}
.user-id-display{font-size:.95rem;font-weight:500;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.sidebar-actions{display:flex;gap:.25rem}
.sidebar-actions button{width:40px;height:40px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:1.1rem;color:var(--text-secondary);transition:background .2s,color .2s}
.sidebar-actions button:hover{background:rgba(134,150,160,0.15);color:var(--text-primary)}

/* Chat list */
.chat-list{flex:1;overflow-y:auto;padding-top:.25rem}
.chat-item{display:flex;align-items:center;gap:.75rem;padding:.75rem 1rem;cursor:pointer;transition:background .15s;position:relative}
.chat-item:hover{background:var(--bg-hover)}.chat-item.active{background:var(--bg-active)}
.chat-item-content{flex:1;min-width:0;display:flex;flex-direction:column;gap:.15rem}
.chat-item-top{display:flex;justify-content:space-between;align-items:baseline}
.chat-item-name{font-weight:500;font-size:.95rem;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.chat-item-time{font-size:.72rem;color:var(--text-secondary);flex-shrink:0;margin-left:.5rem}
.chat-item-bottom{display:flex;justify-content:space-between;align-items:center}
.chat-item-preview{font-size:.82rem;color:var(--text-secondary);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;flex:1}
.chat-item-badge{min-width:20px;height:20px;border-radius:999px;background:var(--accent);color:#0b141a;font-size:.7rem;font-weight:700;display:flex;align-items:center;justify-content:center;padding:0 5px;margin-left:.5rem;flex-shrink:0}
.empty-state-small{display:none;flex-direction:column;align-items:center;justify-content:center;flex:1;color:var(--text-secondary);gap:.5rem;padding:2rem;text-align:center}
.empty-state-small i{font-size:3rem;opacity:.3}.empty-state-small .sub{font-size:.8rem;opacity:.6}

/* Chat view */
.chat-view{flex:1;display:flex;flex-direction:column;height:100%;background:var(--bg-deep);background-image:url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.012'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E")}
.chat-header{height:var(--header-height);padding:0 .75rem;display:flex;align-items:center;gap:.75rem;background:var(--bg-header);flex-shrink:0;border-bottom:1px solid var(--border)}
.btn-back{width:40px;height:40px;border-radius:50%;display:none;align-items:center;justify-content:center;font-size:1.1rem;color:var(--text-secondary);transition:background .2s}
.btn-back:hover{background:rgba(134,150,160,0.15)}
.chat-contact-info{display:flex;align-items:center;gap:.75rem;min-width:0}
.contact-name{font-weight:500;font-size:.95rem;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.contact-encrypt{font-size:.72rem;color:var(--text-secondary);display:flex;align-items:center;gap:.3rem}
.contact-encrypt i{font-size:.65rem}

/* Messages */
.chat-messages{flex:1;overflow-y:auto;padding:.75rem;padding-bottom:.5rem;display:flex;flex-direction:column;gap:.2rem;scroll-behavior:smooth}
.date-separator{text-align:center;margin:.75rem 0}
.date-separator span{display:inline-block;padding:.3rem .75rem;background:rgba(30,44,52,0.9);border-radius:8px;font-size:.72rem;color:var(--text-secondary);backdrop-filter:blur(8px)}
.encrypt-notice{text-align:center;margin:1.5rem .5rem;background:rgba(255,255,255,0.04);border-radius:var(--radius-md);padding:1rem}
.encrypt-notice i{font-size:1.2rem;color:var(--accent);display:block;margin-bottom:.5rem}
.encrypt-notice p{font-size:.78rem;color:var(--text-secondary);line-height:1.5}

.msg-row{display:flex;animation:msgIn .25s ease}
.msg-row.sent{justify-content:flex-end}.msg-row.received{justify-content:flex-start}
@keyframes msgIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}
.msg-bubble{max-width:75%;padding:.45rem .65rem;border-radius:var(--radius-md);position:relative;word-wrap:break-word;overflow-wrap:break-word;line-height:1.45;font-size:.935rem}
.msg-row.sent .msg-bubble{background:var(--bg-sent);border-bottom-right-radius:4px;color:var(--text-sent)}
.msg-row.received .msg-bubble{background:var(--bg-received);border-bottom-left-radius:4px}
.msg-meta{display:flex;align-items:center;justify-content:flex-end;gap:.3rem;margin-top:.15rem;float:right;margin-left:.5rem;position:relative;top:.4rem}
.msg-time{font-size:.68rem;color:rgba(255,255,255,0.5)}
.msg-row.received .msg-time{color:rgba(255,255,255,0.4)}
.msg-ticks{font-size:.85rem;line-height:1}
.tick-sent{color:var(--tick-default)}.tick-delivered{color:var(--tick-default)}.tick-read{color:var(--tick-read)}

/* Input bar */
.chat-input-bar{height:var(--input-bar-height);padding:.5rem .75rem;padding-bottom:calc(.5rem + var(--safe-bottom));display:flex;align-items:center;gap:.5rem;background:var(--bg-header);flex-shrink:0}
.chat-input-wrapper{flex:1;height:42px}
.chat-input-wrapper input{width:100%;height:100%;padding:0 .85rem;background:var(--bg-input);border-radius:999px;font-size:.9rem;color:var(--text-primary);transition:background .2s}
.chat-input-wrapper input:focus{background:#314049}
.chat-input-wrapper input::placeholder{color:var(--text-secondary);opacity:.6}
.btn-send{width:42px;height:42px;border-radius:50%;background:var(--accent);color:#0b141a;display:flex;align-items:center;justify-content:center;font-size:1rem;transition:background .2s,transform .1s,opacity .2s;flex-shrink:0}
.btn-send:hover:not(:disabled){background:var(--accent-hover)}.btn-send:active:not(:disabled){transform:scale(.93)}.btn-send:disabled{opacity:.35;cursor:not-allowed}
.no-chat-selected{flex:1;display:flex;align-items:center;justify-content:center;background:var(--bg-deep);background-image:url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.012'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E")}

/* ===== MODAL ===== */
.modal-overlay{position:fixed;inset:0;background:rgba(0,0,0,0.6);display:flex;align-items:center;justify-content:center;z-index:200;padding:1rem;animation:fadeIn .2s ease}
@keyframes fadeIn{from{opacity:0}to{opacity:1}}
.modal{width:100%;max-width:420px;background:var(--bg-panel);border-radius:var(--radius-lg);overflow:hidden;animation:modalUp .25s ease;box-shadow:0 12px 40px rgba(0,0,0,0.5)}
@keyframes modalUp{from{opacity:0;transform:translateY(20px) scale(.97)}to{opacity:1;transform:translateY(0) scale(1)}}
.modal-header{display:flex;align-items:center;justify-content:space-between;padding:1rem 1.25rem;border-bottom:1px solid var(--border)}
.modal-header h3{font-size:1.05rem;font-weight:600}
.btn-close{width:36px;height:36px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:1.1rem;color:var(--text-secondary);transition:background .2s}
.btn-close:hover{background:var(--bg-hover)}
.modal-body{padding:1.25rem;display:flex;flex-direction:column;gap:1rem}
.modal-hint{font-size:.78rem;color:var(--text-secondary);display:flex;align-items:flex-start;gap:.4rem;line-height:1.4}
.modal-hint i{margin-top:2px;flex-shrink:0}
.modal-footer{display:flex;gap:.75rem;padding:.75rem 1.25rem 1.25rem;justify-content:flex-end}
.modal-footer .btn-primary{width:auto;padding:0 1.5rem}

/* ===== PROFILE ===== */
.profile-body{align-items:center}
.profile-avatar-area{display:flex;flex-direction:column;align-items:center;gap:.75rem;margin-bottom:.5rem}
.profile-avatar-preview{width:100px;height:100px;border-radius:50%;background:var(--bg-input);display:flex;align-items:center;justify-content:center;font-size:2.5rem;color:var(--accent);overflow:hidden;border:3px solid var(--border);transition:border-color .2s}
.profile-avatar-preview:hover{border-color:var(--accent)}
.profile-avatar-preview img{width:100%;height:100%;object-fit:cover}
.btn-upload{display:inline-flex;align-items:center;gap:.4rem;padding:.4rem .85rem;background:var(--bg-input);border-radius:999px;font-size:.82rem;color:var(--accent);cursor:pointer;transition:background .2s;font-weight:500}
.btn-upload:hover{background:var(--bg-active)}
.btn-remove-avatar{font-size:.78rem;color:var(--danger);opacity:.7;transition:opacity .2s}
.btn-remove-avatar:hover{opacity:1}
.profile-id-row{display:flex;align-items:center;gap:.75rem;background:var(--bg-input);border-radius:var(--radius-md);padding:0 .85rem;height:42px}
.profile-id-row span{flex:1;font-family:'Courier New','Consolas',monospace;font-weight:600;letter-spacing:.15em;color:var(--accent);font-size:.95rem}
.profile-id-row button{color:var(--text-secondary);transition:color .2s;font-size:.9rem}
.profile-id-row button:hover{color:var(--text-primary)}
#profile-bio-input{width:100%;padding:.65rem .85rem;background:var(--bg-input);border-radius:var(--radius-md);border:2px solid transparent;transition:border-color .2s;color:var(--text-primary);font-size:.9rem;line-height:1.5;min-height:70px}
#profile-bio-input:focus{border-color:var(--accent)}
#profile-bio-input::placeholder{color:var(--text-secondary);opacity:.6}
.char-count{font-size:.72rem;color:var(--text-secondary);text-align:right}

/* ===== TOAST ===== */
#toast-container{position:fixed;top:1rem;left:50%;transform:translateX(-50%);z-index:9999;display:flex;flex-direction:column;gap:.5rem;pointer-events:none;width:calc(100% - 2rem);max-width:400px}
.toast{padding:.7rem 1rem;border-radius:var(--radius-md);font-size:.85rem;font-weight:500;display:flex;align-items:center;gap:.5rem;animation:toastIn .3s ease,toastOut .3s ease 2.7s forwards;pointer-events:auto;box-shadow:0 4px 20px rgba(0,0,0,0.4)}
.toast.success{background:#065f46;color:#a7f3d0}.toast.error{background:#7f1d1d;color:#fca5a5}.toast.info{background:#1e3a5f;color:#93c5fd}
@keyframes toastIn{from{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}
@keyframes toastOut{from{opacity:1}to{opacity:0;transform:translateY(-10px)}}

/* ===== MOBILE ===== */
@media(max-width:767px){
    :root{--sidebar-width:100%}
    #sidebar{position:absolute;inset:0;z-index:10;width:100%;min-width:100%}
    .chat-view{position:absolute;inset:0;z-index:20;width:100%}
    .btn-back{display:flex}
    .no-chat-selected{display:none!important}
    .msg-bubble{max-width:85%}
    .sidebar-header{padding-top:var(--safe-top);height:calc(var(--header-height) + var(--safe-top))}
    .chat-header{padding-top:var(--safe-top);height:calc(var(--header-height) + var(--safe-top))}
    .brand-icon{width:52px;height:52px;font-size:24px}
    .brand-name{font-size:1.5rem}
    .id-value{font-size:2rem;letter-spacing:.35em;padding-left:.35em}
}
@media(min-width:768px){
    .chat-view[style*="display: none"] + .no-chat-selected{display:flex}
}