/* =========================================
   1. RESET Y VARIABLES GLOBALES
   ========================================= */
:root {
    --bg-app: #ffffff;
    --bg-sidebar: #ffffff;
    --text-main: #1e1e1e;
    --text-muted: #666666;
    --border-color: rgba(0, 0, 0, 0.05);
    --shadow-soft: 0 4px 12px rgba(0, 0, 0, 0.03);
    --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.06);
    --radius-pill: 35px;
    --radius-box: 25px;
    --chat-shell-width: 720px;
    --chat-bubble-radius: 28px;
    --chat-bubble-notch: 12px;
    
    /* 🔥 INYECCIÓN APPLE: Físicas de animación */
    --apple-ease: cubic-bezier(0.25, 0.8, 0.05, 1);
    --apple-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-app);
    color: var(--text-main);
    display: flex;
    height: 100vh;
    overflow: hidden;
}

button:active, .chat-item:active, .nav-btn:active, .btn-primary:active, .btn-submit:active, .master-history-title:active {
    transform: scale(0.97) !important;
    transition: transform 0.1s ease !important;
}