* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    height: 100vh;
    background: url("https://cdn.wallpapersafari.com/98/65/ViTC7s.jpg") no-repeat center center fixed;
    background-size: cover;
    color: whitesmoke;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    overflow: hidden;
}

/* Top Bar */
#top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(10px);
    color: white;
    padding: 6px 16px;
    font-size: 14px;
    font-weight: 500;
}

.os-logo {
    cursor: pointer;
    font-weight: bold;
}

/* Desktop App Icons */
#desktopApps {
    display: flex;
    flex-direction: column;
    gap: 20px;
    padding: 20px;
}

.app-icon {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 70px;
    cursor: pointer;
    text-align: center;
}

.app-icon img, .calc-icon-placeholder {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.3);
}

.calc-icon-placeholder {
    background: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 28px;
}

.app-icon span {
    margin-top: 6px;
    font-size: 12px;
    text-shadow: 0 1px 3px rgba(0,0,0,0.8);
}

/* General Window Styles */
.window {
    position: absolute;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(20px);
    border-radius: 12px;
    box-shadow: 0 15px 35px rgba(0,0,0,0.3);
    color: #333;
    overflow: hidden;
    flex-direction: column;
}

.window-header {
    background: rgba(230, 230, 230, 0.8);
    padding: 10px 14px;
    font-weight: bold;
    cursor: move;
    user-select: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(0,0,0,0.1);
}

.control-btn {
    border: none;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    cursor: pointer;
    line-height: 1;
    font-size: 14px;
    background: #ff5f56;
    color: white;
}

.window-body {
    padding: 15px;
}

/* Window Placement Adjustments */
#welcomeWindow {
    width: 380px;
    top: 20%;
    left: 35%;
}

#myNote {
    width: 420px;
    top: 15%;
    left: 15%;
}

#myCalc {
    width: 280px;
    top: 25%;
    left: 60%;
}

/* Notes App UI */
.notes-toolbar {
    margin-bottom: 10px;
}

.note-textarea {
    width: 100%;
    height: 200px;
    border: 1px solid #ccc;
    border-radius: 8px;
    padding: 10px;
    font-size: 14px;
    resize: none;
    outline: none;
}

/* Calculator UI */
#calcScreen {
    width: 100%;
    height: 45px;
    background: #222;
    color: #fff;
    border: none;
    border-radius: 6px;
    text-align: right;
    padding: 0 10px;
    font-size: 20px;
    margin-bottom: 12px;
}

.calc-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
}

.calc-btn {
    padding: 12px;
    font-size: 16px;
    border: none;
    border-radius: 6px;
    background: #e0e0e0;
    cursor: pointer;
}

.calc-btn:hover {
    background: #d0d0d0;
}

.calc-btn.op { background: #f39c12; color: white; }
.calc-btn.action { background: #e74c3c; color: white; }
.calc-btn.equal { background: #2ecc71; color: white; }
.span-2 { grid-column: span 2; }