* {
    box-sizing: border-box;
    font-family: IRANSans, sans-serif;
}

body {
    margin: 0;
    background: linear-gradient(135deg, #eef2f7, #cfd9df);
}

/* Header */
.header {
    background: #fff;
    box-shadow: 0 4px 10px rgba(0,0,0,.08);
}

.container {
    max-width: 1100px;
    margin: auto;
    padding: 15px;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo img {
    height: 45px;
}

.menu {
    list-style: none;
    display: flex;
    gap: 20px;
}

.menu a {
    text-decoration: none;
    color: #444;
}

/* Main */
.install-section {
    min-height: calc(100vh - 120px);
    display: flex;
    justify-content: center;
    align-items: center;
}

.box {
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(10px);
    padding: 30px;
    width: 100%;
    max-width: 420px;
    border-radius: 18px;
    box-shadow: 0 20px 40px rgba(0,0,0,.2);
    text-align: center;
}

.desc {
    color: #666;
    margin-bottom: 25px;
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 15px;
    border: 2px solid #ddd;
    padding: 12px;
    border-radius: 14px;
    margin-top: 15px;
    text-decoration: none;
    color: #000;
    transition: .3s;
}

.download-btn:hover {
    background: #eef3ff;
    border-color: #4a6cf7;
    transform: scale(1.02);
}

.download-btn img {
    width: 36px;
}

.download-btn span {
    font-weight: bold;
}

.download-btn small {
    color: #666;
}

/* Footer */
footer {
    text-align: center;
    padding: 15px;
    color: #666;
    font-size: 14px;
}

/* 🔔 Popup */
.popup-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.5);
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    pointer-events: none;
    transition: .4s;
}

.popup-overlay.show {
    opacity: 1;
    pointer-events: auto;
}

.popup {
    background: rgba(255,255,255,.9);
    backdrop-filter: blur(12px);
    padding: 25px;
    border-radius: 18px;
    text-align: center;
    width: 300px;
    transform: scale(.7);
    transition: .4s;
}

.popup-overlay.show .popup {
    transform: scale(1);
}

.popup h3 {
    margin-top: 0;
}

.popup button {
    margin-top: 15px;
    padding: 10px 25px;
    border: none;
    border-radius: 10px;
    background: #4a6cf7;
    color: #fff;
    cursor: pointer;
    font-size: 15px;
}