* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', sans-serif;
}

body {
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    transition: 0.4s ease;
}

/* Animated gradient background */
.background {
    position: absolute;
    width: 200%;
    height: 200%;
    background: linear-gradient(-45deg, #000428, #004e92, #000428, #1a1a1a);
    background-size: 400% 400%;
    animation: gradientMove 12s ease infinite;
    z-index: -1;
}

@keyframes gradientMove {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* Container */
.container {
    width: 380px;
    padding: 30px;
    border-radius: 20px;
    backdrop-filter: blur(20px);
    background: rgba(255,255,255,0.05);
    box-shadow: 0 0 25px #00f2ff;
    transition: 0.4s;
}

.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

h2 {
    color: #00f2ff;
}

input {
    width: 100%;
    padding: 12px;
    border-radius: 10px;
    border: none;
    outline: none;
    margin-bottom: 15px;
    font-size: 14px;
}

/* Buttons */
.primary-btn, .secondary-btn, #themeToggle {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 12px;
    font-size: 15px;
    cursor: pointer;
    transition: 0.3s;
    margin-top: 10px;
}

.primary-btn {
    background: #00f2ff;
    color: black;
    font-weight: bold;
    box-shadow: 0 0 15px #00f2ff;
}

.primary-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 0 25px #00f2ff;
}

.secondary-btn {
    background: black;
    color: #00f2ff;
    border: 1px solid #00f2ff;
}

.secondary-btn:hover {
    background: #00f2ff;
    color: black;
}

#themeToggle {
    width: auto;
    padding: 8px 12px;
    background: black;
    color: #00f2ff;
    border: 1px solid #00f2ff;
}

#qrImage {
    margin-top: 20px;
    display: none;
    text-align: center;
    animation: fadeIn 0.5s ease forwards;
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.8); }
    to { opacity: 1; transform: scale(1); }
}

#qrImage img {
    width: 200px;
    height: 200px;
    margin-bottom: 10px;
    border-radius: 15px;
}

/* Light Theme */
body.light .container {
    background: rgba(255,255,255,0.8);
    box-shadow: 0 0 25px #004e92;
}

body.light h2 {
    color: #004e92;
}

body.light .primary-btn {
    background: #004e92;
    color: white;
    box-shadow: 0 0 15px #004e92;
}

body.light .secondary-btn {
    background: white;
    color: #004e92;
    border: 1px solid #004e92;
}

body.light #themeToggle {
    background: white;
    color: #004e92;
    border: 1px solid #004e92;
}