body {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: 'Roboto Mono', monospace;
    transition: background 0.5s ease, color 0.5s ease;
    margin: 0;
    overflow: hidden;
}

.theme-vaporwave body {
    background: linear-gradient(135deg, #ff9a9e, #fad0c4);
    color: #2a2a72;
}

.theme-neon body {
    background: linear-gradient(135deg, #000, #1a1a3d);
    color: #00ffcc;
}

.theme-dark body {
    background: linear-gradient(135deg, #1c2526, #2f4f4f);
    color: #d8e6e7;
}

.container {
    backdrop-filter: blur(8px);
    border-radius: 15px;
    padding: 25px;
    width: 90%;
    max-width: 380px;
    position: relative;
    transform: translateZ(0);
    transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.3s ease, border 0.3s ease;
}

.theme-vaporwave .container {
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid rgba(255, 157, 158, 0.5);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2), inset 0 0 10px rgba(255, 157, 158, 0.3);
}

.theme-neon .container {
    background: rgba(0, 0, 0, 0.5);
    border: 2px solid rgba(255, 20, 147, 0.5);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3), inset 0 0 10px rgba(0, 255, 255, 0.3);
}

.theme-dark .container {
    background: rgba(28, 37, 38, 0.4);
    border: 2px solid rgba(74, 157, 156, 0.5);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3), inset 0 0 10px rgba(74, 157, 156, 0.3);
}

.container:hover {
    transform: translateY(-5px) translateZ(10px);
}

.theme-vaporwave .container:hover {
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.3), inset 0 0 15px rgba(255, 157, 158, 0.5);
}

.theme-neon .container:hover {
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.4), inset 0 0 15px rgba(0, 255, 255, 0.5);
}

.theme-dark .container:hover {
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.4), inset 0 0 15px rgba(74, 157, 156, 0.5);
}

h1 {
    font-size: 2rem;
    text-align: center;
    margin-bottom: 20px;
}

.theme-vaporwave h1 {
    text-shadow: 0 0 8px rgba(255, 157, 158, 0.7);
}

.theme-neon h1 {
    text-shadow: 0 0 8px rgba(0, 255, 255, 0.7);
}

.theme-dark h1 {
    text-shadow: 0 0 8px rgba(74, 157, 156, 0.7);
}

.input-group {
    margin-bottom: 20px;
}

label {
    display: block;
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.theme-vaporwave label {
    text-shadow: 0 0 5px rgba(255, 157, 158, 0.5);
}

.theme-neon label {
    text-shadow: 0 0 5px rgba(0, 255, 255, 0.5);
}

.theme-dark label {
    text-shadow: 0 0 5px rgba(74, 157, 156, 0.5);
}

input[type="date"] {
    width: 100%;
    padding: 10px;
    font-family: 'Roboto Mono', monospace;
    font-size: 1rem;
    border-radius: 8px;
    box-sizing: border-box;
    transition: border 0.3s ease, box-shadow 0.3s ease;
}

.theme-vaporwave input[type="date"] {
    background: rgba(255, 255, 255, 0.3);
    border: 1px solid #ff9a9e;
    color: #2a2a72;
}

.theme-neon input[type="date"] {
    background: rgba(0, 0, 0, 0.4);
    border: 1px solid #00ffcc;
    color: #00ffcc;
}

.theme-dark input[type="date"] {
    background: rgba(0, 0, 0, 0.4);
    border: 1px solid #4a9d9c;
    color: #d8e6e7;
}

input[type="date"]:focus {
    outline: none;
}

.theme-vaporwave input[type="date"]:focus {
    border: 1px solid #2a2a72;
    box-shadow: 0 0 10px rgba(255, 157, 158, 0.7);
}

.theme-neon input[type="date"]:focus {
    border: 1px solid #ff1493;
    box-shadow: 0 0 10px rgba(0, 255, 255, 0.7);
}

.theme-dark input[type="date"]:focus {
    border: 1px solid #d8e6e7;
    box-shadow: 0 0 10px rgba(74, 157, 156, 0.7);
}

input[type="date"]::-webkit-calendar-picker-indicator {
    filter: invert(0.3) hue-rotate(180deg);
}

.theme-neon input[type="date"]::-webkit-calendar-picker-indicator {
    filter: invert(0.8) hue-rotate(90deg);
}

.theme-dark input[type="date"]::-webkit-calendar-picker-indicator {
    filter: invert(0.8) hue-rotate(0deg);
}

button {
    width: 100%;
    padding: 12px;
    font-family: 'Roboto Mono', monospace;
    font-size: 1.2rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.theme-vaporwave button {
    background: linear-gradient(90deg, #ff9a9e, #fad0c4);
    color: #2a2a72;
}

.theme-neon button {
    background: linear-gradient(90deg, #ff1493, #00ffcc);
    color: #000;
}

.theme-dark button {
    background: linear-gradient(90deg, #4a9d9c, #1c2526);
    color: #d8e6e7;
}

button:hover {
    transform: translateY(-2px);
}

.theme-vaporwave button:hover {
    box-shadow: 0 5px 15px rgba(255, 157, 158, 0.5);
}

.theme-neon button:hover {
    box-shadow: 0 5px 15px rgba(0, 255, 255, 0.5);
}

.theme-dark button:hover {
    box-shadow: 0 5px 15px rgba(74, 157, 156, 0.5);
}

button::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
    transition: left 0.5s ease;
}

button:hover::after {
    left: 100%;
}

#result {
    text-align: center;
    font-size: 1.4rem;
    margin-top: 20px;
}

.theme-vaporwave #result {
    text-shadow: 0 0 5px rgba(255, 157, 158, 0.5);
}

.theme-neon #result {
    text-shadow: 0 0 5px rgba(0, 255, 255, 0.5);
}

.theme-dark #result {
    text-shadow: 0 0 5px rgba(74, 157, 156, 0.5);
}

#error {
    text-align: center;
    font-size: 1rem;
    color: #ff4444;
    margin-top: 10px;
    text-shadow: 0 0 3px #ff4444;
}

#error:empty {
    display: none;
}

.theme-toggle {
    position: absolute;
    top: 15px;
    right: 15px;
    padding: 5px;
    background: none;
    border: none;
    cursor: pointer;
}

.theme-toggle svg {
    width: 24px;
    height: 24px;
}

.theme-vaporwave .theme-toggle svg {
    fill: #2a2a72;
}

.theme-neon .theme-toggle svg {
    fill: #00ffcc;
}

.theme-dark .theme-toggle svg {
    fill: #d8e6e7;
}