:root {
    --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --card-bg: rgba(255, 255, 255, 0.2);
    --text-color: #fff;
    --input-bg: rgba(255, 255, 255, 0.3);
    --border-color: rgba(255, 255, 255, 0.3);
    --btn-bg: #fff;
    --btn-text: #764ba2;
    --shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
}

[data-theme="dark"] {
    --bg-gradient: linear-gradient(135deg, #0f2027 0%, #203a43 50%, #2c5364 100%);
    --card-bg: rgba(0, 0, 0, 0.3);
    --text-color: #e0e0e0;
    --input-bg: rgba(0, 0, 0, 0.4);
    --border-color: rgba(255, 255, 255, 0.1);
    --btn-bg: #4ca1af;
    --btn-text: #fff;
}

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

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: var(--bg-gradient);
    transition: background 0.5s ease;
}

.card {
    width: 380px;
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 20px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    padding: 30px;
    color: var(--text-color);
    transition: all 0.3s ease;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.header h2 {
    font-weight: 600;
    font-size: 1.5rem;
}

#theme-toggle {
    background: transparent;
    border: none;
    color: var(--text-color);
    font-size: 1.2rem;
    cursor: pointer;
    transition: transform 0.3s;
}

#theme-toggle:hover {
    transform: rotate(20deg);
}

.amount-box p {
    font-size: 0.9rem;
    margin-bottom: 8px;
    opacity: 0.9;
}

input,
select {
    width: 100%;
    outline: none;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: var(--input-bg);
    color: var(--text-color);
    font-size: 1rem;
    padding: 12px;
}

input:focus {
    border-color: rgba(255, 255, 255, 0.8);
}

/* Remove number spinner arrows */
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

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

.select-box {
    display: flex;
    align-items: center;
    width: 40%;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    padding: 5px 10px;
    background: var(--input-bg);
}

.select-box img {
    width: 25px;
    margin-right: 8px;
    border-radius: 2px;
}

.select-box select {
    border: none;
    background: transparent;
    padding: 5px;
    width: 100%;
    cursor: pointer;
}

/* Dropdown options always dark for visibility */
select option {
    background: #333;
    color: white;
}

.icon-container {
    cursor: pointer;
    font-size: 1.2rem;
    transition: transform 0.4s ease;
}

.icon-container:hover {
    transform: rotate(180deg) scale(1.1);
}

.msg-box {
    margin: 30px 0;
    text-align: center;
}

.result {
    font-size: 1.8rem;
    font-weight: 600;
}

.sub-text {
    font-size: 0.8rem;
    opacity: 0.7;
    margin-top: 5px;
}

button#convert-btn {
    width: 100%;
    height: 50px;
    background: var(--btn-bg);
    color: var(--btn-text);
    border: none;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: 0.3s;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

button#convert-btn:hover {
    transform: translateY(-2px);
    opacity: 0.9;
}