@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;600;700&display=swap');
body {
    background: #fff;
    min-height: 100vh;
    font-family: 'Poppins', 'Segoe UI', Arial, sans-serif;
    color: #222;
    transition: background 0.4s, color 0.4s;
}
body.light-mode {
    background: linear-gradient(135deg, #e0eafc 0%, #cfdef3 100%);
    color: #222;
}
.container {
    max-width: 1300px;
}
.card, .result-box {
    border-radius: 32px;
    border: none;
    box-shadow: 0 8px 32px 0 rgba(0, 60, 120, 0.10);
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(12px);
    transition: box-shadow 0.2s, background 0.4s;
}
.card:hover, .result-box:hover {
    box-shadow: 0 16px 48px 0 rgba(0, 60, 120, 0.18);
    background: rgba(255,255,255,0.95);
}
.card-title, .display-5 {
    color: #007bff;
    font-weight: 700;
    letter-spacing: 1px;
    font-size: 2.5rem;
}
.form-label {
    color: #007bff;
    font-weight: 500;
    font-size: 1rem;
    margin-bottom: 4px;
}
.form-control, .form-select {
    border-radius: 18px;
    border: 1.5px solid #e0eafc;
    font-size: 1.1rem;
    padding: 12px 16px;
    background: #f8fafd;
    transition: border 0.2s, box-shadow 0.2s;
    box-shadow: none;
}
.form-control:focus, .form-select:focus {
    border-color: #00c6ff;
    box-shadow: 0 0 0 2px #00c6ff33;
    background: #fff;
}
.form-control::placeholder {
    color: #b0b8c9;
    opacity: 1;
}
.btn-primary {
    background: linear-gradient(90deg, #007bff 0%, #00c6ff 100%);
    border: none;
    border-radius: 32px;
    font-size: 1.3rem;
    font-weight: 700;
    padding: 16px 0;
    box-shadow: 0 4px 16px 0 rgba(0, 123, 255, 0.10);
    transition: background 0.2s, box-shadow 0.2s;
    color: #fff;
    letter-spacing: 0.5px;
}
.btn-primary:hover {
    background: linear-gradient(90deg, #0056b3 0%, #00aaff 100%);
    box-shadow: 0 8px 32px 0 rgba(0, 123, 255, 0.18);
}
.alert {
    border-radius: 18px;
    font-size: 1.08rem;
}
.icon, .result-icon {
    font-size: 1.5rem;
    margin-right: 6px;
    vertical-align: middle;
}
footer {
    margin-top: 40px;
    padding-bottom: 10px;
}
img.rounded-circle.shadow {
    box-shadow: 0 4px 24px 0 rgba(0, 60, 120, 0.15);
    border: 4px solid #fff;
    background: #f8fafd;
}
@media (max-width: 1400px) {
    .container {
        max-width: 98vw;
    }
}
@media (max-width: 992px) {
    .display-5 {
        font-size: 2rem;
    }
    .card {
        margin: 0 4px;
    }
    .container {
        max-width: 100vw;
    }
}
hr.section {
    border: 0;
    height: 2px;
    background: linear-gradient(90deg, #007bff 0%, #00c6ff 100%);
    opacity: 0.2;
    margin: 32px 0 24px 0;
}
.result-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: #007bff;
    margin-bottom: 4px;
}
.toggle-mode {
    position: absolute;
    top: 24px;
    right: 32px;
    z-index: 10;
    background: rgba(255,255,255,0.15);
    border: none;
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #00c6ff;
    font-size: 1.5rem;
    transition: background 0.3s, color 0.3s;
}
.toggle-mode:hover {
    background: #00c6ff;
    color: #fff;
}