.page-header {
    text-align: center;
    padding: 2.5rem 0 2rem;
    animation: fadeSlideDown 0.7s cubic-bezier(0.16, 1, 0.3, 1) both;
}

.page-header h1 {
    font-size: 2.25rem;
    font-weight: 300;
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}

.page-header h1 strong {
    font-weight: 700;
    background: linear-gradient(90deg, #6ee7d4, #5eead4, #67e8f9);
    background-size: 200% auto;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: shimmer 6s linear infinite;
}

@keyframes shimmer {
    to { background-position: 200% center; }
}

.page-header p {
    color: rgba(255,255,255,0.6);
    font-size: 0.95rem;
}

.card {
    max-width: 520px;
    margin: 0 auto;
    padding: 2.25rem;
    animation: fadeSlideUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.1s both;
}

.form-group,
.checkbox-group,
.btn-row {
    animation: fadeSlideUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) both;
}
.form-group:nth-of-type(1) { animation-delay: 0.2s; }
.form-group:nth-of-type(2) { animation-delay: 0.3s; }
.checkbox-group { animation-delay: 0.4s; }
.btn-row { animation-delay: 0.5s; }

.form-group {
    margin-bottom: 1.25rem;
    position: relative;
    z-index: 1;
}

label {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: rgba(255,255,255,0.65);
    margin-bottom: 0.5rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

input[type="number"] {
    width: 100%;
    padding: 0.8rem 1rem;
    background: rgba(255,255,255,0.08);
    border: 1px solid rgba(255,255,255,0.15);
    border-radius: 14px;
    color: #fff;
    font-size: 1rem;
    font-family: 'Inter', sans-serif;
    outline: none;
    -webkit-appearance: none;
    appearance: none;
    transition: border-color 0.25s ease, background-color 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.2);
}

input[type="number"]:focus {
    border-color: rgba(110, 231, 212, 0.7);
    background: rgba(255,255,255,0.12);
    transform: translateY(-1px);
    box-shadow:
        inset 0 1px 2px rgba(0,0,0,0.2),
        0 0 0 3px rgba(110, 231, 212, 0.2),
        0 4px 16px rgba(110, 231, 212, 0.15);
}

input[type="number"]::placeholder {
    color: rgba(255,255,255,0.3);
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
    margin-top: 0.5rem;
    position: relative;
    z-index: 1;
}

input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: #2dd4bf;
    cursor: pointer;
    flex-shrink: 0;
}

.checkbox-group label {
    margin: 0;
    text-transform: none;
    font-size: 0.95rem;
    color: rgba(255,255,255,0.8);
    letter-spacing: 0;
    cursor: pointer;
}

.btn-row {
    display: flex;
    gap: 0.75rem;
    position: relative;
    z-index: 1;
}

.btn {
    flex: 1;
    padding: 0.85rem;
    border: none;
    border-radius: 14px;
    font-size: 0.95rem;
    font-family: 'Inter', sans-serif;
    font-weight: 600;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.25s ease, background-color 0.25s ease;
}

.btn::after {
    content: '';
    position: absolute;
    top: 0;
    left: -120%;
    width: 80%;
    height: 100%;
    background: linear-gradient(120deg, transparent, rgba(255,255,255,0.35), transparent);
    transform: skewX(-20deg);
    transition: left 0.6s ease;
}

.btn:hover::after {
    left: 130%;
}

.btn:active {
    transform: scale(0.97);
}

.btn-primary {
    background: linear-gradient(135deg, #6ee7d4, #2dd4bf);
    color: #04332b;
    box-shadow:
        0 4px 16px rgba(45, 212, 191, 0.4),
        inset 0 1px 1px rgba(255,255,255,0.5);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow:
        0 6px 22px rgba(45, 212, 191, 0.55),
        inset 0 1px 1px rgba(255,255,255,0.5);
}

.btn-secondary {
    background: linear-gradient(135deg, rgba(255,255,255,0.14), rgba(255,255,255,0.05));
    color: rgba(255,255,255,0.85);
    border: 1px solid rgba(255,255,255,0.2);
    box-shadow: inset 0 1px 1px rgba(255,255,255,0.2);
}

.btn-secondary:hover {
    background: linear-gradient(135deg, rgba(255,255,255,0.22), rgba(255,255,255,0.08));
    color: #fff;
    transform: translateY(-2px);
}

.result {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255,255,255,0.12);
    display: none;
    position: relative;
    z-index: 1;
}

.result.show {
    display: block;
    animation: resultReveal 0.5s cubic-bezier(0.16, 1, 0.3, 1) both;
}

.result h3 {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: rgba(255,255,255,0.5);
    margin-bottom: 1rem;
}

.result-row {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    padding: 0.65rem 0;
    border-bottom: 1px solid rgba(255,255,255,0.08);
    animation: fadeSlideUp 0.5s cubic-bezier(0.16, 1, 0.3, 1) both;
}
.result.show .result-row:nth-child(2) { animation-delay: 0.1s; }
.result.show .result-row:nth-child(3) { animation-delay: 0.2s; }

.result-row:last-child {
    border-bottom: none;
}

.result-label {
    font-size: 0.85rem;
    color: rgba(255,255,255,0.6);
}

.result-value {
    font-size: 1.15rem;
    font-weight: 600;
    color: #fff;
}

.result-value small {
    font-size: 0.75rem;
    color: rgba(255,255,255,0.5);
    font-weight: 400;
    margin-left: 0.4rem;
}

.footer-link {
    text-align: center;
    margin-top: 2rem;
    font-size: 0.8rem;
    color: rgba(255,255,255,0.4);
}

.footer-link a {
    color: rgba(255,255,255,0.5);
    text-decoration: none;
    transition: color 0.25s ease;
}

.footer-link a:hover {
    color: rgba(255,255,255,0.85);
}

@keyframes fadeSlideUp {
    from { opacity: 0; transform: translateY(16px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeSlideDown {
    from { opacity: 0; transform: translateY(-16px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes resultReveal {
    from { opacity: 0; transform: translateY(12px) scale(0.98); }
    to   { opacity: 1; transform: translateY(0) scale(1); }
}

@media (max-width: 600px) {
    .page-header { padding: 1.5rem 0 1.5rem; }
    .page-header h1 { font-size: 1.65rem; }
    .page-header p { font-size: 0.85rem; padding: 0 1rem; }
    .card { padding: 1.5rem; border-radius: 20px; }
    .btn-row { flex-direction: column; }
    .btn { padding: 0.9rem; }
    input[type="number"] { font-size: 16px; }
}

@media (prefers-reduced-motion: reduce) {
    * { animation: none !important; transition: none !important; }
}