:root {
    --primary: #2ecc71; /* Biology Green */
    --primary-dark: #27ae60;
    --secondary: #34495e; /* Dark Blue-Grey */
    --accent: #f1c40f; /* Energy Yellow */
    --bg-light: #f0f7f4;
    --white: #ffffff;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Hind Siliguri', 'Poppins', sans-serif;
    background-color: var(--bg-light);
    color: var(--text-dark);
    overflow-x: hidden;
    line-height: 1.6;
}

/* --- Background Animation --- */
.bg-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
    background: linear-gradient(135deg, #e0f7fa 0%, #e8f5e9 100%);
}

.dna-strand {
    position: absolute;
    width: 100%;
    height: 100%;
    opacity: 0.1;
    background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%232ecc71' fill-opacity='1'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    animation: moveBackground 60s linear infinite;
}

.floating-cell {
    position: absolute;
    border-radius: 50%;
    background: rgba(46, 204, 113, 0.1);
    animation: float 15s infinite ease-in-out;
}

@keyframes float {
    0%, 100% { transform: translateY(0) scale(1); }
    50% { transform: translateY(-20px) scale(1.1); }
}

@keyframes moveBackground {
    from { background-position: 0 0; }
    to { background-position: 100% 100%; }
}

/* --- Header --- */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 5%;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 15px rgba(0,0,0,0.05);
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-dark);
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo i {
    font-size: 1.8rem;
    color: var(--primary);
}

.logo img {
    width: 50px;
    height: 50px;
    object-fit: contain;
    border-radius: 10px;
    flex-shrink: 0;
}

.logo-text {
    /* small spacing between letters */
    letter-spacing: 0.08em;
    color: red;
    font-family: "Broadway", serif;
}



.nav-btn {
    background: var(--secondary);
    color: var(--white);
    padding: 8px 20px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 500;
    transition: 0.3s;
}

.nav-btn:hover {
    background: var(--primary);
}

/* --- Main Layout --- */
main {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 90vh;
    padding: 40px 20px;
}

/* --- Hero Section --- */
.hero {
    text-align: center;
    max-width: 800px;
    margin-bottom: 40px;
    animation: fadeInDown 1s ease-out;
}

.hero h1 {
    font-size: 3rem;
    color: var(--secondary);
    margin-bottom: 10px;
    line-height: 1.2;
}

.hero span {
    color: var(--primary);
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 20px;
}

/* --- Registration Card --- */
.registration-card {
    background: var(--white);
    width: 100%;
    max-width: 500px;
    padding: 40px;
    border-radius: 20px;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
    animation: fadeInUp 1s ease-out 0.3s backwards;
}

.registration-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
}

.form-header {
    text-align: center;
    margin-bottom: 30px;
}

.form-header h2 {
    color: var(--secondary);
    font-size: 1.8rem;
}

.form-group {
    position: relative;
    margin-bottom: 25px;
}

.form-group i {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-light);
    transition: 0.3s;
}

.form-control {
    width: 100%;
    padding: 12px 15px 12px 45px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-family: inherit;
    font-size: 1rem;
    outline: none;
    transition: 0.3s;
    background: #fafafa;
}

.form-control:focus {
    border-color: var(--primary);
    background: var(--white);
    box-shadow: 0 0 0 4px rgba(46, 204, 113, 0.1);
}

.form-control:focus + i {
    color: var(--primary);
}

select.form-control {
    appearance: none;
    cursor: pointer;
}

/* Custom arrow for select */
.select-wrapper {
    position: relative;
}
.select-wrapper::after {
    content: '⬇️';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-light);
    pointer-events: none;
}

.submit-btn {
    width: 100%;
    padding: 15px;
    background: var(--primary);
    color: var(--white);
    border: none;
    border-radius: 10px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: 0.3s;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    box-shadow: 0 5px 15px rgba(46, 204, 113, 0.4);
}

.submit-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.submit-btn:active {
    transform: translateY(0);
}

/* --- Features Section --- */
.features {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 50px;
    flex-wrap: wrap;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-dark);
    background: rgba(255,255,255,0.6);
    padding: 10px 20px;
    border-radius: 50px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
    animation: fadeInUp 1s ease-out 0.6s backwards;
}

.feature-item i {
    color: var(--primary);
}

/* --- Modal / Toast --- */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: 0.3s;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--white);
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    max-width: 400px;
    width: 90%;
    transform: scale(0.8);
    transition: 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.modal-overlay.active .modal-content {
    transform: scale(1);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #f3f3f3;
    border-top: 4px solid var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

@keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }

/* --- Footer --- */
footer {
    text-align: center;
    padding: 20px;
    color: var(--text-light);
    font-size: 0.9rem;
    margin-top: auto;
}

.footer-social {
    margin-bottom: 10px;
}

.footer-title {
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: 10px;
}

.footer-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    border-radius: 50px;
    text-decoration: none;
    background: rgba(255, 255, 255, 0.7);
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
    color: var(--text-dark);
    transition: 0.2s;
}

.social-link i {
    color: var(--primary);
    font-size: 1.1rem;
}

.social-link span {
    font-weight: 600;
}

.social-link:hover {
    transform: translateY(-2px);
    background: rgba(46, 204, 113, 0.12);
}


/* --- Animations Keyframes --- */
@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-30px); }
    to { opacity: 1; transform: translateY(0); }
}
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

/* --- Responsive --- */
@media (max-width: 768px) {
    .hero h1 { font-size: 2.2rem; }
    .registration-card { padding: 30px 20px; }
    .features { flex-direction: column; align-items: center; }

    .logo img {
        width: 38px;
        height: 38px;
    }
}