:root {
    --primary-color: #1f2a38;
    --accent-color: #3498db;
    --text-light: #ecf0f1;
    --transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

body {
    font-family: 'Poppins', sans-serif;
    color: #fff;
    overflow-x: hidden;
    background-color: var(--primary-color);
}

/* __Navbar__ */
.navbar {
    background-color: rgba(31, 42, 56, 0.95) !important;
    backdrop-filter: blur(10px);
    padding: 15px 0;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.2);
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.4rem;
    letter-spacing: 1.5px;
}

.nav-custom-link {
    font-weight: 500;
    padding: 8px 15px !important;
    transition: var(--transition);
    color: #fff !important;
}

.nav-custom-link:hover {
    color: var(--accent-color) !important;
}

.nav-custom-link.active {
    color: var(--accent-color) !important;
}

.nav-admin-btn {
    border: 2px solid #fff !important;
    color: #fff !important;
    font-weight: 600 !important;
    border-radius: 8px;
    transition: var(--transition);
}

.nav-admin-btn:hover {
    background-color: #fff !important;
    color: var(--primary-color) !important;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(255, 255, 255, 0.3);
}

/* __Hero__ */
.hero-section {
    background: linear-gradient(rgba(0, 0, 0, 0.5), rgba(10, 24, 40, 0.7)),
                url('https://images.unsplash.com/photo-1564013799919-ab600027ffc6?ixlib=rb-4.0.3&auto=format&fit=crop&w=1350&q=80');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    color: #fff;
    height: 100vh;
    display: flex;
    align-items: center;
    filter: brightness(1.1) contrast(1.15) saturate(1.2);
    position: relative;
}

.hero-tag {
    display: inline-block;
    background: rgba(52, 152, 219, 0.25);
    border: 1px solid rgba(52, 152, 219, 0.5);
    color: #74c7f0;
    font-size: 0.82rem;
    font-weight: 600;
    letter-spacing: 1.2px;
    padding: 6px 18px;
    border-radius: 50px;
    text-transform: uppercase;
}

.hero-title {
    font-size: 4rem;
    font-weight: 700;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    font-weight: 300;
    max-width: 800px;
    margin: 0 auto 30px;
    opacity: 0.9;
}

.hero-stat-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.18);
    color: #ecf0f1;
    font-size: 0.88rem;
    font-weight: 500;
    padding: 7px 18px;
    border-radius: 50px;
    backdrop-filter: blur(6px);
}

.btn-predict {
    background: linear-gradient(45deg, var(--accent-color), #2980b9);
    border: none;
    padding: 16px 45px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 50px;
    color: white;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: var(--transition);
    display: inline-block;
    text-decoration: none;
}

.btn-predict:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(52, 152, 219, 0.4);
    filter: brightness(1.1);
    color: #fff;
}

.btn-learn-more {
    padding: 14px 35px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
    text-decoration: none;
}

.btn-learn-more:hover {
    background: rgba(255,255,255,0.15);
    transform: translateY(-3px);
}

.hero-scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.hero-scroll-indicator a {
    color: rgba(255,255,255,0.5);
    font-size: 1.5rem;
    text-decoration: none;
    transition: var(--transition);
}

.hero-scroll-indicator a:hover {
    color: var(--accent-color);
}

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(-10px); }
}

/* __Stats Strip__ */
.stats-strip {
    background: rgba(15, 25, 38, 0.98);
    border-top: 1px solid rgba(52, 152, 219, 0.2);
    border-bottom: 1px solid rgba(52, 152, 219, 0.2);
}

.stat-box {
    padding: 10px;
}

.stat-number {
    font-size: 2.4rem;
    font-weight: 700;
    color: var(--accent-color);
    line-height: 1;
}

.stat-label {
    font-size: 0.8rem;
    color: rgba(255,255,255,0.55);
    font-weight: 500;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    margin-top: 4px;
}

/* __About__ */
.about-section {
    background-color: var(--primary-color);
}

.section-tag {
    display: inline-block;
    background: rgba(52, 152, 219, 0.18);
    border: 1px solid rgba(52, 152, 219, 0.4);
    color: #74c7f0;
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 1.5px;
    padding: 5px 16px;
    border-radius: 50px;
    text-transform: uppercase;
}

.about-main-img {
    width: 100%;
    max-height: 420px;
    object-fit: cover;
    border-radius: 20px;
}

.about-badge-float {
    position: absolute;
    bottom: -18px;
    right: 20px;
    background: rgba(31, 42, 56, 0.95);
    border: 1px solid rgba(52, 152, 219, 0.4);
    color: #fff;
    font-size: 0.88rem;
    font-weight: 600;
    padding: 10px 22px;
    border-radius: 50px;
    backdrop-filter: blur(10px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}

.about-text {
    color: rgba(255,255,255,0.75);
    font-weight: 400;
    line-height: 1.8;
    font-size: 0.97rem;
}

.about-list li {
    color: rgba(255,255,255,0.8);
    font-size: 0.95rem;
    padding: 6px 0;
    font-weight: 500;
}

/* __Features__ */
.features-section {
    background: linear-gradient(rgba(0, 0, 0, 0.45), rgba(10, 24, 40, 0.7)),
                url('https://images.unsplash.com/photo-1564013799919-ab600027ffc6?ixlib=rb-4.0.3&auto=format&fit=crop&w=1350&q=80');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    color: #fff;
    filter: brightness(1.05) contrast(1.1) saturate(1.15);
}

/* Headings */
.section-heading {
    color: #fff;
    letter-spacing: -0.5px;
    font-size: 2.2rem;
}

.section-subtext {
    color: rgba(255,255,255,0.6);
    font-size: 1rem;
    max-width: 580px;
    margin: 0 auto;
}

.heading-line {
    height: 4px;
    width: 50px;
    background-color: var(--accent-color);
    border-radius: 2px;
}

/* Feature Cards - Glass Dark */
.feature-card {
    padding: 50px 30px;
    border-radius: 20px;
    background: rgba(0, 0, 0, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    color: #fff;
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-12px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
    border-color: rgba(52, 152, 219, 0.4);
}

.icon-box {
    width: 80px;
    height: 80px;
    background: rgba(52, 152, 219, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    transition: var(--transition);
}

.feature-card:hover .icon-box {
    background: rgba(52, 152, 219, 0.55);
    transform: scale(1.1);
}

.feature-icon {
    font-size: 2.2rem;
    color: #fff;
}

/* __How It Works__ */
.how-section {
    background-color: #141e2b;
}

.step-card {
    background: rgba(31, 42, 56, 0.8);
    border: 1px solid rgba(52, 152, 219, 0.15);
    border-radius: 20px;
    padding: 45px 30px;
    position: relative;
    transition: var(--transition);
}

.step-card:hover {
    transform: translateY(-10px);
    border-color: rgba(52, 152, 219, 0.45);
    box-shadow: 0 20px 40px rgba(0,0,0,0.3);
}

.step-number {
    font-size: 4rem;
    font-weight: 700;
    color: rgba(52, 152, 219, 0.12);
    line-height: 1;
    position: absolute;
    top: 18px;
    right: 22px;
    font-family: 'Poppins', sans-serif;
    user-select: none;
}

.step-icon-wrap {
    width: 72px;
    height: 72px;
    background: linear-gradient(135deg, rgba(52,152,219,0.35), rgba(41,128,185,0.2));
    border: 1px solid rgba(52,152,219,0.4);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: #74c7f0;
    transition: var(--transition);
}

.step-card:hover .step-icon-wrap {
    background: linear-gradient(135deg, rgba(52,152,219,0.6), rgba(41,128,185,0.4));
    transform: scale(1.08);
}

.step-title {
    color: #fff;
    font-size: 1.1rem;
    margin-bottom: 10px;
}

.step-text {
    color: rgba(255,255,255,0.6);
    font-size: 0.93rem;
    line-height: 1.7;
}

/* __Contact__ */
.contact-section {
    background-color: var(--primary-color);
}

.contact-icon-wrap {
    width: 46px;
    height: 46px;
    min-width: 46px;
    background: rgba(52, 152, 219, 0.2);
    border: 1px solid rgba(52, 152, 219, 0.35);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    color: var(--accent-color);
}

.contact-form-wrap {
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.1);
    backdrop-filter: blur(10px);
}

.contact-input {
    background: rgba(255,255,255,0.06) !important;
    border: 1px solid rgba(255,255,255,0.15) !important;
    color: #fff !important;
    border-radius: 10px !important;
    padding: 12px 16px !important;
    font-size: 0.92rem;
    transition: var(--transition);
}

.contact-input:focus {
    background: rgba(255,255,255,0.1) !important;
    border-color: var(--accent-color) !important;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.15) !important;
    outline: none !important;
}

.contact-input::placeholder {
    color: rgba(255,255,255,0.35) !important;
}

.social-btn {
    width: 40px;
    height: 40px;
    background: rgba(52, 152, 219, 0.15);
    border: 1px solid rgba(52, 152, 219, 0.3);
    border-radius: 10px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-color);
    font-size: 1rem;
    text-decoration: none;
    transition: var(--transition);
}

.social-btn:hover {
    background: var(--accent-color);
    color: #fff;
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(52, 152, 219, 0.35);
}

/* __Footer__ */
.footer-brand {
    font-size: 1.1rem;
    font-weight: 700;
    letter-spacing: 1px;
}

.footer-nav-list li {
    margin-bottom: 8px;
}

.footer-link {
    color: rgba(255,255,255,0.5);
    text-decoration: none;
    font-size: 0.88rem;
    transition: var(--transition);
}

.footer-link:hover {
    color: var(--accent-color);
    padding-left: 4px;
}

/* __Responsive Fixes__ */
@media (max-width: 991px) {
    .navbar-nav {
        padding: 15px 0;
        gap: 4px;
    }
    .nav-admin-btn {
        margin-top: 10px;
        width: fit-content;
        margin-left: auto;
        margin-right: auto;
    }
}

@media (max-width: 768px) {
    .hero-title { font-size: 2rem !important; }
    .hero-subtitle { font-size: 1rem !important; margin-bottom: 30px !important; }
    .navbar-brand { font-size: 1.1rem !important; }
    .hero-section { padding: 100px 0 60px 0 !important; height: auto !important; min-height: 80vh; }
    .feature-card { margin-bottom: 20px; }
    .about-img-wrap { margin-bottom: 40px; }
    .stat-box { margin-bottom: 20px; }
    .step-card { margin-bottom: 20px; }
    .contact-form-wrap { margin-top: 30px; }
    .section-heading { font-size: 1.9rem; }
    .about-badge-float { position: static; margin-top: 15px; display: inline-block; }
}

@media (max-width: 576px) {
    .nav-admin-btn { margin-top: 15px; width: 100%; text-align: center; }
    .btn-predict { width: 100%; padding: 15px !important; text-align: center; }
    .hero-badges { flex-direction: column; align-items: center; gap: 10px !important; }
    .section-heading { font-size: 1.7rem; }
    .stat-number { font-size: 2rem !important; }
    .footer-links { flex-direction: column; gap: 10px; }
    .hero-stat-badge { font-size: 0.8rem; padding: 6px 14px; }
    .btn-learn-more { width: 100%; text-align: center; }
    .step-card { padding: 35px 22px; }
}

/* ================= FIXED NAVBAR UNDERLINE ANIMATION ================= */

.navbar .nav-custom-link {
    position: relative !important;
    display: inline-block;
    padding-bottom: 5px; /* space for underline */
}

/* underline */
.navbar .nav-custom-link::after {
    content: "" !important;
    position: absolute;
    left: 50%;
    bottom: 0;
    width: 0%;
    height: 2px;
    background-color: var(--accent-color);
    transition: all 0.4s ease;
    transform: translateX(-50%);
}

/* hover effect */
.navbar .nav-custom-link:hover::after {
    width: 100%;
}

/* active link underline */
.navbar .nav-custom-link.active::after {
    width: 100%;
}