:root {
    --primary: #0a4aa8;
    --secondary: #0d6efd;
    --accent: #f9b233;
    --dark: #0b1320;
    --muted: #f1f4fb;
    --text: #212529;
    --white: #ffffff;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Poppins", Arial, sans-serif;
    color: var(--text);
    background-color: var(--muted);
    line-height: 1.6;
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    max-width: 100%;
    display: block;
    border-radius: 12px;
}

.container {
    width: min(1120px, 92%);
    margin: 0 auto;
}

header {
    background-color: var(--white);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 10px 30px rgba(11, 19, 32, 0.08);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.2rem 0;
}

.logo {
    font-weight: 700;
    font-size: 1.3rem;
    color: var(--primary);
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    font-weight: 500;
}

.nav-links a {
    position: relative;
    padding-bottom: 0.25rem;
}

.nav-links a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 2px;
    background-color: transparent;
    transition: background-color 0.3s ease;
}

.nav-links a:hover::after,
.nav-links a:focus-visible::after {
    background-color: var(--accent);
}

.hero {
    position: relative;
    background: linear-gradient(120deg, rgba(10, 74, 168, 0.82), rgba(13, 110, 253, 0.68)), url("../images/pipes_1.jpg") center/cover no-repeat;
    color: var(--white);
    padding: 6rem 0 7rem;
}

.hero h1 {
    font-size: clamp(2.4rem, 3vw + 1rem, 3.6rem);
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.1rem;
    max-width: 640px;
    margin-bottom: 2rem;
}

.hero-cta {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 0.9rem 2.2rem;
    border-radius: 999px;
    background: var(--accent);
    color: var(--dark);
    font-weight: 600;
    transition: transform 0.2s ease, box-shadow 0.3s ease;
    box-shadow: 0 20px 40px rgba(249, 178, 51, 0.25);
}

.btn:hover,
.btn:focus-visible {
    transform: translateY(-2px);
    box-shadow: 0 25px 45px rgba(249, 178, 51, 0.35);
}

.btn-secondary {
    background: transparent;
    border: 2px solid var(--white);
    color: var(--white);
    box-shadow: none;
}

section {
    padding: clamp(3.5rem, 8vw, 5rem) 0;
}

section:nth-of-type(even) {
    background-color: var(--white);
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
}

.section-title h2 {
    font-size: clamp(1.9rem, 2.6vw + 1rem, 2.7rem);
    color: var(--dark);
    margin-bottom: 0.75rem;
}

.section-title p {
    color: rgba(11, 19, 32, 0.72);
    max-width: 640px;
    margin: 0 auto;
}

.grid {
    display: grid;
    gap: 2rem;
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.feature-card,
.service-card {
    padding: 2rem;
    background: var(--white);
    border-radius: 18px;
    box-shadow: 0 20px 45px rgba(11, 19, 32, 0.08);
    border: 1px solid rgba(10, 74, 168, 0.08);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.feature-card:hover,
.service-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 30px 60px rgba(11, 19, 32, 0.12);
}

.feature-card h3,
.service-card h3 {
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
    color: var(--primary);
}

.feature-card p,
.service-card p {
    color: rgba(33, 37, 41, 0.85);
}

.gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.gallery figure {
    margin: 0;
    overflow: hidden;
    border-radius: 18px;
    position: relative;
}

.gallery figcaption {
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    padding: 1rem 1.2rem;
    background: linear-gradient(0deg, rgba(11, 19, 32, 0.78), transparent);
    color: var(--white);
    font-weight: 600;
}

.cta-section {
    background: linear-gradient(135deg, rgba(10, 74, 168, 0.9), rgba(13, 110, 253, 0.82));
    color: var(--white);
    text-align: center;
    border-radius: 24px;
    padding: 4rem clamp(1.8rem, 5vw, 4rem);
}

.cta-section h2 {
    font-size: clamp(2rem, 2.6vw + 1rem, 2.8rem);
    margin-bottom: 1rem;
}

.cta-section p {
    max-width: 560px;
    margin: 0.5rem auto 2rem;
}

.split {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 3rem;
    align-items: center;
}

.list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 1rem;
}

.list li {
    padding-left: 1.8rem;
    position: relative;
}

.list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.6rem;
    width: 10px;
    height: 10px;
    border-radius: 999px;
    background: var(--accent);
}

.contact-card {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: 0 30px 60px rgba(11, 19, 32, 0.1);
}

.contact-card h3 {
    margin-top: 0;
    color: var(--primary);
    font-size: 1.4rem;
}

.contact-card ul {
    list-style: none;
    padding: 0;
    margin: 1rem 0 0;
    display: grid;
    gap: 0.8rem;
    color: rgba(33, 37, 41, 0.85);
}

form {
    display: grid;
    gap: 1.2rem;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

input,
textarea,
select {
    width: 100%;
    padding: 0.85rem 1rem;
    border-radius: 12px;
    border: 1px solid rgba(10, 74, 168, 0.2);
    background: var(--white);
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input:focus,
textarea:focus,
select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(13, 110, 253, 0.18);
    outline: none;
}

.checkbox-group {
    display: grid;
    gap: 0.6rem;
}

.checkbox {
    display: flex;
    align-items: flex-start;
    gap: 0.6rem;
    font-size: 0.95rem;
    color: rgba(33, 37, 41, 0.85);
}

.checkbox input {
    width: auto;
    margin-top: 0.15rem;
}

.notice {
    font-size: 0.85rem;
    color: rgba(33, 37, 41, 0.6);
}

footer {
    padding: 2.5rem 0;
    background: var(--dark);
    color: var(--white);
    margin-top: 3rem;
}

.footer-grid {
    display: grid;
    gap: 2rem;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.footer-brand {
    font-weight: 700;
    font-size: 1.3rem;
    margin-bottom: 0.6rem;
}

.footer-links {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 0.7rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.82);
}

.footer-links a:hover,
.footer-links a:focus-visible {
    color: var(--accent);
}

.footer-note {
    text-align: center;
    margin-top: 2rem;
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.6);
}

.page-banner {
    background: linear-gradient(135deg, rgba(10, 74, 168, 0.92), rgba(13, 110, 253, 0.78)), url("../images/tank_1.jpg") center/cover no-repeat;
    color: var(--white);
    padding: 4.5rem 0;
    text-align: center;
}

.page-banner h1 {
    margin: 0;
    font-size: clamp(2.2rem, 2.4vw + 1rem, 3rem);
}

.page-content {
    background: var(--white);
    margin-top: -2.5rem;
    border-radius: 24px;
    padding: clamp(2rem, 6vw, 3.2rem);
    box-shadow: 0 20px 45px rgba(11, 19, 32, 0.08);
}

.page-content h2 {
    font-size: 1.6rem;
    margin-top: 2rem;
    color: var(--primary);
}

.page-content h2:first-of-type {
    margin-top: 0;
}

.page-content p,
.page-content li {
    color: rgba(33, 37, 41, 0.82);
}

.page-content ul {
    padding-left: 1.3rem;
}

.page-content li {
    margin-bottom: 0.6rem;
}

.message {
    display: none;
    padding: 1rem 1.2rem;
    border-radius: 12px;
    background: rgba(9, 128, 62, 0.12);
    color: #136f36;
    font-weight: 600;
    border: 1px solid rgba(19, 111, 54, 0.2);
}

.message.visible {
    display: block;
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.6rem;
    color: var(--primary);
}

@media (max-width: 900px) {
    .nav-links {
        position: fixed;
        inset: 0;
        background: rgba(11, 19, 32, 0.92);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 2rem;
        transform: translateY(-100%);
        transition: transform 0.3s ease;
        font-size: 1.2rem;
        color: var(--white);
    }

    .nav-links a::after {
        background-color: var(--accent);
        transform: scaleX(0);
        transform-origin: left;
        transition: transform 0.3s ease;
    }

    .nav-links a:hover::after,
    .nav-links a:focus-visible::after {
        transform: scaleX(1);
    }

    .nav-links.open {
        transform: translateY(0);
    }

    .mobile-toggle {
        display: block;
    }
}

@media (max-width: 600px) {
    .hero {
        padding: 5rem 0 6rem;
    }

    .hero-cta {
        flex-direction: column;
        align-items: stretch;
    }

    .contact-card {
        padding: 2rem;
    }
}