/* ========================================
   RESET & BASE
   ======================================== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-primary: #1e40af;
    --color-primary-dark: #1e3a8a;
    --color-primary-light: #3b82f6;
    --color-accent: #f59e0b;
    --color-bg: #ffffff;
    --color-bg-alt: #f8fafc;
    --color-bg-dark: #0f172a;
    --color-text: #1e293b;
    --color-text-light: #64748b;
    --color-text-white: #f1f5f9;
    --color-border: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 24px;
}

img {
    max-width: 100%;
    display: block;
}

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

/* ========================================
   HEADER
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    transition: box-shadow 0.3s;
}

.header--scrolled {
    box-shadow: var(--shadow-md);
}

.header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.header__logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--color-primary-dark);
}

.logo-icon {
    font-size: 1.4rem;
}

.header__nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-light);
    transition: all 0.2s;
}

.nav-link:hover {
    color: var(--color-primary);
    background: rgba(30, 64, 175, 0.06);
}

.nav-link--cta {
    background: var(--color-primary);
    color: white !important;
    font-weight: 600;
}

.nav-link--cta:hover {
    background: var(--color-primary-dark) !important;
}

.header__burger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.header__burger span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: all 0.3s;
}

/* ========================================
   HERO
   ======================================== */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(135deg, #eff6ff 0%, #f8fafc 50%, #fff7ed 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -200px;
    right: -200px;
    width: 500px;
    height: 500px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(30,64,175,0.06), transparent 70%);
}

.hero__inner {
    display: grid;
    grid-template-columns: 1fr 380px;
    gap: 60px;
    align-items: center;
}

.hero__tag {
    display: inline-block;
    background: var(--color-primary);
    color: white;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.hero__title {
    font-size: 2.8rem;
    font-weight: 800;
    line-height: 1.15;
    color: var(--color-bg-dark);
    margin-bottom: 20px;
}

.hero__desc {
    font-size: 1.1rem;
    color: var(--color-text-light);
    line-height: 1.7;
    margin-bottom: 32px;
    max-width: 540px;
}

.hero__actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.hero__visual {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.hero__card {
    display: flex;
    align-items: center;
    gap: 16px;
    background: white;
    padding: 20px 24px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: transform 0.3s, box-shadow 0.3s;
}

.hero__card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.hero__card-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.hero__card-text {
    font-size: 1rem;
    color: var(--color-text-light);
}

.hero__card-text strong {
    color: var(--color-text);
    font-weight: 700;
    display: block;
    font-size: 1.15rem;
}

/* ========================================
   BUTTONS
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.25s;
    cursor: pointer;
    border: none;
}

.btn--primary {
    background: var(--color-primary);
    color: white;
    box-shadow: 0 4px 12px rgba(30, 64, 175, 0.3);
}

.btn--primary:hover {
    background: var(--color-primary-dark);
    box-shadow: 0 6px 20px rgba(30, 64, 175, 0.4);
    transform: translateY(-2px);
}

.btn--outline {
    background: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

.btn--outline:hover {
    background: var(--color-primary);
    color: white;
}

.btn-icon {
    font-size: 1.1rem;
}

/* ========================================
   SECTIONS COMMON
   ======================================== */
.section-tag {
    display: inline-block;
    color: var(--color-primary);
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-bottom: 8px;
}

.section-title {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--color-bg-dark);
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 1.05rem;
    color: var(--color-text-light);
    max-width: 600px;
    margin-bottom: 40px;
}

/* ========================================
   SERVICES
   ======================================== */
.services {
    padding: 100px 0;
    background: var(--color-bg);
}

.services__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 40px;
}

.service-card {
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    transition: all 0.3s;
}

.service-card:hover {
    border-color: var(--color-primary-light);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.service-card__icon {
    font-size: 2.2rem;
    margin-bottom: 16px;
}

.service-card__title {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--color-bg-dark);
}

.service-card__desc {
    font-size: 0.93rem;
    color: var(--color-text-light);
    line-height: 1.6;
}

.services__note {
    margin-top: 40px;
    padding: 20px 28px;
    background: #fef3c7;
    border-radius: var(--radius-md);
    border-left: 4px solid var(--color-accent);
    font-size: 0.95rem;
    color: #92400e;
}

/* ========================================
   BOILERS
   ======================================== */
.boilers {
    padding: 100px 0;
    background: var(--color-bg-alt);
}

.boilers__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

.boiler-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
    transition: all 0.3s;
}

.boiler-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.boiler-card__brand {
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--color-primary-dark);
    margin-bottom: 12px;
}

.boiler-card__line {
    width: 40px;
    height: 3px;
    background: var(--color-accent);
    border-radius: 2px;
    margin: 0 auto 16px;
}

.boiler-card__desc {
    font-size: 0.93rem;
    color: var(--color-text-light);
    line-height: 1.6;
}

.boilers__cta {
    text-align: center;
}

.boilers__cta p {
    font-size: 1.1rem;
    color: var(--color-text-light);
    margin-bottom: 16px;
}

/* ========================================
   AREA
   ======================================== */
.area {
    padding: 100px 0;
    background: var(--color-bg);
}

.area__content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    margin-top: 40px;
    align-items: start;
}

.area__radius {
    text-align: center;
    margin-bottom: 24px;
    padding: 24px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    border-radius: var(--radius-lg);
    color: white;
}

.area__radius-number {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1;
}

.area__radius-text {
    font-size: 0.9rem;
    opacity: 0.9;
    margin-top: 4px;
}

.area__desc {
    color: var(--color-text-light);
    margin-bottom: 16px;
    font-size: 0.95rem;
}

.area__list {
    list-style: none;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    margin-bottom: 20px;
}

.area__list li {
    padding: 8px 0 8px 24px;
    position: relative;
    font-size: 0.93rem;
    color: var(--color-text);
}

.area__list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: 700;
}

.area__note {
    font-size: 0.88rem;
    color: var(--color-text-light);
    font-style: italic;
}

/* ========================================
   CONTACT
   ======================================== */
.contact {
    padding: 100px 0;
    background: var(--color-bg-dark);
    color: var(--color-text-white);
}

.contact .section-tag {
    color: var(--color-accent);
}

.contact .section-title {
    color: white;
}

.contact__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 40px;
}

.contact-card {
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius-md);
    padding: 28px 24px;
    transition: all 0.3s;
}

.contact-card:hover {
    background: rgba(255,255,255,0.08);
    border-color: rgba(255,255,255,0.2);
}

.contact-card__icon {
    font-size: 1.8rem;
    margin-bottom: 12px;
}

.contact-card__label {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--color-text-light);
    margin-bottom: 6px;
}

.contact-card__value {
    font-size: 1.1rem;
    font-weight: 600;
    color: white;
}

.contact-card__value--link {
    color: var(--color-primary-light);
    transition: color 0.2s;
}

.contact-card__value--link:hover {
    color: var(--color-accent);
}

/* ========================================
   FOOTER
   ======================================== */
.footer {
    background: #080e1f;
    padding: 24px 0;
    border-top: 1px solid rgba(255,255,255,0.05);
}

.footer__inner {
    text-align: center;
    font-size: 0.85rem;
    color: var(--color-text-light);
}

/* ========================================
   ANIMATIONS
   ======================================== */
.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========================================
   RESPONSIVE
   ======================================== */
@media (max-width: 968px) {
    .hero__inner {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .hero__title {
        font-size: 2.2rem;
    }

    .services__grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .boilers__grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .area__content {
        grid-template-columns: 1fr;
    }

    .contact__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header__nav {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 16px 24px;
        border-bottom: 1px solid var(--color-border);
        box-shadow: var(--shadow-lg);
        transform: translateY(-120%);
        opacity: 0;
        transition: all 0.3s;
    }

    .header__nav.open {
        transform: translateY(0);
        opacity: 1;
    }

    .header__burger {
        display: flex;
    }

    .header__burger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .header__burger.active span:nth-child(2) {
        opacity: 0;
    }

    .header__burger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }

    .hero {
        padding: 120px 0 60px;
    }

    .hero__title {
        font-size: 1.8rem;
    }

    .hero__desc {
        font-size: 1rem;
    }

    .hero__visual {
        flex-direction: row;
        flex-wrap: wrap;
    }

    .hero__card {
        flex: 1;
        min-width: 150px;
    }

    .services__grid {
        grid-template-columns: 1fr;
    }

    .boilers__grid {
        grid-template-columns: 1fr;
    }

    .contact__grid {
        grid-template-columns: 1fr;
    }

    .area__list {
        grid-template-columns: 1fr;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .services, .boilers, .area, .contact {
        padding: 60px 0;
    }

    .nav-link--cta {
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero__actions {
        flex-direction: column;
    }

    .btn {
        justify-content: center;
        width: 100%;
    }

    .hero__visual {
        flex-direction: column;
    }

    .hero__card {
        min-width: 100%;
    }
}