```css
/* =====================================================
   TEMEL AYARLAR
===================================================== */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Montserrat", Arial, sans-serif;
    color: #171717;
    background: #ffffff;
    line-height: 1.7;
}

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

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

.container {
    width: min(1180px, 92%);
    margin: auto;
}


/* =====================================================
   HEADER
===================================================== */

.header {
    position: sticky;
    top: 0;
    z-index: 9999;
    background: #ffffff;
    border-bottom: 1px solid #eeeeee;
}

.navbar {
    min-height: 88px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    width: 150px;
    max-height: 65px;
    object-fit: contain;
}

.desktop-menu {
    display: flex;
    align-items: center;
    gap: 35px;
}

.desktop-menu a {
    font-size: 14px;
    font-weight: 600;
    color: #222;
    position: relative;
    transition: .3s;
}

.desktop-menu a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -8px;
    width: 0;
    height: 2px;
    background: #c40000;
    transition: .3s;
}

.desktop-menu a:hover {
    color: #c40000;
}

.desktop-menu a:hover::after {
    width: 100%;
}

.mobile-menu-button {
    display: none;
    border: 0;
    background: none;
    font-size: 30px;
    cursor: pointer;
}

.mobile-menu {
    display: none;
}


/* =====================================================
   ÜST İLETİŞİM
===================================================== */

.top-contact {
    background: #111111;
    color: #ffffff;
}

.top-contact-inner {
    min-height: 45px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 13px;
}

.top-contact-left,
.top-contact-right {
    display: flex;
    gap: 12px;
    align-items: center;
}

.top-contact a:hover {
    color: #e00000;
}


/* =====================================================
   HERO
===================================================== */

.hero {
    min-height: 610px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;

    background:
        linear-gradient(
            90deg,
            rgba(0,0,0,.76),
            rgba(0,0,0,.35)
        ),
        url("images/iletisim.jpg") center / cover no-repeat;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,.15);
}

.hero-content {
    position: relative;
    z-index: 2;
    width: min(850px, 90%);
    text-align: center;
    color: white;
}

.hero-logo {
    width: 180px;
    margin: 0 auto 35px;
    filter: brightness(0) invert(1);
}

.hero h1 {
    font-size: clamp(35px, 5vw, 62px);
    line-height: 1.18;
    font-weight: 700;
    letter-spacing: -1px;
    margin-bottom: 35px;
}

.primary-button {
    display: inline-flex;
    justify-content: center;
    align-items: center;

    background: #c40000;
    color: #ffffff;

    padding: 14px 30px;

    border-radius: 3px;

    font-size: 14px;
    font-weight: 700;

    transition: .3s;
}

.primary-button:hover {
    background: #920000;
    transform: translateY(-2px);
}


/* =====================================================
   GENEL BAŞLIK
===================================================== */

.section-heading {
    max-width: 850px;
    margin: 0 auto 55px;
    text-align: center;
}

.small-title {
    color: #c40000;
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 2px;
}

.section-heading h2,
.welcome h2,
.contact-info h2 {
    margin-top: 10px;
    margin-bottom: 18px;

    font-size: clamp(30px, 4vw, 45px);
    line-height: 1.2;
}

.section-heading p {
    color: #686868;
    font-size: 15px;
}


/* =====================================================
   HOŞ GELDİNİZ
===================================================== */

.welcome {
    padding: 100px 0;
    background: #ffffff;
}

.welcome-content {
    text-align: center;
    max-width: 800px;
}

.welcome p {
    color: #666;
    font-size: 17px;
}


/* =====================================================
   ORTAKLAR
===================================================== */

.partners {
    padding: 100px 0;
    background: #f7f7f7;
}

.partners-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.partner-card {
    background: #ffffff;
    padding: 35px 25px;
    min-height: 370px;

    display: flex;
    flex-direction: column;
    align-items: center;

    text-align: center;

    border: 1px solid #eeeeee;

    transition: .3s;
}

.partner-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(0,0,0,.10);
}

.partner-image {
    width: 150px;
    height: 95px;

    display: flex;
    align-items: center;
    justify-content: center;

    margin-bottom: 20px;
}

.partner-image img {
    max-width: 130px;
    max-height: 80px;
    object-fit: contain;
}

.partner-card h3 {
    font-size: 16px;
    font-weight: 800;
    margin-bottom: 14px;
}

.partner-card p {
    color: #707070;
    font-size: 13px;
}


/* =====================================================
   HİZMETLER
===================================================== */

.services {
    padding: 100px 0;
    background: #ffffff;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.service-card {
    padding: 45px 30px;
    text-align: center;

    border: 1px solid #e9e9e9;

    transition: .3s;
}

.service-card:hover {
    border-color: #c40000;
    box-shadow: 0 15px 35px rgba(0,0,0,.08);
    transform: translateY(-6px);
}

.service-icon {
    width: 70px;
    height: 70px;

    margin: 0 auto 22px;

    display: flex;
    justify-content: center;
    align-items: center;

    border-radius: 50%;

    background: #c40000;
    color: white;

    font-size: 30px;
}

.service-card h3 {
    font-size: 20px;
    margin-bottom: 12px;
}

.service-card p {
    color: #707070;
    font-size: 14px;
    margin-bottom: 25px;
}

.service-button {
    display: inline-block;

    padding: 11px 20px;

    border: 1px solid #222;

    font-size: 12px;
    font-weight: 700;

    transition: .3s;
}

.service-button:hover {
    background: #c40000;
    border-color: #c40000;
    color: white;
}


/* =====================================================
   BLOG
===================================================== */

.blog {
    padding: 100px 0;
    background: #f7f7f7;
}

.blog-placeholder {
    max-width: 650px;
    margin: auto;
    padding: 60px 30px;

    text-align: center;

    background: white;
    border: 1px solid #eeeeee;
}

.blog-icon {
    font-size: 50px;
    margin-bottom: 15px;
}

.blog-placeholder h3 {
    margin-bottom: 10px;
}

.blog-placeholder p {
    color: #777;
}


/* =====================================================
   İLETİŞİM
===================================================== */

.contact {
    padding: 100px 0;
    background: #111111;
    color: #ffffff;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.contact-info h2 {
    color: #ffffff;
}

.contact-info > p {
    color: #cccccc;
}

.contact-item {
    display: flex;
    gap: 18px;
    margin: 30px 0;
}

.contact-icon {
    width: 48px;
    height: 48px;

    flex-shrink: 0;

    display: flex;
    align-items: center;
    justify-content: center;

    background: #c40000;
    border-radius: 50%;
}

.contact-item strong {
    display: block;
    margin-bottom: 3px;
}

.contact-item p {
    color: #cccccc;
    font-size: 14px;
}

.contact-item a:hover {
    color: #e00000;
}

.contact-button {
    margin-top: 15px;
}


/* =====================================================
   FORM
===================================================== */

.contact-form-container {
    background: #ffffff;
    padding: 40px;
}

.contact-form {
    color: #222;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 7px;

    font-size: 13px;
    font-weight: 700;
}

.form-group input,
.form-group textarea {
    width: 100%;

    padding: 14px;

    border: 1px solid #dddddd;

    background: #ffffff;

    font-family: inherit;
    font-size: 14px;

    outline: none;

    transition: .3s;
}

.form-group textarea {
    resize: vertical;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: #c40000;
}

.submit-button {
    width: 100%;

    padding: 15px;

    border: 0;

    background: #c40000;
    color: white;

    font-family: inherit;
    font-weight: 700;

    cursor: pointer;

    transition: .3s;
}

.submit-button:hover {
    background: #950000;
}

.form-message {
    margin-top: 15px;
    text-align: center;
    font-size: 13px;
}


/* =====================================================
   FOOTER
===================================================== */

.footer {
    background: #080808;
    color: #aaaaaa;
    padding: 35px 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer strong {
    color: white;
    letter-spacing: 1px;
}

.footer p {
    font-size: 12px;
}


/* =====================================================
   SABİT TELEFON
===================================================== */

.floating-phone {
    position: fixed;

    right: 22px;
    bottom: 22px;

    width: 58px;
    height: 58px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 50%;

    background: #c40000;
    color: white;

    font-size: 23px;

    box-shadow: 0 8px 25px rgba(0,0,0,.25);

    z-index: 999;
}

.floating-phone:hover {
    background: #950000;
}


/* =====================================================
   TABLET
===================================================== */

@media (max-width: 1000px) {

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

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

    .desktop-menu {
        gap: 18px;
    }

}


/* =====================================================
   MOBİL
===================================================== */

@media (max-width: 700px) {

    .navbar {
        min-height: 72px;
    }

    .desktop-menu {
        display: none;
    }

    .mobile-menu-button {
        display: block;
    }

    .mobile-menu {
        display: none;
        background: white;
        border-top: 1px solid #eee;
    }

    .mobile-menu.active {
        display: block;
    }

    .mobile-menu a {
        display: block;
        padding: 16px 5%;
        border-bottom: 1px solid #eee;

        font-size: 14px;
        font-weight: 600;
    }

    .top-contact-inner {
        flex-direction: column;
        justify-content: center;
        gap: 3px;
        padding: 8px 0;
    }

    .hero {
        min-height: 530px;
    }

    .hero-logo {
        width: 140px;
    }

    .hero h1 {
        font-size: 34px;
    }

    .welcome,
    .partners,
    .services,
    .blog,
    .contact {
        padding: 70px 0;
    }

    .partners-grid,
    .services-grid {
        grid-template-columns: 1fr;
    }

    .contact-grid {
        grid-template-columns: 1fr;
        gap: 45px;
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }

    .contact-form-container {
        padding: 25px;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }

}


/* =====================================================
   KÜÇÜK TELEFON
===================================================== */

@media (max-width: 420px) {

    .hero h1 {
        font-size: 29px;
    }

    .hero-logo {
        width: 120px;
    }

    .section-heading h2,
    .welcome h2,
    .contact-info h2 {
        font-size: 30px;
    }

}
```