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

html {
    font-size: 62.5%;
}

body {
    font-family: "Sen", sans-serif;
    /* background: #fffbf0; */
    background: linear-gradient(90deg, #fffbf0 0%, #d7cdba 100%);
}

body,
input,
textarea,
button {
    font-size: 1.6rem;
    font-family:
        system-ui,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        Oxygen,
        Ubuntu,
        Cantarell,
        "Open Sans",
        "Helvetica Neue",
        sans-serif;
}

a {
    text-decoration: none;
}

main {
    margin: 48px 0;
}

/* Container */
.container {
    display: flex;
    width: 1170px;
    max-width: calc(100% - 48px);
    margin: 0 auto;
    padding: 6px;
    border-radius: 10px;
    background: #fff;
}

.logo-fixed {
    color: black;
}

.logo {
    display: flex;
    align-items: center;
}

.logo span {
    font-family: "Sora", Tahoma, Geneva, Verdana, sans-serif;
    font-weight: 700;
    font-size: 1.8rem;
    margin-left: 5px;
}

/* Heading */
.heading {
    text-align: center;
    padding-bottom: 30px;
}

.heading h1 {
    color: #050545;
    font-weight: 900;
    font-size: 3.2rem;
}

.heading p {
    margin-top: 16px;
    color: #8d8d9f;
}

.header {
    padding: 26px 0 8px 0;
    position: sticky;
    top: -25px;
    z-index: 999;
    /* background: var(--primary); */
    background: rgba(0, 0, 0, 0.05); /* nền mờ */
    backdrop-filter: blur(10px); /* hiệu ứng kính mờ */
    -webkit-backdrop-filter: blur(10px);
}

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

.navbar__list {
    display: flex;
    margin-left: 330px;
}

.navbar__link {
    padding: 8px 18px;
    font-weight: 500;
    font-size: 1.4rem;
    line-height: 1;
    color: #5e6085;
}

.navbar__link:hover {
    color: #8d6e63;
    text-shadow: 1px 0 0 currentColor;
}

.navbar__item--dropdown {
    position: relative;
}

.navbar__dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 140px;
    padding: 8px 0;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    opacity: 0;
    visibility: hidden;
    transform: translateY(8px);
    transition:
        opacity 0.25s ease,
        visibility 0.25s ease,
        transform 0.25s ease;
    z-index: 99;
}

/* Hiện dropdown khi hover */
.navbar__item--dropdown:hover .navbar__dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.navbar__dropdown-link {
    display: block;
    padding: 10px 18px;
    font-size: 1.4rem;
    font-weight: 500;
    color: #5e6085;
    transition:
        background 0.2s ease,
        color 0.2s ease;
}

.navbar__dropdown-link:hover {
    background: #f1f8e9;
}

/* Contact info */
.contact-info {
    position: relative;
    flex-shrink: 0;
    width: 330px;
    padding: 24px 30px 30px;
    border-radius: 10px;
    color: #fff;
    background: #e7d280;
    overflow: hidden;
}

.contact-info h2 {
    font-weight: 600;
    font-size: 2.2rem;
}

.contact-info .desc {
    margin-top: 10px;
    font-size: 1.3rem;
    line-height: 1.6;
    color: #8d8d9f;
}

.contact-info .info-item {
    margin-top: 36px;
}

.contact-info .info-item .icon {
    display: inline-block;
    width: 18px;
    text-align: center;
    color: #8d6e63;
}

.contact-info .info-item .value {
    margin-left: 8px;
    font-size: 1.3rem;
    color: #8d6e63;
}

.socials {
    display: flex;
    column-gap: 10px;
    margin-top: 110px;
}

.socials .item {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 27px;
    height: 27px;
    border-radius: 50%;
    text-decoration: none;
    color: #8d6e63;
    font-size: 1.2rem;
}

.socials .item:hover {
    background: #fff;
}

.circle {
    position: absolute;
    right: 55px;
    bottom: 60px;
    z-index: 1;
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: #6d4c41;
    opacity: 0.95;
}

.circle.large {
    position: absolute;
    right: -110px;
    bottom: -110px;
    z-index: 0;
    width: 250px;
    height: 250px;
    opacity: 1;
    background: #8d6e63;
}

/* Contact form */
.contact-form {
    flex-grow: 1;
    padding: 28px 32px;
}

.contact-form:has(:invalid) .submit-btn {
    opacity: 0.5;
    pointer-events: none;
}

.form-row {
    display: flex;
    gap: 32px;
    margin-bottom: 12px;
}

.form-row:last-child {
    margin-bottom: 0;
}

.form-group {
    flex-grow: 1;
}

.form-group:focus-within .form-label:not(.large) {
    color: #8d6e63;
}

.form-group:focus-within .form-input {
    border-color: #8d6e63;
}

.form-group:has(:invalid:not(:placeholder-shown)) .form-error {
    visibility: visible;
}

.form-label,
.form-input {
    display: block;
}

.form-label {
    font-size: 1.1rem;
    font-weight: 700;
    color: #131434;
}

.form-label.large {
    font-size: 1.3rem;
}

.form-input,
.form-textarea {
    width: 100%;
    outline: none;
    border: none;
    border-bottom: 2px solid #e3e3e9;
    padding: 8px 0 14px 0;
    color: #0d0d3b;
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: #bebfc9;
}

.form-textarea {
    resize: none;
    max-height: 200px;
}

.form-error {
    margin-top: 4px;
    font-size: 1.3rem;
    color: red;
    visibility: hidden;
}

/* Radio */
.radio-group {
    display: flex;
    margin-top: 16px;
}

.radio-btn {
    display: inline-block;
}

.radio-btn + .radio-btn {
    margin-left: 24px;
}

.radio-btn label {
    position: relative;
    display: flex;
    align-items: center;
    white-space: nowrap;
    font-size: 1.3rem;
    color: #474669;
}

.radio-btn label::before,
.radio-btn label::after {
    content: "";
    display: inline-block;
}

.radio-btn label::before {
    width: 12px;
    height: 12px;
    margin-right: 8px;
    border-radius: 50%;
    border: 2px solid #a7a7b6;
}

.radio-btn [type="radio"] {
    display: none;
}

.radio-btn [type="radio"]:checked + label::before {
    background: #8d6e63;
    border-color: #8d6e63;
}

.radio-btn [type="radio"]:checked + label::after {
    position: absolute;
    top: 4px;
    left: 3px;
    width: 7px;
    height: 3px;
    border-left: 2px solid #fff;
    border-bottom: 2px solid #fff;
    rotate: -45deg;
}

.submit-box {
    justify-content: flex-end;
}

.submit-btn {
    min-width: 160px;
    height: 50px;
    color: #fff;
    background: #8d6e63;
    outline: none;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1.3rem;
}

.submit-btn:hover {
    opacity: 0.9;
    cursor: pointer;
}

@media (max-width: 768px) {
    /* ── HEADER ── */
    .header {
        padding: 12px 0;
        top: 0;
    }

    .header__inner {
        flex-wrap: wrap;
        gap: 10px;
    }

    .navbar__list {
        margin-left: 0;
        flex-wrap: wrap;
        gap: 4px;
    }

    .navbar__link {
        padding: 6px 10px;
        font-size: 1.2rem;
    }

    /* ── MAIN ── */
    main {
        margin: 24px 0;
    }

    /* ── HEADING ── */
    .heading h1 {
        font-size: 2.4rem;
        padding: 0 16px;
    }

    .heading p {
        font-size: 1.4rem;
        padding: 0 16px;
    }

    /* ── CONTAINER — stack dọc ── */
    .container {
        flex-direction: column;
        max-width: calc(100% - 32px);
        padding: 0;
        border-radius: 10px;
        overflow: hidden;
    }

    /* ── CONTACT INFO ── */
    .contact-info {
        width: 100%;
        padding: 24px 20px;
        border-radius: 0;
    }

    .contact-info h2 {
        font-size: 2rem;
    }

    .contact-info .info-item {
        margin-top: 20px;
    }

    .socials {
        margin-top: 40px;
    }

    .circle {
        right: 30px;
        bottom: 20px;
        width: 70px;
        height: 70px;
    }

    .circle.large {
        right: -80px;
        bottom: -80px;
        width: 180px;
        height: 180px;
    }

    /* ── CONTACT FORM ── */
    .contact-form {
        padding: 24px 16px;
    }

    /* Stack 2 cột thành 1 cột */
    .form-row {
        flex-direction: column;
        gap: 16px;
    }

    .radio-group {
        flex-wrap: wrap;
        gap: 12px;
    }

    .radio-btn + .radio-btn {
        margin-left: 0;
    }

    .submit-box {
        justify-content: stretch;
    }

    .submit-btn {
        width: 100%;
    }
}