/* =========================================================
   鼎优信科技 - 现代响应式样式表
   自托管，无外部依赖
   ========================================================= */

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --accent: #4f46e5;
    --dark: #0f172a;
    --dark-2: #1e293b;
    --gray: #64748b;
    --light: #f8fafc;
    --light-2: #eef2f7;
    --white: #ffffff;
    --border: #e2e8f0;
    --star: #f59e0b;
    --gradient: linear-gradient(135deg, #2563eb 0%, #4f46e5 100%);
    --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.08);
    --shadow-md: 0 6px 20px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 18px 40px rgba(15, 23, 42, 0.14);
    --radius: 14px;
    --radius-lg: 20px;
    --container: 1200px;
    --header-h: 72px;
    --transition: 0.28s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- Reset ---------- */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
        Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--dark);
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

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

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

ul {
    list-style: none;
}

button {
    font: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

:focus-visible {
    outline: 3px solid rgba(37, 99, 235, 0.45);
    outline-offset: 2px;
    border-radius: 4px;
}

/* ---------- 布局工具 ---------- */
.container {
    width: 100%;
    max-width: var(--container);
    margin-inline: auto;
    padding-inline: 20px;
}

.section {
    padding-block: 72px;
}

.section--white {
    background-color: var(--white);
}

.section--soft {
    background-color: var(--light);
}

.section__header {
    text-align: center;
    max-width: 760px;
    margin: 0 auto 48px;
}

.section__title {
    font-size: clamp(1.8rem, 3.2vw, 2.5rem);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -0.02em;
    color: var(--dark);
}

.section__title::after {
    content: "";
    display: block;
    width: 56px;
    height: 4px;
    margin: 16px auto 0;
    border-radius: 2px;
    background: var(--gradient);
}

.section__title--left {
    margin-bottom: 8px;
}

.section__title--left::after {
    margin-inline: 0;
}

.section__subtitle {
    margin-top: 20px;
    font-size: 1.1rem;
    color: var(--gray);
}

.section__more {
    margin-top: 40px;
    text-align: center;
}

.grid {
    display: grid;
    gap: 28px;
}

.grid--3 {
    grid-template-columns: 1fr;
}

/* ---------- 按钮 ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 30px;
    border-radius: 999px;
    font-size: 1rem;
    font-weight: 600;
    line-height: 1;
    transition: transform var(--transition), box-shadow var(--transition),
        background-color var(--transition), border-color var(--transition);
}

.btn--primary {
    color: var(--white);
    background: var(--gradient);
    box-shadow: 0 8px 20px rgba(37, 99, 235, 0.3);
}

.btn--primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 26px rgba(37, 99, 235, 0.38);
}

.btn--outline {
    color: var(--primary);
    background: var(--white);
    border: 1.5px solid rgba(37, 99, 235, 0.35);
}

.btn--outline:hover {
    transform: translateY(-2px);
    background: rgba(37, 99, 235, 0.05);
    border-color: var(--primary);
}

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

/* ---------- 评分 ---------- */
.rating {
    display: inline-flex;
    gap: 2px;
    color: var(--star);
    font-size: 0.9rem;
}

.rating__value {
    margin-left: 6px;
    font-size: 0.85rem;
    color: var(--gray);
}

/* =========================================================
   顶部导航
   ========================================================= */
.site-header {
    position: fixed;
    inset: 0 0 auto 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid transparent;
    transition: box-shadow var(--transition), border-color var(--transition);
}

.site-header--scrolled {
    box-shadow: var(--shadow-sm);
    border-bottom-color: var(--border);
}

.header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-h);
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
}

.brand__logo {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    border-radius: 12px;
    color: var(--white);
    font-weight: 800;
    font-size: 1.05rem;
    letter-spacing: 0.02em;
    background: var(--gradient);
    box-shadow: 0 6px 16px rgba(37, 99, 235, 0.32);
}

.brand__name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--dark);
}

.nav--desktop {
    display: none;
}

.nav__link {
    position: relative;
    padding: 8px 2px;
    font-weight: 500;
    color: var(--dark);
    transition: color var(--transition);
}

.nav__link::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 0;
    height: 2px;
    border-radius: 2px;
    background: var(--gradient);
    transition: width var(--transition);
}

.nav__link:hover {
    color: var(--primary);
}

.nav__link:hover::after {
    width: 100%;
}

.menu-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    border-radius: 10px;
    font-size: 1.4rem;
    color: var(--dark);
}

.menu-toggle:hover {
    background: var(--light-2);
}

.mobile-menu {
    border-top: 1px solid var(--border);
    background: var(--white);
    box-shadow: var(--shadow-md);
}

.mobile-menu[hidden] {
    display: none;
}

.mobile-menu__nav {
    display: flex;
    flex-direction: column;
    padding: 12px 20px;
}

.mobile-menu__link {
    padding: 12px 4px;
    font-weight: 500;
    color: var(--dark);
    border-bottom: 1px solid var(--light-2);
    transition: color var(--transition), padding-left var(--transition);
}

.mobile-menu__link:last-child {
    border-bottom: none;
}

.mobile-menu__link:hover {
    color: var(--primary);
    padding-left: 10px;
}

/* =========================================================
   Hero
   ========================================================= */
.hero {
    position: relative;
    display: flex;
    align-items: center;
    min-height: 100vh;
    padding-block: calc(var(--header-h) + 40px) 64px;
    overflow: hidden;
    background: var(--white);
}

.hero__bg {
    position: absolute;
    inset: 0;
    pointer-events: none;
    background:
        radial-gradient(640px 420px at 88% 12%, rgba(79, 70, 229, 0.12), transparent 70%),
        radial-gradient(520px 380px at -6% 88%, rgba(37, 99, 235, 0.12), transparent 70%);
}

.hero__inner {
    position: relative;
    display: grid;
    gap: 44px;
    align-items: center;
}

.hero__title {
    font-size: clamp(2.4rem, 6vw, 4rem);
    font-weight: 800;
    line-height: 1.12;
    letter-spacing: -0.02em;
    color: var(--dark);
}

.hero__text {
    max-width: 34rem;
    margin-top: 22px;
    font-size: 1.15rem;
    color: var(--gray);
}

.hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 30px;
}

.hero__stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-top: 44px;
    padding-top: 28px;
    border-top: 1px solid var(--light-2);
}

.hero__stat-value {
    display: block;
    font-size: clamp(1.8rem, 3.5vw, 2.4rem);
    font-weight: 800;
    line-height: 1;
    color: var(--primary);
}

.hero__stat-label {
    display: block;
    margin-top: 8px;
    font-size: 0.9rem;
    color: var(--gray);
}

.hero__media {
    position: relative;
}

.hero__media-glow {
    position: absolute;
    inset: -8% -6%;
    border-radius: 32px;
    background: var(--gradient);
    opacity: 0.16;
    filter: blur(34px);
    z-index: 0;
}

.hero__image {
    position: relative;
    z-index: 1;
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    aspect-ratio: 4 / 3;
    object-fit: cover;
}

/* =========================================================
   服务卡片
   ========================================================= */
.service-card {
    position: relative;
    padding: 32px 28px;
    border-radius: var(--radius);
    background: var(--light);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition);
}

.service-card::before {
    content: "";
    position: absolute;
    top: -48px;
    right: -48px;
    width: 130px;
    height: 130px;
    border-radius: 50%;
    background: rgba(37, 99, 235, 0.06);
}

.service-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}

.service-card__icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    margin-bottom: 22px;
    border-radius: 16px;
    font-size: 1.5rem;
    color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
}

.service-card__title {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--dark);
}

.service-card__text {
    color: var(--gray);
    margin-bottom: 20px;
}

.service-card__link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    color: var(--primary);
    transition: color var(--transition);
}

.service-card__link i {
    transition: transform var(--transition);
}

.service-card__link:hover {
    color: var(--primary-dark);
}

.service-card__link:hover i {
    transform: translateX(4px);
}

/* =========================================================
   关于我们
   ========================================================= */
.about {
    display: grid;
    gap: 48px;
    align-items: center;
}

.about__lead {
    margin-top: 16px;
    font-size: 1.05rem;
    color: var(--gray);
}

.about__list {
    display: grid;
    gap: 24px;
    margin-top: 32px;
}

.about__item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.about__item-icon {
    flex-shrink: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 14px;
    color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
}

.about__item-title {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 4px;
    color: var(--dark);
}

.about__item-text {
    color: var(--gray);
}

.about__stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-top: 32px;
}

.about__stat {
    padding: 20px;
    border-radius: var(--radius);
    background: var(--white);
    box-shadow: var(--shadow-sm);
    text-align: center;
}

.about__stat-value {
    display: block;
    font-size: 1.9rem;
    font-weight: 800;
    line-height: 1;
    color: var(--primary);
}

.about__stat-label {
    display: block;
    margin-top: 8px;
    font-size: 0.85rem;
    color: var(--gray);
}

.about__media {
    position: relative;
}

.about__media-glow {
    position: absolute;
    inset: -6% -5%;
    border-radius: 32px;
    background: var(--gradient);
    opacity: 0.14;
    filter: blur(30px);
    z-index: 0;
}

.about__image {
    position: relative;
    z-index: 1;
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    aspect-ratio: 4 / 3;
    object-fit: cover;
}

.about__badge {
    position: relative;
    z-index: 2;
    max-width: 320px;
    margin: -44px 20px 0 auto;
    padding: 22px;
    border-radius: var(--radius);
    background: var(--white);
    box-shadow: var(--shadow-lg);
}

.about__badge-head {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.about__badge-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    border-radius: 12px;
    color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
}

.about__badge-title {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--dark);
}

.about__badge-text {
    color: var(--gray);
    font-size: 0.95rem;
    margin-bottom: 14px;
}

.about__badge-foot {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.about__badge-link {
    margin-left: auto;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--primary);
}

/* =========================================================
   成功案例
   ========================================================= */
.case-card {
    display: flex;
    flex-direction: column;
    border-radius: var(--radius);
    background: var(--light);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition);
}

.case-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}

.case-card__media {
    position: relative;
    overflow: hidden;
}

.case-card__image {
    width: 100%;
    aspect-ratio: 3 / 2;
    object-fit: cover;
    transition: transform 0.7s var(--transition);
}

.case-card:hover .case-card__image {
    transform: scale(1.08);
}

.case-card__tag {
    position: absolute;
    left: 18px;
    bottom: 18px;
    padding: 6px 14px;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--white);
    background: rgba(37, 99, 235, 0.88);
    backdrop-filter: blur(4px);
}

.case-card__body {
    padding: 24px;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.case-card__title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--dark);
}

.case-card__text {
    color: var(--gray);
    margin-bottom: 18px;
}

.case-card__foot {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    margin-top: auto;
}

.case-card__link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-left: auto;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--primary);
    transition: color var(--transition);
}

.case-card__link:hover {
    color: var(--primary-dark);
}

/* =========================================================
   客户评价
   ========================================================= */
.testimonial-card {
    padding: 30px 28px;
    border-radius: var(--radius);
    background: var(--white);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition), box-shadow var(--transition);
}

.testimonial-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-md);
}

.testimonial-card .rating {
    margin-bottom: 16px;
}

.testimonial-card__quote {
    color: var(--gray);
    font-style: italic;
    margin-bottom: 22px;
}

.testimonial-card__author {
    display: flex;
    align-items: center;
    gap: 14px;
}

.testimonial-card__avatar {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    object-fit: cover;
}

.testimonial-card__name {
    font-size: 1rem;
    font-weight: 700;
    color: var(--dark);
}

.testimonial-card__role {
    font-size: 0.85rem;
    color: var(--gray);
}

/* =========================================================
   联系我们
   ========================================================= */
.contact {
    display: grid;
    gap: 28px;
}

.contact__form {
    padding: 30px;
    border-radius: var(--radius);
    background: var(--light);
    box-shadow: var(--shadow-sm);
}

.form-row {
    display: grid;
    gap: 20px;
    margin-bottom: 20px;
}

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

.form-field__label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--dark);
}

.form-field__input {
    width: 100%;
    padding: 13px 16px;
    border: 1.5px solid var(--border);
    border-radius: 10px;
    background: var(--white);
    color: var(--dark);
    font: inherit;
    transition: border-color var(--transition), box-shadow var(--transition);
}

.form-field__input::placeholder {
    color: #94a3b8;
}

.form-field__input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.form-field__input:invalid:not(:placeholder-shown) {
    border-color: #ef4444;
}

select.form-field__input {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath fill='%2364748b' d='M6 8 0 0h12z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 16px center;
    padding-right: 40px;
}

textarea.form-field__input {
    resize: vertical;
    min-height: 120px;
}

.contact__info {
    padding: 30px;
    border-radius: var(--radius);
    background: var(--light);
    box-shadow: var(--shadow-sm);
}

.contact__info-title {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 26px;
    color: var(--dark);
}

.contact__list {
    display: grid;
    gap: 24px;
}

.contact__item {
    display: flex;
    gap: 14px;
    align-items: flex-start;
}

.contact__item-icon {
    flex-shrink: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 46px;
    height: 46px;
    border-radius: 13px;
    color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
}

.contact__item-title {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 2px;
    color: var(--dark);
}

.contact__item-text {
    color: var(--gray);
    font-size: 0.95rem;
}

.contact__social {
    margin-top: 28px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.contact__social-title {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 14px;
    color: var(--dark);
}

.contact__social-list {
    display: flex;
    gap: 12px;
}

.contact__social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    border-radius: 12px;
    color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
    transition: background-color var(--transition), color var(--transition),
        transform var(--transition);
}

.contact__social-link:hover {
    color: var(--white);
    background: var(--primary);
    transform: translateY(-3px);
}

/* =========================================================
   页脚
   ========================================================= */
.site-footer {
    padding-block: 64px 28px;
    background: var(--dark);
    color: var(--white);
}

.site-footer__grid {
    display: grid;
    gap: 40px;
    margin-bottom: 44px;
}

.brand--footer {
    margin-bottom: 18px;
}

.site-footer__desc {
    max-width: 260px;
    margin-bottom: 22px;
    color: rgba(255, 255, 255, 0.65);
}

.site-footer__social {
    display: flex;
    gap: 12px;
}

.site-footer__social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 12px;
    color: var(--white);
    background: rgba(255, 255, 255, 0.1);
    transition: background-color var(--transition);
}

.site-footer__social-link:hover {
    background: var(--primary);
}

.site-footer__title {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.site-footer__list {
    display: grid;
    gap: 12px;
}

.site-footer__link {
    color: rgba(255, 255, 255, 0.65);
    transition: color var(--transition);
}

.site-footer__link:hover {
    color: var(--white);
}

.site-footer__link--inline {
    color: rgba(255, 255, 255, 0.75);
}

.site-footer__contact {
    display: grid;
    gap: 14px;
}

.site-footer__contact li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    color: rgba(255, 255, 255, 0.65);
}

.site-footer__contact i {
    margin-top: 4px;
    color: var(--primary);
}

.site-footer__bottom {
    display: flex;
    flex-direction: column;
    gap: 12px;
    padding-top: 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.site-footer__copyright,
.site-footer__tech {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.5);
    text-align: center;
}

/* =========================================================
   响应式断点
   ========================================================= */
@media (min-width: 640px) {
    .about__stats {
        grid-template-columns: repeat(4, 1fr);
    }

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

@media (min-width: 768px) {
    .section {
        padding-block: 96px;
    }

    .grid--3 {
        grid-template-columns: repeat(2, 1fr);
    }

    .nav--desktop {
        display: flex;
        gap: 30px;
    }

    .menu-toggle {
        display: none;
    }

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

    .site-footer__bottom {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
    }

    .site-footer__copyright,
    .site-footer__tech {
        text-align: left;
    }
}

@media (min-width: 1024px) {
    .grid--3 {
        grid-template-columns: repeat(3, 1fr);
    }

    .hero__inner {
        grid-template-columns: 1.05fr 1fr;
        gap: 60px;
    }

    .hero__media {
        order: 2;
    }

    .about {
        grid-template-columns: 1.1fr 1fr;
        gap: 60px;
    }

    .about__media {
        order: 2;
    }

    .contact {
        grid-template-columns: 2fr 1fr;
    }

    .contact__form {
        padding: 36px;
    }

    .contact__info {
        padding: 36px;
    }

    .site-footer__grid {
        grid-template-columns: 1.5fr 1fr 1fr 1.4fr;
    }
}

/* ---------- 动效（尊重减少动态偏好） ---------- */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
    }
}