/* =========================================================
   样品申请 CTA 横幅（页脚前）
   ========================================================= */

.sample-cta {
    position: relative;
    padding: var(--space-24) 0;
    background:
        linear-gradient(135deg, rgba(10, 61, 145, 0.95) 0%, rgba(30, 111, 217, 0.92) 100%);
    color: #fff;
    overflow: hidden;
}
/* 背景光效 */
.sample-cta::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 700px;
    height: 700px;
    background: radial-gradient(circle, rgba(77,163,255,0.35) 0%, transparent 60%);
    pointer-events: none;
}
.sample-cta::after {
    content: '';
    position: absolute;
    bottom: -40%;
    left: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(77,163,255,0.2) 0%, transparent 60%);
    pointer-events: none;
}
.sample-cta__inner {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: var(--space-16);
    align-items: center;
}
.sample-cta__eyebrow {
    display: inline-block;
    padding: 6px 14px;
    border-radius: var(--radius-full);
    background: rgba(255,255,255,0.12);
    border: 1px solid rgba(255,255,255,0.25);
    font-size: var(--font-size-caption);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    font-weight: var(--weight-semibold);
    color: #C8DDFF;
    margin-bottom: var(--space-4);
}
.sample-cta__title {
    font-family: var(--font-serif);
    font-size: var(--font-size-h1);
    font-weight: var(--weight-bold);
    color: #fff;
    line-height: 1.15;
    margin-bottom: var(--space-4);
    letter-spacing: -0.02em;
}
.sample-cta__desc {
    color: rgba(255,255,255,0.85);
    font-size: var(--font-size-body);
    line-height: 1.8;
    max-width: 460px;
    margin-bottom: var(--space-8);
}
.sample-cta__features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-4);
    max-width: 500px;
}
.sample-cta__feature {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}
.sample-cta__feature-num {
    font-family: var(--font-serif);
    font-size: 28px;
    font-weight: var(--weight-bold);
    color: var(--color-accent);
    line-height: 1;
}
.sample-cta__feature-label {
    font-size: var(--font-size-caption);
    color: rgba(255,255,255,0.75);
    letter-spacing: 0.05em;
}

/* 样品申请表单 */
.sample-form {
    background: rgba(255,255,255,0.98);
    backdrop-filter: blur(20px);
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    box-shadow: 0 30px 80px rgba(0,0,0,0.25);
    color: var(--color-text);
}
.sample-form__title {
    font-size: 22px;
    font-weight: var(--weight-semibold);
    color: var(--color-text);
    margin-bottom: var(--space-2);
}
.sample-form__subtitle {
    font-size: var(--font-size-small);
    color: var(--color-text-muted);
    margin-bottom: var(--space-6);
}
.sample-form__grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-4);
    margin-bottom: var(--space-5);
}
.sample-form__field {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}
.sample-form__field--full { grid-column: 1 / -1; }
.sample-form__label {
    font-size: var(--font-size-caption);
    font-weight: var(--weight-medium);
    color: var(--color-text-body);
    letter-spacing: 0.03em;
}
.sample-form__label span { color: var(--color-danger); margin-left: 2px; }
.sample-form__input,
.sample-form__select,
.sample-form__textarea {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background: var(--color-bg);
    font-size: var(--font-size-small);
    color: var(--color-text);
    transition: all var(--transition-fast);
    outline: none;
}
.sample-form__input::placeholder,
.sample-form__textarea::placeholder { color: #A8B3C4; }
.sample-form__input:focus,
.sample-form__select:focus,
.sample-form__textarea:focus {
    border-color: var(--color-secondary);
    box-shadow: 0 0 0 4px rgba(30, 111, 217, 0.1);
    background: #fff;
}
.sample-form__textarea {
    resize: vertical;
    min-height: 88px;
}
.sample-form__submit {
    width: 100%;
    padding: 14px;
    border-radius: var(--radius);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: #fff;
    font-size: var(--font-size-body);
    font-weight: var(--weight-semibold);
    letter-spacing: 0.05em;
    transition: all var(--transition);
    box-shadow: var(--shadow);
}
.sample-form__submit:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    filter: brightness(1.06);
}
.sample-form__notice {
    margin-top: var(--space-4);
    font-size: var(--font-size-caption);
    color: var(--color-text-muted);
    text-align: center;
    line-height: 1.6;
}
.sample-form__my-link {
    display: block;
    margin-top: var(--space-3);
    text-align: center;
    font-size: var(--font-size-small);
    font-weight: var(--weight-medium);
    color: var(--color-primary);
    text-decoration: none;
    padding: 8px 0;
    transition: color var(--transition-fast);
}
.sample-form__my-link:hover {
    color: var(--color-primary-hover);
    text-decoration: underline;
}

/* =========================================================
   底部 Footer
   ========================================================= */
.footer {
    background: var(--color-bg-dark);
    color: #B7C2D4;
    padding-top: var(--space-20);
}
/* 单列简化版 footer（首页用） */
.footer--simple .footer__main {
    grid-template-columns: 1fr;
    max-width: 600px;
}
.footer--simple .footer__brand,
.footer--simple .footer__nav,
.footer--simple .footer__products {
    display: none;
}
.footer__main {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-12);
    padding-bottom: var(--space-16);
    border-bottom: 1px solid rgba(255,255,255,0.08);
    max-width: 500px;
}
.footer__brand-desc {
    margin-top: var(--space-4);
    margin-bottom: var(--space-6);
    line-height: 1.8;
    font-size: var(--font-size-small);
    color: #8A9BB8;
    max-width: 340px;
}
.footer__socials {
    display: flex;
    gap: var(--space-3);
}
.footer__social {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.1);
    display: grid;
    place-items: center;
    color: #B7C2D4;
    transition: all var(--transition);
}
.footer__social:hover {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
    transform: translateY(-2px);
}

.footer__title {
    font-size: var(--font-size-small);
    font-weight: var(--weight-semibold);
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: #fff;
    margin-bottom: var(--space-5);
}
.footer__list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.footer__contact {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    font-size: var(--font-size-small);
    color: #8A9BB8;
}
.footer__contact-item {
    display: flex;
    gap: var(--space-3);
    align-items: flex-start;
    line-height: 1.6;
}
.footer__contact-icon {
    flex-shrink: 0;
    width: 18px;
    height: 18px;
    color: var(--color-accent);
    margin-top: 2px;
}

.footer__bottom {
    padding: var(--space-6) 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-6);
    flex-wrap: wrap;
    font-size: var(--font-size-caption);
    color: #6B7A95;
}
.footer__copyright { display: inline-flex; align-items: center; gap: var(--space-3); flex-wrap: wrap; }
.footer__bottom-links { display: flex; gap: var(--space-6); flex-wrap: wrap; }

/* Logo for dark footer */
.footer__logo {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    font-family: var(--font-serif);
    font-weight: var(--weight-bold);
    font-size: 22px;
    color: #fff;
    letter-spacing: -0.02em;
    transition: transform var(--transition-fast);
}
.footer__logo:hover {
    transform: translateX(4px);
}
.footer__logo:hover .footer__logo-mark {
    transform: rotate(-8deg) scale(1.05);
    box-shadow: 0 4px 16px rgba(77, 163, 255, 0.4);
}
.footer__logo-mark {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-secondary) 100%);
    display: grid;
    place-items: center;
    color: var(--color-bg-dark);
    font-family: var(--font-serif);
    font-weight: var(--weight-bold);
    font-size: 16px;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

/* 导航链接 hover */
.footer__list a {
    font-size: var(--font-size-small);
    color: #8A9BB8;
    transition: color var(--transition-fast), transform var(--transition-fast), padding-left var(--transition-fast);
    position: relative;
    display: inline-block;
}
.footer__list a::before {
    content: '';
    position: absolute;
    left: -12px;
    top: 50%;
    transform: translateY(-50%) scaleX(0);
    width: 8px;
    height: 1px;
    background: var(--color-accent);
    transform-origin: left center;
    transition: transform var(--transition-fast);
}
.footer__list a:hover {
    color: var(--color-accent);
    transform: translateX(4px);
    padding-left: 8px;
}
.footer__list a:hover::before {
    transform: translateY(-50%) scaleX(1);
}

/* 底部链接 hover */
.footer__bottom-links a {
    color: #6B7A95;
    font-size: var(--font-size-caption);
    transition: color var(--transition-fast);
    position: relative;
}
.footer__bottom-links a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -2px;
    width: 100%;
    height: 1px;
    background: currentColor;
    transform: scaleX(0);
    transform-origin: right center;
    transition: transform var(--transition-fast);
}
.footer__bottom-links a:hover {
    color: var(--color-accent);
}
.footer__bottom-links a:hover::after {
    transform: scaleX(1);
    transform-origin: left center;
}

/* 联系区邮箱 hover（纯文本 span） */
.footer__contact a {
    color: #8A9BB8;
    transition: color var(--transition-fast);
    text-decoration: none;
}
.footer__contact a:hover {
    color: var(--color-accent);
    text-decoration: underline;
    text-underline-offset: 3px;
}

/* 全局 focus-visible（无障碍） */
.footer a:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 3px;
    border-radius: 2px;
}
.footer__social:focus-visible {
    outline-offset: 3px;
}

/* =========================================================
   返回顶部按钮
   ========================================================= */
.back-to-top {
    position: fixed;
    right: 24px;
    bottom: 24px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--color-primary);
    color: #fff;
    display: grid;
    place-items: center;
    z-index: 90;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(12px);
    transition: all var(--transition);
    border: 1px solid rgba(255,255,255,0.15);
}
.back-to-top.is-visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.back-to-top:hover {
    background: var(--color-primary-hover);
    transform: translateY(-3px);
    box-shadow: var(--shadow-pop);
    color: #fff;
}

/* =========================================================
   响应式
   ========================================================= */
@media (max-width: 1024px) {
    .sample-cta__inner { grid-template-columns: 1fr; gap: var(--space-10); }
    .footer__main { grid-template-columns: 1fr; gap: var(--space-10); }
}
@media (max-width: 640px) {
    .sample-form { padding: var(--space-6); }
    .sample-form__grid { grid-template-columns: 1fr; }
    .sample-cta__features { grid-template-columns: repeat(3, 1fr); }
    .footer__main { grid-template-columns: 1fr; gap: var(--space-8); }
    .footer__bottom { flex-direction: column; align-items: flex-start; }
    .back-to-top { right: 16px; bottom: 16px; }
}