/* ============================================================
   香港铸铁药业有限公司 - 工业混凝土风格样式表
   主色调：混凝土灰 + 安全橙 + 钢蓝
   字体：Oswald(标题) + Barlow(正文)
   ============================================================ */

/* ---------- CSS 变量定义 ---------- */
:root {
    /* 混凝土灰系 */
    --concrete-light: #A8A8A8;
    --concrete-mid: #6C6C6C;
    --concrete-dark: #4A4A4A;
    --concrete-deep: #2E2E2E;
    --concrete-black: #1a1a1a;
    /* 安全橙系 */
    --safety-orange: #FF6600;
    --safety-orange-light: #FF8C00;
    /* 钢蓝系 */
    --steel-blue: #4682B4;
    --steel-blue-dark: #2F5D80;
    /* 文字色 */
    --text-light: #E8E8E8;
    --text-mid: #B0B0B0;
    --text-dark: #1a1a1a;
    /* 字体 */
    --font-head: 'Oswald', sans-serif;
    --font-body: 'Barlow', sans-serif;
    /* 间距 */
    --container: 1200px;
    --nav-h: 72px;
}

/* ---------- 全局重置 ---------- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-body);
    color: var(--text-light);
    background-color: var(--concrete-deep);
    line-height: 1.6;
    overflow-x: hidden;
    /* 混凝土纹理：多层 noise 渐变模拟 */
    background-image:
        radial-gradient(circle at 20% 30%, rgba(255, 255, 255, 0.03) 0%, transparent 40%),
        radial-gradient(circle at 80% 70%, rgba(0, 0, 0, 0.15) 0%, transparent 40%),
        repeating-linear-gradient(45deg, rgba(0, 0, 0, 0.02) 0px, rgba(0, 0, 0, 0.02) 1px, transparent 1px, transparent 3px),
        repeating-linear-gradient(-45deg, rgba(255, 255, 255, 0.02) 0px, rgba(255, 255, 255, 0.02) 1px, transparent 1px, transparent 4px),
        linear-gradient(135deg, #2E2E2E 0%, #3a3a3a 50%, #2E2E2E 100%);
    background-attachment: fixed;
}

a {
    color: var(--safety-orange);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--safety-orange-light);
}

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

ul {
    list-style: none;
}

/* ---------- 容器 ---------- */
.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- 通用区块 ---------- */
.section {
    padding: 100px 0;
    position: relative;
}

.section-head {
    text-align: center;
    margin-bottom: 60px;
    position: relative;
}

.section-num {
    display: block;
    font-family: var(--font-head);
    font-size: 0.95rem;
    color: var(--safety-orange);
    letter-spacing: 4px;
    margin-bottom: 12px;
    font-weight: 500;
}

.section-title {
    font-family: var(--font-head);
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 3px;
    color: var(--text-light);
    position: relative;
    display: inline-block;
}

.section-line {
    width: 80px;
    height: 4px;
    margin: 20px auto 0;
    background: linear-gradient(90deg, var(--safety-orange), var(--safety-orange-light));
    position: relative;
}

.section-line::before,
.section-line::after {
    content: '';
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 8px;
    height: 8px;
    background: var(--concrete-light);
    border: 2px solid var(--concrete-black);
    border-radius: 50%;
}

.section-line::before {
    left: -16px;
}

.section-line::after {
    right: -16px;
}

/* ---------- 按钮通用 ---------- */
.btn-metal,
.btn-hollow {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-family: var(--font-head);
    font-size: 1rem;
    font-weight: 500;
    letter-spacing: 2px;
    text-transform: uppercase;
    padding: 14px 32px;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

/* 金属质感按钮 */
.btn-metal {
    background: linear-gradient(180deg, var(--safety-orange-light) 0%, var(--safety-orange) 100%);
    color: #fff;
    box-shadow:
        0 4px 0 #b34700,
        0 6px 14px rgba(0, 0, 0, 0.5),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.btn-metal:hover {
    color: #fff;
    transform: translateY(2px);
    box-shadow:
        0 2px 0 #b34700,
        0 3px 8px rgba(0, 0, 0, 0.5),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.btn-metal:active {
    transform: translateY(4px);
    box-shadow: 0 0 0 #b34700, inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.btn-arrow {
    transition: transform 0.3s ease;
}

.btn-metal:hover .btn-arrow,
.btn-hollow:hover span {
    transform: translateX(6px);
}

/* 空心按钮 */
.btn-hollow {
    background: transparent;
    color: var(--text-light);
    border: 2px solid var(--concrete-light);
    box-shadow: inset 0 0 0 2px transparent;
}

.btn-hollow:hover {
    color: var(--safety-orange);
    border-color: var(--safety-orange);
    background: rgba(255, 102, 0, 0.08);
}

/* ============================================================
   模块1：导航栏
   ============================================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--nav-h);
    z-index: 1000;
    background: rgba(26, 26, 26, 0.92);
    backdrop-filter: blur(8px);
    border-bottom: 2px solid var(--concrete-dark);
    /* 钢铁质感渐变 */
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.6), inset 0 -1px 0 rgba(255, 255, 255, 0.05);
    transition: background 0.3s ease, box-shadow 0.3s ease;
}

.navbar.scrolled {
    background: rgba(20, 20, 20, 0.98);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.8), inset 0 -1px 0 rgba(255, 102, 0, 0.3);
}

.nav-container {
    max-width: var(--container);
    height: 100%;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* Logo 区域 */
.logo {
    display: flex;
    align-items: center;
    gap: 14px;
    color: var(--text-light);
}

.logo:hover {
    color: var(--text-light);
}

.logo-mark {
    position: relative;
    width: 46px;
    height: 46px;
    background: linear-gradient(135deg, var(--concrete-mid) 0%, var(--concrete-dark) 100%);
    border: 2px solid var(--concrete-light);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.6), inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.logo-text {
    font-family: var(--font-head);
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--safety-orange);
    letter-spacing: 1px;
    z-index: 2;
}

/* 铆钉装饰 */
.rivet {
    position: absolute;
    width: 6px;
    height: 6px;
    background: radial-gradient(circle at 30% 30%, #d0d0d0, #4a4a4a);
    border-radius: 50%;
    box-shadow: inset 0 -1px 1px rgba(0, 0, 0, 0.5);
}

.rivet.r1 { top: 3px; left: 3px; }
.rivet.r2 { top: 3px; right: 3px; }
.rivet.r3 { bottom: 3px; left: 3px; }
.rivet.r4 { bottom: 3px; right: 3px; }

.logo-name {
    font-family: var(--font-head);
    font-weight: 600;
    font-size: 1.35rem;
    letter-spacing: 3px;
    color: var(--text-light);
    text-transform: uppercase;
}

/* 导航菜单 */
.nav-menu ul {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    display: block;
    color: var(--text-light);
    font-family: var(--font-head);
    font-size: 0.95rem;
    font-weight: 400;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    padding: 10px 16px;
    position: relative;
    transition: color 0.3s ease;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 4px;
    left: 16px;
    right: 16px;
    height: 2px;
    background: var(--safety-orange);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--safety-orange);
}

.nav-link:hover::after,
.nav-link.active::after {
    transform: scaleX(1);
}

.nav-cta {
    background: linear-gradient(180deg, var(--safety-orange-light), var(--safety-orange));
    color: #fff !important;
    border-radius: 0;
    box-shadow: 0 3px 0 #b34700;
}

.nav-cta:hover {
    color: #fff !important;
    transform: translateY(1px);
    box-shadow: 0 2px 0 #b34700;
}

.nav-cta::after {
    display: none;
}

/* 汉堡菜单 */
.hamburger {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 32px;
    height: 24px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1001;
}

.hamburger .bar {
    display: block;
    width: 100%;
    height: 3px;
    background: var(--safety-orange);
    transition: all 0.3s ease;
    transform-origin: center;
}

.hamburger.active .bar:nth-child(1) {
    transform: translateY(10.5px) rotate(45deg);
}

.hamburger.active .bar:nth-child(2) {
    opacity: 0;
}

.hamburger.active .bar:nth-child(3) {
    transform: translateY(-10.5px) rotate(-45deg);
}

/* ============================================================
   模块2：全屏轮播图（工业传送带）
   ============================================================ */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    overflow: hidden;
    margin-top: 0;
}

.carousel {
    position: relative;
    width: 100%;
    height: 100%;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0;
    visibility: hidden;
    /* 金属面板滑入过渡 */
    transform: translateX(100%) skewX(-8deg);
    transition: transform 1s cubic-bezier(0.77, 0, 0.18, 1), opacity 0.8s ease, visibility 0.8s;
    z-index: 1;
}

.slide.active {
    opacity: 1;
    visibility: visible;
    transform: translateX(0) skewX(0);
    z-index: 2;
}

.slide.prev {
    transform: translateX(-100%) skewX(8deg);
}

/* 暗色遮罩 + 混凝土纹理叠加 */
.slide-overlay {
    position: absolute;
    inset: 0;
    background:
        linear-gradient(90deg, rgba(20, 20, 20, 0.85) 0%, rgba(30, 30, 30, 0.5) 60%, rgba(20, 20, 20, 0.7) 100%),
        repeating-linear-gradient(45deg, rgba(0, 0, 0, 0.04) 0, rgba(0, 0, 0, 0.04) 2px, transparent 2px, transparent 5px);
}

.slide-content {
    position: absolute;
    top: 50%;
    left: 8%;
    transform: translateY(-50%);
    max-width: 600px;
    z-index: 3;
}

.slide-tag {
    display: inline-block;
    font-family: var(--font-head);
    font-size: 0.9rem;
    color: var(--safety-orange);
    letter-spacing: 3px;
    padding: 6px 14px;
    border: 1px solid var(--safety-orange);
    margin-bottom: 24px;
    background: rgba(255, 102, 0, 0.1);
}

.slide-title {
    font-family: var(--font-head);
    font-size: clamp(2.5rem, 7vw, 5rem);
    font-weight: 700;
    line-height: 1.05;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: #fff;
    margin-bottom: 24px;
    text-shadow: 0 4px 20px rgba(0, 0, 0, 0.8);
}

.slide-desc {
    font-size: 1.15rem;
    color: var(--text-mid);
    margin-bottom: 36px;
    max-width: 480px;
}

/* 传送带控制条 */
.carousel-controls {
    position: absolute;
    bottom: 60px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 24px;
    z-index: 5;
}

.carousel-btn {
    width: 48px;
    height: 48px;
    background: rgba(26, 26, 26, 0.8);
    color: var(--safety-orange);
    border: 2px solid var(--concrete-mid);
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.carousel-btn:hover {
    background: var(--safety-orange);
    color: #fff;
    border-color: var(--safety-orange);
}

.carousel-indicators {
    display: flex;
    gap: 12px;
}

.indicator {
    width: 36px;
    height: 6px;
    background: var(--concrete-mid);
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.indicator.active {
    background: var(--safety-orange);
    width: 60px;
}

/* 安全条纹动画 */
.safety-stripe {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 14px;
    background: repeating-linear-gradient(
        -45deg,
        var(--safety-orange) 0,
        var(--safety-orange) 20px,
        #1a1a1a 20px,
        #1a1a1a 40px
    );
    background-size: 56.57px 100%;
    animation: stripe-move 3s linear infinite;
    z-index: 4;
}

@keyframes stripe-move {
    0% { background-position: 0 0; }
    100% { background-position: 56.57px 0; }
}

/* ============================================================
   模块3：关于我们
   ============================================================ */
.about {
    background:
        repeating-linear-gradient(0deg, rgba(0, 0, 0, 0.08) 0, rgba(0, 0, 0, 0.08) 1px, transparent 1px, transparent 60px),
        linear-gradient(180deg, #2E2E2E 0%, #353535 100%);
}

.about-grid {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 60px;
    align-items: center;
    margin-bottom: 80px;
}

.about-lead {
    font-family: var(--font-head);
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--safety-orange-light);
    margin-bottom: 24px;
    line-height: 1.4;
}

.about-text p {
    margin-bottom: 20px;
    color: var(--text-mid);
    font-size: 1.05rem;
}

.about-text .btn-hollow {
    margin-top: 16px;
}

/* 金属框架图片 */
.metal-frame {
    position: relative;
    padding: 14px;
    background: linear-gradient(135deg, #555 0%, #333 100%);
    border: 3px solid var(--concrete-dark);
    box-shadow:
        0 10px 30px rgba(0, 0, 0, 0.6),
        inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

.metal-frame img {
    width: 100%;
    height: 360px;
    object-fit: cover;
    filter: contrast(1.05) saturate(0.85);
}

.frame-rivet {
    position: absolute;
    width: 12px;
    height: 12px;
    background: radial-gradient(circle at 30% 30%, #c8c8c8, #3a3a3a);
    border-radius: 50%;
    box-shadow: inset 0 -2px 2px rgba(0, 0, 0, 0.6), 0 1px 2px rgba(0, 0, 0, 0.5);
}

.frame-rivet.tl { top: 8px; left: 8px; }
.frame-rivet.tr { top: 8px; right: 8px; }
.frame-rivet.bl { bottom: 8px; left: 8px; }
.frame-rivet.br { bottom: 8px; right: 8px; }

/* 统计数据 */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.stat-card {
    text-align: center;
    padding: 36px 16px;
    background:
        linear-gradient(180deg, #3a3a3a 0%, #2a2a2a 100%);
    border: 1px solid var(--concrete-dark);
    border-top: 3px solid var(--safety-orange);
    position: relative;
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.5);
    transition: transform 0.3s ease, border-color 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-6px);
    border-top-color: var(--steel-blue);
}

.stat-card::before,
.stat-card::after {
    content: '';
    position: absolute;
    width: 8px;
    height: 8px;
    background: radial-gradient(circle at 30% 30%, #c8c8c8, #3a3a3a);
    border-radius: 50%;
}

.stat-card::before { top: 10px; left: 10px; }
.stat-card::after { top: 10px; right: 10px; }

.stat-num {
    font-family: var(--font-head);
    font-size: clamp(2.4rem, 5vw, 3.5rem);
    font-weight: 700;
    color: var(--safety-orange);
    line-height: 1;
}

.stat-unit {
    font-family: var(--font-head);
    font-size: 1.4rem;
    color: var(--safety-orange-light);
    margin-left: 4px;
}

.stat-label {
    display: block;
    margin-top: 14px;
    font-size: 0.95rem;
    color: var(--text-mid);
    letter-spacing: 1px;
}

/* ============================================================
   模块4：服务介绍
   ============================================================ */
.services {
    background:
        repeating-linear-gradient(90deg, rgba(0, 0, 0, 0.06) 0, rgba(0, 0, 0, 0.06) 1px, transparent 1px, transparent 80px),
        linear-gradient(180deg, #353535 0%, #2E2E2E 100%);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.service-card {
    padding: 36px 28px;
    background: linear-gradient(180deg, #3a3a3a 0%, #2a2a2a 100%);
    border: 2px solid var(--concrete-dark);
    position: relative;
    transition: transform 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
    overflow: hidden;
}

/* 工业面板滑入效果 */
.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--safety-orange);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform 0.4s ease;
}

.service-card:hover {
    transform: translateY(-8px);
    border-color: var(--safety-orange);
    box-shadow: 0 14px 36px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 102, 0, 0.3);
}

.service-card:hover::before {
    transform: scaleY(1);
}

.service-icon {
    margin-bottom: 24px;
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--concrete-dark);
}

.service-title {
    font-family: var(--font-head);
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--text-light);
    letter-spacing: 1px;
    margin-bottom: 14px;
    text-transform: uppercase;
}

.service-desc {
    color: var(--text-mid);
    font-size: 0.95rem;
    margin-bottom: 22px;
    min-height: 84px;
}

.service-tag {
    display: inline-block;
    font-family: var(--font-head);
    font-size: 0.78rem;
    color: var(--steel-blue);
    letter-spacing: 2px;
    padding: 5px 12px;
    border: 1px solid var(--steel-blue-dark);
    background: rgba(70, 130, 180, 0.1);
}

/* ============================================================
   模块5：客户案例（横向滑动）
   ============================================================ */
.cases {
    background:
        linear-gradient(180deg, #2E2E2E 0%, #333 100%);
}

.cases-track {
    display: flex;
    gap: 24px;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    padding: 10px 4px 30px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: thin;
    scrollbar-color: var(--safety-orange) var(--concrete-dark);
}

.cases-track::-webkit-scrollbar {
    height: 8px;
}

.cases-track::-webkit-scrollbar-track {
    background: var(--concrete-dark);
}

.cases-track::-webkit-scrollbar-thumb {
    background: var(--safety-orange);
}

.case-card {
    flex: 0 0 320px;
    scroll-snap-align: start;
    background: linear-gradient(180deg, #3a3a3a 0%, #2a2a2a 100%);
    border: 2px solid var(--concrete-dark);
    transition: transform 0.4s ease, border-color 0.4s ease;
    overflow: hidden;
}

.case-card:hover {
    transform: translateY(-6px);
    border-color: var(--safety-orange);
}

.case-img {
    width: 100%;
    aspect-ratio: 1 / 1;
    background-size: cover;
    background-position: center;
    position: relative;
    filter: grayscale(0.3) contrast(1.1);
    transition: filter 0.4s ease;
}

.case-card:hover .case-img {
    filter: grayscale(0) contrast(1.05);
}

.case-num {
    position: absolute;
    top: 12px;
    left: 12px;
    font-family: var(--font-head);
    font-size: 2rem;
    font-weight: 700;
    color: var(--safety-orange);
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.8);
}

.case-info {
    padding: 24px;
}

.case-title {
    font-family: var(--font-head);
    font-size: 1.3rem;
    color: var(--text-light);
    margin-bottom: 10px;
    letter-spacing: 1px;
}

.case-desc {
    color: var(--text-mid);
    font-size: 0.92rem;
    margin-bottom: 16px;
}

.case-meta {
    display: inline-block;
    font-family: var(--font-head);
    font-size: 0.78rem;
    color: var(--steel-blue);
    letter-spacing: 1px;
    padding-top: 12px;
    border-top: 1px solid var(--concrete-dark);
    width: 100%;
}

/* ============================================================
   模块6：新闻资讯
   ============================================================ */
.news {
    background:
        repeating-linear-gradient(0deg, rgba(0, 0, 0, 0.08) 0, rgba(0, 0, 0, 0.08) 1px, transparent 1px, transparent 60px),
        linear-gradient(180deg, #333 0%, #2E2E2E 100%);
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.news-card {
    display: flex;
    gap: 20px;
    padding: 28px;
    background: linear-gradient(180deg, #3a3a3a 0%, #2a2a2a 100%);
    border: 2px solid var(--concrete-dark);
    border-left: 4px solid var(--safety-orange);
    transition: transform 0.3s ease, border-left-color 0.3s ease;
}

.news-card:hover {
    transform: translateY(-4px);
    border-left-color: var(--steel-blue);
}

.news-date {
    flex-shrink: 0;
    text-align: center;
    padding-right: 18px;
    border-right: 1px solid var(--concrete-dark);
}

.news-day {
    display: block;
    font-family: var(--font-head);
    font-size: 2.6rem;
    font-weight: 700;
    color: var(--safety-orange);
    line-height: 1;
}

.news-mon {
    display: block;
    font-family: var(--font-head);
    font-size: 0.85rem;
    color: var(--text-mid);
    letter-spacing: 2px;
    margin-top: 6px;
}

.news-cat {
    display: block;
    font-family: var(--font-head);
    font-size: 0.78rem;
    color: var(--steel-blue);
    letter-spacing: 2px;
    margin-bottom: 10px;
}

.news-title {
    font-family: var(--font-head);
    font-size: 1.15rem;
    color: var(--text-light);
    margin-bottom: 12px;
    line-height: 1.3;
}

.news-excerpt {
    color: var(--text-mid);
    font-size: 0.9rem;
    margin-bottom: 16px;
}

.news-link {
    font-family: var(--font-head);
    font-size: 0.85rem;
    letter-spacing: 1px;
}

/* ============================================================
   模块7：FAQ 手风琴
   ============================================================ */
.faq {
    background:
        linear-gradient(180deg, #2E2E2E 0%, #353535 100%);
}

.faq-list {
    max-width: 860px;
    margin: 0 auto;
}

.faq-item {
    background: linear-gradient(180deg, #3a3a3a 0%, #2a2a2a 100%);
    border: 1px solid var(--concrete-dark);
    border-left: 4px solid var(--concrete-mid);
    margin-bottom: 16px;
    transition: border-left-color 0.3s ease;
}

.faq-item.open {
    border-left-color: var(--safety-orange);
}

.faq-question {
    width: 100%;
    background: transparent;
    border: none;
    color: var(--text-light);
    font-family: var(--font-head);
    font-size: 1.1rem;
    font-weight: 500;
    letter-spacing: 1px;
    text-align: left;
    padding: 22px 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    transition: color 0.3s ease;
}

.faq-question:hover {
    color: var(--safety-orange);
}

.faq-icon {
    flex-shrink: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--concrete-dark);
    color: var(--safety-orange);
    font-size: 1.3rem;
    font-weight: 300;
    transition: all 0.3s ease;
}

.faq-item.open .faq-icon {
    background: var(--safety-orange);
    color: #fff;
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    padding: 0 24px;
}

.faq-item.open .faq-answer {
    max-height: 300px;
    padding: 0 24px 22px;
}

.faq-answer p {
    color: var(--text-mid);
    font-size: 0.98rem;
    border-top: 1px solid var(--concrete-dark);
    padding-top: 16px;
}

/* ============================================================
   模块8：联系我们
   ============================================================ */
.contact {
    background:
        repeating-linear-gradient(90deg, rgba(0, 0, 0, 0.06) 0, rgba(0, 0, 0, 0.06) 1px, transparent 1px, transparent 80px),
        linear-gradient(180deg, #353535 0%, #2E2E2E 100%);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.3fr;
    gap: 50px;
    align-items: start;
}

.contact-subtitle {
    font-family: var(--font-head);
    font-size: 1.6rem;
    color: var(--safety-orange);
    letter-spacing: 2px;
    margin-bottom: 28px;
    text-transform: uppercase;
}

.info-list li {
    display: flex;
    gap: 16px;
    padding: 18px 0;
    border-bottom: 1px solid var(--concrete-dark);
}

.info-label {
    flex-shrink: 0;
    width: 60px;
    font-family: var(--font-head);
    font-size: 0.85rem;
    color: var(--steel-blue);
    letter-spacing: 2px;
    text-transform: uppercase;
    padding-top: 2px;
}

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

.info-value a:hover {
    color: var(--safety-orange-light);
}

/* 工业风表单 */
.contact-form {
    padding: 36px;
    background: linear-gradient(180deg, #3a3a3a 0%, #2a2a2a 100%);
    border: 2px solid var(--concrete-dark);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5), inset 0 1px 0 rgba(255, 255, 255, 0.08);
    position: relative;
}

.contact-form::before,
.contact-form::after {
    content: '';
    position: absolute;
    width: 12px;
    height: 12px;
    background: radial-gradient(circle at 30% 30%, #c8c8c8, #3a3a3a);
    border-radius: 50%;
    box-shadow: inset 0 -2px 2px rgba(0, 0, 0, 0.6);
}

.contact-form::before { top: 12px; left: 12px; }
.contact-form::after { top: 12px; right: 12px; }

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

.form-group label {
    display: block;
    font-family: var(--font-head);
    font-size: 0.85rem;
    color: var(--text-light);
    letter-spacing: 1.5px;
    text-transform: uppercase;
    margin-bottom: 8px;
}

.req {
    color: var(--safety-orange);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 14px;
    background: rgba(0, 0, 0, 0.35);
    border: 1px solid var(--concrete-dark);
    color: var(--text-light);
    font-family: var(--font-body);
    font-size: 1rem;
    transition: border-color 0.3s ease, background 0.3s ease;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: #777;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--safety-orange);
    background: rgba(0, 0, 0, 0.5);
    box-shadow: 0 0 0 2px rgba(255, 102, 0, 0.15);
}

.form-group select {
    cursor: pointer;
    appearance: none;
    background-image: linear-gradient(45deg, transparent 50%, var(--safety-orange) 50%), linear-gradient(135deg, var(--safety-orange) 50%, transparent 50%);
    background-position: calc(100% - 18px) center, calc(100% - 12px) center;
    background-size: 6px 6px, 6px 6px;
    background-repeat: no-repeat;
}

.form-group select option {
    background: #2a2a2a;
    color: var(--text-light);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

/* 表单错误状态 */
.form-group.invalid input,
.form-group.invalid textarea {
    border-color: #e74c3c;
    background: rgba(231, 76, 60, 0.08);
}

.form-error {
    display: block;
    color: #e74c3c;
    font-size: 0.82rem;
    margin-top: 6px;
    min-height: 1em;
}

.form-submit {
    width: 100%;
    justify-content: center;
    margin-top: 8px;
}

.form-success {
    margin-top: 16px;
    padding: 14px;
    background: rgba(70, 130, 180, 0.15);
    border: 1px solid var(--steel-blue);
    color: var(--steel-blue);
    text-align: center;
    font-family: var(--font-head);
    letter-spacing: 1px;
}

/* ============================================================
   模块9：页脚 + 友情链接
   ============================================================ */
.footer {
    background: #1a1a1a;
    padding: 60px 0 0;
    border-top: 3px solid var(--concrete-dark);
    position: relative;
}

.links-block {
    padding-bottom: 36px;
    border-bottom: 1px solid var(--concrete-dark);
    margin-bottom: 36px;
}

.links-title {
    font-family: var(--font-head);
    font-size: 1.1rem;
    color: var(--safety-orange);
    letter-spacing: 2px;
    margin-bottom: 20px;
    text-transform: uppercase;
}

.links-list {
    display: flex;
    flex-wrap: wrap;
    gap: 28px;
}

.links-list a {
    color: var(--text-mid);
    font-size: 0.95rem;
    position: relative;
    padding-left: 16px;
    transition: color 0.3s ease;
}

.links-list a::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--safety-orange);
}

.links-list a:hover {
    color: var(--safety-orange);
}

.footer-main {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 30px;
    padding-bottom: 40px;
    flex-wrap: wrap;
}

.footer-brand .logo-name {
    font-size: 1.4rem;
    color: var(--text-light);
    display: block;
    margin-bottom: 10px;
}

.footer-brand p {
    color: var(--text-mid);
    font-size: 0.9rem;
    max-width: 360px;
}

.footer-meta {
    text-align: right;
    color: #888;
    font-size: 0.85rem;
}

.footer-meta p {
    margin-bottom: 6px;
}

.footer-stripe {
    position: relative;
    bottom: 0;
}

/* ============================================================
   滚动揭示动画（IntersectionObserver 触发）
   ============================================================ */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.2, 0.7, 0.3, 1);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 错开动画延迟 */
.services-grid .reveal:nth-child(2),
.news-grid .reveal:nth-child(2),
.stats-grid .reveal:nth-child(2) { transition-delay: 0.1s; }
.services-grid .reveal:nth-child(3),
.news-grid .reveal:nth-child(3),
.stats-grid .reveal:nth-child(3) { transition-delay: 0.2s; }
.services-grid .reveal:nth-child(4),
.stats-grid .reveal:nth-child(4) { transition-delay: 0.3s; }

/* ============================================================
   响应式：平板
   ============================================================ */
@media (max-width: 992px) {
    .section { padding: 70px 0; }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .metal-frame img { height: 300px; }

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

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

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

    .contact-grid {
        grid-template-columns: 1fr;
        gap: 36px;
    }

    .footer-main {
        flex-direction: column;
    }

    .footer-meta {
        text-align: left;
    }
}

/* ============================================================
   响应式：移动端
   ============================================================ */
@media (max-width: 768px) {
    :root { --nav-h: 64px; }

    /* 移动端导航 */
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: var(--nav-h);
        left: 0;
        width: 100%;
        height: calc(100vh - var(--nav-h));
        background: rgba(20, 20, 20, 0.98);
        backdrop-filter: blur(10px);
        transform: translateX(100%);
        transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        overflow-y: auto;
    }

    .nav-menu.open {
        transform: translateX(0);
    }

    .nav-menu ul {
        flex-direction: column;
        align-items: stretch;
        padding: 20px;
        gap: 0;
    }

    .nav-link {
        padding: 16px;
        border-bottom: 1px solid var(--concrete-dark);
        font-size: 1.1rem;
    }

    .nav-link::after { display: none; }

    .nav-cta {
        margin-top: 16px;
        text-align: center;
    }

    .logo-name { font-size: 1.15rem; }

    /* 轮播 */
    .slide-content { left: 6%; max-width: 88%; }

    .carousel-controls {
        bottom: 40px;
        gap: 14px;
    }

    .carousel-btn { width: 40px; height: 40px; }

    .indicator { width: 24px; }
    .indicator.active { width: 40px; }

    /* 区块间距 */
    .section { padding: 56px 0; }

    .section-head { margin-bottom: 40px; }

    /* 服务 / 案例 */
    .services-grid { grid-template-columns: 1fr; }

    .service-desc { min-height: auto; }

    .case-card { flex: 0 0 280px; }

    /* 表单 */
    .contact-form { padding: 24px; }

    /* 统计 */
    .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }

    .stat-card { padding: 26px 12px; }

    /* 新闻卡片 */
    .news-card { flex-direction: row; }

    .footer-meta { font-size: 0.8rem; }
}

/* ============================================================
   响应式：超小屏
   ============================================================ */
@media (max-width: 480px) {
    .stats-grid { grid-template-columns: 1fr; }

    .slide-tag { font-size: 0.78rem; letter-spacing: 2px; }

    .case-card { flex: 0 0 85%; }

    .links-list { gap: 16px; }

    .news-card { flex-direction: column; gap: 14px; }

    .news-date {
        border-right: none;
        border-bottom: 1px solid var(--concrete-dark);
        padding-right: 0;
        padding-bottom: 12px;
        display: flex;
        align-items: baseline;
        gap: 10px;
    }
}