/* =============================================
   顺昌弹簧厂 - 官网样式
   ============================================= */

/* === CSS Variables === */
:root {
    --bg-primary: #060f1e;
    --bg-secondary: #0a1628;
    --bg-section-alt: #0d1f3c;
    --bg-card: #112038;
    --bg-card-hover: #162848;
    --border-color: rgba(77, 166, 255, 0.12);
    --border-hover: rgba(77, 166, 255, 0.4);
    --accent-gold: #d4a520;
    --accent-gold-light: #f0c040;
    --accent-blue: #4da6ff;
    --accent-blue-dark: #1a6ec5;
    --accent-blue-mid: #2d8de8;
    --text-primary: #f0f4ff;
    --text-secondary: #8fafd4;
    --text-muted: #5a7a9e;
    --navbar-height: 70px;
    --transition: all 0.3s ease;
    --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.5);
    --shadow-blue: 0 8px 32px rgba(77, 166, 255, 0.2);
    --radius: 12px;
    --radius-lg: 18px;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', -apple-system, sans-serif;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.75;
    overflow-x: hidden;
}

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

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

/* Custom scrollbar */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--accent-blue-dark); border-radius: 3px; }

/* === Layout === */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 96px 0;
}

.section-dark {
    background-color: var(--bg-section-alt);
}

/* === Section Header === */
.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-tag {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-blue-dark), var(--accent-blue));
    color: #fff;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 2.5px;
    padding: 5px 18px;
    border-radius: 20px;
    margin-bottom: 18px;
    text-transform: uppercase;
}

.section-header h2 {
    font-size: clamp(1.8rem, 3vw, 2.4rem);
    font-weight: 800;
    margin-bottom: 18px;
    background: linear-gradient(135deg, #ffffff 0%, var(--accent-blue) 60%, var(--accent-gold) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.3;
}

.section-desc {
    font-size: 0.98rem;
    color: var(--text-secondary);
    max-width: 580px;
    margin: 0 auto;
    line-height: 1.8;
}

/* =============================================
   NAVBAR
   ============================================= */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: var(--navbar-height);
    transition: background 0.4s ease, box-shadow 0.4s ease;
    background: transparent;
}

#navbar.scrolled {
    background: rgba(6, 15, 30, 0.96);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    box-shadow: 0 2px 24px rgba(0, 0, 0, 0.5);
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1300px;
    margin: 0 auto;
    padding: 0 28px;
    height: 100%;
    display: flex;
    align-items: center;
    gap: 28px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 9px;
    font-size: 1.25rem;
    font-weight: 800;
    color: #fff;
    white-space: nowrap;
    transition: opacity 0.2s;
}

.nav-logo:hover { opacity: 0.85; }

.logo-icon {
    font-size: 1.5rem;
    color: var(--accent-gold);
    display: inline-block;
    animation: spin-slow 10s linear infinite;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2px;
    flex: 1;
}

.nav-links a {
    display: block;
    padding: 8px 14px;
    font-size: 0.93rem;
    color: rgba(240, 244, 255, 0.8);
    border-radius: 7px;
    transition: var(--transition);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 3px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--accent-gold);
    border-radius: 1px;
    transition: width 0.3s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: #fff;
    background: rgba(77, 166, 255, 0.1);
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 55%;
}

.nav-phone {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--accent-gold);
    font-weight: 700;
    font-size: 0.88rem;
    white-space: nowrap;
    border: 1px solid rgba(212, 165, 32, 0.45);
    padding: 7px 16px;
    border-radius: 22px;
    transition: var(--transition);
}

.nav-phone:hover {
    background: var(--accent-gold);
    color: var(--bg-primary);
    border-color: var(--accent-gold);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: #fff;
    border-radius: 2px;
    transition: var(--transition);
}

.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* =============================================
   HERO
   ============================================= */
#hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    text-align: center;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.hero-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
    filter: saturate(0.7) brightness(0.5);
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(
        160deg,
        rgba(6, 15, 30, 0.85) 0%,
        rgba(10, 22, 40, 0.75) 40%,
        rgba(6, 15, 30, 0.92) 100%
    );
}

.hero-particles {
    position: absolute;
    inset: 0;
    z-index: 1;
    pointer-events: none;
    overflow: hidden;
}

.hero-content {
    position: relative;
    z-index: 2;
    padding: 110px 24px 80px;
    max-width: 920px;
    width: 100%;
}

.hero-subtitle-top {
    font-size: 0.95rem;
    color: var(--accent-gold);
    letter-spacing: 4px;
    margin-bottom: 22px;
    font-weight: 600;
    text-transform: uppercase;
}

#hero h1 {
    font-size: clamp(2.6rem, 6vw, 4.8rem);
    font-weight: 900;
    line-height: 1.15;
    margin-bottom: 28px;
    background: linear-gradient(135deg, #ffffff 0%, #a8d4ff 40%, var(--accent-gold) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 0.02em;
}

.hero-desc {
    font-size: 1.05rem;
    color: rgba(240, 244, 255, 0.75);
    margin-bottom: 52px;
    line-height: 2.1;
}

.hero-desc strong {
    color: var(--accent-gold-light);
    -webkit-text-fill-color: var(--accent-gold-light);
    font-weight: 700;
}

/* Hero stats */
.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0;
    margin-bottom: 52px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-lg);
    padding: 8px 0;
    flex-wrap: wrap;
    backdrop-filter: blur(8px);
}

.stat-item {
    text-align: center;
    padding: 16px 36px;
}

.stat-num {
    display: inline;
    font-size: 2rem;
    font-weight: 900;
    color: var(--accent-gold);
    line-height: 1;
}

.stat-unit {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--accent-gold);
}

.stat-item p {
    font-size: 0.78rem;
    color: var(--text-secondary);
    margin-top: 7px;
    letter-spacing: 0.5px;
}

.stat-divider {
    width: 1px;
    height: 44px;
    background: rgba(255, 255, 255, 0.12);
    flex-shrink: 0;
}

/* Hero buttons */
.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Scroll hint */
.hero-scroll-hint {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
    color: rgba(255, 255, 255, 0.45);
    animation: bounce-y 2.2s ease-in-out infinite;
    font-size: 1.1rem;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 50%;
    transition: color 0.3s;
}

.hero-scroll-hint:hover { color: var(--accent-gold); }

/* =============================================
   BUTTONS
   ============================================= */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    padding: 14px 34px;
    border-radius: 9px;
    font-size: 0.97rem;
    font-weight: 700;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-blue-dark), var(--accent-blue-mid));
    color: #fff;
    box-shadow: 0 4px 20px rgba(45, 141, 232, 0.35);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 32px rgba(77, 166, 255, 0.5);
    background: linear-gradient(135deg, var(--accent-blue-mid), var(--accent-blue));
}

.btn-outline {
    background: transparent;
    color: #fff;
    border: 2px solid rgba(255, 255, 255, 0.35);
}

.btn-outline:hover {
    border-color: var(--accent-gold);
    color: var(--accent-gold);
    transform: translateY(-3px);
    background: rgba(212, 165, 32, 0.07);
}

/* =============================================
   ABOUT
   ============================================= */
.about-content {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 64px;
    align-items: start;
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 22px;
    font-size: 0.98rem;
    line-height: 2;
}

.about-text strong {
    color: var(--accent-blue);
    font-weight: 700;
}

.about-quote {
    display: flex;
    align-items: center;
    gap: 14px;
    margin-top: 32px;
    padding: 18px 22px;
    border-left: 3px solid var(--accent-gold);
    background: rgba(212, 165, 32, 0.06);
    border-radius: 0 var(--radius) var(--radius) 0;
    font-size: 1.07rem;
    font-weight: 700;
    color: var(--accent-gold);
}

.about-quote i { font-size: 1.2rem; opacity: 0.6; flex-shrink: 0; }

.about-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px;
}

.about-stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 30px 20px;
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.about-stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent-blue-dark), var(--accent-blue));
    opacity: 0;
    transition: opacity 0.3s;
}

.about-stat-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-5px);
    box-shadow: var(--shadow-blue);
}

.about-stat-card:hover::before { opacity: 1; }

.about-stat-icon {
    font-size: 1.7rem;
    color: var(--accent-blue);
    margin-bottom: 14px;
    opacity: 0.85;
}

.about-stat-num {
    font-size: 1.9rem;
    font-weight: 900;
    color: var(--accent-gold);
    line-height: 1;
    margin-bottom: 8px;
}

.about-stat-num .small-unit {
    font-size: 1.1rem;
}

.about-stat-label {
    font-size: 0.82rem;
    color: var(--text-muted);
    letter-spacing: 0.5px;
}

/* =============================================
   PRODUCTS
   ============================================= */
.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 22px;
}

.product-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: transform 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
    will-change: transform;
}

.product-card:hover {
    border-color: var(--border-hover);
    box-shadow: 0 16px 48px rgba(77, 166, 255, 0.18);
}

.product-img-wrap {
    position: relative;
    height: 220px;
    overflow: hidden;
}

.product-img-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.55s ease;
}

/* Dark-background product shots (processed images) */
.product-img-wrap.product-img-dark {
    background: #070e1c;
}

.product-img-wrap.product-img-dark img {
    object-fit: contain;
    padding: 6px;
}

.product-card:hover .product-img-wrap img {
    transform: scale(1.09);
}

.product-overlay {
    position: absolute;
    inset: 0;
    background: rgba(26, 110, 197, 0.72);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.35s ease;
}

.product-card:hover .product-overlay { opacity: 1; }

.product-overlay span {
    color: #fff;
    font-size: 0.95rem;
    font-weight: 700;
    border: 2px solid rgba(255, 255, 255, 0.85);
    padding: 8px 22px;
    border-radius: 22px;
    letter-spacing: 1px;
}

.product-info {
    padding: 20px 22px 22px;
}

.product-info h3 {
    font-size: 1.05rem;
    font-weight: 800;
    margin-bottom: 9px;
    color: var(--text-primary);
}

.product-info p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.75;
    margin-bottom: 14px;
}

.product-tag {
    display: inline-block;
    font-size: 0.72rem;
    color: var(--accent-blue);
    background: rgba(77, 166, 255, 0.08);
    border: 1px solid rgba(77, 166, 255, 0.25);
    padding: 3px 11px;
    border-radius: 12px;
    letter-spacing: 0.5px;
}

/* =============================================
   SERVICES
   ============================================= */
.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 22px;
    margin-bottom: 48px;
}

.service-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 34px 26px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.service-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-blue-dark), var(--accent-blue));
    transform: scaleX(0);
    transition: transform 0.35s ease;
    transform-origin: left;
}

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

.service-card:hover::after { transform: scaleX(1); }

.service-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius);
    background: linear-gradient(135deg, var(--accent-blue-dark), var(--accent-blue-mid));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.35rem;
    color: #fff;
    margin-bottom: 22px;
    box-shadow: 0 4px 16px rgba(26, 110, 197, 0.4);
}

.service-card h3 {
    font-size: 1.03rem;
    font-weight: 800;
    margin-bottom: 13px;
    color: var(--text-primary);
}

.service-card p {
    font-size: 0.87rem;
    color: var(--text-secondary);
    line-height: 1.85;
}

/* Services banner */
.services-banner {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 28px;
    padding: 30px 48px;
    background: linear-gradient(135deg, rgba(26, 110, 197, 0.12), rgba(77, 166, 255, 0.07));
    border: 1px solid rgba(77, 166, 255, 0.25);
    border-radius: var(--radius-lg);
    flex-wrap: wrap;
}

.banner-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.05rem;
    font-weight: 800;
    color: var(--accent-gold);
    white-space: nowrap;
}

.banner-item i { font-size: 1.2rem; }

.banner-divider {
    color: rgba(255, 255, 255, 0.2);
    font-size: 1.4rem;
    font-weight: 300;
}

/* =============================================
   EQUIPMENT
   ============================================= */
.equipment-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 26px;
    margin-bottom: 48px;
}

.equipment-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition);
}

.equipment-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-blue);
    transform: translateY(-5px);
}

.equipment-img-wrap {
    height: 230px;
    overflow: hidden;
}

.equipment-img-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.55s ease;
}

.equipment-card:hover .equipment-img-wrap img { transform: scale(1.06); }

.equipment-info {
    padding: 26px;
}

.equipment-info h3 {
    font-size: 1rem;
    font-weight: 800;
    margin-bottom: 13px;
    color: var(--accent-blue);
    display: flex;
    align-items: center;
    gap: 9px;
}

.equipment-info p {
    font-size: 0.86rem;
    color: var(--text-secondary);
    line-height: 1.85;
    margin-bottom: 18px;
}

.equipment-specs {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 7px;
}

.equipment-specs li {
    display: flex;
    align-items: center;
    gap: 9px;
    font-size: 0.82rem;
    color: var(--text-muted);
}

.equipment-specs li i {
    color: var(--accent-gold);
    font-size: 0.72rem;
    flex-shrink: 0;
}

/* Equipment highlights */
.equipment-highlights {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.eq-highlight {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 28px 20px;
    text-align: center;
    transition: var(--transition);
}

.eq-highlight:hover {
    border-color: rgba(212, 165, 32, 0.4);
    background: rgba(212, 165, 32, 0.04);
    transform: translateY(-3px);
}

.eq-highlight i {
    font-size: 2rem;
    color: var(--accent-gold);
    display: block;
    margin-bottom: 13px;
}

.eq-highlight strong {
    display: block;
    font-size: 1.08rem;
    color: var(--text-primary);
    margin-bottom: 5px;
    font-weight: 800;
}

.eq-highlight span {
    font-size: 0.78rem;
    color: var(--text-muted);
}

/* =============================================
   CONTACT
   ============================================= */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: start;
}

.contact-info h3 {
    font-size: 1.2rem;
    font-weight: 800;
    margin-bottom: 30px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--accent-gold);
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-primary);
}

.contact-items {
    display: flex;
    flex-direction: column;
    gap: 22px;
    margin-bottom: 36px;
}

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

.contact-icon {
    width: 46px;
    height: 46px;
    border-radius: 11px;
    background: rgba(77, 166, 255, 0.08);
    border: 1px solid rgba(77, 166, 255, 0.18);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-blue);
    font-size: 1rem;
    flex-shrink: 0;
    margin-top: 2px;
    transition: var(--transition);
}

.contact-item:hover .contact-icon {
    background: rgba(77, 166, 255, 0.15);
    border-color: rgba(77, 166, 255, 0.4);
}

.contact-item strong {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 5px;
    text-transform: uppercase;
    letter-spacing: 1.2px;
}

.contact-item p {
    font-size: 0.98rem;
    color: var(--text-primary);
    line-height: 1.5;
}

.contact-item a {
    color: var(--accent-blue);
    transition: color 0.2s;
}

.contact-item a:hover { color: var(--accent-gold); }

.contact-buttons {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

/* Map & QR */
.contact-map-qr {
    display: flex;
    flex-direction: column;
    gap: 28px;
}

.map-wrap,
.qr-wrap {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 22px;
    transition: var(--transition);
}

.map-wrap:hover,
.qr-wrap:hover {
    border-color: var(--border-hover);
}

.map-wrap h3,
.qr-wrap h3 {
    font-size: 0.93rem;
    font-weight: 700;
    margin-bottom: 15px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 8px;
    border: none;
    padding: 0;
}

.map-img {
    width: 100%;
    border-radius: 9px;
    margin-bottom: 12px;
    border: 1px solid rgba(255, 255, 255, 0.06);
}

.qr-img {
    width: 168px;
    height: 168px;
    object-fit: contain;
    border-radius: 10px;
    background: #fff;
    padding: 10px;
    display: block;
    margin: 0 auto 13px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

.map-caption,
.qr-caption {
    text-align: center;
    font-size: 0.82rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

/* =============================================
   FOOTER
   ============================================= */
footer {
    background: rgba(0, 0, 0, 0.45);
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    padding: 64px 0 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr 1.5fr;
    gap: 44px;
    margin-bottom: 44px;
}

.footer-logo {
    font-size: 1.35rem;
    font-weight: 800;
    color: var(--accent-gold);
    display: block;
    margin-bottom: 14px;
}

.footer-brand p {
    font-size: 0.84rem;
    color: var(--text-muted);
    line-height: 1.9;
}

.footer-links h4,
.footer-products h4,
.footer-keywords h4 {
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text-secondary);
    margin-bottom: 18px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 9px;
}

.footer-links a {
    font-size: 0.86rem;
    color: var(--text-muted);
    transition: color 0.2s;
}

.footer-links a:hover { color: var(--accent-blue); }

.footer-products,
.footer-keywords {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.footer-products span,
.footer-keywords span {
    font-size: 0.82rem;
    color: var(--text-muted);
    padding: 4px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.04);
    transition: color 0.2s;
    cursor: default;
}

.footer-products span:hover,
.footer-keywords span:hover {
    color: var(--accent-blue);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    padding: 22px 0 24px;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.8rem;
    color: var(--text-muted);
    line-height: 2;
}

/* =============================================
   BACK TO TOP
   ============================================= */
#backToTop {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    background: var(--accent-blue-dark);
    color: #fff;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.95rem;
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.35s, transform 0.35s, background 0.2s;
    z-index: 999;
    box-shadow: 0 4px 18px rgba(26, 110, 197, 0.45);
}

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

#backToTop:hover {
    background: var(--accent-blue-mid);
    transform: translateY(-3px);
}

/* =============================================
   ANIMATIONS
   ============================================= */
@keyframes spin-slow {
    from { transform: rotate(0deg); }
    to   { transform: rotate(360deg); }
}

@keyframes bounce-y {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50%       { transform: translateX(-50%) translateY(-9px); }
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(32px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes float-particle {
    0%   { opacity: 0; transform: translate(0, 0) scale(0); }
    20%  { opacity: 0.65; }
    80%  { opacity: 0.25; }
    100% { opacity: 0; transform: translate(var(--tx, 60px), var(--ty, -120px)) scale(0.4); }
}

/* Hero fade-in classes */
.fade-in-up {
    opacity: 0;
    animation: fadeInUp 0.85s ease forwards;
}

.delay-1 { animation-delay: 0.25s; }
.delay-2 { animation-delay: 0.45s; }
.delay-3 { animation-delay: 0.65s; }
.delay-4 { animation-delay: 0.85s; }
.delay-5 { animation-delay: 1.05s; }

/* Scroll reveal */
.reveal {
    opacity: 0;
    transform: translateY(44px);
    transition: opacity 0.75s ease, transform 0.75s ease;
}

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

/* Stagger delays for grids */
.products-grid .reveal:nth-child(3n+2) { transition-delay: 0.12s; }
.products-grid .reveal:nth-child(3n)   { transition-delay: 0.24s; }
.services-grid .reveal:nth-child(3n+2) { transition-delay: 0.12s; }
.services-grid .reveal:nth-child(3n)   { transition-delay: 0.24s; }
.equipment-grid .reveal:nth-child(2)   { transition-delay: 0.14s; }
.equipment-grid .reveal:nth-child(3)   { transition-delay: 0.28s; }

/* Particles */
.particle {
    position: absolute;
    border-radius: 50%;
    opacity: 0;
    animation: float-particle var(--duration, 7s) var(--delay, 0s) infinite ease-in-out;
}

/* =============================================
   RESPONSIVE
   ============================================= */
@media (max-width: 1100px) {
    .equipment-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-content { grid-template-columns: 1fr 1fr; gap: 32px; }
}

@media (max-width: 900px) {
    .products-grid { grid-template-columns: repeat(2, 1fr); }
    .services-grid { grid-template-columns: repeat(2, 1fr); }
    .about-content { grid-template-columns: 1fr; gap: 44px; }
    .contact-content { grid-template-columns: 1fr; gap: 44px; }
    .equipment-highlights { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: var(--navbar-height);
        left: 0;
        right: 0;
        background: rgba(6, 15, 30, 0.98);
        backdrop-filter: blur(16px);
        flex-direction: column;
        padding: 16px 20px 24px;
        gap: 2px;
        transform: translateY(calc(-100% - var(--navbar-height)));
        transition: transform 0.35s ease;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-links.open { transform: translateY(0); }
    .nav-links li { width: 100%; }
    .nav-links a { padding: 13px 16px; }
    .nav-toggle { display: flex; }
    .nav-phone span { display: none; }
    .nav-phone { padding: 7px 12px; }

    #navbar { background: rgba(6, 15, 30, 0.95); backdrop-filter: blur(16px); }
    #hero { align-items: flex-start; }
    .hero-content { padding: calc(var(--navbar-height) + 28px) 20px 60px; width: 100%; max-width: 100%; }
    .hero-desc { font-size: 0.97rem; margin-bottom: 36px; line-height: 1.95; }
    .hero-stats { border-radius: var(--radius); }
    .stat-item { padding: 12px 20px; }
    .stat-divider { height: 32px; }
    .stat-num { font-size: 1.6rem; }

    .section { padding: 64px 0; }
    .section-header { margin-bottom: 40px; }
    .services-banner { padding: 20px 20px; gap: 16px; flex-wrap: wrap; justify-content: center; }
    .banner-divider { display: none; }
    .banner-item { min-width: 120px; }

    .equipment-grid { grid-template-columns: 1fr; }
    .footer-content { grid-template-columns: 1fr; gap: 28px; }

    .contact-map-qr { flex-direction: row; flex-wrap: wrap; gap: 16px; }
    .contact-map-qr > * { flex: 1 1 280px; }
}

@media (max-width: 520px) {
    .container { padding: 0 16px; }

    .hero-content { padding: calc(var(--navbar-height) + 20px) 16px 48px; }
    #hero h1 { font-size: 2rem; line-height: 1.2; }
    .hero-subtitle-top { letter-spacing: 2px; font-size: 0.82rem; }
    .hero-desc { font-size: 0.9rem; margin-bottom: 28px; }

    /* stats 折成 2×2 */
    .hero-stats { flex-wrap: wrap; }
    .stat-item { width: 50%; padding: 12px 8px; }
    .stat-divider { display: none; }
    .stat-num { font-size: 1.45rem; }

    .hero-buttons { flex-direction: column; align-items: stretch; }
    .hero-buttons .btn { text-align: center; }

    .section { padding: 48px 0; }
    .section-header { margin-bottom: 32px; }

    .products-grid { grid-template-columns: repeat(2, 1fr); gap: 14px; }
    .product-img-wrap { height: 180px; }
    .services-grid { grid-template-columns: 1fr; }
    .about-stats { grid-template-columns: 1fr 1fr; }

    .equipment-highlights { grid-template-columns: 1fr 1fr; }

    .contact-buttons { flex-direction: column; }
    .contact-buttons .btn { text-align: center; }

    .footer-bottom { flex-direction: column; gap: 10px; text-align: center; }
}

@media (max-width: 380px) {
    #hero h1 { font-size: 1.75rem; }
    .products-grid { grid-template-columns: 1fr; }
    .stat-item { padding: 10px 6px; }
    .stat-num { font-size: 1.3rem; }
}