/* ========================================
   Beijing Baite CPA - Main Stylesheet
   ======================================== */

/* --- CSS Variables --- */
:root {
    /* Colors - Midnight Executive palette */
    --color-primary: #1E2761;
    --color-primary-light: #2a3580;
    --color-primary-dark: #141c47;
    --color-secondary: #CADCFC;
    --color-secondary-dark: #a8c4f0;
    --color-accent: #3B82F6;
    --color-accent-hover: #2563EB;
    --color-white: #FFFFFF;
    --color-bg: #FAFBFD;
    --color-bg-alt: #F0F4F8;
    --color-bg-dark: #0F172A;
    --color-text: #1E293B;
    --color-text-light: #64748B;
    --color-text-muted: #94A3B8;
    --color-border: #E2E8F0;
    --color-border-light: #F1F5F9;

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-cn: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;

    /* Spacing */
    --section-padding: 100px 0;
    --container-max: 1200px;
    --container-padding: 0 24px;

    /* Transitions */
    --transition: all 0.3s ease;
    --transition-slow: all 0.5s ease;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.08);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.12);
    --shadow-xl: 0 20px 60px rgba(0,0,0,0.15);
}

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

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

body {
    font-family: var(--font-primary);
    color: var(--color-text);
    background: var(--color-white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

body[data-lang="zh"] {
    font-family: var(--font-cn), var(--font-primary);
}

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--container-padding);
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

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

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: 8px;
    font-family: inherit;
    font-size: 15px;
    font-weight: 600;
    letter-spacing: 0.01em;
    transition: var(--transition);
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    background: var(--color-primary-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background: transparent;
    color: var(--color-white);
    border: 2px solid rgba(255,255,255,0.4);
}

.btn-outline:hover {
    background: var(--color-white);
    color: var(--color-primary);
    border-color: var(--color-white);
}

.btn-lg {
    padding: 18px 42px;
    font-size: 16px;
}

/* --- Navigation --- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 20px 0;
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(20px);
    padding: 12px 0;
    box-shadow: var(--shadow-sm);
}

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

.nav-logo {
    z-index: 1001;
}

.logo-text {
    font-size: 24px;
    font-weight: 800;
    color: var(--color-white);
    letter-spacing: -0.02em;
    transition: var(--transition);
}

.logo-accent {
    color: var(--color-secondary);
}

.navbar.scrolled .logo-text {
    color: var(--color-primary);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 36px;
}

.nav-menu a {
    font-size: 14px;
    font-weight: 500;
    color: rgba(255,255,255,0.85);
    letter-spacing: 0.02em;
    position: relative;
    padding: 4px 0;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-secondary);
    transition: var(--transition);
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

.navbar.scrolled .nav-menu a {
    color: var(--color-text);
}

.navbar.scrolled .nav-menu a:hover {
    color: var(--color-primary);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    z-index: 1001;
}

.lang-toggle {
    padding: 8px 18px;
    border-radius: 6px;
    border: 1.5px solid rgba(255,255,255,0.35);
    background: transparent;
    color: var(--color-white);
    font-family: inherit;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    letter-spacing: 0.02em;
}

.lang-toggle:hover {
    background: rgba(255,255,255,0.1);
    border-color: rgba(255,255,255,0.6);
}

.navbar.scrolled .lang-toggle {
    border-color: var(--color-border);
    color: var(--color-primary);
}

.navbar.scrolled .lang-toggle:hover {
    background: var(--color-primary);
    color: var(--color-white);
    border-color: var(--color-primary);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    z-index: 1001;
}

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

.navbar.scrolled .nav-toggle span {
    background: var(--color-primary);
}

/* --- Hero Section --- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 50%, #253078 100%);
    overflow: hidden;
    padding-top: 80px;
}

.hero-bg {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.hero-shape {
    position: absolute;
    border-radius: 50%;
    opacity: 0.08;
}

.shape-1 {
    width: 600px;
    height: 600px;
    background: var(--color-secondary);
    top: -200px;
    right: -100px;
    animation: float 20s ease-in-out infinite;
}

.shape-2 {
    width: 400px;
    height: 400px;
    background: var(--color-accent);
    bottom: -150px;
    left: -100px;
    animation: float 15s ease-in-out infinite reverse;
}

.shape-3 {
    width: 200px;
    height: 200px;
    background: var(--color-white);
    top: 40%;
    left: 60%;
    animation: float 12s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -30px) scale(1.05); }
    66% { transform: translate(-20px, 20px) scale(0.95); }
}

.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-tag {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.15em;
    color: var(--color-secondary);
    margin-bottom: 24px;
    display: inline-block;
    padding: 6px 16px;
    border: 1px solid rgba(202, 220, 252, 0.3);
    border-radius: 4px;
}

.hero-title {
    font-size: 56px;
    font-weight: 800;
    line-height: 1.15;
    color: var(--color-white);
    letter-spacing: -0.03em;
    margin-bottom: 24px;
}

.hero-highlight {
    background: linear-gradient(135deg, var(--color-secondary) 0%, #ffffff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 17px;
    line-height: 1.7;
    color: rgba(255,255,255,0.75);
    max-width: 520px;
    margin-bottom: 36px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    margin-bottom: 60px;
}

.hero-stats {
    display: flex;
    align-items: center;
    gap: 32px;
}

.stat-number {
    font-size: 36px;
    font-weight: 800;
    color: var(--color-white);
    letter-spacing: -0.02em;
}

.stat-label {
    font-size: 13px;
    color: rgba(255,255,255,0.6);
    letter-spacing: 0.02em;
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-divider {
    width: 1px;
    height: 48px;
    background: rgba(255,255,255,0.15);
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-card {
    width: 360px;
    height: 360px;
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(10px);
    animation: float 8s ease-in-out infinite;
}

.hero-card-inner {
    text-align: center;
}

.hero-icon {
    width: 120px;
    height: 120px;
    color: var(--color-secondary);
    margin-bottom: 24px;
}

.hero-card-text {
    display: flex;
    flex-direction: column;
    gap: 8px;
    color: var(--color-white);
}

.hero-card-text span:first-child {
    font-size: 18px;
    font-weight: 600;
}

.hero-card-text span:last-child {
    font-size: 14px;
    color: rgba(255,255,255,0.6);
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
}

.scroll-line {
    width: 1px;
    height: 60px;
    background: linear-gradient(to bottom, rgba(255,255,255,0.4), transparent);
    animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
    0%, 100% { opacity: 1; transform: scaleY(1); }
    50% { opacity: 0.3; transform: scaleY(0.6); }
}

/* --- Section Common --- */
.section {
    padding: var(--section-padding);
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-tag {
    display: inline-block;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.15em;
    color: var(--color-accent);
    text-transform: uppercase;
    margin-bottom: 16px;
}

.section-title {
    font-size: 40px;
    font-weight: 800;
    color: var(--color-text);
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.section-desc {
    font-size: 17px;
    color: var(--color-text-light);
    max-width: 600px;
    margin: 16px auto 0;
    line-height: 1.7;
}

/* --- About Section --- */
.about {
    background: var(--color-bg);
}

.about-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 60px;
    align-items: start;
}

.about-content p {
    font-size: 16px;
    line-height: 1.8;
    color: var(--color-text-light);
    margin-bottom: 16px;
}

.about-lead {
    font-size: 18px !important;
    color: var(--color-text) !important;
    font-weight: 500;
    line-height: 1.7 !important;
}

.about-credentials {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.credential-card {
    padding: 28px;
    background: var(--color-white);
    border-radius: 16px;
    border: 1px solid var(--color-border-light);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.credential-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.credential-icon {
    width: 48px;
    height: 48px;
    color: var(--color-primary);
    margin-bottom: 16px;
}

.credential-card h4 {
    font-size: 16px;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 6px;
}

.credential-card p {
    font-size: 14px;
    color: var(--color-text-light);
}

/* --- Advantages Section --- */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.advantage-card {
    padding: 36px 28px;
    background: var(--color-bg);
    border-radius: 16px;
    border: 1px solid var(--color-border-light);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.advantage-card:hover {
    background: var(--color-primary);
    border-color: var(--color-primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.advantage-card:hover h3,
.advantage-card:hover p {
    color: var(--color-white);
}

.advantage-card:hover .advantage-number {
    color: rgba(255,255,255,0.15);
}

.advantage-number {
    font-size: 60px;
    font-weight: 900;
    color: var(--color-border);
    line-height: 1;
    margin-bottom: 20px;
    letter-spacing: -0.04em;
    transition: var(--transition);
}

.advantage-card h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 12px;
    transition: var(--transition);
}

.advantage-card p {
    font-size: 14px;
    line-height: 1.7;
    color: var(--color-text-light);
    transition: var(--transition);
}

/* --- Industries Section --- */
.industries {
    background: var(--color-bg);
}

.industries-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 20px;
}

.industry-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding: 32px 16px;
    background: var(--color-white);
    border-radius: 12px;
    border: 1px solid var(--color-border-light);
    transition: var(--transition);
    font-size: 15px;
    font-weight: 500;
    color: var(--color-text);
}

.industry-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-secondary-dark);
}

.industry-icon {
    font-size: 32px;
}

/* --- Services Section --- */
.services-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.service-card {
    padding: 36px;
    background: var(--color-bg);
    border-radius: 16px;
    border: 1px solid var(--color-border-light);
    transition: var(--transition);
}

.service-card:hover {
    background: var(--color-white);
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
    border-color: var(--color-secondary-dark);
}

.service-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 16px;
}

.service-icon {
    width: 48px;
    height: 48px;
    color: var(--color-primary);
    flex-shrink: 0;
}

.service-header h3 {
    font-size: 19px;
    font-weight: 700;
    color: var(--color-text);
}

.service-card > p {
    font-size: 15px;
    line-height: 1.7;
    color: var(--color-text-light);
    margin-bottom: 20px;
}

.service-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.service-list li {
    font-size: 14px;
    color: var(--color-text);
    padding-left: 20px;
    position: relative;
    line-height: 1.5;
}

.service-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--color-accent);
}

/* --- Team Section --- */
.team {
    background: var(--color-bg);
}

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

.team-card {
    background: var(--color-white);
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid var(--color-border-light);
    transition: var(--transition);
}

.team-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.team-avatar {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    padding: 40px;
    display: flex;
    justify-content: center;
}

.avatar-placeholder {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: rgba(255,255,255,0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 700;
    color: var(--color-white);
    letter-spacing: 0.05em;
}

.team-photo {
    width: 120px;
    height: 150px;
    object-fit: cover;
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.2);
}

.team-info {
    padding: 28px;
}

.team-info h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 4px;
}

.team-name-en {
    font-size: 14px;
    font-weight: 400;
    color: var(--color-text-light);
}

.team-title {
    display: inline-block;
    font-size: 13px;
    font-weight: 600;
    color: var(--color-accent);
    background: rgba(59, 130, 246, 0.08);
    padding: 4px 12px;
    border-radius: 4px;
    margin-bottom: 12px;
}

.team-credentials {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 16px;
}

.team-credentials span {
    font-size: 11px;
    font-weight: 500;
    color: var(--color-text-light);
    background: var(--color-bg);
    padding: 3px 10px;
    border-radius: 4px;
}

.team-experience p {
    font-size: 13px;
    line-height: 1.6;
    color: var(--color-text-light);
    margin-bottom: 8px;
    padding-left: 14px;
    border-left: 2px solid var(--color-border);
}

/* --- CTA Section --- */
.cta {
    background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 100%);
    text-align: center;
}

.cta-content h2 {
    font-size: 36px;
    font-weight: 800;
    color: var(--color-white);
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.cta-content p {
    font-size: 17px;
    color: rgba(255,255,255,0.7);
    max-width: 560px;
    margin: 0 auto 32px;
    line-height: 1.7;
}

/* --- Contact Section --- */
.contact {
    background: var(--color-bg);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: center;
}

.contact-item {
    display: flex;
    gap: 20px;
    margin-bottom: 32px;
}

.contact-icon {
    width: 48px;
    height: 48px;
    color: var(--color-primary);
    flex-shrink: 0;
}

.contact-item h4 {
    font-size: 15px;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 4px;
}

.contact-item p {
    font-size: 15px;
    color: var(--color-text-light);
}

.map-placeholder {
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.map-placeholder svg {
    width: 100%;
    height: auto;
}

/* --- Footer --- */
.footer {
    background: var(--color-bg-dark);
    padding: 60px 0 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: 60px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}

.footer-brand .logo-text {
    font-size: 28px;
    margin-bottom: 12px;
    display: inline-block;
}

.footer-brand p {
    font-size: 15px;
    color: rgba(255,255,255,0.5);
    max-width: 300px;
    line-height: 1.6;
}

.footer-links {
    display: flex;
    gap: 60px;
}

.footer-col h4 {
    font-size: 14px;
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: 20px;
    letter-spacing: 0.02em;
}

.footer-col a {
    display: block;
    font-size: 14px;
    color: rgba(255,255,255,0.5);
    margin-bottom: 12px;
}

.footer-col a:hover {
    color: var(--color-secondary);
}

.footer-bottom {
    padding: 20px 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 13px;
    color: rgba(255,255,255,0.35);
}

/* --- Animations --- */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}