/* ==========================================================================
   咸鱼云 (xianyucloud.my) - Design System & Stylesheet (v2.1 Cache-Busted)
   ========================================================================== */

:root {
    /* Color Palette */
    --color-bg: #f8fafc;
    --color-surface: #ffffff;
    --color-surface-hover: #f1f5f9;
    --color-text: #0f172a;
    --color-text-muted: #475569;
    --color-text-light: #64748b;
    
    /* Primary / Accent Hue: 215 (Tech Blue) */
    --color-accent: #2563eb;
    --color-accent-hover: #1d4ed8;
    --color-accent-light: #eff6ff;
    --color-accent-border: #bfdbfe;
    
    --color-success: #10b981;
    --color-danger: #ef4444;
    --color-warning: #f59e0b;
    
    /* Border & Radii */
    --border-color: #e2e8f0;
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 9999px;
    
    /* Shadows */
    --elevation-1: 0 1px 3px rgba(15, 23, 42, 0.05), 0 1px 2px rgba(15, 23, 42, 0.1);
    --elevation-2: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -1px rgba(15, 23, 42, 0.04);
    --elevation-3: 0 20px 25px -5px rgba(15, 23, 42, 0.1), 0 10px 10px -5px rgba(15, 23, 42, 0.04);
    
    /* Fonts */
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

html {
    scroll-behavior: smooth;
    font-family: var(--font-family);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
}

body {
    overflow-x: hidden;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Responsive Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Typography Defaults */
h1, h2, h3, h4 {
    color: var(--color-text);
    font-weight: 700;
    line-height: 1.25;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--color-accent-hover);
}

/* Header & Nav */
.header {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--color-text);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-badge {
    background: var(--color-accent);
    color: white;
    font-size: 0.8rem;
    padding: 2px 8px;
    border-radius: var(--radius-full);
}

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

.nav-links a {
    color: var(--color-text-muted);
    font-weight: 500;
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--color-text);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.65rem 1.4rem;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: transform 0.28s cubic-bezier(0.34, 1.56, 0.64, 1), background-color 0.2s, border-color 0.2s, box-shadow 0.2s;
    cursor: pointer;
    border: 1px solid transparent;
    text-align: center;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn:active {
    transform: translateY(0);
}

.btn-primary {
    background-color: var(--color-accent);
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
    background-color: var(--color-accent-hover);
    color: #ffffff;
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.45);
}

.btn-outline {
    background-color: transparent;
    color: var(--color-text);
    border-color: var(--border-color);
}

.btn-outline:hover {
    background-color: var(--color-surface-hover);
    border-color: var(--color-text-muted);
}

.btn-large {
    padding: 0.85rem 1.8rem;
    font-size: 1.05rem;
}

.btn-block {
    width: 100%;
}

/* Hero Section */
.hero {
    padding: 4.5rem 0 3.5rem;
    background: linear-gradient(180deg, #ffffff 0%, var(--color-bg) 100%);
    position: relative;
    overflow: hidden;
}

.hero-container {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 3rem;
    align-items: center;
}

.hero-title {
    font-size: 2.75rem;
    line-height: 1.2;
    margin-bottom: 1.2rem;
    color: var(--color-text);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--color-text-muted);
    margin-bottom: 1.8rem;
    line-height: 1.6;
}

/* Hero Trust Pills (Section 6.1 C1) */
.hero-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.trust-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: var(--color-surface);
    border: 1px solid var(--border-color);
    padding: 0.4rem 0.85rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    color: var(--color-text);
    font-weight: 500;
    box-shadow: var(--elevation-1);
}

.btn-group {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.hero-trust-microcopy {
    font-size: 0.875rem;
    color: var(--color-text-light);
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.hero-visual {
    position: relative;
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.floating-card {
    background: var(--color-surface);
    padding: 1.25rem 1.5rem;
    border-radius: var(--radius-md);
    box-shadow: var(--elevation-2);
    border: 1px solid var(--border-color);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.8rem;
    transition: transform 0.3s ease;
}

.floating-card:hover {
    transform: translateY(-4px);
}

/* Promo Banner (Section 6.3 C3) */
.promo-banner {
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border: 1px solid var(--color-accent-border);
    border-radius: var(--radius-md);
    padding: 1rem 1.5rem;
    margin-bottom: 2.5rem;
    text-align: center;
    font-size: 1.05rem;
    color: #1e40af;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.promo-code-tag {
    background: var(--color-accent);
    color: white;
    padding: 0.2rem 0.6rem;
    border-radius: var(--radius-sm);
    font-family: monospace;
    font-size: 1.1rem;
    letter-spacing: 1px;
}

/* Sections & Cards */
.bg-light { background-color: var(--color-bg); }
.bg-white { background-color: var(--color-surface); }

section {
    padding: 4.5rem 0;
}

.section-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 3rem;
    color: var(--color-text);
}

.grid {
    display: grid;
    gap: 1.75rem;
}

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

.card {
    background: var(--color-surface);
    padding: 2rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    box-shadow: var(--elevation-1);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--elevation-2);
}

.card .icon {
    font-size: 2.2rem;
    margin-bottom: 1rem;
}

.card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.card p {
    color: var(--color-text-muted);
    font-size: 0.95rem;
}

/* Pricing Section */
.pricing-card {
    position: relative;
    display: flex;
    flex-direction: column;
}

.pricing-card.popular {
    border: 2px solid var(--color-accent);
    box-shadow: var(--elevation-3);
}

.pricing-card .badge {
    position: absolute;
    top: -14px;
    right: 1.5rem;
    background: var(--color-accent);
    color: white;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: var(--radius-full);
    text-transform: uppercase;
}

.price {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--color-text);
    margin: 1rem 0;
}

.price span {
    font-size: 1rem;
    color: var(--color-text-muted);
    font-weight: 400;
}

.features-list {
    list-style: none;
    margin-bottom: 2rem;
    flex-grow: 1;
}

.features-list li {
    padding: 0.5rem 0;
    border-bottom: 1px dashed var(--border-color);
    font-size: 0.925rem;
    color: var(--color-text-muted);
}

.features-list li::before {
    content: "✓ ";
    color: var(--color-success);
    font-weight: bold;
}

.pricing-guarantee {
    text-align: center;
    font-size: 0.8rem;
    color: var(--color-text-light);
    margin-top: 0.6rem;
}

/* Page Header & Page Content */
.page-header {
    background: var(--color-surface);
    padding: 3rem 0 2rem;
    border-bottom: 1px solid var(--border-color);
}

.page-content {
    padding: 3rem 1.5rem 4rem;
    max-width: 900px;
    margin: 0 auto;
}

.page-content h2 {
    margin: 2rem 0 1rem;
    font-size: 1.5rem;
}

.page-content p {
    margin-bottom: 1.2rem;
    color: var(--color-text-muted);
}

.page-content ul {
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
}

.page-content li {
    margin-bottom: 0.5rem;
    color: var(--color-text-muted);
}

/* FAQ */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.faq-item {
    background: var(--color-surface);
    padding: 1.5rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.faq-item h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.faq-item p {
    color: var(--color-text-muted);
    font-size: 0.95rem;
}

/* Footer */
.footer {
    background: var(--color-text);
    color: #94a3b8;
    padding: 3.5rem 0 2.5rem;
    margin-top: auto;
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 1.5rem;
}

.footer-links a {
    color: #cbd5e1;
}

.footer-links a:hover {
    color: #ffffff;
}

.copyright {
    text-align: center;
}

.friend-links {
    text-align: center;
    margin-top: 1rem;
    font-size: 0.85rem;
}

.friend-links a {
    color: #64748b;
}

.friend-links a:hover {
    color: #94a3b8;
}

/* C4 Sticky Mobile CTA Bar (Section 6.4) */
.mobile-sticky-bar {
    display: none;
}

@media (max-width: 768px) {
    body {
        padding-bottom: 72px; /* Prevent footer clipping */
    }
    
    .mobile-sticky-bar {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        height: 64px;
        background: rgba(255, 255, 255, 0.92);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        border-top: 1px solid var(--border-color);
        z-index: 99;
        padding: 8px 16px;
        padding-bottom: calc(8px + env(safe-area-inset-bottom));
        gap: 12px;
        box-shadow: 0 -4px 12px rgba(0, 0, 0, 0.08);
    }
    
    .mobile-sticky-bar .btn {
        flex: 1;
        padding: 0 10px;
        font-size: 0.9rem;
        height: 100%;
    }
}

/* C5 Exit-Intent Popup Modal (Section 6.5 - Bulletproof Hidden by Default) */
.modal-overlay {
    display: none !important;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.25s ease;
}

.modal-overlay.active {
    display: flex !important;
    opacity: 1;
}

.modal-box {
    background: var(--color-surface);
    width: 90%;
    max-width: 480px;
    padding: 2.2rem 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--elevation-3);
    position: relative;
    text-align: center;
    transform: scale(0.95);
    transition: transform 0.28s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal-overlay.active .modal-box {
    transform: scale(1);
}

.modal-close {
    position: absolute;
    top: 1rem;
    right: 1.25rem;
    background: none;
    border: none;
    font-size: 1.75rem;
    color: var(--color-text-light);
    cursor: pointer;
    line-height: 1;
    z-index: 10;
    padding: 4px 8px;
}

.modal-close:hover {
    color: var(--color-text);
}

.modal-title {
    font-size: 1.4rem;
    margin-bottom: 0.5rem;
    color: var(--color-text);
}

.modal-desc {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
}

.coupon-box {
    background: var(--color-bg);
    border: 2px dashed var(--color-accent-border);
    padding: 1rem;
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.coupon-code {
    font-family: monospace;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--color-accent);
}

.copy-btn {
    background: var(--color-accent-light);
    color: var(--color-accent);
    border: 1px solid var(--color-accent-border);
    padding: 0.4rem 0.8rem;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.copy-btn:hover {
    background: var(--color-accent);
    color: white;
}

.copy-btn.copied {
    background: var(--color-success);
    color: white;
    border-color: var(--color-success);
}

.modal-trust-line {
    font-size: 0.8rem;
    color: var(--color-text-light);
    margin-top: 0.8rem;
}

/* Backward compatibility for old notice-modal if any cached DOM exists */
#notice-modal {
    display: none !important;
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* Responsive Media Queries */
@media (max-width: 992px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-pills, .btn-group, .hero-trust-microcopy {
        justify-content: center;
    }
    
    .grid-3 { grid-template-columns: 1fr; }
    .grid-2 { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--color-surface);
        flex-direction: column;
        padding: 1.5rem;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--elevation-2);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .mobile-toggle {
        display: block;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .nav-actions {
        display: none; /* Handled by Sticky Mobile CTA Bar */
    }
}