/* ============================================
   agentstash.me - DESIGN.md Implementation
   ============================================ */

/* CSS Custom Properties (Design Tokens) */
:root {
    /* Colors - Neutrals */
    --color-background: #F8FAFB;
    --color-surface: #FFFFFF;
    --color-surface-hover: #F1F5F6;
    --color-text-primary: #1A2332;
    --color-text-secondary: #5A6B7D;
    --color-text-tertiary: #8B9DB0;
    --color-border: #E2E8F0;
    --color-border-strong: #CBD5E1;

    /* Colors - Brand Accents */
    --color-primary: #2563EB;
    --color-primary-hover: #1D4ED8;
    --color-primary-light: #DBEAFE;
    --color-secondary: #059669;
    --color-secondary-light: #D1FAE5;
    --color-warning: #F59E0B;
    --color-error: #DC2626;

    /* Typography */
    --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-mono: "JetBrains Mono", "Fira Code", Consolas, monospace;

    /* Type Scale - Major Third (1.25) */
    --text-display: 3.052rem;
    --text-h1: 2.441rem;
    --text-h2: 1.953rem;
    --text-h3: 1.563rem;
    --text-h4: 1.25rem;
    --text-body-lg: 1.125rem;
    --text-body: 1rem;
    --text-body-sm: 0.875rem;
    --text-caption: 0.75rem;
    --text-code: 0.875rem;

    /* Spacing Scale */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.025);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.05), 0 10px 10px -5px rgba(0, 0, 0, 0.02);

    /* Layout */
    --container-max: 1200px;
    --content-max: 800px;
    --nav-height: 72px;

    /* Transitions */
    --transition-fast: 150ms;
    --transition-normal: 200ms;
    --transition-slow: 300ms;
    --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
}

/* ============================================
   Base Styles
   ============================================ */

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

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

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

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

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

ul, ol {
    list-style: none;
}

/* ============================================
   Layout Utilities
   ============================================ */

.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.section-header {
    text-align: center;
    max-width: var(--content-max);
    margin: 0 auto var(--space-12);
}

.section-title {
    font-size: var(--text-h2);
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--space-4);
}

.section-subtitle {
    font-size: var(--text-body-lg);
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.section-cta {
    text-align: center;
    margin-top: var(--space-12);
}

/* ============================================
   Typography
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--color-text-primary);
}

p {
    line-height: 1.6;
    color: var(--color-text-secondary);
}

/* ============================================
   Navigation
   ============================================ */

.nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    height: var(--nav-height);
    display: flex;
    align-items: center;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-weight: 600;
    font-size: var(--text-h4);
    color: var(--color-text-primary);
}

.logo-mark {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--color-primary);
    color: white;
    border-radius: 8px;
    font-weight: 700;
    font-size: var(--text-body-lg);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.nav-link {
    padding: var(--space-2) var(--space-3);
    border-radius: 6px;
    font-size: var(--text-body-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: all var(--transition-normal) var(--ease-out-quart);
}

.nav-link:hover {
    color: var(--color-primary);
    background: var(--color-primary-light);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-2);
}

.hamburger {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text-primary);
    position: relative;
    transition: background var(--transition-normal);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 24px;
    height: 2px;
    background: var(--color-text-primary);
    transition: transform var(--transition-normal) var(--ease-out-quart);
}

.hamburger::before {
    top: -7px;
}

.hamburger::after {
    bottom: -7px;
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-3) var(--space-6);
    border-radius: 8px;
    font-weight: 500;
    font-size: var(--text-body-sm);
    cursor: pointer;
    border: none;
    transition: all var(--transition-normal) var(--ease-out-quart);
    white-space: nowrap;
}

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

.btn-primary:hover {
    background: var(--color-primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: transparent;
    color: var(--color-primary);
    border: 1px solid var(--color-border-strong);
}

.btn-secondary:hover {
    background: var(--color-primary-light);
    border-color: var(--color-primary);
}

.btn-sm {
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-caption);
}

/* ============================================
   Hero Section
   ============================================ */

.hero {
    padding: var(--space-16) 0;
    overflow: hidden;
}

.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-12);
    align-items: center;
}

.hero-content {
    max-width: 560px;
}

.hero-title {
    font-size: var(--text-h1);
    font-weight: 700;
    line-height: 1.15;
    margin-bottom: var(--space-6);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: var(--text-body-lg);
    line-height: 1.7;
    margin-bottom: var(--space-8);
    color: var(--color-text-secondary);
}

.hero-actions {
    display: flex;
    gap: var(--space-4);
    margin-bottom: var(--space-10);
}

.hero-stats {
    display: flex;
    gap: var(--space-8);
    padding-top: var(--space-6);
    border-top: 1px solid var(--color-border);
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: var(--text-h3);
    font-weight: 700;
    color: var(--color-primary);
}

.stat-label {
    font-size: var(--text-body-sm);
    color: var(--color-text-tertiary);
    margin-top: var(--space-1);
}

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

.hero-creed-panel {
    width: 100%;
    min-height: 320px;
    border-radius: 20px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: var(--space-10) var(--space-8);
    position: relative;
    overflow: hidden;
}

.hero-creed-panel::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--color-primary) 0%, #3B82F6 100%);
}

.creed-mark {
    font-size: 4rem;
    line-height: 1;
    color: var(--color-primary);
    opacity: 0.25;
    font-family: Georgia, 'Times New Roman', serif;
    margin-bottom: var(--space-4);
}

.hero-creed-text {
    color: var(--color-text-primary);
    font-size: 1.35rem;
    font-weight: 500;
    line-height: 1.6;
    text-align: center;
    letter-spacing: -0.01em;
    position: relative;
    z-index: 1;
}

.creed-attr {
    margin-top: var(--space-6);
    font-size: var(--text-body-sm);
    color: var(--color-text-tertiary);
    letter-spacing: 0.05em;
    font-weight: 500;
}


/* ============================================
   Values Section
   ============================================ */

.values {
    padding: var(--space-16) 0;
    background: var(--color-surface);
}

.values-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-8);
}

.value-card {
    background: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: 16px;
    padding: var(--space-8);
    transition: all var(--transition-normal) var(--ease-out-quart);
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

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

.value-icon {
    width: 56px;
    height: 56px;
    background: var(--color-primary-light);
    color: var(--color-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.value-title {
    font-size: var(--text-h4);
    font-weight: 600;
}

.value-description {
    font-size: var(--text-body-sm);
    line-height: 1.6;
    flex-grow: 1;
}

.value-link {
    font-size: var(--text-body-sm);
    font-weight: 500;
    color: var(--color-primary);
    transition: gap var(--transition-normal) var(--ease-out-quart);
}

.value-card:hover .value-link {
    gap: var(--space-2);
}

/* ============================================
   Projects Section
   ============================================ */

.projects {
    padding: var(--space-16) 0;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-8);
}

.project-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 16px;
    overflow: hidden;
    transition: all var(--transition-normal) var(--ease-out-quart);
}

.project-card:hover {
    border-color: var(--color-border-strong);
    box-shadow: var(--shadow-md);
}

.project-image {
    height: 200px;
    background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-surface) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-placeholder {
    color: var(--color-primary);
    opacity: 0.5;
}

.project-content {
    padding: var(--space-6);
}

.project-tags {
    display: flex;
    gap: var(--space-2);
    margin-bottom: var(--space-3);
}

.tag {
    display: inline-flex;
    align-items: center;
    padding: var(--space-1) var(--space-3);
    border-radius: 9999px;
    font-size: var(--text-caption);
    font-weight: 500;
    background: var(--color-primary-light);
    color: var(--color-primary);
}

.project-title {
    font-size: var(--text-h4);
    font-weight: 600;
    margin-bottom: var(--space-3);
}

.project-description {
    font-size: var(--text-body-sm);
    margin-bottom: var(--space-5);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.project-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-4);
    border-top: 1px solid var(--color-border);
}

.project-tech {
    display: flex;
    gap: var(--space-2);
}

.project-tech span {
    font-size: var(--text-caption);
    color: var(--color-text-tertiary);
    font-family: var(--font-mono);
}

.project-link {
    font-size: var(--text-body-sm);
    font-weight: 500;
    color: var(--color-primary);
}

/* ============================================
   Blog Section
   ============================================ */

.blog {
    padding: var(--space-16) 0;
    background: var(--color-surface);
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-8);
}

.blog-card {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.blog-meta {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-size: var(--text-caption);
}

.blog-date {
    color: var(--color-text-tertiary);
}

.blog-category {
    color: var(--color-primary);
    font-weight: 500;
}

.blog-title {
    font-size: var(--text-h4);
    font-weight: 600;
    line-height: 1.3;
}

.blog-excerpt {
    font-size: var(--text-body-sm);
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    flex-grow: 1;
}

.blog-link {
    font-size: var(--text-body-sm);
    font-weight: 500;
    color: var(--color-primary);
    align-self: flex-start;
}

/* ============================================
   CTA Section
   ============================================ */

.cta-section {
    padding: var(--space-16) 0;
    background: linear-gradient(135deg, #1E40AF 0%, var(--color-primary) 100%);
}

.cta-content {
    text-align: center;
    max-width: var(--content-max);
    margin: 0 auto;
}

.cta-title {
    font-size: var(--text-h2);
    font-weight: 700;
    color: white;
    margin-bottom: var(--space-4);
}

.cta-subtitle {
    font-size: var(--text-body-lg);
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: var(--space-8);
}

.cta-actions {
    display: flex;
    justify-content: center;
    gap: var(--space-4);
}

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

.cta-actions .btn-primary:hover {
    background: var(--color-surface-hover);
}

.cta-actions .btn-secondary {
    border-color: rgba(255, 255, 255, 0.3);
    color: white;
}

.cta-actions .btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: white;
}

/* ============================================
   Footer
   ============================================ */

.footer {
    background: var(--color-text-primary);
    color: rgba(255, 255, 255, 0.7);
    padding: var(--space-16) 0 var(--space-8);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-12);
    margin-bottom: var(--space-12);
}

.footer-brand {
    max-width: 320px;
}

.footer-logo {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    margin-bottom: var(--space-4);
}

.footer-logo .logo-mark {
    background: var(--color-primary);
}

.footer-logo .logo-text {
    color: white;
}

.footer-description {
    font-size: var(--text-body-sm);
    line-height: 1.6;
}

.footer-heading {
    color: white;
    font-size: var(--text-body-sm);
    font-weight: 600;
    margin-bottom: var(--space-4);
}

.footer-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.footer-list a {
    font-size: var(--text-body-sm);
    transition: color var(--transition-fast);
}

.footer-list a:hover {
    color: white;
}

.footer-bottom {
    padding-top: var(--space-8);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    font-size: var(--text-caption);
}

/* ============================================
   WeChat Button & Modal
   ============================================ */

.wechat-btn {
    background: none;
    border: none;
    color: inherit;
    font-size: var(--text-body-sm);
    font-family: var(--font-sans);
    cursor: pointer;
    padding: 0;
    transition: color var(--transition-fast);
}

.wechat-btn:hover {
    color: white;
}

.modal {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--color-surface);
    border-radius: 16px;
    padding: var(--space-8);
    max-width: 320px;
    width: 90%;
    position: relative;
    text-align: center;
    box-shadow: var(--shadow-xl);
}

.modal-close {
    position: absolute;
    top: var(--space-3);
    right: var(--space-3);
    background: none;
    border: none;
    font-size: var(--text-h3);
    color: var(--color-text-tertiary);
    cursor: pointer;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all var(--transition-fast);
}

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

.modal-title {
    font-size: var(--text-h4);
    font-weight: 600;
    margin-bottom: var(--space-1);
}

.modal-subtitle {
    font-size: var(--text-body-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-6);
}

.modal-qr {
    width: 240px;
    height: 240px;
    object-fit: contain;
    border-radius: 8px;
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 1024px) {
    .hero-container {
        grid-template-columns: 1fr;
        gap: var(--space-10);
        text-align: center;
    }

    .hero-content {
        max-width: 100%;
        order: 2;
    }

    .hero-visual {
        order: 1;
    }

    .hero-image-wrapper {
        display: none;
    }

    .hero-creed-panel {
        padding: var(--space-6) var(--space-4);
        min-height: 220px;
    }

    .hero-creed-text {
        font-size: 1.1rem;
    }

    .creed-mark {
        font-size: 3rem;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-stats {
        justify-content: center;
    }

    .values-grid {
        grid-template-columns: 1fr;
        max-width: 480px;
        margin: 0 auto;
    }

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

    .blog-grid {
        grid-template-columns: 1fr;
        max-width: 480px;
        margin: 0 auto;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-8);
    }

    .footer-brand {
        grid-column: 1 / -1;
        max-width: 100%;
        text-align: center;
    }
}

@media (max-width: 768px) {
    :root {
        --nav-height: 64px;
    }

    .nav-links {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: var(--color-surface);
        flex-direction: column;
        padding: var(--space-6);
        border-bottom: 1px solid var(--color-border);
        transform: translateY(-100%);
        opacity: 0;
        transition: all var(--transition-normal) var(--ease-out-quart);
        pointer-events: none;
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
    }

    .nav-toggle {
        display: block;
    }

    .hero {
        padding: var(--space-10) 0;
    }

    .hero-title {
        font-size: var(--text-h2);
    }

    .section-title {
        font-size: var(--text-h3);
    }

    .values,
    .projects,
    .blog,
    .cta-section {
        padding: var(--space-10) 0;
    }

    .cta-actions {
        flex-direction: column;
        align-items: center;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-brand {
        grid-column: auto;
    }
}

/* ============================================
   Accessibility
   ============================================ */

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

    html {
        scroll-behavior: auto;
    }
}

/* ============================================
   Creed / Motto Section
   ============================================ */

.creed {
    padding: var(--space-20) 0;
    text-align: center;
    background: var(--color-background);
}

.creed-quote {
    font-size: var(--text-h2);
    font-weight: 600;
    line-height: 1.4;
    color: var(--color-text-primary);
    max-width: 700px;
    margin: 0 auto var(--space-4);
    letter-spacing: -0.01em;
}

.creed-signature {
    font-size: var(--text-body-sm);
    color: var(--color-text-tertiary);
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

@media (max-width: 768px) {
    .creed { padding: var(--space-12) 0; }
    .creed-quote { font-size: var(--text-h3); }
}

/* Focus visible styles */
:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Skip to main content link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: white;
    padding: var(--space-2) var(--space-4);
    z-index: 1000;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 0;
}