/* ==========================================================================
   HK Tango — Landing Page Styles
   Mobile-first CSS3, no frameworks
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Custom Properties
   -------------------------------------------------------------------------- */
:root {
    /* Colors */
    --color-primary: #000000;
    --color-background: #FFFFFF;
    --color-accent: #5C1A1B;
    --color-alt-bg: #FAFAF7;
    --color-text-body: #1A1A1A;
    --color-text-secondary: #666666;
    --color-border: #E0E0E0;

    /* Typography */
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4rem;
    --space-3xl: 6rem;

    /* Layout */
    --max-width: 1200px;
    --header-height: 80px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text-body);
    background-color: var(--color-background);
}

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

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

a:hover,
a:focus {
    color: var(--color-primary);
}

a:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* --------------------------------------------------------------------------
   Layout Utilities
   -------------------------------------------------------------------------- */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-md);
}

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

/* --------------------------------------------------------------------------
   Typography
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.2;
    color: var(--color-primary);
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 1.75rem;
    margin-bottom: var(--space-lg);
}

h3 {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
}

p {
    margin-bottom: var(--space-sm);
}

p:last-child {
    margin-bottom: 0;
}

/* --------------------------------------------------------------------------
   Header
   -------------------------------------------------------------------------- */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background-color: var(--color-background);
    border-bottom: 1px solid var(--color-border);
    z-index: 100;
}

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

/* Logo */
.logo {
    display: flex;
    flex-direction: column;
    font-family: var(--font-display);
    text-decoration: none;
    line-height: 1;
}

.logo-the {
    font-size: 0.65rem;
    font-weight: 400;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--color-text-secondary);
    margin-bottom: 2px;
}

.logo-main {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    letter-spacing: -0.02em;
}

.logo-subtitle {
    font-size: 0.5rem;
    font-weight: 500;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-text-secondary);
    margin-top: 4px;
    line-height: 1.3;
}

/* Navigation Toggle (Mobile) */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 44px;
    height: 44px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-xs);
}

.nav-toggle-bar {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-primary);
    transition: var(--transition-fast);
}

.nav-toggle-bar + .nav-toggle-bar {
    margin-top: 5px;
}

/* Main Navigation */
.main-nav ul {
    display: flex;
    list-style: none;
    gap: var(--space-lg);
}

.main-nav a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-body);
    padding: var(--space-xs) 0;
    position: relative;
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--color-accent);
    transition: width var(--transition-medium);
}

.main-nav a:hover::after,
.main-nav a:focus::after {
    width: 100%;
}

/* --------------------------------------------------------------------------
   Hero Section
   -------------------------------------------------------------------------- */
.hero {
    padding: calc(var(--header-height) + var(--space-3xl)) 0 var(--space-3xl);
    min-height: 80vh;
    display: flex;
    align-items: center;
}

.hero .container {
    text-align: center;
}

.hero-tagline {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 400;
    color: var(--color-text-body);
    max-width: 28em;
    margin: 0 auto var(--space-lg);
}

.cta-button {
    display: inline-block;
    padding: var(--space-sm) var(--space-lg);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-background);
    background-color: var(--color-primary);
    border: 1px solid var(--color-primary);
    transition: all var(--transition-fast);
}

.cta-button:hover,
.cta-button:focus {
    color: var(--color-primary);
    background-color: transparent;
}

/* --------------------------------------------------------------------------
   Mission Section
   -------------------------------------------------------------------------- */
.mission {
    padding: var(--space-3xl) 0;
}

.mission h2 {
    text-align: center;
}

.mission-content {
    max-width: 42em;
    margin: 0 auto;
    text-align: center;
}

.mission-content p {
    font-size: 1.0625rem;
    color: var(--color-text-body);
}

.mission-content p + p {
    margin-top: var(--space-md);
}

/* --------------------------------------------------------------------------
   What We Do Section
   -------------------------------------------------------------------------- */
.what-we-do {
    padding: var(--space-3xl) 0;
}

.what-we-do h2 {
    text-align: center;
}

.cards-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-md);
}

.card {
    padding: var(--space-lg);
    border: 1px solid var(--color-border);
    transition: border-color var(--transition-fast);
}

.card:hover {
    border-color: var(--color-accent);
}

.card h3 {
    position: relative;
    padding-bottom: var(--space-sm);
    margin-bottom: var(--space-md);
}

.card h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background-color: var(--color-accent);
}

.card p {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin: 0;
}

/* --------------------------------------------------------------------------
   Gallery Section
   -------------------------------------------------------------------------- */
.gallery {
    padding: var(--space-3xl) 0;
}

.gallery h2 {
    text-align: center;
}

.gallery-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-md);
}

.gallery-item {
    aspect-ratio: 4 / 3;
    overflow: hidden;
    background-color: var(--color-alt-bg);
}

.gallery-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #E8E8E8;
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.gallery-placeholder span {
    opacity: 0.5;
}

/* --------------------------------------------------------------------------
   Contact Section
   -------------------------------------------------------------------------- */
.contact {
    padding: var(--space-3xl) 0;
}

.contact .container {
    text-align: center;
}

.contact-intro {
    font-size: 1.0625rem;
    max-width: 28em;
    margin: 0 auto var(--space-lg);
    color: var(--color-text-secondary);
}

.contact-links {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
}

.contact-link {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--color-primary);
    padding: var(--space-xs) 0;
    position: relative;
}

.contact-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--color-accent);
    transition: width var(--transition-medium);
}

.contact-link:hover::after {
    width: 100%;
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.site-footer {
    padding: var(--space-xl) 0;
    background-color: var(--color-primary);
    color: var(--color-background);
    text-align: center;
}

.site-footer .org-name {
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: var(--space-xs);
}

.site-footer .registration {
    font-size: 0.8125rem;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: var(--space-xs);
}

.site-footer .copyright {
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.5);
}

/* --------------------------------------------------------------------------
   Media Queries — Tablet (768px)
   -------------------------------------------------------------------------- */
@media (min-width: 768px) {
    h1 {
        font-size: 3rem;
    }

    h2 {
        font-size: 2.25rem;
    }

    .hero-tagline {
        font-size: 2.25rem;
    }

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

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

    .contact-link {
        font-size: 1.5rem;
    }
}

/* --------------------------------------------------------------------------
   Media Queries — Desktop (1280px)
   -------------------------------------------------------------------------- */
@media (min-width: 1280px) {
    :root {
        --header-height: 100px;
    }

    h1 {
        font-size: 4rem;
    }

    h2 {
        font-size: 2.75rem;
    }

    .hero {
        padding: calc(var(--header-height) + var(--space-3xl)) 0 var(--space-3xl);
        min-height: 90vh;
    }

    .hero-tagline {
        font-size: 2.75rem;
    }

    .cards-grid {
        grid-template-columns: repeat(4, 1fr);
    }

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

    .contact-links {
        flex-direction: row;
        gap: var(--space-xl);
    }
}

/* --------------------------------------------------------------------------
   Navigation Toggle — Mobile Only
   -------------------------------------------------------------------------- */
@media (max-width: 767px) {
    .nav-toggle {
        display: flex;
    }

    .main-nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        background-color: var(--color-background);
        border-bottom: 1px solid var(--color-border);
        padding: var(--space-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-medium);
    }

    .main-nav.is-open {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .main-nav ul {
        flex-direction: column;
        gap: 0;
        text-align: center;
    }

    .main-nav li + li {
        margin-top: var(--space-md);
    }

    .main-nav a {
        display: block;
        padding: var(--space-sm);
        font-size: 1.125rem;
    }
}

/* --------------------------------------------------------------------------
   Reduced Motion
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}