/*
 * HandRecorder Website - Main Stylesheet
 * Mobile-first responsive design
 * Constitution compliant: Performance & Privacy First, SEO & Accessibility, Brand Consistency
 */

/* ============================================
   CSS Custom Properties (Brand Colors & Typography)
   ============================================ */
:root {
    /* Brand Colors - TODO: Update with actual brand colors from HandRecorder-Brand-Guide.md */
    --color-primary: #2563eb;       /* Primary brand color (blue) */
    --color-secondary: #10b981;     /* Secondary brand color (green) */
    --color-accent: #f59e0b;        /* Accent color (amber) */
    --color-text: #1f2937;          /* Main text color (dark gray) */
    --color-text-light: #6b7280;    /* Light text color (medium gray) */
    --color-background: #ffffff;    /* Background color (white) */
    --color-background-alt: #f9fafb; /* Alternate background (light gray) */
    --color-border: #e5e7eb;        /* Border color (light gray) */

    /* Typography */
    --font-family-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-family-mono: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, "Courier New", monospace;

    /* Font Sizes - Responsive scale */
    --font-size-xs: 0.75rem;     /* 12px */
    --font-size-sm: 0.875rem;    /* 14px */
    --font-size-base: 1rem;      /* 16px */
    --font-size-lg: 1.125rem;    /* 18px */
    --font-size-xl: 1.25rem;     /* 20px */
    --font-size-2xl: 1.5rem;     /* 24px */
    --font-size-3xl: 1.875rem;   /* 30px */
    --font-size-4xl: 2.25rem;    /* 36px */
    --font-size-5xl: 3rem;       /* 48px */

    /* Line Heights */
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;

    /* Spacing Scale */
    --spacing-xs: 0.25rem;   /* 4px */
    --spacing-sm: 0.5rem;    /* 8px */
    --spacing-md: 1rem;      /* 16px */
    --spacing-lg: 1.5rem;    /* 24px */
    --spacing-xl: 2rem;      /* 32px */
    --spacing-2xl: 3rem;     /* 48px */
    --spacing-3xl: 4rem;     /* 64px */

    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 200ms ease-in-out;
    --transition-slow: 300ms ease-in-out;

    /* Z-index layers */
    --z-base: 1;
    --z-dropdown: 10;
    --z-sticky: 20;
    --z-fixed: 30;
    --z-modal: 40;
    --z-toast: 50;
}

/* ============================================
   CSS Reset & Base Styles
   ============================================ */
*, *::before, *::after {
    box-sizing: border-box;
}

* {
    margin: 0;
    padding: 0;
}

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

body {
    font-family: var(--font-family-sans);
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--color-text);
    background-color: var(--color-background);
    min-height: 100vh;
}

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: var(--line-height-tight);
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

h1 {
    font-size: var(--font-size-4xl);
    margin-bottom: var(--spacing-lg);
}

h2 {
    font-size: var(--font-size-3xl);
}

h3 {
    font-size: var(--font-size-2xl);
}

h4 {
    font-size: var(--font-size-xl);
}

h5 {
    font-size: var(--font-size-lg);
}

h6 {
    font-size: var(--font-size-base);
}

p {
    margin-bottom: var(--spacing-md);
}

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

a:hover {
    color: var(--color-secondary);
    text-decoration: underline;
}

a:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}

strong, b {
    font-weight: 600;
}

/* ============================================
   Layout Utilities
   ============================================ */
.container {
    width: 100%;
    max-width: 1280px;
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--spacing-md);
    padding-right: var(--spacing-md);
}

.section {
    padding-top: var(--spacing-3xl);
    padding-bottom: var(--spacing-3xl);
}

/* ============================================
   Skip to Main Content (Accessibility)
   ============================================ */
.skip-to-main {
    position: absolute;
    left: -9999px;
    top: 0;
    z-index: var(--z-toast);
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--color-primary);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-md);
}

.skip-to-main:focus {
    left: var(--spacing-md);
    top: var(--spacing-md);
}

/* ============================================
   Responsive Breakpoints
   ============================================ */

/* Tablet: 768px and up */
@media (min-width: 768px) {
    :root {
        --font-size-4xl: 2.5rem;   /* 40px */
        --font-size-5xl: 3.5rem;   /* 56px */
    }

    .container {
        padding-left: var(--spacing-lg);
        padding-right: var(--spacing-lg);
    }

    h1 {
        font-size: var(--font-size-5xl);
    }
}

/* Desktop: 1024px and up */
@media (min-width: 1024px) {
    :root {
        --font-size-4xl: 3rem;     /* 48px */
        --font-size-5xl: 4rem;     /* 64px */
    }

    .container {
        padding-left: var(--spacing-xl);
        padding-right: var(--spacing-xl);
    }
}

/* Large Desktop: 1280px and up */
@media (min-width: 1280px) {
    .container {
        padding-left: var(--spacing-2xl);
        padding-right: var(--spacing-2xl);
    }
}

/* ============================================
   Navigation Menu Styles
   ============================================ */
nav {
    position: relative;
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    gap: var(--spacing-lg);
}

nav li {
    margin: 0;
}

nav a {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-text);
    text-decoration: none;
    font-weight: 500;
    transition: all var(--transition-fast);
    border-radius: var(--radius-sm);
}

nav a:hover {
    color: var(--color-primary);
    background-color: var(--color-background-alt);
}

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

nav a[aria-current="page"] {
    color: var(--color-primary);
    font-weight: 600;
    background-color: var(--color-background-alt);
}

/* Mobile Hamburger Menu (CSS-only) */
.menu-toggle {
    display: none;
}

.menu-toggle-checkbox {
    display: none;
}

.menu-toggle-label {
    display: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    user-select: none;
}

@media (max-width: 768px) {
    .menu-toggle-label {
        display: block;
    }

    nav ul {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--color-background);
        border: 1px solid var(--color-border);
        border-radius: var(--radius-md);
        padding: var(--spacing-md);
        box-shadow: var(--shadow-lg);
        z-index: var(--z-dropdown);
    }

    .menu-toggle-checkbox:checked ~ ul {
        display: flex;
    }

    nav li {
        width: 100%;
    }

    nav a {
        display: block;
        width: 100%;
    }
}

/* ============================================
   CTA Button Styles
   ============================================ */
.btn {
    display: inline-block;
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-base);
    font-weight: 600;
    text-align: center;
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
    min-width: 200px;
}

.btn:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 4px;
}

/* Primary CTA (App Store Download) */
.btn-primary {
    background-color: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
}

.btn-primary:hover {
    background-color: var(--color-secondary);
    border-color: var(--color-secondary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    text-decoration: none;
    color: white;
}

.btn-primary:active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

/* Secondary CTA (Learn More, Features) */
.btn-secondary {
    background-color: transparent;
    color: var(--color-primary);
    border-color: var(--color-primary);
}

.btn-secondary:hover {
    background-color: var(--color-primary);
    color: white;
    text-decoration: none;
}

/* CTA Button Container */
.cta-buttons {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
    flex-wrap: wrap;
}

@media (max-width: 768px) {
    .btn {
        min-width: 100%;
    }

    .cta-buttons {
        flex-direction: column;
    }
}

/* ============================================
   Grid & Flexbox Layouts
   ============================================ */
.grid {
    display: grid;
    gap: var(--spacing-lg);
}

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

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

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

/* Responsive grid - stacks on mobile */
@media (max-width: 768px) {
    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .grid-3,
    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
}

.flex {
    display: flex;
    gap: var(--spacing-md);
}

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

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

.flex-wrap {
    flex-wrap: wrap;
}

/* ============================================
   Hero Section Styles
   ============================================ */
.hero {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-background);
    text-align: center;
}

.hero h1 {
    margin-bottom: var(--spacing-lg);
    color: var(--color-text);
}

.hero p {
    font-size: var(--font-size-lg);
    color: var(--color-text-light);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: var(--spacing-xl);
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
}

/* ============================================
   Feature Section Styles
   ============================================ */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
}

.feature {
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    background-color: var(--color-background-alt);
    transition: all var(--transition-base);
}

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

.feature-icon {
    font-size: var(--font-size-4xl);
    margin-bottom: var(--spacing-md);
}

.feature h3 {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.feature p {
    color: var(--color-text-light);
    margin-bottom: 0;
}

/* ============================================
   Footer Styles
   ============================================ */
.footer {
    background-color: var(--color-background-alt);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
    margin-top: var(--spacing-3xl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-section h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

.footer-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: var(--color-text-light);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
    color: var(--color-text-light);
    font-size: var(--font-size-sm);
}

.footer-bottom p {
    margin-bottom: var(--spacing-sm);
}

/* ============================================
   Breadcrumb Styles
   ============================================ */
.breadcrumbs {
    padding: var(--spacing-md) 0;
    background-color: var(--color-background-alt);
    font-size: var(--font-size-sm);
}

.breadcrumbs a {
    color: var(--color-primary);
    text-decoration: none;
}

.breadcrumbs a:hover {
    text-decoration: underline;
}

.breadcrumbs span {
    color: var(--color-text-light);
}

/* ============================================
   Print Styles
   ============================================ */
@media print {
    body {
        background-color: white;
        color: black;
    }

    a {
        text-decoration: underline;
    }

    /* Hide navigation and footers when printing */
    nav, footer {
        display: none;
    }
}