/* ============================================
   TECHNASM LANDING PAGE
   Design-token-first system demonstration
   ============================================ */

/* ============================================
   RESET & BASE
   ============================================ */

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

html {
    scroll-behavior: smooth;
    scroll-snap-type: y mandatory;
    overflow-y: scroll;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    line-height: 1.6;
    color: #1a1a1a;
    background-color: #fafafa;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   SITE HEADER (appears from Section 4.5 onwards)
   ============================================ */

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: #fafafa;
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-md) var(--space-lg);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.4s ease, visibility 0.4s ease;
}

.site-header.visible {
    opacity: 1;
    visibility: visible;
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-logo {
    font-size: var(--text-size-medium);
    font-weight: 500;
    color: var(--color-text-primary);
    letter-spacing: -0.01em;
}

.header-link {
    font-size: var(--text-size-base);
    color: var(--color-text-primary);
    text-decoration: none;
    font-weight: 400;
    transition: opacity var(--transition-base);
}

.header-link:hover {
    opacity: 0.6;
}

/* ============================================
   DESIGN TOKENS (System Foundation)
   ============================================ */

:root {
    /* Colors - Neutral palette only */
    --color-text-primary: #1a1a1a;
    --color-text-secondary: #4a4a4a;
    --color-text-tertiary: #6a6a6a;
    --color-surface: #ffffff;
    --color-surface-alt: #f5f5f5;
    --color-border: #e0e0e0;
    
    /* Spacing - Mathematical rhythm */
    --space-xs: 0.5rem;    /* 8px */
    --space-sm: 1rem;      /* 16px */
    --space-md: 1.5rem;    /* 24px */
    --space-lg: 3rem;      /* 48px */
    --space-xl: 6rem;      /* 96px */
    --space-xxl: 12rem;    /* 192px */
    
    /* Typography scale - Restricted system */
    --text-size-small: 0.875rem;    /* 14px */
    --text-size-base: 1rem;         /* 16px */
    --text-size-medium: 1.125rem;   /* 18px */
    --text-size-large: 3rem;        /* 48px */
    --text-size-statement: 2rem;    /* 32px */
    
    /* Line heights - Fixed ratios */
    --line-height-tight: 1.2;
    --line-height-normal: 1.6;
    --line-height-loose: 1.8;
    
    /* Border radius - Limited set */
    --radius-none: 0;
    --radius-sm: 2px;
    --radius-md: 4px;
    
    /* Transitions - Minimal */
    --transition-base: 0.2s ease;
}

/* ============================================
   SECTION SYSTEM
   ============================================ */

.section {
    min-height: 100vh;
    padding: var(--space-xl) var(--space-lg);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    max-width: 1400px;
    margin: 0 auto;
    scroll-snap-align: start;
    scroll-snap-stop: always;
    scroll-margin-top: 0;
}

/* Vertical rhythm enforcement */
.section + .section {
    margin-top: 0;
}

/* ============================================
   SECTION 1 — Cold Open
   ============================================ */

.section--cold-open {
    text-align: center;
}

.text--large {
    font-size: var(--text-size-large);
    line-height: var(--line-height-tight);
    font-weight: 400;
    color: var(--color-text-primary);
    margin-bottom: var(--space-lg);
    letter-spacing: -0.02em;
}

.text--small {
    font-size: var(--text-size-medium);
    line-height: var(--line-height-normal);
    color: var(--color-text-tertiary);
    font-weight: 300;
}

/* ============================================
   SECTION 2 — Visual Entropy
   ============================================ */

.section--entropy {
    padding: var(--space-lg) var(--space-lg) var(--space-xl) var(--space-lg);
    justify-content: flex-start;
}

.entropy-container {
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
    align-items: start;
    align-content: start;
}

.entropy-column {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.entropy-column--left {
    align-items: flex-start;
}

.entropy-column--right {
    align-items: flex-start;
    min-height: auto;
    padding-top: 0;
}

.entropy-column--left {
    padding-top: 0;
}

/* Both columns now have captions, so no alignment padding needed */
.entropy-column--left .ui-examples,
.entropy-column--right .ui-examples {
    margin-top: 0;
}

.caption {
    font-size: var(--text-size-small);
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-lg);
    margin-top: 0;
    font-weight: 500;
}

.ui-examples {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
    width: 100%;
}

/* Entropy cards - identical content, subtle inconsistencies */
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    width: 100%;
}

.card-title {
    font-size: var(--text-size-medium);
    font-weight: 500;
    color: var(--color-text-primary);
    line-height: var(--line-height-normal);
    margin: 0 0 0.75rem 0;
}

.card-body {
    font-size: var(--text-size-base);
    line-height: var(--line-height-loose);
    color: var(--color-text-secondary);
    font-weight: 300;
    margin: 0 0 0.875rem 0;
}

.card-meta {
    font-size: var(--text-size-small);
    color: var(--color-text-tertiary);
    margin: 0 0 1rem 0;
    font-weight: 400;
}

.card-action {
    padding: var(--space-xs) var(--space-md);
    background: var(--color-text-primary);
    color: var(--color-surface);
    border: none;
    font-size: var(--text-size-small);
    cursor: pointer;
    font-family: inherit;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 500;
    display: inline-block;
}

/* Variant 1 - Subtle entropy */
.card--variant-1 {
    padding: 1.15rem 1.35rem 1.25rem 1.4rem;
    border-radius: 5px;
}

.card--variant-1 .card-title {
    font-size: 1.125rem;
    line-height: 1.5;
    margin-bottom: 0.7rem;
}

.card--variant-1 .card-body {
    max-width: 92%;
    margin-bottom: 0.9rem;
}

.card--variant-1 .card-action {
    padding: 0.45rem 1.25rem;
    border-radius: 3px;
    margin-left: 0;
}

/* Variant 2 - Subtle entropy */
.card--variant-2 {
    padding: 1.35rem 1.5rem 1.4rem 1.45rem;
    border-radius: 4px;
}

.card--variant-2 .card-title {
    font-size: 1.15rem;
    line-height: 1.45;
    margin-bottom: 0.85rem;
}

.card--variant-2 .card-body {
    max-width: 95%;
    margin-bottom: 0.95rem;
}

.card--variant-2 .card-action {
    padding: 0.5rem 1.35rem;
    border-radius: 2px;
    margin-left: 0.1rem;
}

/* Variant 3 - Subtle entropy */
.card--variant-3 {
    padding: 1.25rem 1.4rem 1.3rem 1.38rem;
    border-radius: 6px;
}

.card--variant-3 .card-title {
    font-size: 1.1rem;
    line-height: 1.55;
    margin-bottom: 0.8rem;
}

.card--variant-3 .card-body {
    max-width: 94%;
    margin-bottom: 0.88rem;
}

.card--variant-3 .card-action {
    padding: 0.48rem 1.3rem;
    border-radius: 4px;
    margin-left: 0.05rem;
}

/* Variant 4 - Subtle entropy */
.card--variant-4 {
    padding: 1.2rem 1.38rem 1.35rem 1.42rem;
    border-radius: 4.5px;
}

.card--variant-4 .card-title {
    font-size: 1.13rem;
    line-height: 1.48;
    margin-bottom: 0.75rem;
}

.card--variant-4 .card-body {
    max-width: 93%;
    margin-bottom: 0.92rem;
}

.card--variant-4 .card-action {
    padding: 0.47rem 1.28rem;
    border-radius: 3.5px;
    margin-left: 0.08rem;
}

/* ============================================
   SECTION 3 — Naming the Problem
   ============================================ */

.section--problem {
    text-align: center;
}

.text--statement {
    font-size: var(--text-size-statement);
    line-height: var(--line-height-tight);
    font-weight: 400;
    color: var(--color-text-primary);
    margin-bottom: var(--space-lg);
    letter-spacing: -0.01em;
}

.text--medium {
    font-size: var(--text-size-medium);
    line-height: var(--line-height-loose);
    color: var(--color-text-secondary);
    font-weight: 300;
    max-width: 600px;
}

/* ============================================
   SECTION 4 — Introduction of Structure
   ============================================ */

.section--structure {
    padding: var(--space-lg) var(--space-lg) var(--space-xl) var(--space-lg);
    justify-content: flex-start;
}

/* Consistent UI blocks - system demonstration */
.ui-block--system {
    padding: var(--space-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}

.ui-surface--system {
    height: 60px;
    background: var(--color-surface-alt);
    border-radius: var(--radius-sm);
    margin-bottom: var(--space-sm);
}

.ui-button--system {
    border-radius: var(--radius-sm);
    padding: var(--space-xs) var(--space-md);
}

/* ============================================
   SECTION 4.5 — Introduction
   ============================================ */

.section--introduction {
    text-align: center;
    padding-top: calc(var(--space-xxl) + 60px);
    padding-bottom: var(--space-xxl);
}

/* Add top padding to sections after header appears */
.section--language,
.section--anti-marketing,
.section--proof,
.section--cta {
    padding-top: calc(var(--space-lg) + 60px);
}

.introduction {
    text-align: center;
}

.name {
    font-size: var(--text-size-large);
    line-height: var(--line-height-tight);
    font-weight: 400;
    color: var(--color-text-primary);
    letter-spacing: -0.02em;
    margin-bottom: var(--space-md);
}

/* ============================================
   SECTION 5 — Principles
   ============================================ */

.section--principles {
    text-align: center;
    padding-top: calc(var(--space-lg) + 60px);
    padding-bottom: var(--space-xxl);
}

.principles-list {
    list-style: none;
    margin: var(--space-xl) auto 0;
    text-align: left;
    max-width: 500px;
    margin-bottom: var(--space-xxl);
}

.principles-list li {
    font-size: var(--text-size-medium);
    line-height: var(--line-height-loose);
    color: var(--color-text-secondary);
    padding: var(--space-sm) 0;
    border-bottom: 1px solid var(--color-border);
    font-weight: 300;
}

.principles-list li:last-child {
    border-bottom: none;
}

.principles-list li::before {
    content: "—";
    margin-right: var(--space-sm);
    color: var(--color-text-primary);
}

/* ============================================
   SECTION 6 — Language Example
   ============================================ */

.section--language {
    text-align: center;
}

.code-example {
    margin-top: var(--space-xl);
    max-width: 600px;
}

.code-example pre {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    text-align: left;
    overflow-x: auto;
    margin-bottom: var(--space-md);
}

.code-example code {
    font-family: 'Monaco', 'Menlo', 'Courier New', monospace;
    font-size: var(--text-size-small);
    color: var(--color-text-primary);
    line-height: var(--line-height-normal);
}

/* ============================================
   SECTION 7 — Anti-Marketing
   ============================================ */

.section--anti-marketing {
    text-align: center;
}

.exclusions-list {
    list-style: none;
    margin-top: var(--space-xl);
    text-align: left;
    max-width: 500px;
}

.exclusions-list li {
    font-size: var(--text-size-medium);
    line-height: var(--line-height-loose);
    color: var(--color-text-secondary);
    padding: var(--space-sm) 0;
    border-bottom: 1px solid var(--color-border);
    font-weight: 300;
}

.exclusions-list li:last-child {
    border-bottom: none;
}

.exclusions-list li::before {
    content: "×";
    margin-right: var(--space-sm);
    color: var(--color-text-tertiary);
}

/* ============================================
   SECTION 8 — Self-Proof
   ============================================ */

.section--proof {
    text-align: center;
}

/* ============================================
   SECTION 9 — Quiet CTA
   ============================================ */

.section--cta {
    min-height: auto;
    height: auto;
    padding-bottom: var(--space-xxl);
}

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

.cta-link {
    font-size: var(--text-size-medium);
    color: var(--color-text-primary);
    text-decoration: none;
    font-weight: 400;
    transition: opacity var(--transition-base);
    border-bottom: 1px solid transparent;
}

.cta-link:hover {
    opacity: 0.6;
    border-bottom-color: var(--color-text-primary);
}

/* ============================================
   RESPONSIVE ADJUSTMENTS
   ============================================ */

@media (max-width: 768px) {
    :root {
        --text-size-large: 2rem;
        --text-size-statement: 1.5rem;
        --space-xl: 4rem;
        --space-xxl: 6rem;
    }
    
    .section {
        padding: var(--space-lg) var(--space-md);
    }
    
    .entropy-container {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }
    
    .entropy-column--right {
        min-height: auto;
    }
    
    .ui-examples {
        grid-template-columns: 1fr;
        gap: var(--space-md);
    }
    
    .principles-list,
    .exclusions-list {
        max-width: 100%;
    }
}