/* ============================================
   TANGENTS - VOICE LEARNING LANDING PAGE
   Design: Sonic Cartography
   Aesthetic: Editorial refinement meets exploration
   ============================================ */

:root {
    /* Color Palette - Warm exploration theme */
    --color-bg: #0A192F;
    --color-surface: #1A2332;
    --color-text: #E8E6E3;
    --color-text-muted: #9CA3AF;
    --color-accent: #D4A574;
    --color-accent-dim: #B8936A;
    --color-accent-bright: #E8C9A0;

    /* Typography */
    --font-display: 'Crimson Pro', serif;
    --font-body: 'DM Sans', sans-serif;

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2.5rem;
    --space-xl: 4rem;

    /* Effects */
    --glow-amber: 0 0 20px rgba(212, 165, 116, 0.15);
    --shadow-soft: 0 4px 24px rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: var(--font-body);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
}

/* ============================================
   NAVIGATION
   ============================================ */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(10, 25, 47, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(212, 165, 116, 0.1);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--space-md) var(--space-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-accent);
    text-decoration: none;
    letter-spacing: -0.01em;
}

.nav-links {
    display: flex;
    gap: var(--space-lg);
}

.nav-link {
    color: var(--color-text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.3s ease;
}

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

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
    min-height: 100vh;
    padding: calc(80px + var(--space-xl)) 0 var(--space-xl);
    display: flex;
    flex-direction: column;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

/* Subtle texture overlay */
.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(212, 165, 116, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(212, 165, 116, 0.02) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: var(--space-xl);
    align-items: center;
    position: relative;
    z-index: 1;
}

/* ============================================
   HERO TEXT
   ============================================ */

.hero-text {
    max-width: 540px;
}

.eyebrow {
    display: inline-block;
    font-size: 0.813rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-accent);
    margin-bottom: var(--space-md);
    opacity: 0;
    animation: fadeSlideUp 0.8s ease forwards;
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(3rem, 6vw, 5rem);
    font-weight: 600;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: var(--space-md);
    color: var(--color-text);
    opacity: 0;
    animation: fadeSlideUp 0.8s ease 0.2s forwards;
}

.hero-subtitle {
    font-size: 1.125rem;
    line-height: 1.7;
    color: var(--color-text-muted);
    max-width: 480px;
    opacity: 0;
    animation: fadeSlideUp 0.8s ease 0.4s forwards;
}

/* ============================================
   DEMO CONTAINER
   ============================================ */

.demo-container {
    background: var(--color-surface);
    border: 1px solid rgba(212, 165, 116, 0.15);
    border-radius: 20px;
    padding: var(--space-lg);
    box-shadow: var(--shadow-soft);
    opacity: 0;
    animation: fadeSlideUp 0.8s ease 0.6s forwards;
}

.demo-label {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-size: 0.813rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-accent-dim);
    margin-bottom: var(--space-sm);
}

.waveform-icon {
    color: var(--color-accent);
}

.voice-question {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-style: italic;
    color: var(--color-text);
    margin-bottom: var(--space-lg);
    padding-left: var(--space-sm);
    border-left: 2px solid var(--color-accent);
}

/* ============================================
   CONSTELLATION VISUALIZATION
   ============================================ */

.constellation-wrapper {
    position: relative;
    width: 100%;
    height: 400px;
    margin-top: var(--space-lg);
}

.constellation-lines {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.connection {
    stroke-width: 2;
    stroke-linecap: round;
    fill: none;
    stroke-dasharray: 1000;
    stroke-dashoffset: 1000;
}

.connection.c-0 { animation: drawLine 1.2s ease 1s forwards; }
.connection.c-1 { animation: drawLine 1.2s ease 1.3s forwards; }
.connection.c-2 { animation: drawLine 1.2s ease 1.3s forwards; }
.connection.c-3 { animation: drawLine 1.2s ease 1.6s forwards; }
.connection.c-4 { animation: drawLine 1.2s ease 1.6s forwards; }

@keyframes drawLine {
    to {
        stroke-dashoffset: 0;
    }
}

/* ============================================
   TOPIC NODES
   ============================================ */

.topic-node {
    position: absolute;
    transform: translate(-50%, -50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
    z-index: 2;
    opacity: 0;
    cursor: pointer;
    transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.topic-node[data-index="0"] { animation: nodeAppear 0.6s ease 1.2s forwards; }
.topic-node[data-index="1"] { animation: nodeAppear 0.6s ease 1.5s forwards; }
.topic-node[data-index="2"] { animation: nodeAppear 0.6s ease 1.5s forwards; }
.topic-node[data-index="3"] { animation: nodeAppear 0.6s ease 1.8s forwards; }
.topic-node[data-index="4"] { animation: nodeAppear 0.6s ease 1.8s forwards; }

@keyframes nodeAppear {
    0% {
        opacity: 0;
        transform: translate(-50%, -50%) scale(0.6);
    }
    100% {
        opacity: 1;
        transform: translate(-50%, -50%) scale(1);
    }
}

.node-ring {
    position: absolute;
    width: 80px;
    height: 80px;
    border: 2px solid var(--color-accent);
    border-radius: 50%;
    opacity: 0.3;
    transition: all 0.4s ease;
}

.node-image {
    width: 70px;
    height: 70px;
    border-radius: 50%;
    background-size: cover;
    background-position: center;
    border: 3px solid var(--color-accent);
    box-shadow: var(--glow-amber);
    position: relative;
    transition: all 0.4s ease;
}

.topic-node:hover .node-image {
    transform: scale(1.1);
    box-shadow: 0 0 30px rgba(212, 165, 116, 0.4);
}

.topic-node:hover .node-ring {
    transform: scale(1.2);
    opacity: 0.6;
}

.node-label {
    font-size: 0.813rem;
    font-weight: 500;
    color: var(--color-text-muted);
    text-align: center;
    white-space: nowrap;
    transition: color 0.3s ease;
}

.topic-node:hover .node-label {
    color: var(--color-accent);
}

/* ============================================
   CTA SECTION
   ============================================ */

.cta-section {
    margin-top: var(--space-lg);
    opacity: 0;
    animation: fadeSlideUp 0.8s ease 0.8s forwards;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: 1rem 2rem;
    background: var(--color-accent);
    color: var(--color-bg);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    border-radius: 50px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 20px rgba(212, 165, 116, 0.3);
}

.btn-primary:hover {
    background: var(--color-accent-bright);
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(212, 165, 116, 0.4);
}

.btn-primary svg {
    transition: transform 0.3s ease;
}

.btn-primary:hover svg {
    transform: translateX(4px);
}

/* TestFlight Badge - Apple Official Style */
.testflight-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem 1.25rem 0.5rem 0.5rem;
    background: #000;
    border: 1px solid #A6A6A6;
    border-radius: 10px;
    text-decoration: none;
    transition: all 0.3s ease;
}

.testflight-badge:hover {
    background: #1a1a1a;
    transform: translateY(-2px);
}

.testflight-icon {
    flex-shrink: 0;
    border-radius: 9px;
}

.testflight-text-stack {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}

.testflight-subtitle {
    font-size: 0.65rem;
    font-weight: 400;
    color: #fff;
    letter-spacing: 0.02em;
}

.testflight-title {
    font-size: 1.4rem;
    font-weight: 500;
    color: #fff;
    letter-spacing: -0.01em;
}

.cta-note {
    margin-top: var(--space-sm);
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
    border-top: 1px solid rgba(212, 165, 116, 0.1);
    padding: var(--space-xl) var(--space-lg);
    background: var(--color-surface);
}

.container {
    max-width: 1400px;
    margin: 0 auto;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.footer-section h4 {
    font-family: var(--font-display);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-accent);
    margin-bottom: var(--space-sm);
}

.footer-section p {
    color: var(--color-text-muted);
    font-size: 0.938rem;
}

.footer-section a {
    display: block;
    color: var(--color-text-muted);
    text-decoration: none;
    margin-bottom: var(--space-xs);
    transition: color 0.3s ease;
    font-size: 0.938rem;
}

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

.footer-bottom {
    padding-top: var(--space-lg);
    border-top: 1px solid rgba(212, 165, 116, 0.1);
    text-align: center;
}

.footer-bottom p {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

/* ============================================
   ANIMATIONS
   ============================================ */

@keyframes fadeSlideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }

    .hero-text {
        text-align: center;
        max-width: 100%;
    }

    .hero-subtitle {
        max-width: 100%;
    }

    .constellation-wrapper {
        height: 350px;
    }
}

@media (max-width: 768px) {
    .nav-container {
        padding: var(--space-sm) var(--space-md);
    }

    .hero {
        padding: calc(70px + var(--space-lg)) 0 var(--space-lg);
    }

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

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .voice-question {
        font-size: 1.25rem;
    }

    .constellation-wrapper {
        height: 300px;
    }

    .node-image {
        width: 60px;
        height: 60px;
    }

    .node-ring {
        width: 70px;
        height: 70px;
    }

    .node-label {
        font-size: 0.75rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .demo-container {
        padding: var(--space-md);
    }

    .node-image {
        width: 50px;
        height: 50px;
    }

    .node-ring {
        width: 60px;
        height: 60px;
    }
}

/* ============================================
   HIDDEN SECTIONS
   ============================================ */

.proof-section {
    display: none;
}