/* ==========================================
   Nick Yeh - Skill Alchemist Portfolio
   Apple-inspired Design System
   ========================================== */

/* CSS Variables */
:root {
    /* Colors */
    --bg-primary: #F5F5F7;
    --bg-dark: #1D1D1F;
    --text-primary: #1D1D1F;
    --text-secondary: #86868B;
    --text-light: #F5F5F7;
    --accent-blue: #0071E3;
    --accent-blue-hover: #0077ED;
    --glass-bg: rgba(255, 255, 255, 0.72);
    --glass-border: rgba(255, 255, 255, 0.18);
    --card-bg: rgba(255, 255, 255, 0.9);
    --overlay-dark: rgba(0, 0, 0, 0.5);

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-5xl: 3.5rem;
    --font-size-6xl: 4.5rem;

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

    /* Effects */
    --blur-amount: 20px;
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow: hidden;
    -ms-overflow-style: none;
    scrollbar-width: none;
}

body::-webkit-scrollbar {
    display: none;
}

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

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* ==========================================
   Navigation - Glassmorphism
   ========================================== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-amount));
    -webkit-backdrop-filter: blur(var(--blur-amount));
    border-bottom: 1px solid var(--glass-border);
    transition: var(--transition-base);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-weight: 600;
    font-size: var(--font-size-lg);
    letter-spacing: -0.02em;
}

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

.nav-link {
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition-fast);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--accent-blue);
    border-radius: 1px;
}

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

.lang-toggle {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: var(--space-xs) var(--space-sm);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--text-primary);
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
}

.lang-label {
    color: var(--text-secondary);
    font-weight: 400;
}

.lang-current {
    min-width: 65px;
    text-align: left;
}

.lang-toggle:hover {
    background: rgba(0, 0, 0, 0.05);
    color: var(--text-primary);
}

.nav-hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.nav-hamburger span {
    width: 20px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 1px;
    transition: var(--transition-fast);
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 56px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-amount));
    -webkit-backdrop-filter: blur(var(--blur-amount));
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-base);
}

.mobile-menu.active {
    opacity: 1;
    visibility: visible;
}

.mobile-menu-content {
    display: flex;
    flex-direction: column;
    padding: var(--space-xl);
    gap: var(--space-lg);
}

.mobile-link {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--text-primary);
}

/* ==========================================
   Sections - Common Styles
   ========================================== */
.section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 80px var(--space-lg) var(--space-2xl);
    position: relative;
    overflow: hidden;
}

@media (max-width: 1100px) {
    .scroll-indicator {
        display: none;
    }

    .section {
        display: block;
        /* Remove flex centering to avoid clipping */
        height: auto !important;
        /* Override fullpage.js */
        min-height: auto;
        overflow: visible;
        padding: 100px var(--space-md) var(--space-xl);
        /* Adjusted padding for smaller screens */
    }

    .section-content {
        padding-bottom: var(--space-2xl);
    }

    .hero-content {
        padding-top: var(--space-2xl);
        padding-bottom: var(--space-xl);
    }
}

.section-content {
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.section-label {
    display: inline-block;
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--accent-blue);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-sm);
}

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.1;
    margin-bottom: var(--space-md);
}

.section-description {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Light text variant for dark backgrounds */
.section-header-light .section-label {
    color: rgba(255, 255, 255, 0.8);
}

.section-header-light .section-title,
.section-header-light .section-description {
    color: var(--text-light);
}

/* ==========================================
   Hero Section
   ========================================== */
.section-hero {
    background: linear-gradient(135deg, #F5F5F7 0%, #E8E8ED 100%);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
}

.hero-brand {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--accent-blue);
    letter-spacing: 0.05em;
    margin-bottom: var(--space-sm);
}

.hero-title {
    font-size: var(--font-size-6xl);
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 1;
    margin-bottom: var(--space-sm);
}

.hero-subtitle {
    font-size: var(--font-size-2xl);
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

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

.tagline-zh {
    display: block;
    margin-bottom: var(--space-xs);
}

.tagline-en {
    display: block;
    font-style: italic;
    opacity: 0.8;
}

.hero-cta {
    display: flex;
    gap: var(--space-md);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-lg);
    font-size: var(--font-size-base);
    font-weight: 500;
    border-radius: var(--radius-xl);
    transition: var(--transition-base);
}

.btn-icon {
    width: 18px;
    height: 18px;
}

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

.btn-primary:hover {
    background: var(--accent-blue-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: transparent;
    color: var(--accent-blue);
    border: 1.5px solid var(--accent-blue);
}

.btn-secondary:hover {
    background: var(--accent-blue);
    color: white;
}

.hero-image {
    display: flex;
    justify-content: center;
}

.hero-image-wrapper {
    position: relative;
    width: 380px;
    height: 380px;
}

.hero-image-wrapper img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
    box-shadow: var(--shadow-lg);
}

.hero-image-glow {
    position: absolute;
    inset: -20px;
    background: radial-gradient(circle, rgba(0, 113, 227, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    z-index: -1;
}

.scroll-indicator {
    position: absolute;
    bottom: var(--space-xl);
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    margin: var(--space-sm) auto 0;
    border-right: 2px solid var(--text-secondary);
    border-bottom: 2px solid var(--text-secondary);
    transform: rotate(45deg);
    animation: scrollBounce 2s infinite;
}

@keyframes scrollBounce {

    0%,
    100% {
        transform: rotate(45deg) translateY(0);
    }

    50% {
        transform: rotate(45deg) translateY(8px);
    }
}