/* ===================================
   Apple Style Design System
   =================================== */
:root {
    /* Colors - Light Theme */
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f7;
    --bg-tertiary: #fbfbfd;

    /* Text Colors */
    --text-primary: #1d1d1f;
    --text-secondary: #86868b;
    --text-tertiary: #a1a1a6;

    /* Accent Colors */
    --accent-blue: #0071e3;
    --accent-blue-hover: #0077ed;
    --accent-green: #00c878;
    --accent-orange: #ff6600;
    --accent-pink: #ff2d55;
    --accent-purple: #af52de;

    /* Gradients */
    --gradient-blue: linear-gradient(90deg, #0071e3, #42a5f5);
    --gradient-rainbow: linear-gradient(90deg, #ff2d55, #ff9500, #ffcc00, #4cd964, #5ac8fa, #007aff, #5856d6, #ff2d55);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 3rem;
    --spacing-xl: 5rem;

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
    --font-size-base: 17px;
    --line-height: 1.47059;

    /* Transitions */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 18px;
    --radius-xl: 24px;
}

/* ===================================
   Reset & Base Styles
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    color: var(--text-primary);
    background-color: var(--bg-primary);
    line-height: var(--line-height);
    overflow-x: hidden;
    font-weight: 400;
    letter-spacing: -0.022em;
}

/* ===================================
   Container
   =================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===================================
   Section Styles
   =================================== */
section {
    padding: var(--spacing-xl) 0;
    position: relative;
}

.section-title {
    font-size: 56px;
    line-height: 1.07143;
    font-weight: 600;
    text-align: center;
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.005em;
}

.section-subtitle {
    font-size: 24px;
    line-height: 1.16667;
    font-weight: 400;
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* ===================================
   Typography
   =================================== */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    font-weight: 600;
}

p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-block;
    padding: 12px 22px;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-size: 17px;
    font-weight: 400;
    transition: all var(--transition-normal);
    border: none;
    cursor: pointer;
    letter-spacing: -0.022em;
}

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

.btn-primary:hover {
    background: var(--accent-blue-hover);
    transform: scale(1.02);
}

.btn-secondary {
    background: transparent;
    color: var(--accent-blue);
    padding: 12px 18px;
}

.btn-secondary:hover {
    text-decoration: underline;
}

.btn-outline {
    background: transparent;
    color: var(--accent-blue);
    border: 1px solid var(--accent-blue);
}

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

.btn-large {
    padding: 18px 30px;
    font-size: 19px;
    border-radius: var(--radius-lg);
}

/* ===================================
   About Section
   =================================== */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
    max-width: 1000px;
    margin: var(--spacing-lg) auto 0;
}

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

.profile-placeholder {
    width: 280px;
    height: 280px;
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
    font-size: 18px;
    color: var(--text-secondary);
    font-weight: 500;
}

.profile-photo {
    width: 360px;
    height: 360px;
    border-radius: var(--radius-xl);
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
    object-fit: cover;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.profile-photo:hover {
    transform: scale(1.02);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
}

.about-text {
    font-size: 21px;
    line-height: 1.381;
    font-weight: 400;
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.about-text .btn {
    margin-top: var(--spacing-md);
}

/* ===================================
   Skills Section
   =================================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.skill-card {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    transition: all var(--transition-normal);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.skill-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.skill-icon {
    font-size: 48px;
    margin-bottom: var(--spacing-sm);
    text-align: center;
}

.skill-name {
    font-size: 21px;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    text-align: center;
    color: var(--text-primary);
}

.skill-level {
    height: 4px;
    background: rgba(0, 0, 0, 0.1);
    border-radius: 2px;
    overflow: hidden;
    margin-top: var(--spacing-sm);
}

.skill-progress {
    height: 100%;
    background: var(--gradient-blue);
    transition: width 1s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 2px;
}

/* ===================================
   Projects Section
   =================================== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.project-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-normal);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
}

.project-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1);
}

.project-image-placeholder {
    width: 100%;
    height: 220px;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 17px;
    font-weight: 500;
}

.project-content {
    padding: var(--spacing-md);
}

.project-title {
    font-size: 24px;
    line-height: 1.16667;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.project-description {
    font-size: 17px;
    line-height: 1.47059;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.tech-tag {
    background: var(--bg-tertiary);
    padding: 6px 14px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 500;
}

.project-links {
    display: flex;
    gap: var(--spacing-sm);
}

.project-link {
    flex: 1;
    text-align: center;
    padding: 10px 18px;
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: all var(--transition-normal);
    font-size: 15px;
    font-weight: 500;
}

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

.btn-demo:hover {
    background: var(--accent-blue-hover);
}

.btn-code {
    background: transparent;
    color: var(--accent-blue);
    border: 1px solid var(--accent-blue);
}

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

/* ===================================
   Experience Section - Timeline
   =================================== */
.timeline {
    position: relative;
    max-width: 900px;
    margin: var(--spacing-lg) auto 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 1px;
    height: 100%;
    background: rgba(0, 0, 0, 0.1);
}

.timeline-item {
    padding: var(--spacing-md);
    position: relative;
    width: 50%;
    margin-bottom: var(--spacing-lg);
}

.timeline-item:nth-child(odd) {
    left: 0;
    padding-right: var(--spacing-lg);
    text-align: right;
}

.timeline-item:nth-child(even) {
    left: 50%;
    padding-left: var(--spacing-lg);
}

.timeline-content {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    transition: all var(--transition-normal);
}

.timeline-content:hover {
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
}

.timeline-dot {
    position: absolute;
    width: 12px;
    height: 12px;
    background: var(--accent-blue);
    border-radius: 50%;
    top: var(--spacing-md);
    box-shadow: 0 0 0 4px var(--bg-primary);
}

.timeline-item:nth-child(odd) .timeline-dot {
    right: -6px;
}

.timeline-item:nth-child(even) .timeline-dot {
    left: -6px;
}

.timeline-date {
    display: inline-block;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.timeline-title {
    font-size: 21px;
    line-height: 1.381;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.timeline-company {
    color: var(--accent-blue);
    font-size: 17px;
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
}

.timeline-description {
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.47059;
}

/* ===================================
   Contact Section
   =================================== */
.contact-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact-text {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    font-size: 21px;
    line-height: 1.381;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.social-link {
    width: 56px;
    height: 56px;
    background: var(--bg-secondary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-normal);
    color: var(--text-primary);
}

.social-link:hover {
    background: var(--accent-blue);
    color: white;
    transform: scale(1.1);
}

/* ===================================
   Footer
   =================================== */
.footer {
    text-align: center;
    padding: var(--spacing-lg) 0;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    font-size: 12px;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}

.footer p {
    font-size: 12px;
    color: var(--text-tertiary);
}

/* ===================================
   Links
   =================================== */
a {
    color: var(--accent-blue);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--accent-blue-hover);
}

/* ===================================
   Selection
   =================================== */
::selection {
    background: rgba(0, 113, 227, 0.2);
    color: var(--text-primary);
}

::-moz-selection {
    background: rgba(0, 113, 227, 0.2);
    color: var(--text-primary);
}