/* =======================================================
 *  MOBILE-FIRST PORTFOLIO STYLES
 *  Starting from mobile, scaling up to desktop
 * ======================================================= */

:root {
  --primary-color: #008cff;
  --accent-color: #00a2ff;
  --text-color: #4d4d4d;
  --text-dark: #000;
  --bg-color: #fff;
  --bg-alt: #f8f9fa;
  --border-color: #e9ecef;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --container-padding: 1rem;
  --border-radius: 0.5rem;
  --transition: all 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px; /* Prevent iOS zoom */
}

body {
  font-family: 'Space Mono', monospace;
  font-size: 1rem;
  line-height: 1.7;
  color: var(--text-color);
  background: var(--bg-color);
  overflow-x: hidden;
  overflow-y: auto;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: 'Space Mono', monospace;
  color: var(--text-dark);
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
}

h1 {
  font-size: clamp(2rem, 6vw, 3.5rem);
  font-weight: 700;
}

h2 {
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  font-weight: 700;
}

h3 {
  font-size: clamp(1.25rem, 4vw, 1.5rem);
  font-weight: 700;
}

p {
  margin-bottom: var(--spacing-sm);
  font-size: clamp(0.95rem, 2.5vw, 1rem);
}

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

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

ul {
  list-style: none;
}

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

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* Navigation - Mobile First */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.95);
  backdrop-filter: blur(10px);
  z-index: 1000;
  box-shadow: var(--shadow);
}

.nav-container {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  padding: var(--spacing-sm) var(--container-padding);
  max-width: 100%;
  margin: 0 auto;
  width: 100%;
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  z-index: 1001;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--bg-color);
  transition: var(--transition);
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(6px, 6px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

.nav-menu {
  position: fixed;
  top: 60px;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.98);
  flex-direction: column;
  padding: var(--spacing-lg) 0;
  transform: translateX(-100%);
  transition: transform 0.3s ease;
  box-shadow: var(--shadow-lg);
}

.nav-menu.active {
  transform: translateX(0);
}

.nav-menu li {
  margin: 0;
  flex: 1;
}

.nav-link {
  display: block;
  padding: var(--spacing-sm) var(--container-padding);
  color: var(--bg-color);
  font-size: 1.1rem;
  transition: var(--transition);
  text-align: center;
  width: 100%;
}

.nav-link:hover,
.nav-link:focus {
  background: rgba(255, 255, 255, 0.1);
  color: var(--primary-color);
}

/* Hero Section */
.hero {
  min-height: 100vh;
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: var(--spacing-xl) var(--container-padding);
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: var(--bg-color);
  position: relative;
  overflow: hidden;
  scroll-snap-align: start;
  scroll-snap-stop: always;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('images/cover_bg_3.jpg') center/cover;
  opacity: 0.3;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 600px;
}

.profile-image {
  width: clamp(150px, 40vw, 250px);
  height: clamp(150px, 40vw, 250px);
  margin: 0 auto var(--spacing-md);
  border-radius: 50%;
  overflow: hidden;
  border: 4px solid var(--bg-color);
  box-shadow: var(--shadow-lg);
}

.profile-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-title {
  color: var(--bg-color);
  margin-bottom: var(--spacing-sm);
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
  font-size: clamp(1rem, 3vw, 1.25rem);
  margin-bottom: var(--spacing-lg);
  color: rgba(255, 255, 255, 0.95);
  min-height: 1.5rem;
}

.hero-cta {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  align-items: center;
}

.scroll-indicator {
  position: relative;
  bottom: var(--spacing-lg);
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
}

.scroll-indicator .scroll-indicator-link {
  display: block;
  width: 30px;
  height: 50px;
  border: 2px solid var(--bg-color);
  border-radius: 25px;
  position: relative;
  background: transparent;
}

.scroll-indicator .scroll-indicator-link:hover,
.scroll-indicator .scroll-indicator-link:focus {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-4px);
}

.scroll-indicator span {
  position: absolute;
  top: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 8px;
  background: var(--bg-color);
  border-radius: 2px;
  animation: scroll 2s infinite;
}

.scroll-indicator .scroll-indicator-link::before {
  bottom: auto;
  top: 100%;
  transform: translateX(-50%) translateY(10px);
  margin-bottom: 0;
  margin-top: 0.5rem;
}

.scroll-indicator .scroll-indicator-link:hover::before,
.scroll-indicator .scroll-indicator-link:focus::before {
  transform: translateX(-50%) translateY(0);
}

.scroll-indicator .scroll-indicator-link::after {
  bottom: auto;
  top: 100%;
  transform: translateX(-50%) translateY(2px);
  border-top-color: transparent;
  border-bottom-color: var(--text-dark);
  margin-bottom: 0;
  margin-top: 0.5rem;
}

.scroll-indicator .scroll-indicator-link:hover::after,
.scroll-indicator .scroll-indicator-link:focus::after {
  transform: translateX(-50%) translateY(0);
}

@keyframes scroll {
  0%, 100% { opacity: 1; transform: translateX(-50%) translateY(0); }
  50% { opacity: 0.5; transform: translateX(-50%) translateY(10px); }
}

/* Section Scroll Indicators */
.section-scroll-indicator {
  position: absolute;
  bottom: var(--spacing-lg);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 10;
  width: 100%;
}

.scroll-indicator-link {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 50px;
  height: 50px;
  background: var(--primary-color);
  color: var(--bg-color);
  border-radius: 50%;
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  z-index: 10;
}

.scroll-indicator-link:hover,
.scroll-indicator-link:focus {
  background: var(--accent-color);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.scroll-arrow {
  font-size: 1.5rem;
  font-weight: bold;
  line-height: 1;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-5px); }
}

/* Tooltip */
.scroll-indicator-link::before {
  content: attr(data-tooltip);
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(-10px);
  background: var(--text-dark);
  color: var(--bg-color);
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius);
  font-size: 0.875rem;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: var(--transition);
  margin-bottom: 0.5rem;
  z-index: 1000;
  box-shadow: var(--shadow);
}

.scroll-indicator-link::after {
  content: '';
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(-2px);
  border: 6px solid transparent;
  border-top-color: var(--text-dark);
  opacity: 0;
  pointer-events: none;
  transition: var(--transition);
  margin-bottom: 0.5rem;
  z-index: 1000;
}

.scroll-indicator-link:hover::before,
.scroll-indicator-link:focus::before {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.scroll-indicator-link:hover::after,
.scroll-indicator-link:focus::after {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: 2rem;
  font-weight: 600;
  text-align: center;
  transition: var(--transition);
  border: 2px solid transparent;
  cursor: pointer;
  min-height: 44px; /* Touch target */
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

.btn-primary {
  background: var(--primary-color);
  color: var(--bg-color);
  border-color: var(--primary-color);
}

.btn-primary:hover,
.btn-primary:focus {
  background: var(--accent-color);
  border-color: var(--accent-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.btn-secondary {
  background: transparent;
  color: var(--bg-color);
  border-color: var(--bg-color);
}

.btn-secondary:hover,
.btn-secondary:focus {
  background: var(--bg-color);
  color: var(--text-dark);
}

/* Section Styles - Full Viewport Height */
html {
  scroll-snap-type: y proximity;
  scroll-behavior: smooth;
}

.section {
  min-height: 100vh;
  height: 100vh;
  display: flex;
  flex-direction: column;
  padding: var(--spacing-xl) 0;
  scroll-snap-align: start;
  scroll-snap-stop: always;
  position: relative;
  overflow: hidden;
}

.section-alt {
  background: var(--bg-alt);
}

.section .container {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 0;
  max-height: calc(100vh - var(--spacing-xl) * 2 - 80px);
  overflow-y: auto;
  padding-bottom: calc(var(--spacing-xl) + 80px);
}

.section .container > * {
  flex-shrink: 0;
}

/* Ensure content fits within viewport */
.about-content,
.skills-content,
.timeline {
  max-height: 100%;
  overflow-y: auto;
}

.section-container {
  padding: 0px 150px;
}

.section-title {
  text-align: center;
  margin-bottom: var(--spacing-xl);
  position: relative;
  padding-bottom: var(--spacing-sm);
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: var(--primary-color);
}

/* About Section */
.about-content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.about-info {
  padding: var(--spacing-lg);
  border-radius: var(--border-radius);
}

.info-item {
  display: flex;
  flex-direction: column;
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--border-color);
}

.info-item:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.info-label {
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 0.25rem;
}

.info-value {
  color: var(--text-color);
}

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

.social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--primary-color);
  color: var(--bg-color);
  border-radius: 50%;
  transition: var(--transition);
  font-size: 1.25rem;
}

.social-link svg {
  width: 1.25rem;
  height: 1.25rem;
  fill: currentColor;
}

.social-link:hover,
.social-link:focus {
  background: var(--accent-color);
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}

.about-text h3 {
  margin-bottom: var(--spacing-md);
}

/* Skills Section */
.skills-content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.skills-intro {
  text-align: center;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-sm);
}

.skill-badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  padding: var(--spacing-md);
  background: var(--bg-color);
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  transition: var(--transition);
  text-align: center;
  min-height: 100px;
}

.skill-badge:hover,
.skill-badge:focus {
  border-color: var(--primary-color);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  background: var(--bg-alt);
}

.skill-badge i {
  font-size: 2.5rem;
  color: var(--primary-color);
}

.skill-badge span {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-dark);
}

/* Timeline - Mobile First (Vertical) */
.timeline {
  height: 25%;
  position: relative;
  padding: var(--spacing-lg) 0;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 1.25rem;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--primary-color);
  z-index: 0;
}

.timeline-item {
  position: relative;
  margin-bottom: var(--spacing-xl);
  padding-left: 3.5rem;
}

.timeline-marker {
  position: absolute;
  left: 0.75rem;
  top: 0.5rem;
  width: 1rem;
  height: 1rem;
  background: var(--primary-color);
  border: 3px solid var(--bg-color);
  border-radius: 50%;
  z-index: 1;
  box-shadow: var(--shadow);
}

.timeline-content {
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: var(--spacing-md);
  box-shadow: var(--shadow);
  position: relative;
}

.timeline-content::before {
  content: '';
  position: absolute;
  left: -8px;
  top: 1.5rem;
  width: 0;
  height: 0;
  border-top: 8px solid transparent;
  border-bottom: 8px solid transparent;
  border-right: 8px solid var(--border-color);
}

.timeline-title {
  color: var(--text-dark);
  margin-bottom: 0.5rem;
}

.timeline-date {
  display: block;
  color: var(--primary-color);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  font-size: 0.9rem;
}

.timeline-body ul {
  list-style: disc;
  padding-left: 1.5rem;
  margin-top: var(--spacing-sm);
}

.timeline-body li {
  margin-bottom: 0.75rem;
  line-height: 1.6;
}

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

.contact-links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-lg);
}

.contact-link {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md);
  background: var(--primary-color);
  color: var(--bg-color);
  border-radius: var(--border-radius);
  transition: var(--transition);
  min-height: 44px;
  font-weight: 600;
}

.contact-link:hover,
.contact-link:focus {
  background: var(--accent-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.contact-link i {
  font-size: 1.5rem;
}

/* Footer */
.footer {
  background: var(--text-dark);
  color: var(--bg-color);
  text-align: center;
  padding: var(--spacing-lg) 0;
}

/* Back to Top Button */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-lg);
  right: var(--spacing-lg);
  width: 50px;
  height: 50px;
  background: var(--primary-color);
  color: var(--bg-color);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: none;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: var(--shadow-lg);
  z-index: 999;
  transition: var(--transition);
}

.back-to-top.visible {
  display: flex;
}

.back-to-top:hover,
.back-to-top:focus {
  background: var(--accent-color);
  transform: translateY(-4px);
}

/* Tablet Styles (min-width: 768px) */
@media screen and (min-width: 768px) {
  :root {
    --container-padding: 2rem;
    --spacing-xl: 4rem;
  }

  .nav-toggle {
    display: none;
  }

  .nav-container {
    justify-content: center;
  }

  .nav-menu {
    position: static;
    flex-direction: row;
    background: transparent;
    transform: none;
    padding: 0;
    box-shadow: none;
    display: flex;
    width: 100%;
    justify-content: space-around;
    align-items: center;
  }

  .nav-menu li {
    flex: 1;
    text-align: center;
  }

  .nav-link {
    padding: var(--spacing-sm) var(--spacing-xs);
    width: 100%;
  }

  .hero-cta {
    flex-direction: row;
    justify-content: center;
  }

  .about-content {
    flex-direction: row;
    align-items: flex-start;
  }

  .about-info {
    flex: 0 0 40%;
  }

  .about-text {
    flex: 1;
  }

  .info-item {
    flex-direction: row;
  }

  .info-label {
    width: 35%;
    margin-bottom: 0;
  }

  .info-value {
    width: 65%;
  }

  .skills-content {
    flex-direction: row;
  }

  .skills-intro {
    flex: 0 0 40%;
    text-align: left;
  }

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

  .contact-links {
    flex-direction: row;
    justify-content: center;
  }
}

/* Desktop Styles (min-width: 992px) */
@media screen and (min-width: 992px) {
  :root {
    --container-padding: 3rem;
  }

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

  .timeline::before {
    left: 50%;
    transform: translateX(-50%);
  }

  .timeline-item {
    width: 45%;
    padding-left: 0;
  }

  .timeline-item:nth-child(odd) {
    margin-left: 0;
    margin-right: auto;
  }

  .timeline-item:nth-child(even) {
    margin-left: auto;
    margin-right: 0;
  }

  .timeline-marker {
    left: 50%;
    transform: translateX(-50%);
  }

  .timeline-content::before {
    display: none;
  }

  .timeline-item:nth-child(odd) .timeline-content::after {
    content: '';
    position: absolute;
    right: -8px;
    top: 1.5rem;
    width: 0;
    height: 0;
    border-top: 8px solid transparent;
    border-bottom: 8px solid transparent;
    border-left: 8px solid var(--border-color);
  }

  .timeline-item:nth-child(even) .timeline-content::before {
    content: '';
    position: absolute;
    left: -8px;
    top: 1.5rem;
    width: 0;
    height: 0;
    border-top: 8px solid transparent;
    border-bottom: 8px solid transparent;
    border-right: 8px solid var(--border-color);
  }
}

/* Large Desktop (min-width: 1200px) */
@media screen and (min-width: 1200px) {
  .skills-grid {
    grid-template-columns: repeat(5, 1fr);
  }
}

/* Accessibility & Performance */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Print Styles */
@media print {
  .navbar,
  .back-to-top,
  .scroll-indicator {
    display: none;
  }

  .section {
    page-break-inside: avoid;
  }
}