/* ==========================================================
   Executive Slate — Shared Design System
   Personal site for Noah Yejia Tong
   ========================================================== */

/* --- Design Tokens --- */
:root {
  --color-primary: #1A365D;
  --color-secondary: #4A5568;
  --color-accent: #2D3748;
  --color-bg: #FFFFFF;
  --color-surface: #F7FAFC;
  --radius: 4px;
}

/* --- Base --- */
html {
  scroll-behavior: smooth;
}

body,
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: "Manrope", sans-serif;
}

body {
  color: var(--color-secondary);
  line-height: 1.7;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-primary);
  font-weight: 700;
  letter-spacing: -0.025em;
}

h1 {
  font-weight: 800;
  letter-spacing: -0.04em;
}

h2 {
  font-size: 2rem;
  margin-bottom: 4px;
}

p {
  color: var(--color-secondary);
}

/* --- Links --- */
a {
  color: var(--color-primary);
  transition: color 0.3s;
}

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

/* --- Horizontal Rules --- */
hr.w3-opacity {
  border-color: #E2E8F0;
  opacity: 1;
}

/* --- Slate-Themed Buttons --- */
.w3-button.w3-light-grey {
  background-color: var(--color-accent) !important;
  color: #ffffff !important;
  border-radius: var(--radius);
  transition: all 0.3s;
}

.w3-button.w3-light-grey:hover {
  background-color: var(--color-primary) !important;
}

.w3-button.w3-dark-grey {
  background-color: var(--color-primary) !important;
  color: #ffffff !important;
  border-radius: var(--radius);
  transition: all 0.3s;
}

.w3-button.w3-dark-grey:hover {
  background-color: var(--color-accent) !important;
}

/* --- Secondary CTA — text link with arrow --- */
.cta-secondary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--color-primary);
  font-weight: 600;
  font-size: 14px;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, gap 0.3s;
  background: none !important;
  padding: 0 !important;
  border-radius: 0 !important;
}

.cta-secondary:hover {
  border-bottom-color: var(--color-primary);
  gap: 10px;
  color: var(--color-primary) !important;
  background: none !important;
}

.cta-secondary i {
  font-size: 12px;
  transition: transform 0.3s;
}

/* --- Alternating Section Backgrounds --- */
.section-surface {
  background-color: var(--color-surface);
  margin-left: -16px;
  margin-right: -16px;
  padding-left: 16px;
  padding-right: 16px;
}

/* --- Card Light — hairline border, no shadow --- */
.card-light {
  border: 1px solid #E2E8F0;
  border-radius: var(--radius);
  background: var(--color-bg);
  padding: 24px;
  transition: border-color 0.3s, transform 0.3s;
}

.card-light:hover {
  border-color: #CBD5E0;
  transform: translateY(-2px);
}

/* --- Form Card --- */
.form-card {
  border: 1px solid #E2E8F0;
  border-radius: var(--radius);
  background: var(--color-bg);
}

/* --- Cert Icon Circles --- */
.cert-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: 20px;
  margin-bottom: 8px;
}

/* --- Contact Icons --- */
address i.fa-solid {
  color: var(--color-primary);
}

/* --- Footer --- */
footer a {
  color: var(--color-primary);
  margin: 0 8px;
}

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

/* --- Timeline --- */
.timeline {
  position: relative;
  max-width: 100%;
  margin: 24px 0;
  padding-left: 32px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 11px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: #E2E8F0;
}

.timeline-item {
  position: relative;
  margin-bottom: 32px;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: -32px;
  top: 4px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--color-bg);
  border: 2px solid #CBD5E0;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1;
}

.timeline-dot i {
  font-size: 10px;
  color: var(--color-secondary);
}

.timeline-item.career .timeline-dot {
  border-color: var(--color-primary);
  background: var(--color-primary);
}

.timeline-item.career .timeline-dot i {
  color: #ffffff;
}

.timeline-item.education .timeline-dot {
  border-color: var(--color-accent);
  background: var(--color-accent);
}

.timeline-item.education .timeline-dot i {
  color: #ffffff;
}

.timeline-year {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 2px;
}

.timeline-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-primary);
  margin: 0;
}

.timeline-location {
  font-size: 0.875rem;
  color: var(--color-secondary);
  margin: 2px 0 0 0;
}

/* --- Image Grid Spacing --- */
.w3-row-padding img {
  margin-bottom: 12px;
}