/* ————————————————————————————————
   Volker Tietz — monochrome glass
   ———————————————————————————————— */

:root {
  --bg: #050505;
  --fg: #fafafa;
  --grey: #8a8a8a;
  --grey-dim: #555;
  --glass-fill: rgba(255, 255, 255, 0.04);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-border-bright: rgba(255, 255, 255, 0.28);
  --font-display: "Space Grotesk", "Helvetica Neue", sans-serif;
  --font-body: "Inter", "Helvetica Neue", sans-serif;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  font-weight: 300;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection {
  background: var(--fg);
  color: var(--bg);
}

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

/* ————— texture & glows ————— */

.grain {
  position: fixed;
  inset: -50%;
  width: 200%;
  height: 200%;
  pointer-events: none;
  z-index: 100;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)'/%3E%3C/svg%3E");
  animation: grain-shift 0.9s steps(4) infinite;
}

@keyframes grain-shift {
  0% { transform: translate(0, 0); }
  25% { transform: translate(-2%, 1%); }
  50% { transform: translate(1%, -2%); }
  75% { transform: translate(-1%, 2%); }
  100% { transform: translate(0, 0); }
}

.glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
  z-index: 0;
}

.glow-a {
  width: 55vw;
  height: 55vw;
  top: -20vw;
  right: -15vw;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.09), transparent 65%);
  animation: drift-a 24s ease-in-out infinite alternate;
}

.glow-b {
  width: 45vw;
  height: 45vw;
  bottom: -15vw;
  left: -12vw;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.06), transparent 65%);
  animation: drift-b 30s ease-in-out infinite alternate;
}

@keyframes drift-a {
  from { transform: translate(0, 0) scale(1); }
  to { transform: translate(-8vw, 10vh) scale(1.15); }
}

@keyframes drift-b {
  from { transform: translate(0, 0) scale(1); }
  to { transform: translate(10vw, -8vh) scale(1.1); }
}

/* ————— glass ————— */

.glass {
  background: var(--glass-fill);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: transform 0.6s var(--ease-out), border-color 0.6s var(--ease-out),
    background 0.6s var(--ease-out);
}

.glass:hover {
  transform: translateY(-4px);
  border-color: var(--glass-border-bright);
  background: rgba(255, 255, 255, 0.06);
}

/* ————— nav ————— */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.1rem clamp(1.5rem, 5vw, 4rem);
  border-bottom: 1px solid transparent;
  animation: nav-blur linear both;
  animation-timeline: scroll(root);
  animation-range: 0 200px;
}

@keyframes nav-blur {
  to {
    background: rgba(5, 5, 5, 0.55);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom-color: var(--glass-border);
  }
}

@supports not (animation-timeline: scroll()) {
  .nav {
    background: rgba(5, 5, 5, 0.55);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom-color: var(--glass-border);
  }
}

.nav-logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.08em;
}

.nav-links {
  display: flex;
  gap: clamp(1.2rem, 3vw, 2.5rem);
}

.nav-links a {
  font-size: 0.78rem;
  font-weight: 400;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--grey);
  position: relative;
  transition: color 0.4s var(--ease-out);
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 100%;
  height: 1px;
  background: var(--fg);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.5s var(--ease-out);
}

.nav-links a:hover {
  color: var(--fg);
}

.nav-links a:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}

/* ————— hero ————— */

.hero {
  position: relative;
  z-index: 1;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 0 clamp(1.5rem, 6vw, 6rem);
}

.hero-eyebrow {
  font-size: clamp(0.72rem, 1.4vw, 0.85rem);
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--grey);
  margin-bottom: 2rem;
}

.hero-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(4rem, 14vw, 13rem);
  line-height: 0.92;
  letter-spacing: -0.03em;
  text-transform: uppercase;
}

.hero-title .line {
  display: block;
}

.hero-title .line:last-child {
  color: transparent;
  -webkit-text-stroke: 1.5px rgba(250, 250, 250, 0.85);
}

.hero-sub {
  max-width: 34rem;
  margin-top: 2.5rem;
  font-size: clamp(1rem, 1.8vw, 1.25rem);
  color: var(--grey);
}

.hero-sub a {
  color: var(--fg);
  border-bottom: 1px solid var(--grey-dim);
  transition: border-color 0.4s var(--ease-out);
}

.hero-sub a:hover {
  border-color: var(--fg);
}

.hero-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 3.5rem;
  font-size: 0.75rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--grey-dim);
}

.hero-meta .dot {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--grey-dim);
}

.hero-scroll {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  width: 26px;
  height: 44px;
  border: 1px solid var(--grey-dim);
  border-radius: 14px;
  display: flex;
  justify-content: center;
  padding-top: 8px;
}

.hero-scroll span {
  width: 3px;
  height: 8px;
  border-radius: 2px;
  background: var(--grey);
  animation: scroll-hint 2s var(--ease-out) infinite;
}

@keyframes scroll-hint {
  0% { transform: translateY(0); opacity: 1; }
  70% { transform: translateY(14px); opacity: 0; }
  100% { transform: translateY(0); opacity: 0; }
}

/* load-in animation */

.reveal-load {
  opacity: 0;
  animation: rise 1.2s var(--ease-out) forwards;
}

.d1 { animation-delay: 0.15s; }
.d2 { animation-delay: 0.3s; }
.d3 { animation-delay: 0.55s; }
.d4 { animation-delay: 0.75s; }
.d5 { animation-delay: 1s; }

@keyframes rise {
  from { opacity: 0; transform: translateY(40px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ————— marquee ————— */

.marquee {
  position: relative;
  z-index: 1;
  overflow: hidden;
  border-top: 1px solid var(--glass-border);
  border-bottom: 1px solid var(--glass-border);
  padding: 1.4rem 0;
  white-space: nowrap;
}

.marquee-track {
  display: inline-flex;
  animation: marquee 28s linear infinite;
}

.marquee-track span {
  font-family: var(--font-display);
  font-size: clamp(1rem, 2.4vw, 1.6rem);
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--grey-dim);
}

@keyframes marquee {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* ————— sections ————— */

.section {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: clamp(6rem, 14vh, 10rem) clamp(1.5rem, 5vw, 3rem) 0;
}

.section-head {
  display: flex;
  align-items: baseline;
  gap: 1.5rem;
  margin-bottom: clamp(3rem, 7vh, 5rem);
  border-bottom: 1px solid var(--glass-border);
  padding-bottom: 1.5rem;
}

.section-index {
  font-family: var(--font-display);
  font-size: 0.85rem;
  letter-spacing: 0.2em;
  color: var(--grey-dim);
}

.section-title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(2.2rem, 6vw, 4.5rem);
  letter-spacing: -0.02em;
  text-transform: uppercase;
  line-height: 1;
}

/* scroll reveal */

.reveal {
  animation: reveal-rise 1s var(--ease-out) both;
  animation-timeline: view();
  animation-range: entry 0% entry 40%;
}

@keyframes reveal-rise {
  from { opacity: 0; transform: translateY(48px); }
  to { opacity: 1; transform: translateY(0); }
}

@supports not (animation-timeline: view()) {
  .reveal {
    animation: none;
  }
}

/* ————— about ————— */

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 6vw, 5rem);
}

.about-lead {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: clamp(1.4rem, 2.8vw, 2rem);
  line-height: 1.35;
  letter-spacing: -0.01em;
}

.about-body {
  color: var(--grey);
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
  font-size: 1.02rem;
}

/* ————— timeline ————— */

.timeline {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.t-item {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: start;
}

.t-period {
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--grey-dim);
  padding-top: 1.9rem;
  white-space: nowrap;
}

.t-card {
  padding: clamp(1.6rem, 3vw, 2.4rem);
}

.t-role-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  margin-bottom: 0.9rem;
}

.t-role-row h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(1.15rem, 2.2vw, 1.5rem);
  letter-spacing: -0.01em;
}

.t-company {
  font-size: 0.8rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--grey);
}

a.t-company {
  border-bottom: 1px solid var(--grey-dim);
  transition: color 0.4s var(--ease-out), border-color 0.4s var(--ease-out);
}

a.t-company:hover {
  color: var(--fg);
  border-color: var(--fg);
}

.t-card p {
  color: var(--grey);
  font-size: 0.98rem;
  max-width: 56ch;
}

/* ————— expertise ————— */

.expertise-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.e-card {
  padding: 2rem 1.8rem;
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  min-height: 220px;
}

.e-num {
  font-family: var(--font-display);
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  color: var(--grey-dim);
}

.e-card h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.2rem;
  letter-spacing: -0.01em;
  margin-top: auto;
}

.e-card p {
  color: var(--grey);
  font-size: 0.92rem;
}

/* ————— education ————— */

.edu-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.edu-card {
  padding: 2.2rem;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}

.edu-degree {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 2.2rem;
  letter-spacing: -0.02em;
  color: transparent;
  -webkit-text-stroke: 1px rgba(250, 250, 250, 0.7);
}

.edu-card h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.15rem;
}

.edu-card p {
  color: var(--grey);
  font-size: 0.95rem;
}

/* ————— contact ————— */

.contact {
  padding-bottom: clamp(6rem, 14vh, 10rem);
}

.contact-inner {
  padding: clamp(3rem, 8vw, 6rem);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2rem;
}

.contact-eyebrow {
  font-size: 0.78rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--grey);
}

.contact-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.4rem, 7vw, 5.5rem);
  line-height: 1.05;
  letter-spacing: -0.03em;
  text-transform: uppercase;
}

.contact-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
  margin-top: 1rem;
}

.contact-links a {
  font-size: 0.8rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  padding: 0.9rem 1.8rem;
  border: 1px solid var(--glass-border);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.03);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background 0.5s var(--ease-out), color 0.5s var(--ease-out),
    border-color 0.5s var(--ease-out), transform 0.5s var(--ease-out);
}

.contact-links a:hover {
  background: var(--fg);
  color: var(--bg);
  border-color: var(--fg);
  transform: translateY(-3px);
}

/* ————— footer ————— */

.footer {
  position: relative;
  z-index: 1;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 2rem clamp(1.5rem, 5vw, 4rem);
  border-top: 1px solid var(--glass-border);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--grey-dim);
}

/* ————— responsive ————— */

@media (max-width: 900px) {
  .expertise-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 720px) {
  .about-grid,
  .edu-grid {
    grid-template-columns: 1fr;
  }

  .t-item {
    grid-template-columns: 1fr;
    gap: 0.6rem;
  }

  .t-period {
    padding-top: 0;
  }

  .expertise-grid {
    grid-template-columns: 1fr;
  }

  .e-card {
    min-height: 0;
  }

  .nav-links {
    gap: 1rem;
  }

  .nav-links a {
    font-size: 0.68rem;
    letter-spacing: 0.12em;
  }
}

/* ————— reduced motion ————— */

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .grain,
  .glow-a,
  .glow-b,
  .marquee-track,
  .hero-scroll span {
    animation: none;
  }

  .reveal,
  .reveal-load {
    animation: none;
    opacity: 1;
  }
}