/* ===== Rivaldo Siregar - Portfolio Stylesheet ===== */
:root{
  --bg:        #0a0a0a;
  --surface:   #131313;
  --line:      #2a2a2a;
  --line-soft:#1c1c1c;
  --ink:       #f2f1ed;
  --ink-dim:   #9a9a95;
  --ink-mute:  #5c5c58;
  --accent:    #f2f1ed;
  --radius: 2px;
  --maxw: 1120px;
}

*{ box-sizing:border-box; }
html{ background:var(--bg); scroll-behavior:smooth; }
body{
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font-family:'Inter', sans-serif;
  font-size:16px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
::selection{ background:var(--ink); color:var(--bg); }

h1,h2,h3,h4{
  font-family:'Space Grotesk', sans-serif;
  font-weight:600;
  margin:0;
  letter-spacing:-0.01em;
}
.mono{ font-family:'IBM Plex Mono', monospace; }

a{ color:inherit; text-decoration:none; }
.wrap{ max-width:var(--maxw); margin:0 auto; padding:0 28px; }

@media (prefers-reduced-motion: reduce){
  *{ animation-duration:0.001ms !important; animation-iteration-count:1 !important; transition-duration:0.001ms !important; }
}

/* ---------- Reveal on scroll ---------- */
.reveal{ opacity:0; transform:translateY(10px); transition:opacity .5s ease, transform .5s ease; }
.reveal.is-visible{ opacity:1; transform:translateY(0); }
.reveal-delay-1{ transition-delay:.05s; }
.reveal-delay-2{ transition-delay:.10s; }
.reveal-delay-3{ transition-delay:.15s; }

/* ---------- Header ---------- */
header{
  position:sticky; top:0; z-index:50;
  background:rgba(10,10,10,.85);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line-soft);
}
nav.wrap{
  display:flex; align-items:center; justify-content:space-between;
  height:74px;
}
.brand{
  font-family:'Space Grotesk', sans-serif;
  font-weight:700; font-size:18px; letter-spacing:-0.02em;
  display:flex; align-items:center; gap:10px;
}
.brand .dot{
  width:8px; height:8px; border-radius:50%;
  background:var(--ink);
  animation:pulse-dot 3s ease-in-out infinite;
}
@keyframes pulse-dot{
  0%,100%{ opacity:1; }
  50%{ opacity:.4; }
}
.nav-links{ display:flex; gap:36px; font-size:14px; color:var(--ink-dim); }
.nav-links a{ position:relative; padding:4px 0; transition:color .25s ease; }
.nav-links a::after{
  content:''; position:absolute; left:0; bottom:-2px; width:0; height:1px; background:var(--ink);
  transition:width .3s ease;
}
.nav-links a:hover{ color:var(--ink); }
.nav-links a:hover::after{ width:100%; }
.nav-cta{
  font-size:13px; border:1px solid var(--line); padding:9px 18px; border-radius:100px;
  transition:background .25s ease, color .25s ease, border-color .25s ease;
}
.nav-cta:hover{ background:var(--ink); color:var(--bg); border-color:var(--ink); }
.menu-toggle{ display:none; background:none; border:none; color:var(--ink); font-size:22px; cursor:pointer; }
#mobileMenu{
  display:none; flex-direction:column; gap:0; border-top:1px solid var(--line-soft);
  background:var(--bg);
}
#mobileMenu a{ padding:16px 28px; border-bottom:1px solid var(--line-soft); font-size:15px; color:var(--ink-dim); }
#mobileMenu.open{ display:flex; }

@media (max-width:860px){
  .nav-links, .nav-cta{ display:none; }
  .menu-toggle{ display:block; }
}

/* ---------- Hero ---------- */
.hero{
  position:relative;
  min-height:92vh;
  display:flex; align-items:center;
  overflow:hidden;
  border-bottom:1px solid var(--line-soft);
}
.hero-grid{
  position:absolute; inset:0;
  background-image:
    linear-gradient(to right, var(--line-soft) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line-soft) 1px, transparent 1px);
  background-size:56px 56px;
  mask-image:radial-gradient(ellipse 70% 60% at 50% 40%, black 30%, transparent 80%);
  opacity:.4;
  animation:grid-pulse 8s ease-in-out infinite;
}

@keyframes grid-pulse {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 0.5; }
}

.scanline{ display:none; }

.hero-inner{ position:relative; z-index:2; padding:140px 0 100px; width:100%; }
.eyebrow{
  display:inline-flex; align-items:center; gap:10px;
  font-size:12.5px; letter-spacing:.14em; text-transform:uppercase;
  color:var(--ink-dim); margin-bottom:26px;
}
.eyebrow .bar{ width:28px; height:1px; background:var(--ink-dim); }
.hero h1{
  font-size:clamp(2.6rem, 7vw, 5.4rem);
  line-height:1.02;
  max-width:14ch;
}
.hero h1 .role{
  display:block; color:var(--ink-dim); font-weight:500;
  font-size:clamp(1.1rem, 2.4vw, 1.6rem);
  margin-top:20px;
  font-family:'Inter',sans-serif;
}
.cursor{ display:inline-block; width:2px; height:.9em; background:var(--ink); margin-left:4px; vertical-align:-2px; animation:blink 1s step-start infinite; }
@keyframes blink{ 50%{ opacity:0; } }

.hero-sub{ max-width:52ch; color:var(--ink-dim); font-size:16.5px; margin-top:28px; }

.hero-actions{ display:flex; gap:16px; margin-top:44px; flex-wrap:wrap; }
.btn{
  font-size:14.5px; padding:14px 30px; border-radius:100px;
  display:inline-flex; align-items:center; gap:10px;
  transition:transform .3s ease, background .3s ease, color .3s ease, border-color .3s ease;
}
.btn-solid{ background:var(--ink); color:var(--bg); }
.btn-solid:hover{ transform:translateY(-2px); }
.btn-outline{ border:1px solid var(--line); color:var(--ink); }
.btn-outline:hover{ border-color:var(--ink); transform:translateY(-2px); }

/* diagnostic */
.diagnostic{
  position:absolute; right:6%; top:50%; transform:translateY(-50%);
  width:280px;
  border:1px solid var(--line); border-radius:var(--radius);
  background:rgba(19,19,19,.7); backdrop-filter:blur(6px);
  padding:20px 20px 16px;
  font-family:'IBM Plex Mono', monospace; font-size:11.5px; color:var(--ink-dim);
}
.diagnostic .d-head{ display:flex; justify-content:space-between; color:var(--ink); margin-bottom:14px; letter-spacing:.05em; }
.diagnostic .d-row{ display:flex; justify-content:space-between; padding:6px 0; border-top:1px solid var(--line-soft); }
.diagnostic .ok{ color:var(--ink); }
.diagnostic .ok::before{ content:'● '; }
@media (max-width:1080px){ .diagnostic{ display:none; } }

.scroll-cue{
  position:absolute; bottom:34px; left:50%; transform:translateX(-50%);
  display:flex; flex-direction:column; align-items:center; gap:10px;
  color:var(--ink-mute); font-size:11px; letter-spacing:.1em; text-transform:uppercase;
}
.scroll-cue .line{ width:1px; height:34px; background:var(--line); position:relative; overflow:hidden; }
.scroll-cue .line::after{
  content:''; position:absolute; top:-40%; left:0; width:100%; height:40%; background:var(--ink);
  animation:down 2.2s ease-in-out infinite;
}
@keyframes down{ 0%{ top:-40%; } 100%{ top:100%; } }

/* ---------- Section shell ---------- */
section{ padding:110px 0; border-bottom:1px solid var(--line-soft); }
.section-head{ margin-bottom:64px; max-width:640px; }
.section-head .eyebrow{ margin-bottom:18px; }
.section-head h2{ font-size:clamp(1.8rem, 4vw, 2.6rem); }
.section-head p{ color:var(--ink-dim); margin-top:16px; font-size:15.5px; }

/* ---------- Profile ---------- */
#profile .grid{ display:grid; grid-template-columns:1fr 1.6fr; gap:64px; }
.stat-block{ display:flex; flex-direction:column; gap:34px; }
.stat{ border-top:1px solid var(--line-soft); padding-top:16px; }
.stat .num{ font-family:'Space Grotesk',sans-serif; font-size:2.2rem; font-weight:600; }
.stat .label{ color:var(--ink-dim); font-size:13.5px; margin-top:4px; }
#profile .bio p{ color:var(--ink-dim); font-size:16px; margin:0 0 20px; }
#profile .bio strong{ color:var(--ink); font-weight:600; }
@media (max-width:860px){ #profile .grid{ grid-template-columns:1fr; gap:40px; } }

/* ---------- Experience timeline ---------- */
.timeline{ position:relative; }
.timeline::before{
  content:''; position:absolute; left:150px; top:6px; bottom:6px; width:1px; background:var(--line);
}
.tl-item{ position:relative; padding-left:210px; padding-bottom:64px; }
.tl-item:last-child{ padding-bottom:0; }
.tl-item::before{
  content:''; position:absolute; left:145px; top:6px; width:11px; height:11px; border-radius:50%;
  background:var(--bg); border:1px solid var(--ink); z-index:2;
}
.tl-date{
  position:absolute; left:0; top:2px; width:130px; text-align:right;
  font-family:'IBM Plex Mono',monospace; font-size:12px; color:var(--ink-dim); line-height:1.5;
}
.tl-role{ font-family:'Space Grotesk',sans-serif; font-size:1.3rem; font-weight:600; }
.tl-org{ color:var(--ink-dim); font-size:14.5px; margin-top:4px; }
.tl-proj{ margin-top:26px; padding-top:22px; border-top:1px solid var(--line-soft); }
.tl-proj:first-of-type{ margin-top:22px; }
.tl-proj-title{ font-size:15.5px; font-weight:600; margin-bottom:8px; }
.tl-stack{ font-family:'IBM Plex Mono',monospace; font-size:11.5px; color:var(--ink-mute); margin-bottom:14px; line-height:1.7; }
.tl-list{ margin:0; padding-left:18px; color:var(--ink-dim); font-size:14.5px; }
.tl-list li{ margin-bottom:7px; }
@media (max-width:760px){
  .timeline::before{ left:8px; }
  .tl-item{ padding-left:34px; }
  .tl-item::before{ left:3px; }
  .tl-date{ position:static; text-align:left; margin-bottom:8px; width:auto; }
}

/* ---------- Projects ---------- */
.proj-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:1px; background:var(--line-soft); border:1px solid var(--line-soft); }
.proj-card{
  background:var(--bg); padding:32px; display:flex; flex-direction:column; gap:14px;
  transition:background .3s ease;
}
.proj-card:hover{ background:var(--surface); }
.proj-index{ font-family:'IBM Plex Mono',monospace; color:var(--ink-mute); font-size:12px; }
.proj-card h3{ font-size:1.1rem; }
.proj-card p{ color:var(--ink-dim); font-size:13.8px; margin:0; flex-grow:1; }
.proj-tags{ display:flex; flex-wrap:wrap; gap:6px; margin-top:8px; }
.tag{ font-family:'IBM Plex Mono',monospace; font-size:10.5px; color:var(--ink-dim); border:1px solid var(--line); border-radius:100px; padding:4px 10px; }
@media (max-width:860px){ .proj-grid{ grid-template-columns:1fr; } }
@media (min-width:861px) and (max-width:1080px){ .proj-grid{ grid-template-columns:repeat(2,1fr); } }

/* ---------- Skills ---------- */
.skills-grid{ display:grid; grid-template-columns:repeat(4,1fr); gap:44px 32px; }
.skill-cat h4{ font-size:14px; text-transform:uppercase; letter-spacing:.08em; color:var(--ink-dim); margin-bottom:16px; font-family:'IBM Plex Mono',monospace; font-weight:400; }
.skill-cat ul{ list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:9px; }
.skill-cat li{ font-size:14.5px; position:relative; padding-left:16px; }
.skill-cat li::before{ content:'-'; position:absolute; left:0; color:var(--ink-mute); }
@media (max-width:900px){ .skills-grid{ grid-template-columns:repeat(2,1fr); } }
@media (max-width:560px){ .skills-grid{ grid-template-columns:1fr; } }

/* ---------- Education / Awards / Certs ---------- */
.three-col{ display:grid; grid-template-columns:repeat(3,1fr); gap:48px; }
.col-block h4{ font-size:13px; text-transform:uppercase; letter-spacing:.1em; color:var(--ink-dim); margin-bottom:22px; font-family:'IBM Plex Mono',monospace; font-weight:400; }
.edu-card .school{ font-family:'Space Grotesk',sans-serif; font-size:1.15rem; font-weight:600; }
.edu-card .deg{ color:var(--ink-dim); font-size:14px; margin-top:6px; }
.edu-card .gpa{ margin-top:16px; font-family:'IBM Plex Mono',monospace; font-size:13px; }
.list-plain{ list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:16px; }
.list-plain li{ font-size:14px; color:var(--ink-dim); padding-bottom:16px; border-bottom:1px solid var(--line-soft); }
.list-plain li:last-child{ border-bottom:none; padding-bottom:0; }
.list-plain li strong{ display:block; color:var(--ink); font-size:14.5px; margin-bottom:3px; font-weight:600; }
@media (max-width:860px){ .three-col{ grid-template-columns:1fr; gap:48px; } }

/* ---------- Contact ---------- */
#contact{ border-bottom:none; }
.contact-inner{ display:flex; justify-content:space-between; align-items:flex-end; gap:40px; flex-wrap:wrap; }
#contact h2{ font-size:clamp(2rem,5vw,3rem); max-width:11ch; }
.contact-links{ display:flex; flex-direction:column; gap:0; min-width:260px; }
.contact-links a{
  display:flex; justify-content:space-between; align-items:center;
  padding:18px 0; border-bottom:1px solid var(--line-soft); font-size:15px;
  transition:opacity .25s ease, gap .25s ease;
}
.contact-links a:hover{ opacity:.7; }
.contact-links a .arrow{ transition:transform .25s ease; }
.contact-links a:hover .arrow{ transform:translateX(4px); }
.contact-meta{ margin-top:60px; display:flex; gap:56px; flex-wrap:wrap; color:var(--ink-dim); font-size:13.5px; }
.contact-meta .m-label{ font-family:'IBM Plex Mono',monospace; font-size:11px; text-transform:uppercase; letter-spacing:.08em; color:var(--ink-mute); margin-bottom:6px; }

footer{ padding:34px 0; }
footer .wrap{ display:flex; justify-content:space-between; align-items:center; color:var(--ink-mute); font-size:12.5px; flex-wrap:wrap; gap:12px; }
footer .socials{ display:flex; gap:22px; }
footer .socials a{ color:var(--ink-dim); transition:color .25s ease; }
footer .socials a:hover{ color:var(--ink); }

::-webkit-scrollbar{ width:10px; }
::-webkit-scrollbar-track{ background:var(--bg); }
::-webkit-scrollbar-thumb{ background:var(--line); border-radius:10px; }