script.js

'use strict';

// Smooth scroll for anchor links and arrow button (respects reduced motion)
(function(){
  const prefersReduced = window.matchMedia && window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  function smoothScrollTo(target) {
    if (!target) return;
    const el = (typeof target === 'string') ? document.querySelector(target) : target;
    if (!el) return;
    el.scrollIntoView({ behavior: prefersReduced ? 'auto' : 'smooth', block: 'start' });
  }

  document.querySelectorAll('a[href^="#"]').forEach(a => {
    a.addEventListener('click', e => {
      const href = a.getAttribute('href');
      if (href && href.length > 1) {
        e.preventDefault();
        smoothScrollTo(href);
      }
    }, { passive: false });
  });

  document.querySelectorAll('.down-arrow').forEach(btn => {
    btn.addEventListener('click', () => {
      const target = btn.getAttribute('data-scroll-target') || '#mission';
      smoothScrollTo(target);
    });
  });
})();

// Reveal-on-scroll with IntersectionObserver (fallback: show all)
(function(){
  const items = document.querySelectorAll('.reveal');
  if (!('IntersectionObserver' in window)) {
    items.forEach(i => i.classList.add('is-visible'));
    return;
  }
  const obs = new IntersectionObserver((entries, observer) => {
    entries.forEach(entry => {
      if (entry.isIntersecting) {
        entry.target.classList.add('is-visible');
        observer.unobserve(entry.target);
      }
    });
  }, { threshold: 0.15, rootMargin: '0px 0px -40px 0px' });
  items.forEach(i => obs.observe(i));
})();

// Glassy navbar: shrink on scroll, hide on scroll-down, show on scroll-up
(function(){
  const header = document.getElementById('site-header');
  const toggle = document.querySelector('.nav-toggle');
  const menu = document.getElementById('nav-menu');
  if (!header) return;
  let lastY = window.scrollY || 0;
  const onScroll = () => {
    const y = window.scrollY || 0;
    if (y > 20) header.classList.add('scrolled'); else header.classList.remove('scrolled');
    if (y > lastY + 10 && y > 80) header.classList.add('hide');
    if (y < lastY - 10) header.classList.remove('hide');
    lastY = y;
  };
  window.addEventListener('scroll', onScroll, { passive: true });

  if (toggle && menu) {
    function setOpen(open){
      header.classList.toggle('open', open);
      toggle.setAttribute('aria-expanded', String(open));
      document.body.style.overflow = open ? 'hidden' : '';
    }
    toggle.addEventListener('click', () => {
      const willOpen = !header.classList.contains('open');
      setOpen(willOpen);
    });
    // Close on link click (for mobile)
    document.querySelectorAll('.nav-menu a').forEach(a => a.addEventListener('click', () => {
      setOpen(false);
    }));
    // Close on Escape
    document.addEventListener('keydown', (e) => {
      if (e.key === 'Escape') setOpen(false);
    });
    // Close on overlay click
    header.addEventListener('click', (e) => {
      if (header.classList.contains('open') && e.target === header) setOpen(false);
    });
  }
})();

// Internationalization (EN/TR) with safe textContent updates
(function(){
  const allowed = ['en','tr'];
  const langBtns = document.querySelectorAll('.lang-btn');
  const t = {
    en: {
      brand: 'Cosotech',
      'nav.home': 'Home',
      'nav.about': 'About',
      'nav.team': 'Team',
      'nav.missions': 'Our Missions',
      'nav.contact': 'Contact',
      'hero.title': 'Cosotech Reaching for the Stars',
      'hero.lead': "We are five passionate high school students dedicated to aerospace engineering, united by our mission to innovate, create, and push the boundaries of what's possible through the Teknofest Model Rocket Competition.",
      'hero.scroll': 'Scroll to explore',
      'mission.title': 'Our Mission',
      'mission.p1': 'At Cosotech, we believe that the future of space exploration begins with young minds 敢于梦想和创新. Our team is dedicated to designing, building, and launching model rockets that push the boundaries of what\'s possible while learning the fundamentals of aerospace engineering.',
      'mission.p2': "Through the prestigious Teknofest Model Rocket Competition, we showcase our technical skills, creativity, and teamwork, inspiring others to pursue careers in STEM fields and contribute to Turkey\'s growing aerospace sector.",
      'team.title': 'Meet Our Team',
      'team.subtitle': 'Five passionate students on a mission to the stars',
      'role.leader': 'Team Leader',
      'role.propulsion': 'Propulsion Engineer',
      'role.aero': 'Aerodynamics Specialist',
      'role.structural': 'Structural Engineer',
      'role.electronics': 'Electronics Engineer',
      'competition.title': 'Teknofest Model Rocket Competition',
      'competition.p1': "Teknofest is Turkey\'s premier aerospace and technology festival, bringing together the brightest young minds to compete in various categories including model rocketry. Our team is proud to participate in this prestigious competition, where we test our engineering skills against the best teams from across Turkey and beyond.",
      'stats.members': 'Team Members',
      'stats.altitude': 'Target Altitude',
      'stats.mission': 'Mission',
      'btn.explore': 'Explore Our Missions',
      'cta.title': 'Ready to Launch',
      'cta.text': 'Follow our journey as we reach for the stars',
      'cta.btn': 'Get In Touch',
'stars.skip': 'Skip animation',
      'contact.title': 'Get in Touch',
      'contact.subtitle': "We'd love to hear from you. Reach out with questions, partnerships, or encouragement.",
      'contact.info': 'Contact Information',
      'contact.cards.emailTitle': 'Email',
      'contact.cards.emailText': 'For general inquiries and media.',
      'contact.cards.socialTitle': 'Social',
      'contact.cards.socialText': 'Follow our journey on social media.',
      'contact.cards.locationTitle': 'Location',
      'contact.cards.locationText': 'Turkey • Remote collaboration',
      'contact.form.title': 'Send us a message',
      'contact.form.nameLabel': 'Name',
      'contact.form.emailLabel': 'Email',
      'contact.form.msgLabel': 'Message',
      'contact.form.submit': 'Send',
      'contact.form.emailInvalid': 'Please enter a valid email address.',
'contact.form.opening': 'Opening your email app...',
      'team.page.title': 'Meet Our Team',
      'team.page.subtitle': 'Five passionate students on a mission to the stars.',
      'team.page.members': 'Team Members',
      'about.title': 'About Cosotech',
      'about.subtitle': 'A student team united by curiosity, engineering, and the spirit of flight.',
      'about.story.title': 'Our Story',
      'about.story.p1': 'We started Cosotech with a shared dream: to learn by building, test by launching, and grow by collaborating. Teknofest’s Model Rocket Competition became our stage to apply theory in the real world.',
      'about.story.p2': 'From CAD and aerodynamics to propulsion and electronics, our workflow is hands-on and iterative. We document, test, and improve continuously—celebrating both successes and lessons.',
      'about.values.title': 'Values',
      'about.values.v1t': 'Innovation',
      'about.values.v1d': 'We design boldly and iterate responsibly.',
      'about.values.v2t': 'Collaboration',
      'about.values.v2d': 'We learn fastest when we learn together.',
      'about.values.v3t': 'Safety',
      'about.values.v3d': 'We put safety first in design, testing, and launches.',
      'missions.title': 'Our Missions',
      'missions.subtitle': 'From design to launch — pushing boundaries with every flight.',
      'missions.current': 'Current Mission',
      'missions.m1.title': 'Model Rocket — Target 1000m+',
      'missions.m1.desc': 'A lightweight, stable rocket optimized for altitude, with reliable recovery and telemetry.',
      'missions.cta.title': 'Follow the Journey',
      'missions.cta.text': 'Stay updated as we build, test, and launch. Your feedback helps us improve.',
      'missions.cta.btn': 'Contact Us'
    },
    tr: {
      brand: 'Cosotech',
      'nav.home': 'Ana Sayfa',
      'nav.about': 'Hakkımızda',
      'nav.team': 'Ekip',
      'nav.missions': 'Misyonlarımız',
      'nav.contact': 'İletişim',
      'hero.title': 'Cosotech Yıldızlara Ulaşıyor',
      'hero.lead': 'Biz, Teknofest Model Roket Yarışması aracılığıyla yenilik üretmeye, tasarlamaya ve mümkün olanın sınırlarını zorlamaya adanmış beş tutkulu lise öğrencisiyiz.',
      'hero.scroll': 'Keşfetmek için kaydırın',
      'mission.title': 'Misyonumuz',
      'mission.p1': 'Cosotech\'te, uzay keşfinin geleceğinin genç zihinlerle başladığına inanıyoruz 敢于梦想和创新. Ekibimiz, havacılık ve uzay mühendisliğinin temellerini öğrenirken mümkün olanın sınırlarını zorlayan model roketler tasarlamaya, inşa etmeye ve fırlatmaya kendini adamıştır.',
      'mission.p2': 'Prestijli Teknofest Model Roket Yarışması ile teknik becerilerimizi, yaratıcılığımızı ve takım çalışmamızı sergileyerek, STEM alanlarına ilgiyi artırmayı ve Türkiye\'nin büyüyen havacılık ve uzay ekosistemine katkı sunmayı amaçlıyoruz.',
      'team.title': 'Ekibimizle Tanışın',
      'team.subtitle': 'Yıldızlara giden yolda beş tutkulu öğrenci',
      'role.leader': 'Takım Lideri',
      'role.propulsion': 'İtki Mühendisi',
      'role.aero': 'Aerodinamik Uzmanı',
      'role.structural': 'Yapısal Mühendis',
      'role.electronics': 'Elektronik Mühendisi',
      'competition.title': 'Teknofest Model Roket Yarışması',
      'competition.p1': 'Teknofest, Türkiye\'nin önde gelen havacılık ve teknoloji festivalidir; model roketçilik de dahil olmak üzere pek çok kategoride en parlak gençleri bir araya getirir. Ekibimiz, Türkiye ve ötesindeki en iyi takımlarla mühendislik yeteneklerimizi sınadığımız bu prestijli yarışmada yer almaktan gurur duyuyor.',
      'stats.members': 'Takım Üyesi',
      'stats.altitude': 'Hedef İrtifa',
      'stats.mission': 'Misyon',
      'btn.explore': 'Misyonlarımızı Keşfedin',
      'cta.title': 'Fırlatmaya Hazır',
      'cta.text': 'Yıldızlara uzanan yolculuğumuzu takip edin',
      'cta.btn': 'İletişime Geçin',
'stars.skip': 'Animasyonu geç',
      'contact.title': 'İletişime Geçin',
      'contact.subtitle': 'Sizden haber almak isteriz. Sorular, iş birlikleri veya destek için bize ulaşın.',
      'contact.info': 'İletişim Bilgileri',
      'contact.cards.emailTitle': 'E-posta',
      'contact.cards.emailText': 'Genel sorular ve medya için.',
      'contact.cards.socialTitle': 'Sosyal',
      'contact.cards.socialText': 'Yolculuğumuzu sosyal medyada takip edin.',
      'contact.cards.locationTitle': 'Konum',
      'contact.cards.locationText': 'Türkiye • Uzaktan çalışma',
      'contact.form.title': 'Bize mesaj gönderin',
      'contact.form.nameLabel': 'Ad Soyad',
      'contact.form.emailLabel': 'E-posta',
      'contact.form.msgLabel': 'Mesaj',
      'contact.form.submit': 'Gönder',
      'contact.form.emailInvalid': 'Geçerli bir e‑posta adresi girin.',
'contact.form.opening': 'E-posta uygulamanız açılıyor...',
      'team.page.title': 'Ekibimizle Tanışın',
      'team.page.subtitle': 'Yıldızlara giden yolda beş tutkulu öğrenci',
      'team.page.members': 'Takım Üyeleri',
      'about.title': 'Cosotech Hakkında',
      'about.subtitle': 'Merak, mühendislik ve uçuş ruhuyla birleşen bir öğrenci takımı.',
      'about.story.title': 'Hikayemiz',
      'about.story.p1': 'Cosotech\'i ortak bir hayalle kurduk: yaparak öğrenmek, fırlatarak sınamak ve birlikte çalışarak büyümek. Teknofest Model Roket Yarışması, teoriyi gerçeğe dönüştürdüğümüz sahnemiz oldu.',
      'about.story.p2': 'CAD ve aerodinamikten itkiye ve elektroniğe kadar iş akışımız uygulamalı ve yinelemelidir. Başarıları ve çıkarımları sürekli belgeliyor, test ediyor ve geliştiriyoruz.',
      'about.values.title': 'Değerler',
      'about.values.v1t': 'İnovasyon',
      'about.values.v1d': 'Cesur tasarlarız ve sorumlu şekilde iterasyon yaparız.',
      'about.values.v2t': 'İş Birliği',
      'about.values.v2d': 'En hızlı birlikte öğrenirken öğreniriz.',
      'about.values.v3t': 'Güvenlik',
      'about.values.v3d': 'Tasarımda, testte ve fırlatmalarda güvenliği önceleyiz.',
      'missions.title': 'Misyonlarımız',
      'missions.subtitle': 'Tasarım aşamasından fırlatmaya — her uçuşla sınırları zorluyoruz.',
      'missions.current': 'Güncel Misyon',
      'missions.m1.title': 'Model Roket — Hedef 1000m+',
      'missions.m1.desc': 'Yüksek irtifa için optimize edilmiş, kararlı, güvenilir kurtarma ve telemetriye sahip hafif bir roket.',
      'missions.cta.title': 'Yolculuğu Takip Edin',
      'missions.cta.text': 'Geliştirirken, test ederken ve fırlatırken güncel kalın. Geri bildirimleriniz bize güç verir.',
      'missions.cta.btn': 'Bize Ulaşın'
    }
  };

  function applyLanguage(lang){
    const safeLang = allowed.includes(lang) ? lang : 'en';
    document.documentElement.setAttribute('lang', safeLang);
    try {
      localStorage.setItem('lang', safeLang);
    } catch(e) {
      // localStorage might be disabled or full
      console.warn('Could not save language preference');
    }
    // Update pressed state
    langBtns.forEach(btn => btn.setAttribute('aria-pressed', String(btn.dataset.lang === safeLang)));
    // Apply translations
    document.querySelectorAll('[data-i18n]').forEach(el => {
      const key = el.getAttribute('data-i18n');
      const val = key ? t[safeLang][key] : null;
      if (typeof val === 'string') el.textContent = val;
    });
  }

  // Expose a read-only getter for other modules (e.g., form) to retrieve translations safely
  const i18nGet = function(key){
    try {
      const lang = document.documentElement.getAttribute('lang') || 'en';
      const dict = (t && t[lang]) ? t[lang] : t.en;
      return (dict && typeof dict[key] === 'string') ? dict[key] : '';
    } catch { return ''; }
  };
  
  // Make it read-only and non-configurable
  Object.defineProperty(window, '__i18nGet', {
    value: i18nGet,
    writable: false,
    configurable: false,
    enumerable: false
  });

  let saved = null;
  try {
    saved = localStorage.getItem('lang');
  } catch(e) {
    // localStorage might be disabled
  }
  const initial = allowed.includes(saved) ? saved : ((navigator.language || '').toLowerCase().startsWith('tr') ? 'tr' : 'en');
  applyLanguage(initial);

  langBtns.forEach(btn => btn.addEventListener('click', () => {
    const lang = btn.dataset.lang;
    if (lang && allowed.includes(lang)) applyLanguage(lang);
  }));
})();

// First-visit fullscreen starfield (respects reduced motion, can be skipped)
(function(){
  const canvas = document.getElementById('stars-canvas');
  if (!canvas) return;
  const skipBtn = document.querySelector('.stars-skip');
  const prefersReduced = window.matchMedia && window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  if (prefersReduced) { canvas.remove(); if (skipBtn) skipBtn.remove(); return; }

  const page = (document.body && document.body.dataset && document.body.dataset.page) || '';
  const alwaysPlay = page === 'home';
  let played = false;
  try {
    played = sessionStorage.getItem('starsPlayed') === '1';
  } catch(e) {
    // sessionStorage might be disabled
  }
  if (!alwaysPlay && played) { canvas.remove(); if (skipBtn) skipBtn.remove(); return; }

  const ctx = canvas.getContext('2d');
  let w=0, h=0, dpr=1, rafId, running = true, started = false;

  function resize(){
    dpr = Math.max(1, Math.min(2, window.devicePixelRatio || 1));
    w = Math.max(1, Math.floor((window.innerWidth || 1) * dpr));
    h = Math.max(1, Math.floor((window.innerHeight || 1) * dpr));
    canvas.width = w; canvas.height = h;
    ctx.setTransform(1,0,0,1,0,0); // draw in device pixels then scale coords
  }
  window.addEventListener('resize', resize, { passive: true });
  resize();

  // Pre-rendered star sprites with color variation
  const sprites = [];
  const colors = [
    {r:255,g:255,b:255,a:1},     // white
    {r:200,g:220,b:255,a:0.95},  // blue-white
    {r:255,g:240,b:220,a:0.92},  // warm white
    {r:180,g:200,b:255,a:0.9},   // blue
    {r:255,g:230,b:180,a:0.88}   // yellow-white
  ];
  for (let c of colors){
    const sp = document.createElement('canvas'); sp.width = sp.height = 32;
    const sc = sp.getContext('2d');
    const g = sc.createRadialGradient(16,16,0,16,16,16);
    g.addColorStop(0, `rgba(${c.r},${c.g},${c.b},${c.a})`);
    g.addColorStop(0.35, `rgba(${Math.floor(c.r*0.9)},${Math.floor(c.g*0.9)},${Math.floor(c.b*0.9)},${c.a*0.6})`);
    g.addColorStop(1, 'rgba(0,0,0,0)');
    sc.fillStyle = g; sc.beginPath(); sc.arc(16,16,16,0,Math.PI*2); sc.fill();
    sprites.push(sp);
  }

  // Layers with depth
  const area = (window.innerWidth||800)*(window.innerHeight||600);
  const TWINKLES = Math.max(30, Math.min(280, Math.round(area/11000)));
  const FIELDS = Math.max(40, Math.min(180, Math.round(area/22000)));
  const DISTANT = Math.max(30, Math.min(140, Math.round(area/28000)));
  const METEOR_RATE = Math.max(600, Math.min(1400, 1200 - Math.round(area/12000)));

  const twinkles = []; // {x,y,size,phase,speed,alpha,sprite}
  const field = [];    // {x,y,dx,dy,size,depth}
  const distant = [];  // {x,y,size,alpha} static deep background
  const meteors = [];  // {x,y,dx,dy,len,life,ttl,colorIdx}
  const rnd = (a,b)=>a+Math.random()*(b-a);
  const pickSprite = ()=> sprites[Math.floor(Math.random()*sprites.length)];

  for (let i=0;i<DISTANT;i++){
    distant.push({x:Math.random()*w, y:Math.random()*h, size:rnd(0.4,1.0), alpha:rnd(0.15,0.35)});
  }
  for (let i=0;i<TWINKLES;i++){
    twinkles.push({
      x: Math.random()*w, y: Math.random()*h,
      size: rnd(0.8, 2.2), phase: Math.random()*Math.PI*2,
      speed: rnd(0.006, 0.024), alpha: rnd(0.4, 1.0),
      sprite: pickSprite()
    });
  }
  for (let i=0;i<FIELDS;i++){
    const sp = rnd(0.03, 0.16); const depth = rnd(0.3,1.0);
    field.push({
      x: Math.random()*w, y: Math.random()*h,
      dx: sp * depth * (Math.random()<0.5?1:-1),
      dy: sp * depth * (Math.random()<0.5?0.5:0.25),
      size: rnd(0.9, 2.0), depth
    });
  }

  let lastMeteorTime = 0;
  function maybeSpawnMeteor(t){
    if (t - lastMeteorTime < METEOR_RATE) return;
    lastMeteorTime = t;
    const fromTop = Math.random() < 0.65;
    const startX = fromTop ? Math.random()*w*0.7 : -80;
    const startY = fromTop ? -30 : Math.random()*h*0.35;
    const ang = rnd(Math.PI*0.6, Math.PI*0.95);
    const speed = rnd(4.5, 8.5);
    meteors.push({ x:startX, y:startY, dx: Math.cos(ang)*speed, dy: Math.sin(ang)*speed, len: rnd(80, 180), life: 1, ttl: rnd(900, 1600), colorIdx: Math.floor(Math.random()*3) });
    if (meteors.length>6) meteors.shift();
  }

  function drawBackground(){
    const g = ctx.createLinearGradient(0,0,0,h);
    g.addColorStop(0, '#0d1220');
    g.addColorStop(0.5, '#0b0f1a');
    g.addColorStop(1, '#09090f');
    ctx.fillStyle = g; ctx.fillRect(0,0,w,h);
  }

  function drawDistant(){
    ctx.fillStyle = 'rgba(255,255,255,0.6)';
    for (let i=0;i<distant.length;i++){
      const d = distant[i];
      ctx.globalAlpha = d.alpha;
      ctx.beginPath(); ctx.arc(d.x, d.y, d.size, 0, Math.PI*2); ctx.fill();
    }
    ctx.globalAlpha = 1;
  }

  function drawTwinkles(dt){
    for (let i=0;i<twinkles.length;i++){
      const s = twinkles[i];
      s.phase += s.speed*dt;
      const tw = 0.65 + 0.35*Math.sin(s.phase);
      ctx.globalAlpha = Math.max(0.1, Math.min(1, s.alpha*tw));
      const size = s.size*9;
      ctx.drawImage(s.sprite, s.x-size, s.y-size, size*2, size*2);
    }
    ctx.globalAlpha = 1;
  }

  function drawField(){
    for (let i=0;i<field.length;i++){
      const f = field[i];
      f.x += f.dx; f.y += f.dy;
      if (f.x < -10) f.x = w+10; if (f.x > w+10) f.x = -10;
      if (f.y < -10) f.y = h+10; if (f.y > h+10) f.y = -10;
      ctx.globalAlpha = 0.7 + f.depth*0.25;
      ctx.fillStyle = 'rgba(255,255,255,0.9)';
      ctx.beginPath(); ctx.arc(f.x, f.y, f.size, 0, Math.PI*2); ctx.fill();
    }
    ctx.globalAlpha = 1;
  }

  function drawMeteors(dt){
    ctx.globalCompositeOperation = 'lighter';
    const meteorColors = [
      ['rgba(100,180,255,0)','rgba(200,230,255,0.95)'],
      ['rgba(80,200,255,0)','rgba(255,255,255,0.98)'],
      ['rgba(120,150,255,0)','rgba(180,210,255,0.92)']
    ];
    for (let i=0;i<meteors.length;i++){
      const m = meteors[i];
      m.x += m.dx; m.y += m.dy; m.ttl -= dt; m.life = Math.max(0, m.ttl/1400);
      const trailFactor = 0.18;
      const trailX = m.x - m.dx*m.len*trailFactor, trailY = m.y - m.dy*m.len*trailFactor;
      const pal = meteorColors[m.colorIdx%3];
      const grd = ctx.createLinearGradient(trailX, trailY, m.x, m.y);
      grd.addColorStop(0, pal[0]); grd.addColorStop(0.7, pal[1]); grd.addColorStop(1, pal[1]);
      ctx.strokeStyle = grd; ctx.lineWidth = 2.5; ctx.lineCap = 'round';
      ctx.beginPath(); ctx.moveTo(trailX, trailY); ctx.lineTo(m.x, m.y); ctx.stroke();
      // Head glow
      const headGrad = ctx.createRadialGradient(m.x,m.y,0,m.x,m.y,4);
      headGrad.addColorStop(0, 'rgba(255,255,255,1)');
      headGrad.addColorStop(1, 'rgba(200,230,255,0)');
      ctx.fillStyle = headGrad; ctx.beginPath(); ctx.arc(m.x, m.y, 4, 0, Math.PI*2); ctx.fill();
    }
    for (let i=meteors.length-1;i>=0;i--){
      const m = meteors[i];
      if (m.ttl<=0 || m.x> w+200 || m.y> h+200) meteors.splice(i,1);
    }
    ctx.globalCompositeOperation = 'source-over';
  }

  let last = performance.now();
  function step(now){
    if (!running) return;
    const dt = Math.min(32, now - last); last = now; if (!started) started = true;
    drawBackground();
    drawDistant();
    drawField();
    drawTwinkles(dt);
    maybeSpawnMeteor(now);
    drawMeteors(dt);
    rafId = requestAnimationFrame(step);
  }

  function end(){
    if (!running) return;
    running = false;
    try {
      sessionStorage.setItem('starsPlayed','1');
    } catch(e) {
      // sessionStorage might be disabled
    }
    if (skipBtn) skipBtn.hidden = true;
    // Fade out canvas for a smooth transition
    canvas.style.transition = 'opacity 400ms ease';
    canvas.style.opacity = '0';
    const cleanup = () => { if (rafId) cancelAnimationFrame(rafId); canvas.removeEventListener('transitionend', cleanup); canvas.remove(); };
    canvas.addEventListener('transitionend', cleanup);
    // Safety cleanup
    setTimeout(cleanup, 700);
  }

  if (skipBtn) { skipBtn.hidden = false; skipBtn.addEventListener('click', end); }
  requestAnimationFrame((t)=>{ last = t; step(t); });
  setTimeout(end, alwaysPlay ? 7000 : 6000);
})();

// Contact form: validate safely and open mailto link
(function(){
  const form = document.getElementById('contact-form');
  if (!form) return;
  const status = document.getElementById('form-status');
  const emailRe = /^[^\s@]+@[^\s@]+\.[^\s@]{2,}$/;
  const MAX_NAME_LENGTH = 80;
  const MAX_MESSAGE_LENGTH = 1000;

  function setStatus(msg){ if (status) status.textContent = msg || ''; }
  function clearStatus(){ setStatus(''); }
  
  function sanitizeText(text) {
    return text.replace(/[<>]/g, '').trim();
  }

  form.addEventListener('submit', (e) => {
    e.preventDefault();
    if (!form.checkValidity()) { form.reportValidity(); return; }
    
    let name = (form.elements['name']?.value || '').trim();
    let email = (form.elements['email']?.value || '').trim();
    let message = (form.elements['message']?.value || '').trim();
    
    // Sanitize and validate
    name = sanitizeText(name).substring(0, MAX_NAME_LENGTH);
    email = sanitizeText(email);
    message = sanitizeText(message).substring(0, MAX_MESSAGE_LENGTH);
    
    if (!emailRe.test(email)) { setStatus(window.__i18nGet('contact.form.emailInvalid') || 'Invalid email'); return; }
    if (name.length < 2 || message.length < 10) { setStatus('Please provide valid name and message.'); return; }
    
    const subject = `Cosotech contact from ${name || 'visitor'}`;
    const body = `Name: ${name}\nEmail: ${email}\n\n${message}`;
    const href = `mailto:contact@cosotech.team?subject=${encodeURIComponent(subject)}&body=${encodeURIComponent(body)}`;
    setStatus(window.__i18nGet('contact.form.opening') || 'Opening your email app...');
    // Use location.href to avoid popup blockers (no window.open)
    window.location.href = href;
  }, { passive: false });

  form.addEventListener('input', clearStatus);
})();