/* ===== RESET ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{min-height:100vh;line-height:1.6;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}
img,svg,video{display:block;max-width:100%}
ul,ol{list-style:none}
a{color:inherit;text-decoration:none}
button,input,textarea,select{font:inherit;color:inherit;border:none;background:none;cursor:pointer}
:focus-visible{outline:3px solid var(--color-primary-gold);outline-offset:2px;border-radius:2px}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:0.01ms!important;animation-iteration-count:1!important;transition-duration:0.01ms!important;scroll-behavior:auto!important}}

/* ===== CSS VARIABLES ===== */
:root{
  --color-primary-deep-blue:#0A1F44;
  --color-primary-gold:#D4A84B;
  --color-secondary-warm-paper:#F5F0E6;
  --color-secondary-dark-ink:#1C1E21;
  --color-accent-cyan:#00B4D8;
  --color-accent-orange:#FF6B35;
  --color-neutral-light-gray:#E0DDD5;
  --color-neutral-white:#FFFFFF;
  --font-primary:system-ui,-apple-system,'Segoe UI',Roboto,'Noto Sans SC','PingFang SC','Microsoft YaHei','Helvetica Neue',sans-serif;
  --border-width-thick:4px;
  --border-width-medium:2px;
  --shadow-strong:8px 8px 0 rgba(0,0,0,0.12);
  --shadow-stronger:12px 12px 0 rgba(0,0,0,0.08);
  --shadow-gold:0 0 0 2px var(--color-primary-gold),0 0 0 4px var(--color-primary-deep-blue);
  --header-height:72px;
  --content-max-width:1200px;
  --content-padding:clamp(16px,4vw,48px);
  --transition-base:0.25s cubic-bezier(0.4,0,0.2,1);
}

/* ===== GLOBAL ===== */
body{font-family:var(--font-primary);background:var(--color-secondary-warm-paper);color:var(--color-secondary-dark-ink)}
::selection{background:var(--color-primary-gold);color:var(--color-primary-deep-blue)}

/* ===== SKIP LINK ===== */
.skip-link{position:fixed;top:0;left:0;z-index:10000;padding:12px 24px;background:var(--color-primary-deep-blue);color:var(--color-neutral-white);font-weight:600;transform:translateY(-120%);transition:transform var(--transition-base)}
.skip-link:focus{transform:translateY(0)}

/* ===== SITE HEADER ===== */
.site-header{position:fixed;top:0;left:0;width:100%;z-index:1000;height:var(--header-height);transition:background var(--transition-base),box-shadow var(--transition-base);background:transparent;pointer-events:none}
.site-header[data-scrolled]{background:var(--color-primary-deep-blue);box-shadow:0 4px 20px rgba(0,0,0,0.15)}
.header__inner{display:flex;align-items:center;justify-content:space-between;max-width:var(--content-max-width);margin:0 auto;padding:0 var(--content-padding);height:100%;pointer-events:auto}
.header__brand{font-size:clamp(1.25rem,2.5vw,1.75rem);font-weight:800;color:var(--color-primary-gold);letter-spacing:0.02em;position:relative;z-index:1002}
.header__brand::after{content:'';display:block;width:100%;height:3px;background:var(--color-primary-gold);margin-top:2px;transform:scaleX(0.3);transform-origin:left;transition:transform var(--transition-base)}
.header__brand:hover::after{transform:scaleX(1)}

/* ===== HEADER NAV ===== */
.header__nav ul{display:flex;gap:clamp(12px,2vw,28px);align-items:center}
.header__nav a{font-size:clamp(0.875rem,1.1vw,1rem);font-weight:500;color:var(--color-neutral-white);padding:6px 0;position:relative;transition:color var(--transition-base);letter-spacing:0.03em}
.header__nav a::after{content:'';position:absolute;bottom:0;left:0;width:100%;height:2px;background:var(--color-primary-gold);transform:scaleX(0);transform-origin:right;transition:transform var(--transition-base)}
.header__nav a:hover::after,.header__nav a[aria-current="page"]::after{transform:scaleX(1);transform-origin:left}
.header__nav a:hover{color:var(--color-primary-gold)}
.header__nav a[aria-current="page"]{color:var(--color-primary-gold);font-weight:600}

/* ===== MOBILE TOGGLE ===== */
.header__toggle{display:none;flex-direction:column;justify-content:center;align-items:center;width:44px;height:44px;position:relative;z-index:1002;background:transparent;border:var(--border-width-medium) solid var(--color-primary-gold);border-radius:4px;padding:8px 6px;transition:border-color var(--transition-base)}
.toggle__line{display:block;width:100%;height:2px;background:var(--color-primary-gold);border-radius:2px;transition:all var(--transition-base)}
.toggle__line+.toggle__line{margin-top:5px}
.header__toggle[aria-expanded="true"] .toggle__line:nth-child(1){transform:translateY(7px) rotate(45deg)}
.header__toggle[aria-expanded="true"] .toggle__line:nth-child(2){opacity:0}
.header__toggle[aria-expanded="true"] .toggle__line:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
@media(max-width:768px){
  .header__toggle{display:flex}
  .header__nav{position:fixed;top:0;left:0;width:100%;height:100dvh;background:var(--color-primary-deep-blue);display:flex;align-items:center;justify-content:center;opacity:0;visibility:hidden;transition:opacity 0.35s ease,visibility 0.35s ease;z-index:1001}
  .header__nav[data-open]{opacity:1;visibility:visible}
  .header__nav ul{flex-direction:column;gap:28px;text-align:center}
  .header__nav a{font-size:1.5rem;color:var(--color-primary-gold);font-weight:600;letter-spacing:0.08em}
  .header__nav a::after{display:none}
  .header__nav a[aria-current="page"]{text-decoration:underline;text-underline-offset:8px;text-decoration-thickness:3px}
  .site-header[data-scrolled] .header__toggle{border-color:var(--color-primary-gold)}
}

/* ===== SITE FOOTER ===== */
.site-footer{background:var(--color-primary-deep-blue);color:var(--color-neutral-light-gray);padding:48px 0 32px;border-top:var(--border-width-thick) solid var(--color-primary-gold)}
.footer__inner{max-width:var(--content-max-width);margin:0 auto;padding:0 var(--content-padding);display:grid;grid-template-columns:1fr 1fr;gap:32px 48px}
.footer__brand{grid-column:1/2}
.footer__logo{font-size:1.5rem;font-weight:800;color:var(--color-primary-gold);display:inline-block;margin-bottom:6px}
.footer__tagline{font-size:0.875rem;color:var(--color-neutral-light-gray);opacity:0.7}
.footer__links{grid-column:2/3;display:flex;flex-direction:column;gap:10px;justify-self:end}
.footer__links a{color:var(--color-neutral-light-gray);font-size:0.925rem;transition:color var(--transition-base);position:relative;width:fit-content}
.footer__links a::after{content:'';position:absolute;bottom:-2px;left:0;width:0;height:1px;background:var(--color-primary-gold);transition:width var(--transition-base)}
.footer__links a:hover{color:var(--color-primary-gold)}
.footer__links a:hover::after{width:100%}
.footer__contact{grid-column:1/2;font-size:0.875rem;line-height:1.8;color:var(--color-neutral-light-gray)}
.footer__contact p{opacity:0.75}
.footer__meta{grid-column:1/3;border-top:1px solid rgba(212,168,75,0.2);padding-top:20px;margin-top:8px;display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px}
.footer__note{font-size:0.8rem;opacity:0.6;max-width:480px}
.footer__icp{font-size:0.8rem;opacity:0.5;white-space:nowrap}
@media(max-width:640px){
  .footer__inner{grid-template-columns:1fr;gap:24px}
  .footer__brand{grid-column:1/2}
  .footer__links{grid-column:1/2;justify-self:start}
  .footer__meta{grid-column:1/2;flex-direction:column;align-items:start}
}

/* ===== TYPOGRAPHY ===== */
.display-text{font-size:clamp(2.5rem,6vw,5.5rem);font-weight:900;line-height:1.05;letter-spacing:-0.02em;color:var(--color-primary-deep-blue);text-transform:none}
.display-text--gold{color:var(--color-primary-gold)}
.display-text--white{color:var(--color-neutral-white)}
.annotation-vertical{writing-mode:vertical-rl;font-size:0.75rem;letter-spacing:0.2em;opacity:0.5;text-orientation:upright}
.annotation-rotated{transform:rotate(-90deg);transform-origin:left top;font-size:0.75rem;letter-spacing:0.15em;opacity:0.45;white-space:nowrap}

/* ===== COLOR BLOCK & GEO SHAPE ===== */
.color-block{background:var(--color-primary-deep-blue);border:var(--border-width-thick) solid var(--color-primary-gold);padding:clamp(20px,4vw,48px);box-shadow:var(--shadow-strong);transition:box-shadow var(--transition-base),transform var(--transition-base)}
.color-block:hover{box-shadow:var(--shadow-stronger);transform:translate(-2px,-2px)}
.color-block--warm{background:var(--color-secondary-warm-paper);border-color:var(--color-primary-deep-blue);color:var(--color-secondary-dark-ink)}
.color-block--accent{background:var(--color-primary-gold);border-color:var(--color-primary-deep-blue);color:var(--color-primary-deep-blue)}
.geo-shape{width:80px;height:80px;border:var(--border-width-thick) solid var(--color-primary-gold);transform:rotate(12deg);position:absolute;pointer-events:none;opacity:0.15}
.geo-shape--circle{border-radius:50%}
.geo-shape--small{width:40px;height:40px;border-width:3px}

/* ===== SKILL TREE ===== */
.skill-tree{display:flex;flex-wrap:wrap;gap:clamp(16px,3vw,36px);position:relative;padding:20px 0}
.skill-tree::before{content:'';position:absolute;top:50%;left:0;right:0;height:3px;background:var(--color-primary-gold);opacity:0.2;transform:translateY(-50%);pointer-events:none}
.skill-tree__node{flex:1;min-width:160px;padding:20px 16px;background:var(--color-neutral-white);border:var(--border-width-medium) solid var(--color-primary-deep-blue);box-shadow:var(--shadow-strong);position:relative;transition:transform var(--transition-base),box-shadow var(--transition-base)}
.skill-tree__node:hover{transform:translateY(-4px);box-shadow:var(--shadow-stronger)}
.skill-tree__node::before{content:attr(data-step);position:absolute;top:-14px;left:-14px;width:32px;height:32px;background:var(--color-primary-gold);color:var(--color-primary-deep-blue);font-weight:800;font-size:0.875rem;display:flex;align-items:center;justify-content:center;border:2px solid var(--color-primary-deep-blue);border-radius:50%}

/* ===== BUTTONS ===== */
.btn{display:inline-flex;align-items:center;justify-content:center;padding:14px 36px;font-size:1rem;font-weight:700;border:var(--border-width-thick) solid var(--color-primary-deep-blue);background:var(--color-primary-gold);color:var(--color-primary-deep-blue);transition:all var(--transition-base);box-shadow:var(--shadow-strong);letter-spacing:0.04em}
.btn:hover{background:var(--color-primary-deep-blue);color:var(--color-primary-gold);border-color:var(--color-primary-gold);box-shadow:var(--shadow-stronger);transform:translate(-2px,-2px)}
.btn--outline{background:transparent;color:var(--color-primary-gold);border-color:var(--color-primary-gold);box-shadow:none}
.btn--outline:hover{background:var(--color-primary-gold);color:var(--color-primary-deep-blue);border-color:var(--color-primary-deep-blue);box-shadow:var(--shadow-strong)}
.btn--small{padding:10px 20px;font-size:0.875rem;border-width:3px}

/* ===== SECTION ===== */
.section{max-width:var(--content-max-width);margin:0 auto;padding:clamp(48px,8vw,96px) var(--content-padding);position:relative}

/* ===== CARD ===== */
.card{background:var(--color-secondary-warm-paper);border:var(--border-width-thick) solid var(--color-primary-deep-blue);padding:clamp(20px,3vw,40px);box-shadow:var(--shadow-strong);transition:box-shadow var(--transition-base),transform var(--transition-base)}
.card:hover{box-shadow:var(--shadow-stronger);transform:translate(-2px,-2px)}
.card--white{background:var(--color-neutral-white)}
.card--gold{border-color:var(--color-primary-gold)}

/* ===== BREADCRUMB ===== */
.breadcrumb{display:flex;flex-wrap:wrap;gap:8px;align-items:center;font-size:0.85rem;color:var(--color-secondary-dark-ink);opacity:0.6;padding:16px 0}
.breadcrumb a{color:var(--color-primary-deep-blue);transition:color var(--transition-base)}
.breadcrumb a:hover{color:var(--color-primary-gold)}
.breadcrumb span+span::before{content:'/';margin-right:8px;color:var(--color-primary-gold);opacity:0.5}

/* ===== SCROLL TOP ===== */
.scroll-top{position:fixed;bottom:32px;right:32px;width:52px;height:52px;background:var(--color-primary-deep-blue);border:var(--color-primary-gold) solid 3px;color:var(--color-primary-gold);font-size:1.5rem;display:flex;align-items:center;justify-content:center;z-index:900;opacity:0;visibility:hidden;transform:translateY(20px);transition:all var(--transition-base);box-shadow:var(--shadow-strong)}
.scroll-top[data-visible]{opacity:1;visibility:visible;transform:translateY(0)}
.scroll-top:hover{background:var(--color-primary-gold);color:var(--color-primary-deep-blue);border-color:var(--color-primary-deep-blue);transform:translateY(-4px)}
@media(prefers-reduced-motion:reduce){.scroll-top{transition:none}}

/* ===== RESPONSIVE GRID ===== */
.grid{display:grid;gap:clamp(16px,3vw,36px)}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.grid--4{grid-template-columns:repeat(auto-fit,minmax(200px,1fr))}
@media(max-width:480px){.grid--2,.grid--3,.grid--4{grid-template-columns:1fr}}

/* ===== UTILITY ===== */
.content-container{max-width:var(--content-max-width);margin:0 auto;padding:0 var(--content-padding)}
.text-center{text-align:center}
.mt-1{margin-top:16px}
.mt-2{margin-top:32px}
.mt-3{margin-top:48px}
.mb-1{margin-bottom:16px}
.mb-2{margin-bottom:32px}
.mb-3{margin-bottom:48px}
.gold{color:var(--color-primary-gold)}
.deep-blue{color:var(--color-primary-deep-blue)}
.warm-paper{background:var(--color-secondary-warm-paper)}