/* ==========================================================================
   Bridge Flow Corporate Site - Main Stylesheet
   ========================================================================== */

/* --- Reset & Base --- */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --color-navy: #0A1E3F;
    --color-navy-dark: #05122A;
    --color-blue: #1E5AA8;
    --color-blue-light: #3A7BD5;
    --color-gold: #D4A857;
    --color-gold-light: #E8C883;
    --color-white: #FFFFFF;
    --color-off-white: #F7F9FC;
    --color-gray: #8892A6;
    --color-gray-light: #E5E9F0;
    --color-text: #1A2A44;
    --color-text-light: #5A6A85;

    --font-jp: 'Noto Sans JP', 'Hiragino Sans', 'Yu Gothic', sans-serif;
    --font-en: 'Montserrat', 'Helvetica Neue', Arial, sans-serif;
    --font-serif: 'Playfair Display', 'Times New Roman', serif;

    --shadow-sm: 0 2px 8px rgba(10, 30, 63, 0.06);
    --shadow-md: 0 8px 24px rgba(10, 30, 63, 0.1);
    --shadow-lg: 0 20px 60px rgba(10, 30, 63, 0.15);
    --shadow-gold: 0 10px 30px rgba(212, 168, 87, 0.3);

    --ease: cubic-bezier(0.4, 0, 0.2, 1);
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-jp);
    font-weight: 400;
    color: var(--color-text);
    line-height: 1.8;
    background: var(--color-white);
    overflow-x: hidden;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color 0.3s var(--ease);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    letter-spacing: 0.02em;
}

/* --- Utility --- */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.container-wide {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 120px 0;
    position: relative;
}

.section-sm {
    padding: 80px 0;
}

.section-label {
    display: inline-block;
    font-family: var(--font-en);
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 0.3em;
    color: var(--color-gold);
    text-transform: uppercase;
    margin-bottom: 16px;
    position: relative;
    padding-left: 48px;
}

.section-label::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    width: 36px;
    height: 1px;
    background: var(--color-gold);
}

.section-title {
    font-size: clamp(28px, 4vw, 44px);
    font-weight: 700;
    color: var(--color-navy);
    margin-bottom: 24px;
    letter-spacing: 0.04em;
}

.section-title .en {
    display: block;
    font-family: var(--font-serif);
    font-size: 0.5em;
    font-weight: 400;
    color: var(--color-gold);
    letter-spacing: 0.2em;
    margin-top: 12px;
    font-style: italic;
}

.section-lead {
    font-size: 16px;
    color: var(--color-text-light);
    max-width: 720px;
    margin-bottom: 60px;
    line-height: 2;
}

.text-center {
    text-align: center;
}

.text-center .section-label {
    padding-left: 0;
}

.text-center .section-label::before {
    display: none;
}

.text-center .section-label::after {
    content: '';
    display: block;
    width: 40px;
    height: 1px;
    background: var(--color-gold);
    margin: 12px auto 0;
}

.text-center .section-lead {
    margin-left: auto;
    margin-right: auto;
}

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 18px 42px;
    font-family: var(--font-jp);
    font-size: 15px;
    font-weight: 600;
    letter-spacing: 0.1em;
    border-radius: 2px;
    transition: all 0.4s var(--ease-out);
    position: relative;
    overflow: hidden;
    cursor: pointer;
    white-space: nowrap;
}

.btn i, .btn svg {
    transition: transform 0.4s var(--ease-out);
}

.btn:hover i, .btn:hover svg {
    transform: translateX(6px);
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-gold) 0%, var(--color-gold-light) 100%);
    color: var(--color-navy);
    box-shadow: var(--shadow-gold);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(212, 168, 87, 0.5);
}

.btn-outline {
    background: transparent;
    color: var(--color-white);
    border: 1px solid rgba(255, 255, 255, 0.4);
}

.btn-outline:hover {
    background: var(--color-white);
    color: var(--color-navy);
    border-color: var(--color-white);
}

.btn-navy {
    background: var(--color-navy);
    color: var(--color-white);
}

.btn-navy:hover {
    background: var(--color-blue);
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

/* --- Header --- */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 20px 0;
    transition: all 0.4s var(--ease);
    background: transparent;
}

.site-header.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 14px 0;
    box-shadow: 0 2px 20px rgba(10, 30, 63, 0.08);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 32px;
}

.site-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    z-index: 1001;
}

.site-logo-mark {
    width: 52px;
    height: 52px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.site-logo-mark img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    filter: drop-shadow(0 2px 6px rgba(11, 30, 63, 0.15));
}

.site-logo-text {
    display: flex;
    flex-direction: column;
    line-height: 1;
}

.site-logo-text .main {
    font-family: var(--font-serif);
    font-size: 22px;
    font-weight: 700;
    font-style: italic;
    color: var(--color-white);
    letter-spacing: 0.04em;
    transition: color 0.4s var(--ease);
}

.site-logo-text .sub {
    font-family: var(--font-en);
    font-size: 9px;
    font-weight: 500;
    color: var(--color-gold);
    letter-spacing: 0.35em;
    margin-top: 4px;
    text-transform: uppercase;
}

.site-header.scrolled .site-logo-text .main {
    color: var(--color-navy);
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 40px;
}

.nav-list {
    display: flex;
    gap: 36px;
    list-style: none;
}

.nav-list a {
    position: relative;
    font-size: 14px;
    font-weight: 500;
    color: var(--color-white);
    letter-spacing: 0.1em;
    padding: 8px 0;
    transition: color 0.3s var(--ease);
}

.nav-list a .en {
    display: block;
    font-family: var(--font-en);
    font-size: 10px;
    font-weight: 500;
    color: var(--color-gold);
    letter-spacing: 0.2em;
    margin-bottom: 4px;
    transition: color 0.3s var(--ease);
}

.nav-list a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 0;
    height: 1px;
    background: var(--color-gold);
    transition: width 0.4s var(--ease-out);
}

.nav-list a:hover::after,
.nav-list a.active::after {
    width: 100%;
}

.site-header.scrolled .nav-list a {
    color: var(--color-navy);
}

.nav-contact-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 12px 28px;
    background: var(--color-gold);
    color: var(--color-navy);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.1em;
    border-radius: 2px;
    transition: all 0.3s var(--ease);
}

.nav-contact-btn:hover {
    background: var(--color-gold-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-gold);
}

/* Mobile nav toggle */
.nav-toggle {
    display: none;
    width: 44px;
    height: 44px;
    position: relative;
    z-index: 1001;
    background: transparent;
    cursor: pointer;
}

.nav-toggle span {
    display: block;
    position: absolute;
    left: 10px;
    width: 24px;
    height: 1.5px;
    background: var(--color-white);
    transition: all 0.4s var(--ease);
}

.site-header.scrolled .nav-toggle span {
    background: var(--color-navy);
}

.nav-toggle span:nth-child(1) { top: 16px; }
.nav-toggle span:nth-child(2) { top: 22px; }
.nav-toggle span:nth-child(3) { top: 28px; }

.nav-toggle.active span {
    background: var(--color-white);
}

.nav-toggle.active span:nth-child(1) {
    top: 22px;
    transform: rotate(45deg);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    top: 22px;
    transform: rotate(-45deg);
}

/* --- Footer --- */
.site-footer {
    background: var(--color-navy-dark);
    color: rgba(255, 255, 255, 0.7);
    padding: 100px 0 40px;
    position: relative;
    overflow: hidden;
}

.site-footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-gold), transparent);
}

.footer-wave {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100px;
    opacity: 0.08;
    pointer-events: none;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 60px;
    position: relative;
}

.footer-brand .site-logo-text .main {
    color: var(--color-white);
    font-size: 26px;
}

.footer-desc {
    font-size: 14px;
    line-height: 2;
    margin-top: 24px;
    color: rgba(255, 255, 255, 0.6);
}

.footer-title {
    font-family: var(--font-en);
    font-size: 13px;
    font-weight: 600;
    color: var(--color-gold);
    letter-spacing: 0.25em;
    margin-bottom: 24px;
    text-transform: uppercase;
}

.footer-list {
    list-style: none;
}

.footer-list li {
    margin-bottom: 12px;
}

.footer-list a {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
    transition: all 0.3s var(--ease);
    display: inline-block;
}

.footer-list a:hover {
    color: var(--color-gold);
    transform: translateX(4px);
}

.footer-info {
    font-size: 13px;
    line-height: 1.9;
    color: rgba(255, 255, 255, 0.65);
}

.footer-info strong {
    color: var(--color-white);
    font-weight: 500;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.copyright {
    font-family: var(--font-en);
    font-size: 12px;
    letter-spacing: 0.15em;
    color: rgba(255, 255, 255, 0.5);
}

.footer-socials {
    display: flex;
    gap: 14px;
}

.footer-socials a {
    width: 38px;
    height: 38px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    font-size: 13px;
    color: rgba(255, 255, 255, 0.6);
    transition: all 0.3s var(--ease);
}

.footer-socials a:hover {
    border-color: var(--color-gold);
    color: var(--color-gold);
    transform: translateY(-3px);
}

/* --- Page Hero (sub-pages) --- */
.page-hero {
    position: relative;
    height: 60vh;
    min-height: 440px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--color-white);
    overflow: hidden;
    background: linear-gradient(135deg, var(--color-navy-dark) 0%, var(--color-navy) 50%, var(--color-blue) 100%);
}

.page-hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 20% 30%, rgba(30, 90, 168, 0.4), transparent 50%),
        radial-gradient(ellipse at 80% 70%, rgba(212, 168, 87, 0.15), transparent 50%);
    pointer-events: none;
}

.page-hero-wave {
    position: absolute;
    inset: 0;
    opacity: 0.25;
    pointer-events: none;
}

.page-hero-content {
    position: relative;
    z-index: 2;
    padding: 0 24px;
}

.page-hero-en {
    font-family: var(--font-en);
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 0.5em;
    color: var(--color-gold);
    margin-bottom: 20px;
    text-transform: uppercase;
}

.page-hero h1 {
    font-size: clamp(36px, 6vw, 64px);
    font-weight: 700;
    letter-spacing: 0.1em;
    margin-bottom: 20px;
    text-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

.page-hero-desc {
    font-size: 15px;
    color: rgba(255, 255, 255, 0.85);
    letter-spacing: 0.1em;
    max-width: 640px;
    margin: 0 auto;
}

/* Breadcrumb */
.breadcrumb {
    background: var(--color-off-white);
    padding: 20px 0;
    font-size: 13px;
}

.breadcrumb ul {
    display: flex;
    list-style: none;
    flex-wrap: wrap;
    gap: 8px;
    color: var(--color-text-light);
}

.breadcrumb li:not(:last-child)::after {
    content: '/';
    margin-left: 12px;
    color: var(--color-gold);
}

.breadcrumb a {
    color: var(--color-text-light);
    transition: color 0.3s var(--ease);
}

.breadcrumb a:hover {
    color: var(--color-gold);
}

.breadcrumb li:last-child {
    color: var(--color-navy);
    font-weight: 500;
}

/* --- Reveal Animations --- */
[data-reveal] {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 1s var(--ease-out), transform 1s var(--ease-out);
}

[data-reveal].is-visible {
    opacity: 1;
    transform: translateY(0);
}

[data-reveal="fade"] {
    transform: none;
}

[data-reveal="left"] {
    transform: translateX(-40px);
}

[data-reveal="left"].is-visible {
    transform: translateX(0);
}

[data-reveal="right"] {
    transform: translateX(40px);
}

[data-reveal="right"].is-visible {
    transform: translateX(0);
}

[data-reveal-delay="1"] { transition-delay: 0.1s; }
[data-reveal-delay="2"] { transition-delay: 0.2s; }
[data-reveal-delay="3"] { transition-delay: 0.3s; }
[data-reveal-delay="4"] { transition-delay: 0.4s; }
[data-reveal-delay="5"] { transition-delay: 0.5s; }

/* --- Common Cards --- */
.card {
    background: var(--color-white);
    border-radius: 4px;
    overflow: hidden;
    transition: all 0.5s var(--ease-out);
    box-shadow: var(--shadow-sm);
    position: relative;
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

/* --- CTA Section --- */
.cta-section {
    position: relative;
    padding: 120px 0;
    background: linear-gradient(135deg, var(--color-navy-dark) 0%, var(--color-navy) 60%, var(--color-blue) 100%);
    color: var(--color-white);
    overflow: hidden;
    text-align: center;
}

.cta-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, rgba(212, 168, 87, 0.15), transparent 70%);
}

.cta-wave {
    position: absolute;
    inset: 0;
    opacity: 0.3;
    pointer-events: none;
}

.cta-inner {
    position: relative;
    z-index: 2;
    max-width: 720px;
    margin: 0 auto;
    padding: 0 24px;
}

.cta-en {
    font-family: var(--font-en);
    font-size: 13px;
    color: var(--color-gold);
    letter-spacing: 0.4em;
    margin-bottom: 24px;
    text-transform: uppercase;
}

.cta-title {
    font-size: clamp(28px, 4vw, 42px);
    font-weight: 700;
    margin-bottom: 24px;
    letter-spacing: 0.06em;
    line-height: 1.5;
}

.cta-text {
    font-size: 15px;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 48px;
    line-height: 2;
}

.cta-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .section {
        padding: 80px 0;
    }

    .nav-toggle {
        display: block;
    }

    .main-nav {
        position: fixed;
        top: 0;
        right: 0;
        width: 100%;
        height: 100vh;
        background: linear-gradient(135deg, var(--color-navy-dark) 0%, var(--color-navy) 100%);
        flex-direction: column;
        justify-content: center;
        gap: 40px;
        transform: translateX(100%);
        transition: transform 0.5s var(--ease-out);
        z-index: 1000;
    }

    .main-nav.is-open {
        transform: translateX(0);
    }

    .nav-list {
        flex-direction: column;
        gap: 28px;
        text-align: center;
    }

    .nav-list a {
        color: var(--color-white) !important;
        font-size: 18px;
    }

    .site-header.scrolled .nav-list a {
        color: var(--color-white);
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .footer-bottom {
        justify-content: center;
        text-align: center;
    }

    .page-hero {
        height: 50vh;
        min-height: 360px;
    }

    .cta-section {
        padding: 80px 0;
    }

    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }

    .cta-buttons .btn {
        width: 100%;
        max-width: 320px;
    }
}

@media (max-width: 480px) {
    .header-inner {
        padding: 0 20px;
    }

    .site-logo-mark {
        width: 42px;
        height: 42px;
    }

    .site-logo-text .main {
        font-size: 18px;
    }

    .site-logo-text .sub {
        font-size: 8px;
        letter-spacing: 0.25em;
    }

    .btn {
        padding: 16px 32px;
        font-size: 14px;
    }
}