/* ============================================
   开屏页面 - 极简风格
   ============================================ */

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial,
                 "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
    background-color: #f5f5f5;
    color: #000000;
    height: 100vh;
    overflow: hidden;
    opacity: 0;
    transition: opacity 0.8s ease;
}

body.loaded {
    opacity: 1;
}

body.fade-out {
    opacity: 0;
    transition: opacity 0.6s ease;
}

/* ============================================
   Loading Progress Bar - 黑白简约进度条
   ============================================ */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #f5f5f5;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.loading-overlay.active {
    opacity: 1;
    pointer-events: all;
}

.loading-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
    width: 100%;
    max-width: 400px;
    padding: 0 2rem;
}

.loading-logo {
    font-size: 1rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: #000000;
    font-weight: 400;
}

.progress-container {
    width: 100%;
    height: 1px;
    background-color: rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
}

.progress-bar {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    background-color: #000000;
    width: 0%;
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.loading-text {
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    color: rgba(0, 0, 0, 0.4);
    font-weight: 300;
    text-transform: uppercase;
}

/* ============================================
   Page Transition - 页面转场动效
   ============================================ */
@keyframes slideOutLeft {
    from {
        transform: translateX(0);
        opacity: 1;
    }
    to {
        transform: translateX(-30px);
        opacity: 0;
    }
}

@keyframes slideOutUp {
    from {
        transform: translateY(0);
        opacity: 1;
    }
    to {
        transform: translateY(-20px);
        opacity: 0;
    }
}

body.transitioning .splash-container {
    animation: slideOutUp 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

body.transitioning .top-nav,
body.transitioning .bottom-bar {
    animation: slideOutLeft 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* ============================================
   Top Navigation
   ============================================ */
.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 50;
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    background-color: #f5f5f5;
}

.nav-left {
    display: flex;
    align-items: center;
}

.nav-brand {
    font-weight: 400;
    text-transform: uppercase;
}

.nav-right {
    display: flex;
    align-items: center;
}

.footer-year {
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    font-weight: 400;
}

/* ============================================
   Main Splash Container
   ============================================ */
.splash-container {
    display: flex;
    height: 100vh;
    width: 100%;
    padding-top: 4rem;
}

/* Left Side - Text Content (40%) */
.splash-left {
    width: 40%;
    display: flex;
    align-items: center;
    padding: 0 4rem;
    border-right: 1px solid rgba(0, 0, 0, 0.08);
}

.splash-content {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 3rem;
    width: 100%;
}

.splash-logo {
    width: 168px;
}

.splash-logo img {
    width: 100%;
    height: auto;
    display: block;
}

.divider {
    height: 1px;
    background-color: rgba(0, 0, 0, 0.1);
    width: 100%;
}

.splash-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.splash-tagline {
    font-size: 0.7rem;
    letter-spacing: 0.25em;
    text-transform: uppercase;
    color: rgba(0, 0, 0, 0.4);
    font-weight: 300;
}

.splash-description {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    font-size: 0.875rem;
    line-height: 1.6;
    color: rgba(0, 0, 0, 0.55);
    font-weight: 300;
}

/* Enter Button */
.enter-button {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0;
    background: none;
    border: none;
    border-bottom: 1px solid rgba(0, 0, 0, 0.15);
    padding-bottom: 0.5rem;
    font-size: 0.75rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    cursor: pointer;
    font-weight: 300;
    color: #000000;
    transition: all 0.3s ease;
}

.enter-button:hover {
    border-bottom-color: #000000;
    gap: 1rem;
}

.enter-button .arrow {
    font-size: 1rem;
    transition: transform 0.3s ease;
}

.enter-button:hover .arrow {
    transform: translateX(3px);
}

/* Right Side - Visual Element (60%) */
.splash-right {
    width: 60%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #ffffff;
    position: relative;
}

.visual-container {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Grid Pattern */
.grid-pattern {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0.1;
}

.grid-line {
    position: absolute;
    background-color: #000000;
}

.grid-line.horizontal {
    width: 100%;
    height: 1px;
    left: 0;
}

.grid-line.horizontal:nth-child(1) {
    top: 25%;
}

.grid-line.horizontal:nth-child(2) {
    top: 50%;
}

.grid-line.horizontal:nth-child(3) {
    top: 75%;
}

.grid-line.vertical {
    height: 100%;
    width: 1px;
    top: 0;
}

.grid-line.vertical:nth-child(4) {
    left: 25%;
}

.grid-line.vertical:nth-child(5) {
    left: 50%;
}

.grid-line.vertical:nth-child(6) {
    left: 75%;
}

/* Center Text */
.center-text {
    text-align: center;
    z-index: 10;
    margin-top: -8rem;
}

.large-x {
    font-size: 20rem;
    font-weight: 200;
    letter-spacing: 0;
    line-height: 1;
    color: #000000;
}

/* ============================================
   Bottom Status Bar
   ============================================ */
.bottom-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 3rem;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    background-color: #f5f5f5;
    text-transform: uppercase;
}

.status-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: rgba(0, 0, 0, 0.6);
    font-weight: 300;
}

.status-dot {
    width: 4px;
    height: 4px;
    background-color: #000000;
    border-radius: 50%;
}

/* ============================================
   Responsive Design
   ============================================ */

/* Tablet */
@media (max-width: 1024px) {
    .splash-left {
        width: 45%;
        padding: 0 3rem;
    }

    .splash-right {
        width: 55%;
    }

    .splash-title {
        font-size: 3rem;
    }

    .large-number {
        font-size: 10rem;
    }
}

/* Mobile */
@media (max-width: 768px) {
    .splash-container {
        flex-direction: column;
    }

    .splash-left,
    .splash-right {
        width: 100%;
        border: none;
    }

    .splash-left {
        height: 60%;
        padding: 2rem 1.5rem;
        align-items: flex-start;
        padding-top: 3rem;
    }

    .splash-right {
        height: 40%;
        border-top: 1px solid rgba(0, 0, 0, 0.08);
    }

    .splash-title {
        font-size: 2.5rem;
    }

    .large-number {
        font-size: 6rem;
    }

    .bottom-bar {
        gap: 1.5rem;
        font-size: 0.7rem;
        padding: 1rem;
    }

    .nav-brand {
        font-size: 0.7rem;
    }

    .footer-year {
        font-size: 0.7rem;
    }
}

/* Small Mobile */
@media (max-width: 480px) {
    .splash-title {
        font-size: 2rem;
    }

    .large-number {
        font-size: 4rem;
    }

    .splash-description {
        font-size: 0.875rem;
    }

    .enter-button {
        padding: 0.875rem 1.5rem;
        font-size: 0.8rem;
    }
}