:root {
    --primary: #4f6df5;
    --primary-light: #6b8aff;
    --primary-dark: #3a56e6;
    --primary-darker: #2a42c2;
    --text-primary: #2d3748;
    --text-secondary: #4a5568;
    --bg-light: linear-gradient(135deg, #f0f4f9 0%, #e6edf5 100%);
    --card-bg: #ffffff;
    --border-radius: 20px;
    --shadow-sm: 0 4px 12px rgba(148, 163, 184, 0.1);
    --shadow-md: 0 8px 24px rgba(148, 163, 184, 0.15);
    --shadow-lg: 0 12px 36px rgba(148, 163, 184, 0.18);
    --transition: all 0.35s cubic-bezier(0.25, 0.8, 0.25, 1);
    --tech-glow: 0 0 15px rgba(79, 109, 245, 0.3);
    --tech-glow-hover: 0 0 25px rgba(79, 109, 245, 0.5);
    --tech-border: 1px solid rgba(79, 109, 245, 0.2);
    --tech-grid: linear-gradient(rgba(79, 109, 245, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(79, 109, 245, 0.05) 1px, transparent 1px);
    --dark-text-primary: #edf2f7;
    --dark-text-secondary: #a0aec0;
    --dark-bg: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    --dark-card-bg: rgba(30, 41, 59, 0.9);
    --dark-shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.15);
    --dark-shadow-md: 0 8px 24px rgba(0, 0, 0, 0.2);
    --dark-shadow-lg: 0 12px 36px rgba(0, 0, 0, 0.25);
    --dark-tech-glow: 0 0 15px rgba(79, 109, 245, 0.5);
    --dark-tech-glow-hover: 0 0 25px rgba(79, 109, 245, 0.8);
    --dark-tech-border: 1px solid rgba(79, 109, 245, 0.3);
    --dark-tech-grid: linear-gradient(rgba(79, 109, 245, 0.1) 1px, transparent 1px),
        linear-gradient(90deg, rgba(79, 109, 245, 0.1) 1px, transparent 1px);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

body {
    font-family: 'Poppins', 'Segoe UI', '微软雅黑', system-ui, sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--bg-light), var(--tech-grid);
    background-size: 20px 20px;
    padding: 20px 15px;
    line-height: 1.6;
    transition: var(--transition);
    position: relative;
}

body.dark-mode {
    --text-primary: var(--dark-text-primary);
    --text-secondary: var(--dark-text-secondary);
    --bg-light: var(--dark-bg);
    --card-bg: var(--dark-card-bg);
    --shadow-sm: var(--dark-shadow-sm);
    --shadow-md: var(--dark-shadow-md);
    --shadow-lg: var(--dark-shadow-lg);
    --tech-glow: var(--dark-tech-glow);
    --tech-glow-hover: var(--dark-tech-glow-hover);
    --tech-border: var(--dark-tech-border);
    --tech-grid: var(--dark-tech-grid);
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    width: 52px;
    height: 52px;
    border-radius: 50%;
    background: var(--card-bg);
    box-shadow: var(--shadow-sm), var(--tech-glow);
    border: var(--tech-border);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    backdrop-filter: blur(5px);
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

.theme-toggle:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md), var(--tech-glow-hover);
}

.theme-toggle i {
    font-size: 1.5rem;
    color: var(--text-primary);
    transition: var(--transition);
}

.particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 1;
}

.particles span {
    position: absolute;
    display: block;
    width: 20px;
    height: 20px;
    background: rgba(79, 109, 245, 0.1);
    border-radius: 50%;
    box-shadow: 0 0 10px rgba(100, 108, 255, 0.5),
        0 0 20px rgba(100, 108, 255, 0.3),
        0 0 30px rgba(100, 108, 255, 0.1);
    animation: float 15s linear infinite;
    bottom: -150px;
}

body.dark-mode .particles span {
    background: rgba(79, 109, 245, 0.2);
    box-shadow: 0 0 15px rgba(100, 108, 255, 0.8),
        0 0 25px rgba(100, 108, 255, 0.5),
        0 0 35px rgba(100, 108, 255, 0.2);
}

@keyframes float {
    0% {
        transform: translateY(0) rotate(0deg);
        opacity: 1;
        border-radius: 0;
    }

    100% {
        transform: translateY(-1000px) rotate(720deg);
        opacity: 0;
        border-radius: 50%;
    }
}

.container {
    width: 100%;
    max-width: 520px;
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 40px 28px;
    box-shadow: var(--shadow-lg), var(--tech-glow);
    border: var(--tech-border);
    position: relative;
    overflow: hidden;
    transition: var(--transition);
    backdrop-filter: blur(5px);
    z-index: 2;
}

.header {
    position: relative;
    margin-bottom: 30px;
}

.back-button {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    right: 20px;
    z-index: 100;
    width: 52px;
    height: 52px;
    border-radius: 50%;
    background: linear-gradient(45deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(79, 109, 245, 0.25), var(--tech-glow);
    transition: var(--transition);
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

.back-button::after {
    content: '';
    display: block;
    padding-bottom: 100%;
}

.back-button i {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 18px;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s ease;
}

.back-button:hover,
.back-button:focus {
    transform: translateY(-50%) scale(1.05);
    box-shadow: 0 6px 18px rgba(79, 109, 245, 0.3), var(--tech-glow-hover);
}

.back-button:hover i {
    transform: translate(-50%, -50%) rotate(-15deg);
}

.container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--primary-dark) 50%, var(--primary-darker) 100%);
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    animation: gradientShift 8s linear infinite;
}

@keyframes gradientShift {
    0% {
        background-position: 0% 50%;
    }

    100% {
        background-position: 100% 50%;
    }
}

h1 {
    color: var(--text-primary);
    font-size: clamp(1.4rem, 4vw, 1.6rem);
    margin-bottom: 38px;
    text-align: center;
    font-weight: 600;
    letter-spacing: 0.03em;
    position: relative;
    padding-bottom: 12px;
}

h1::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background: var(--primary);
    border-radius: 2px;
    transition: width 0.3s ease;
    box-shadow: 0 0 10px var(--primary);
    animation: glowPulse 2s infinite alternate;
}

@keyframes glowPulse {
    0% {
        box-shadow: 0 0 10px var(--primary);
    }

    100% {
        box-shadow: 0 0 20px var(--primary);
    }
}

.btn-group {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.jump-btn {
    width: 100%;
    padding: 18px 24px;
    border: none;
    border-radius: 14px;
    font-size: clamp(1rem, 3.5vw, 1.1rem);
    font-weight: 500;
    cursor: pointer;
    text-align: left;
    position: relative;
    overflow: hidden;
    transition: var(--transition);
    background: linear-gradient(45deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: 0 4px 14px rgba(79, 109, 245, 0.22), var(--tech-glow);
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 64px;
    backdrop-filter: blur(5px);
    border: var(--tech-border);
}

.btn-content {
    display: flex;
    align-items: center;
    gap: 16px;
    flex: 1;
    transition: transform 0.3s ease;
}

.btn-icon {
    font-size: 1.3rem;
    transition: transform 0.3s ease;
    color: rgba(255, 255, 255, 0.9);
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

.btn-text {
    transition: transform 0.3s ease;
}

.btn-arrow {
    font-size: 1.1rem;
    opacity: 0.8;
    transition: transform 0.3s ease;
    color: rgba(255, 255, 255, 0.9);
}

.jump-btn:hover,
.jump-btn:focus-visible {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(79, 109, 245, 0.3), var(--tech-glow-hover);
    background: linear-gradient(45deg, var(--primary-dark) 0%, var(--primary) 100%);
}

.jump-btn:hover .btn-content {
    transform: translateX(8px);
}

.jump-btn:hover .btn-icon {
    transform: scale(1.1);
    text-shadow: 0 0 15px rgba(255, 255, 255, 0.8);
}

.jump-btn:hover .btn-arrow {
    transform: translateX(4px);
}

.jump-btn:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

.jump-btn:active {
    transform: scale(0.985);
    box-shadow: 0 3px 10px rgba(79, 109, 245, 0.25), var(--tech-glow);
    background: linear-gradient(45deg, var(--primary-darker) 0%, var(--primary-dark) 100%);
}

.jump-btn::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(to right,
            rgba(255, 255, 255, 0) 0%,
            rgba(255, 255, 255, 0.3) 50%,
            rgba(255, 255, 255, 0) 100%);
    transform: rotate(30deg);
    animation: shine 3s infinite;
}

@keyframes shine {
    0% {
        transform: rotate(30deg) translateX(-100%);
    }

    100% {
        transform: rotate(30deg) translateX(100%);
    }
}

.back-to-top {
    position: fixed;
    right: 2rem;
    bottom: 2rem;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md), var(--tech-glow);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 1000;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(79, 109, 245, 0.4), var(--tech-glow-hover);
    background: var(--primary-dark);
}

.back-to-top svg {
    transition: transform 0.3s ease;
}

.back-to-top:hover svg {
    transform: translateY(-2px);
}

.tech-footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 60px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1;
    border-top: 1px solid rgba(79, 109, 245, 0.2);
}

body.dark-mode .tech-footer {
    background: rgba(15, 23, 42, 0.1);
    border-top: 1px solid rgba(79, 109, 245, 0.3);
}

.tech-footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    letter-spacing: 1px;
}

.tech-footer span {
    color: var(--primary);
    font-weight: 600;
}

@media (max-width: 380px) {
    .container {
        padding: 32px 20px;
    }

    h1 {
        margin-bottom: 32px;
        font-size: 1.4rem;
    }

    .jump-btn {
        padding: 16px 20px;
        font-size: 1rem;
    }

    .btn-content {
        gap: 14px;
    }

    .btn-icon {
        font-size: 1.2rem;
    }

    .btn-arrow {
        font-size: 1rem;
    }
}

@media (max-width: 768px) {
    .back-button {
        display: none;
    }
}