/* ========================================
   CSS Variables & Base Reset
   Apple-inspired Glass UI
======================================== */
:root {
    /* Helvetica Font Stack */
    --font-system: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    
    /* Colors */
    --text-primary: rgba(255, 255, 255, 0.95);
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-tertiary: rgba(255, 255, 255, 0.55);
    
    /* Apple Glass Material */
    --glass-bg: rgba(180, 185, 195, 0.10);
    --glass-bg-elevated: rgba(180, 185, 195, 0.14);
    --glass-border: rgba(255, 255, 255, 0.18);
    
    /* Background opacity controls - reduce to show more background, increase for readability */
    /* REVERT: Change both values back to 0.05 and 0.025 respectively */
    --glass-panel-opacity: 0.02;
    --icon-panel-opacity: 0.01;
    --glass-shadow: 0 8px 40px rgba(0, 0, 0, 0.35),
                    0 0 1px rgba(255, 255, 255, 0.1);
    
    /* Transitions - Apple's spring-like curves */
    --transition-smooth: cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --transition-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
    
    /* Overlay - Fade from edges with light grey translucency (65px fade) */
    /* Calculated opacity: For desired ~0.45 at edges when doubled: 0.45 = 1 - (1-x)^2, solving: x ≈ 0.26 */
    /* Higher rate of change near start (ease-out curve) for more natural fade */
    --overlay-gradient: 
        linear-gradient(to right,
            rgba(200, 200, 200, 0.26) 0px,
            rgba(200, 200, 200, 0.21) 6px,
            rgba(200, 200, 200, 0.16) 12px,
            rgba(200, 200, 200, 0.13) 18px,
            rgba(200, 200, 200, 0.09) 24px,
            rgba(200, 200, 200, 0.07) 30px,
            rgba(200, 200, 200, 0.05) 36px,
            rgba(200, 200, 200, 0.04) 42px,
            rgba(200, 200, 200, 0.03) 48px,
            rgba(200, 200, 200, 0.02) 54px,
            rgba(200, 200, 200, 0.01) 59px,
            rgba(200, 200, 200, 0) 65px,
            transparent 65px,
            transparent calc(100% - 65px),
            rgba(200, 200, 200, 0) calc(100% - 65px),
            rgba(200, 200, 200, 0.01) calc(100% - 59px),
            rgba(200, 200, 200, 0.02) calc(100% - 54px),
            rgba(200, 200, 200, 0.03) calc(100% - 48px),
            rgba(200, 200, 200, 0.04) calc(100% - 42px),
            rgba(200, 200, 200, 0.05) calc(100% - 36px),
            rgba(200, 200, 200, 0.07) calc(100% - 30px),
            rgba(200, 200, 200, 0.09) calc(100% - 24px),
            rgba(200, 200, 200, 0.13) calc(100% - 18px),
            rgba(200, 200, 200, 0.16) calc(100% - 12px),
            rgba(200, 200, 200, 0.21) calc(100% - 6px),
            rgba(200, 200, 200, 0.26) 100%
        ),
        linear-gradient(to bottom,
            rgba(200, 200, 200, 0.26) 0px,
            rgba(200, 200, 200, 0.21) 6px,
            rgba(200, 200, 200, 0.16) 12px,
            rgba(200, 200, 200, 0.13) 18px,
            rgba(200, 200, 200, 0.09) 24px,
            rgba(200, 200, 200, 0.07) 30px,
            rgba(200, 200, 200, 0.05) 36px,
            rgba(200, 200, 200, 0.04) 42px,
            rgba(200, 200, 200, 0.03) 48px,
            rgba(200, 200, 200, 0.02) 54px,
            rgba(200, 200, 200, 0.01) 59px,
            rgba(200, 200, 200, 0) 65px,
            transparent 65px,
            transparent calc(100% - 65px),
            rgba(200, 200, 200, 0) calc(100% - 65px),
            rgba(200, 200, 200, 0.01) calc(100% - 59px),
            rgba(200, 200, 200, 0.02) calc(100% - 54px),
            rgba(200, 200, 200, 0.03) calc(100% - 48px),
            rgba(200, 200, 200, 0.04) calc(100% - 42px),
            rgba(200, 200, 200, 0.05) calc(100% - 36px),
            rgba(200, 200, 200, 0.07) calc(100% - 30px),
            rgba(200, 200, 200, 0.09) calc(100% - 24px),
            rgba(200, 200, 200, 0.13) calc(100% - 18px),
            rgba(200, 200, 200, 0.16) calc(100% - 12px),
            rgba(200, 200, 200, 0.21) calc(100% - 6px),
            rgba(200, 200, 200, 0.26) 100%
        );
}

*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-system);
    background-color: #000;
    color: var(--text-primary);
    overflow-x: hidden;
    min-height: 100vh;
    font-feature-settings: 'kern' 1;
    text-rendering: optimizeLegibility;
}

/* ========================================
   Loading Screen
======================================== */
.loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 0.6s var(--transition-smooth), 
                visibility 0.6s var(--transition-smooth);
}

.loader.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader-spinner {
    width: 32px;
    height: 32px;
    border: 2.5px solid rgba(255, 255, 255, 0.15);
    border-top-color: rgba(255, 255, 255, 0.9);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* ========================================
   Landing Section
======================================== */
.landing {
    position: relative;
    width: 100%;
    height: 100vh;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* ========================================
   Blurred Background Fill
======================================== */
.bg-blur {
    display: none; /* Hidden - main image now covers full viewport */
}

/* ========================================
   Parallax Background
======================================== */
.parallax-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    will-change: transform;
    transform: translateZ(0);
    overflow: hidden;
}

.bg-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center center;
    filter: saturate(1.05) brightness(0.95);
    transition: transform 0.15s var(--transition-smooth);
}

/* ========================================
   Overlay
======================================== */
.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--overlay-gradient);
    z-index: 2;
    pointer-events: none;
}

/* ========================================
   Email Icon with Notification - Minimal & Sleek
======================================== */
.email-icon-container {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 56px;
    height: 56px;
    /* REVERT: Change back to rgba(255, 255, 255, 0.025) */
    background: rgba(255, 255, 255, var(--icon-panel-opacity));
    backdrop-filter: blur(12px) saturate(1.2);
    -webkit-backdrop-filter: blur(12px) saturate(1.2);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 14px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2),
                inset 0 1px 0 rgba(255, 255, 255, 0.1);
    cursor: pointer;
    z-index: 5;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.25s var(--transition-smooth);
    opacity: 1;
    visibility: visible;
    padding: 6px;
    margin: 0;
    box-sizing: border-box;
}

/* Liquid glass border effect - fits tightly around icon */
.email-icon-container::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 14px;
    padding: 1px;
    background: linear-gradient(135deg, 
        rgba(255, 255, 255, 0.3) 0%,
        rgba(255, 255, 255, 0.1) 25%,
        rgba(255, 255, 255, 0.05) 50%,
        rgba(255, 255, 255, 0.1) 75%,
        rgba(255, 255, 255, 0.3) 100%);
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    opacity: 0;
    transition: opacity 0.3s var(--transition-smooth);
    pointer-events: none;
}

/* Rotating rainbow glow border on hover - follows existing border/trim exactly */
.email-icon-container {
    --rainbow-angle: 0deg;
}

.email-icon-container::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 14px;
    padding: 1px;
    background: conic-gradient(
        from var(--rainbow-angle),
        #ff0080 0deg,
        #ff8000 45deg,
        #ffff00 90deg,
        #80ff00 135deg,
        #00ff80 180deg,
        #00ffff 225deg,
        #0080ff 270deg,
        #8000ff 315deg,
        #ff0080 360deg
    );
    -webkit-mask: 
        linear-gradient(#fff 0 0) content-box, 
        linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    opacity: 0;
    animation: rotateRainbowGradient 3s linear infinite;
    pointer-events: none;
    z-index: 0;
}

@keyframes rotateRainbowGradient {
    from {
        --rainbow-angle: 0deg;
    }
    to {
        --rainbow-angle: 360deg;
    }
}

@property --rainbow-angle {
    syntax: '<angle>';
    initial-value: 0deg;
    inherits: false;
}

.email-icon-container:hover {
    transform: translate(-50%, -50%) scale(1.05);
    background: rgba(255, 255, 255, 0.08);
    border-color: transparent;
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.3),
                inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

.email-icon-container:hover::before {
    opacity: 1;
}

.email-icon-container:hover::after {
    opacity: 1;
}

.email-icon-container:active {
    transform: translate(-50%, -50%) scale(0.98);
}

.email-icon-container.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.email-icon-svg {
    width: 44px;
    height: 44px;
    color: rgba(255, 255, 255, 0.95);
    stroke: currentColor;
    transition: color 0.2s var(--transition-smooth);
    flex-shrink: 0;
}

.email-icon-container:hover .email-icon-svg {
    color: rgba(255, 255, 255, 1);
}

.email-notification {
    position: absolute;
    top: -6px;
    right: -6px;
    min-width: 20px;
    height: 20px;
    background: linear-gradient(135deg, #ff3b30 0%, #ff2d55 100%);
    border: 1.5px solid rgba(255, 255, 255, 0.3);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-system);
    font-size: 11px;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.95);
    z-index: 10;
    box-shadow: 0 2px 8px rgba(255, 59, 48, 0.4),
                0 0 0 1px rgba(255, 255, 255, 0.1);
    padding: 0 5px;
    transition: opacity 0.3s var(--transition-smooth),
                transform 0.3s var(--transition-spring);
    line-height: 1;
}


/* ========================================
   Letter Overlay Container
======================================== */
.letter-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 10;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 24px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.8s var(--transition-smooth),
                visibility 0.8s var(--transition-smooth);
}

/* Expansion animation from icon */
.letter-overlay.expanding {
    transition: none;
}

.letter-overlay.expanding .glass-letter {
    transform-origin: var(--expand-origin-x, 50%) var(--expand-origin-y, 50%);
    animation: expandFromIcon 0.6s var(--transition-spring) forwards;
}

@keyframes expandFromIcon {
    0% {
        transform: scale(0.1) translateY(0);
        opacity: 0;
    }
    50% {
        opacity: 0.8;
    }
    100% {
        transform: scale(1) translateY(0);
        opacity: 1;
    }
}

.letter-overlay.visible {
    opacity: 1;
    visibility: visible;
}

.letter-overlay.fade-out {
    opacity: 0;
    visibility: hidden;
}

/* ========================================
   Apple Glass Modal
======================================== */
.glass-letter {
    position: relative;
    width: 100%;
    max-width: 720px;
    /* REVERT: Change back to rgba(180, 185, 195, 0.05) */
    background: rgba(180, 185, 195, var(--glass-panel-opacity));
    backdrop-filter: blur(40px) saturate(1.8);
    -webkit-backdrop-filter: blur(40px) saturate(1.8);
    border-radius: 20px;
    box-shadow: var(--glass-shadow);
    overflow: visible;
    
    /* Fade-in effect from edges (photo visible) to center (clear glass) */
    -webkit-mask-image: radial-gradient(
        ellipse 100% 100% at center,
        rgba(0, 0, 0, 1) 40%,
        rgba(0, 0, 0, 0.85) 60%,
        rgba(0, 0, 0, 0.6) 75%,
        rgba(0, 0, 0, 0.3) 90%,
        rgba(0, 0, 0, 0) 100%
    );
    mask-image: radial-gradient(
        ellipse 100% 100% at center,
        rgba(0, 0, 0, 1) 40%,
        rgba(0, 0, 0, 0.85) 60%,
        rgba(0, 0, 0, 0.6) 75%,
        rgba(0, 0, 0, 0.3) 90%,
        rgba(0, 0, 0, 0) 100%
    );
    
    /* Entrance animation - default state */
    opacity: 0;
    transform: scale(0.96) translateY(12px);
    transition: opacity 0.5s var(--transition-smooth) 0.2s,
                transform 0.6s var(--transition-spring) 0.2s;
}

.letter-overlay.visible .glass-letter:not(.expanding) {
    opacity: 1;
    transform: scale(1) translateY(0);
}

/* Subtle inner highlight */
.glass-letter::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(
        90deg,
        transparent 0%,
        rgba(255, 255, 255, 0.3) 50%,
        transparent 100%
    );
}

/* ========================================
   Letter Content
======================================== */
.letter-content {
    padding: 24px 28px 24px;
}

/* ========================================
   Email Metadata Header
======================================== */
.email-meta {
    margin-bottom: 13px;
    padding-bottom: 11px;
    border-bottom: 0.5px solid rgba(255, 255, 255, 0.12);
    
    /* Hidden until JS triggers */
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.4s var(--transition-smooth),
                transform 0.4s var(--transition-smooth);
}

.email-meta.visible {
    opacity: 1;
    transform: translateY(0);
}

.meta-row {
    display: flex;
    align-items: baseline;
    gap: 6px;
    margin-bottom: 2px;
    font-family: var(--font-system);
    font-size: 11px;
    line-height: 1.35;
}

.meta-row:last-child {
    margin-bottom: 0;
}

.meta-label {
    font-weight: 600;
    color: var(--text-primary);
    min-width: 48px;
}

.meta-value {
    font-weight: 400;
    color: var(--text-secondary);
}

#email-subject {
    font-weight: 500;
    font-size: 13px;
    color: var(--text-primary);
}

/* ========================================
   Email Body - Split-Flap Display
======================================== */
.email-body {
    font-family: var(--font-system);
    font-size: 13px;
    font-weight: 400;
    line-height: 1.55;
    color: var(--text-secondary);
    letter-spacing: -0.01em;
    min-height: auto;
    overflow-wrap: break-word;
    word-wrap: break-word;
    word-break: normal;
    overflow: visible;
    /* Enhanced readability with more transparent background */
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.email-body p {
    margin-bottom: 10px;
    overflow-wrap: break-word;
    word-wrap: break-word;
    word-break: normal;
}

.email-body .email-header,
.email-body h3.email-header {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 12px;
    margin-top: 0;
    font-family: var(--font-system);
    letter-spacing: -0.01em;
}

.email-body p:last-child {
    margin-bottom: 0;
}

/* Split-flap character styling */
.split-flap-char {
    display: inline-block;
    position: relative;
    transition: transform 0.05s ease-out;
}

.split-flap-char.flipping {
    animation: splitFlapFlip 0.08s ease-out;
}

@keyframes splitFlapFlip {
    0% {
        transform: rotateX(0deg);
        opacity: 0.7;
    }
    50% {
        transform: rotateX(-90deg);
        opacity: 0.5;
    }
    100% {
        transform: rotateX(0deg);
        opacity: 1;
    }
}

/* Cursor for split-flap effect */
.split-flap-cursor {
    display: inline-block;
    width: 2px;
    height: 1em;
    background: var(--text-secondary);
    margin-left: 1px;
    animation: cursorBlink 0.6s ease-in-out infinite;
    vertical-align: text-bottom;
}

@keyframes cursorBlink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0; }
}

/* ========================================
   Email Signature
======================================== */
.email-signature {
    margin-top: 11px;
    opacity: 0;
    transition: opacity 0.4s var(--transition-smooth);
}

.email-signature.visible {
    opacity: 1;
}

.email-signature .signature-name {
    font-family: var(--font-system);
    font-size: 12px;
    font-weight: 500;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

/* ========================================
   Continue Button - Apple Style with Prismatic Trim
======================================== */
.letter-continue {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    width: 100%;
    margin-top: 14px;
    padding: 12px 20px;
    background: var(--glass-bg-elevated);
    border: 0.5px solid rgba(255, 255, 255, 0.12);
    border-radius: 12px;
    color: var(--text-primary);
    font-family: var(--font-system);
    font-size: 14px;
    font-weight: 500;
    letter-spacing: -0.01em;
    cursor: pointer;
    overflow: hidden;
    transition: all 0.2s var(--transition-smooth);
    
    /* CSS variables for prismatic effect */
    --omx: 50%;
    --omy: 50%;
    --prism: 0;
    
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.4s var(--transition-smooth),
                transform 0.4s var(--transition-smooth),
                background 0.2s var(--transition-smooth);
}

.letter-continue.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Edge-proximity glass lighting effect */
.letter-continue {
    --edge-x: 50%;
    --edge-y: 50%;
    --glow: 0;
    --hue: 0;
    /* Offset from center in pixels - calculated by JS */
    --shadow-x: 0px;
    --shadow-y: 0px;
}

/* Prismatic edge glow using positioned box-shadow */
.letter-continue::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    pointer-events: none;
    z-index: -1;
    background: transparent;
    
    /* Multi-colored box-shadows offset toward edge point */
    /* These naturally appear ONLY on the outer edge */
    box-shadow: 
        var(--shadow-x) var(--shadow-y) 12px 0px hsla(calc(var(--hue)), 85%, 60%, calc(var(--glow) * 0.7)),
        var(--shadow-x) var(--shadow-y) 20px 2px hsla(calc(var(--hue) + 60), 80%, 55%, calc(var(--glow) * 0.5)),
        var(--shadow-x) var(--shadow-y) 28px 4px hsla(calc(var(--hue) + 120), 75%, 50%, calc(var(--glow) * 0.35)),
        var(--shadow-x) var(--shadow-y) 36px 6px hsla(calc(var(--hue) + 180), 70%, 50%, calc(var(--glow) * 0.2));
    
    animation: hueFlow 4s linear infinite;
}

@keyframes hueFlow {
    from { --hue: 0; }
    to { --hue: 360; }
}

@property --hue {
    syntax: '<number>';
    inherits: true;
    initial-value: 0;
}

.letter-continue > span,
.letter-continue .continue-arrow {
    position: relative;
    z-index: 1;
}

/* Default state - static white text */
.letter-continue > span {
    color: var(--text-primary);
    font-weight: 600;
    transition: all 0.3s ease;
}

.letter-continue .continue-arrow {
    stroke: var(--text-primary);
    transition: all 0.3s ease;
}

/* Hover - liquid prismatic flow activates */
.letter-continue:hover > span {
    background: linear-gradient(
        90deg,
        rgba(255, 255, 255, 1) 0%,
        rgba(230, 180, 200, 1) 12.5%,
        rgba(230, 200, 170, 1) 25%,
        rgba(180, 220, 180, 1) 37.5%,
        rgba(170, 210, 220, 1) 50%,
        rgba(180, 190, 230, 1) 62.5%,
        rgba(210, 180, 220, 1) 75%,
        rgba(230, 180, 210, 1) 87.5%,
        rgba(255, 255, 255, 1) 100%
    );
    background-size: 200% 100%;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: liquidFlow 2.5s linear infinite;
}

.letter-continue:hover .continue-arrow {
    animation: arrowLiquidFlow 2.5s linear infinite;
}

@keyframes liquidFlow {
    0% {
        background-position: 200% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

/* Arrow color synced - muted prismatic tones */
@keyframes arrowLiquidFlow {
    0%, 100% {
        stroke: rgba(255, 255, 255, 1);
        filter: drop-shadow(0 0 2px rgba(230, 180, 200, 0.5));
    }
    12.5% {
        stroke: rgba(230, 180, 200, 1);
        filter: drop-shadow(0 0 2px rgba(230, 180, 200, 0.6));
    }
    25% {
        stroke: rgba(230, 200, 170, 1);
        filter: drop-shadow(0 0 2px rgba(230, 200, 170, 0.6));
    }
    37.5% {
        stroke: rgba(180, 220, 180, 1);
        filter: drop-shadow(0 0 2px rgba(180, 220, 180, 0.6));
    }
    50% {
        stroke: rgba(170, 210, 220, 1);
        filter: drop-shadow(0 0 2px rgba(170, 210, 220, 0.6));
    }
    62.5% {
        stroke: rgba(180, 190, 230, 1);
        filter: drop-shadow(0 0 2px rgba(180, 190, 230, 0.6));
    }
    75% {
        stroke: rgba(210, 180, 220, 1);
        filter: drop-shadow(0 0 2px rgba(210, 180, 220, 0.6));
    }
    87.5% {
        stroke: rgba(230, 180, 210, 1);
        filter: drop-shadow(0 0 2px rgba(230, 180, 210, 0.6));
    }
}

.letter-continue:hover {
    background: rgba(255, 255, 255, 0.22);
    transform: scale(1.01);
}

.letter-continue:active {
    transform: scale(0.98);
    background: rgba(255, 255, 255, 0.16);
}

.letter-continue .continue-arrow {
    width: 16px;
    height: 16px;
    stroke-width: 2.5;
    transition: transform 0.2s var(--transition-smooth);
}

.letter-continue:hover .continue-arrow {
    transform: translateX(3px);
}

/* Edge glow entice - no longer animates glow/edge vars; JS handles tracking */
.letter-continue.prismatic-entice {
    /* Class kept for JS detection but no animation that overrides tracking */
}

/* ========================================
   Fade Transition
======================================== */
.landing.fade-out {
    animation: fadeOut 1s var(--transition-smooth) forwards;
}

@keyframes fadeOut {
    0% {
        opacity: 1;
    }
    100% {
        opacity: 0;
    }
}

/* ========================================
   Next Section
======================================== */
.next-section {
    position: relative;
    width: 100%;
    min-height: 100vh;
    background: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    transition: opacity 0.8s var(--transition-smooth);
}

.next-section.visible {
    opacity: 1;
}

.next-content {
    text-align: center;
    padding: 24px;
}

.next-content h2 {
    font-family: var(--font-system);
    font-size: clamp(28px, 5vw, 44px);
    font-weight: 600;
    letter-spacing: -0.03em;
    color: var(--text-primary);
}

/* ========================================
   Responsive Adjustments
======================================== */
@media (max-width: 768px) {
    .letter-overlay {
        padding: 20px;
    }
    
    .letter-content {
        padding: 28px 24px 24px;
    }
    
    .glass-letter {
        max-width: 100%;
        border-radius: 16px;
    }
    
    .letter-header {
        font-size: 20px;
    }
    
    .letter-body {
        font-size: 14px;
    }
}

@media (max-width: 480px) {
    .letter-overlay {
        padding: 16px;
    }
    
    .letter-content {
        padding: 24px 20px 20px;
    }
    
    .letter-header {
        font-size: 18px;
        margin-bottom: 16px;
    }
    
    .letter-body {
        font-size: 14px;
        line-height: 1.55;
    }
    
    .letter-body p {
        margin-bottom: 14px;
    }
    
    .letter-signature {
        margin-top: 20px;
        padding-top: 16px;
    }
    
    .letter-continue {
        margin-top: 20px;
        padding: 12px 16px;
        font-size: 14px;
        border-radius: 10px;
    }
}

/* Landscape orientation on mobile */
@media (max-height: 600px) and (orientation: landscape) {
    .glass-letter {
        transform: scale(0.85);
        transform-origin: center center;
    }
    
    .letter-content {
        padding: 16px;
    }
    
    .email-body {
        font-size: 11px;
        line-height: 1.4;
    }
    
    .email-body p {
        margin-bottom: 6px;
    }
    
    .email-signature {
        margin-top: 10px;
        padding-top: 8px;
    }
    
    .letter-continue {
        margin-top: 10px;
        padding: 8px 16px;
    }
}

/* Reduced motion preference */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .letter-header,
    .letter-body p,
    .letter-signature,
    .letter-continue {
        opacity: 1;
        transform: none;
    }
}

/* ========================================
   Selection Styling
======================================== */
::selection {
    background: rgba(0, 122, 255, 0.3);
    color: var(--text-primary);
}

/* ========================================
   Scrollbar (WebKit)
======================================== */
.glass-letter::-webkit-scrollbar {
    width: 6px;
}

.glass-letter::-webkit-scrollbar-track {
    background: transparent;
}

.glass-letter::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 3px;
}

.glass-letter::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* ========================================
   X Feed Modal
======================================== */
.x-feed-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 20;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 24px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.5s var(--transition-smooth),
                visibility 0.5s var(--transition-smooth);
}

.x-feed-overlay.visible {
    opacity: 1;
    visibility: visible;
}

.x-feed-modal {
    max-width: 720px;
    max-height: 85vh;
    display: flex;
    flex-direction: column;
    /* Override glass-letter defaults for x-feed context */
    opacity: 0;
    transform: scale(0.96) translateY(12px);
    transition: opacity 0.5s var(--transition-smooth),
                transform 0.5s var(--transition-smooth);
}

.x-feed-overlay.visible .x-feed-modal {
    opacity: 1;
    transform: scale(1) translateY(0);
}

.x-feed-content {
    position: relative;
    padding: 16px;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.x-feed-close {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 32px;
    height: 32px;
    border: none;
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    font-size: 24px;
    line-height: 1;
    border-radius: 50%;
    cursor: pointer;
    transition: background 0.2s ease, transform 0.2s ease;
    z-index: 10;
}

.x-feed-close:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: scale(1.1);
}

.x-feed-close:focus {
    outline: 2px solid rgba(255, 255, 255, 0.5);
    outline-offset: 2px;
}

.x-feed-container {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    margin-top: 32px;
    border-radius: 12px;
    min-height: 400px;
}

/* Loading state */
.x-feed-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 200px;
}

/* Style the Twitter iframe container */
.x-feed-container .twitter-timeline {
    border-radius: 12px;
}

/* Twitter timeline iframe styling */
.x-feed-container .twitter-timeline-rendered,
.x-feed-container iframe {
    border-radius: 12px !important;
    background: transparent !important;
}

/* Scrollbar for X feed container */
.x-feed-container::-webkit-scrollbar {
    width: 6px;
}

.x-feed-container::-webkit-scrollbar-track {
    background: transparent;
}

.x-feed-container::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 3px;
}

.x-feed-container::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .x-feed-overlay {
        padding: 16px;
    }
    
    .x-feed-modal {
        max-width: 100%;
        max-height: 90vh;
    }
}

@media (max-width: 480px) {
    .x-feed-overlay {
        padding: 12px;
    }
    
    .x-feed-content {
        padding: 12px;
    }
    
    .x-feed-close {
        top: 8px;
        right: 8px;
        width: 28px;
        height: 28px;
        font-size: 20px;
    }
}