:root {
    /* Light theme colors */
    --background-color: #ffffff;
    --background-secondary: #F0F0F4;
    --background-tertiary: #E0E0E4;
    --text-primary: rgba(0, 0, 0, 1);      /* 100% opacity */
    --text-secondary: rgba(0, 0, 0, 0.64);  /* 64% opacity */
    --text-tertiary: rgba(0, 0, 0, 0.4);    /* 40% opacity */
    --primary-color: #007AFF;
    --padding: 64px;
    --radius: 24px;
    --font-size-xl: 32px;
    --font-size-lg: 24px;
    --font-size-md: 18px;
    --font-size-sm: 14px;
    --border-color: rgba(0, 0, 0, 0.08);
    --width: 960px;
  }
  
  @media (prefers-color-scheme: dark) {
    :root {
      /* Dark theme colors */
      --background-color: #1C1C1E;
      --background-secondary: #000000;
      --background-tertiary: #2C2C2E;
      --text-primary: rgba(255, 255, 255, 1);      /* 100% opacity */
      --text-secondary: rgba(255, 255, 255, 0.64);  /* 64% opacity */
      --text-tertiary: rgba(255, 255, 255, 0.4);    /* 40% opacity */
      --primary-color: #0A84FF;
      --border-color: rgba(255, 255, 255, 0.08);
    }
  }
  a {
    color: var(--primary-color);
  }

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
    list-style: none;
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}
body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Helvetica Neue', sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
}

h1, h2 {
    font-weight: 600;
    font-size: var(--font-size-xl);
}

#hero p, #footer p {
    font-size: var(--font-size-md);
    color: var(--text-secondary);
    margin-top: 8px;
}

.inner {
    width: var(--width);
    margin: 0 auto;
    text-align: center;
}

#icon .icon {
    width: 96px;
    height: 96px;
}
#icon h3 {
    font-size: var(--font-size-md);
    font-weight: 500;
}

header {
    /* position: sticky; */
    background-color: var(--background-color);
    /* top: 0; */
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    /* border-bottom: 1px solid var(--border-color); */
}
#footer header {
    background: none;
    border-top: 1px solid var(--border-color);
    border-bottom: none;
    margin-top: var(--padding);
}
#footer {
    background: none;
    border-top: 1px solid var(--border-color);
}
header .logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--text-primary);
}
header .logo img {
    width: 32px;
    height: 32px;
}
header .inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
header .nav {
    display: flex;
    gap: calc(var(--padding) / 2);
    font-size: var(--font-size-sm);
}
header a {
    color: var(--text-secondary);
}

.section {
    background-color: var(--background-secondary);
    padding: calc(var(--padding) * 2) 0;
    margin-bottom: calc(var(--padding) / 2);
}
#hero, #footer {
    margin-bottom: 0;
}
#hero, #tech-specs {
    background-color: var(--background-color);
}
#icon {
    margin-bottom: calc(var(--padding) / 2);
}

#buttons {
    margin-top: 16px;
    display: inline-block;
}
#hero #buttons, #footer #buttons {
    margin: calc(var(--padding) / 2) auto 0;
    display: flex;
    gap: 12px;
    justify-content: center;
}
#buttons a {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0 16px;
    height: 40px;
    border-radius: 20px;
    background: var(--background-secondary);
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 600;
    font-size: 16px;
    gap: 6px;
}
#buttons a:hover {
    opacity: 0.8;
    text-decoration: none;
}
#buttons a.primary {
    background: var(--primary-color);
    color: #fff;
}


.section h2 {
    margin-bottom: var(--padding);
}
.grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: calc(var(--padding) / 2);
}
.card {
    min-height: calc(var(--width) / 2);
    background-color: var(--background-color);
    padding: var(--padding);
    border-radius: var(--radius);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: space-between;
    text-align: left;
}
#tech-specs .card {
    background-color: var(--background-secondary);
    justify-content: flex-start;
}
.card.wrapper {
    /* border: 1px solid var(--border-color); */
}
#tech-specs .table {
    width: 100%;
    gap: var(--padding);
}
#tech-specs .table .card {
    padding: 0;
    gap: calc(var(--padding) / 3);
    min-height: auto;
}
.table .row {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    line-height: 1.5;
}
.table .row h5 {
    font-size: var(--font-size-sm);
    color: var(--text-tertiary);
    font-weight: 400;
}
.table .row h6 {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    font-weight: 500;
    text-align: right;
}
.table a {
    color: var(--text-primary);
}
.card h4 {
    font-size: var(--font-size-md);
    font-weight: 600;
}
.card hr {
    border: none;
    width: 100%;
    background: none;
    border-top: 1px solid var(--border-color);
    margin: calc(var(--padding) / 2) 0;
}
.card.prominent {
    background-color: var(--primary-color);
    color: var(--background-color);
}
.card.full-width {
    grid-column: span 2;
}
.grid.third {
    grid-template-columns: repeat(3, 1fr);
}
.grid.third .card {
    min-height: calc(var(--width) / 3);
    padding: calc(var(--padding) / 1.5);
}
.card svg {
    width: 56px;
    stroke: var(--primary-color);
}
.card.prominent svg {
    stroke: var(--background-color);
}
.card h3 {
    color: var(--text-primary);
    font-size: var(--font-size-lg);
    font-weight: 500;
}
.card p {
    font-size: var(--font-size-md);
    color: var(--text-secondary);
    margin-top: 8px;
}
.card h3, .card p {
    max-width: calc((var(--width) / 2) - var(--padding));
}
.card.prominent h3 {
    color: var(--background-color);
}
.card.prominent p {
    color: var(--background-color);
    opacity: 0.64;
}



#platforms .card {
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}
.card.vision {
    background-image: url(images/devices/vision.png);
}
.card.ipad {
    background-image: url(images/devices/ipad.png);
}
.card.mac {
    background-image: url(images/devices/mac.png);
}
.card.phone {
    background-image: url(images/devices/phone.png);
}



.card.hero-phone {
    background-image: url(images/devices/hero.png);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: bottom right;
}
.card.personalize {
    background-image: url(images/devices/personalize.png);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: top right;
}




/* dark mode */
@media (prefers-color-scheme: dark) {
    .card.prominent h3 {
        color: var(--text-primary);
    }
    .card.prominent svg {
        stroke: var(--text-primary);
    }
    .card.prominent p {
        color: var(--text-primary);
    }
    #buttons a {
        background: var(--background-tertiary)
    }
    .prominent #buttons a {
        background: var(--text-primary);
        color: var(--background-color);
    }
    #platforms .card {
        border: 1px solid var(--background-tertiary);
    }
}

@media (max-width: 1024px) {
    :root {
        --padding: 32px;
        --radius: 16px;
        --font-size-xl: 24px;
        --font-size-lg: 18px;
        --font-size-md: 16px;
        --font-size-sm: 14px;
    }
    .inner {
        width: 100%;
        padding: var(--padding);
    }
    .card.hero-phone h3 {
        max-width: 40%;
    }
}
@media (max-width: 768px) {
    :root {
        --width: 640px;
    }
    header {
        height: 64px;
    }
    header .logo img {
        width: 24px;
        height: 24px;
    }
    .grid, .grid.third {
        grid-template-columns: 1fr;
    }
    .card {
        grid-column: span 2;
    }
    /* .card.phone {
        gap: var(--padding);
        justify-content: flex-start;
    } */
    .card svg {
        width: 48px;
    }
    .card h3, .card p,
    .card.hero-phone h3 {
        max-width: 100%;
    }
    .card.half {
        grid-column: span 1;
        aspect-ratio: 1/1;
        min-height: auto;
    }
    #platforms .grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .card.hero-phone {
        justify-content: flex-start;
        gap: var(--padding);
        background-size: calc(var(--width) / 1.5);
        background-position: bottom center;
        min-height: calc(var(--width) - var(--padding) * 2);
    }
    .card.personalize {
        justify-content: flex-end;
        gap: var(--padding);
        background-size: calc(var(--width) / 1.5);
        background-position: top center;
        min-height: calc(var(--width) - var(--padding) * 2);
    }
}
@media (max-width: 480px) {
    .card.half {
        grid-column: span 2;
    }
    .card.hero-phone, .card.personalize {
        background-size: contain;
    }
}