/* ===================================
   AI Summit Speakers — Stripe-inspired
   =================================== */

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

:root {
    --purple: #533afd;
    --purple-hover: #4434d4;
    --purple-light: #ededff;
    --navy: #061b31;
    --body-color: #64748d;
    --label-color: #273951;
    --white: #ffffff;
    --bg: #f7f8fa;
    --border: #e5edf5;
    --border-purple: #b9b9f9;
    --shadow-blue: rgba(50, 50, 93, 0.25);
    --shadow-black: rgba(0, 0, 0, 0.1);
    --shadow-soft: rgba(23, 23, 23, 0.06);
    --radius: 8px;
    --radius-sm: 4px;
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font);
    font-size: 16px;
    line-height: 1.5;
    color: var(--body-color);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
}

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

a {
    color: var(--purple);
    text-decoration: none;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 24px;
}

/* === Header === */
.header {
    background: var(--white);
    border-bottom: 1px solid var(--border);
    padding: 16px 0;
}

.header .container {
    display: flex;
    align-items: baseline;
    gap: 12px;
}

.header__brand {
    font-size: 18px;
    font-weight: 600;
    color: var(--navy);
    letter-spacing: -0.3px;
}

.header__sub {
    font-size: 13px;
    color: var(--body-color);
    font-weight: 400;
}

/* === Hero === */
.hero {
    padding: 80px 0 48px;
    background: var(--white);
    border-bottom: 1px solid var(--border);
}

.hero__label {
    font-size: 13px;
    font-weight: 500;
    color: var(--purple);
    text-transform: uppercase;
    letter-spacing: 0.8px;
    margin-bottom: 12px;
}

.hero__title {
    font-size: 48px;
    font-weight: 300;
    color: var(--navy);
    letter-spacing: -0.96px;
    line-height: 1.15;
    margin-bottom: 16px;
}

.hero__lead {
    font-size: 18px;
    font-weight: 300;
    color: var(--body-color);
    line-height: 1.55;
    max-width: 560px;
}

@media (max-width: 640px) {
    .hero {
        padding: 48px 0 32px;
    }
    .hero__title {
        font-size: 32px;
        letter-spacing: -0.64px;
    }
    .hero__lead {
        font-size: 16px;
    }
}

/* === Bubble Message === */
.message {
    padding: 48px 0 0;
}

.bubble {
    display: flex;
    gap: 20px;
    align-items: flex-start;
}

.bubble__avatar {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--purple);
    flex-shrink: 0;
    margin-top: 4px;
}

.bubble__content {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: 4px 16px 16px 16px;
    padding: 32px 36px;
    box-shadow: var(--shadow-blue) 0px 20px 35px -25px, var(--shadow-black) 0px 12px 28px -14px;
    position: relative;
    flex: 1;
    min-width: 0;
}

.bubble__content::before {
    content: "";
    position: absolute;
    left: -8px;
    top: 18px;
    width: 16px;
    height: 16px;
    background: var(--white);
    border-left: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    transform: rotate(45deg);
}

.bubble__name {
    font-size: 15px;
    font-weight: 500;
    color: var(--navy);
    margin-bottom: 4px;
}

.bubble__role {
    font-size: 11px;
    font-weight: 600;
    color: var(--purple);
    background: var(--purple-light);
    padding: 2px 8px;
    border-radius: var(--radius-sm);
    margin-left: 6px;
    vertical-align: middle;
    letter-spacing: 0.5px;
}

.bubble__title {
    font-size: 22px;
    font-weight: 300;
    color: var(--navy);
    letter-spacing: -0.22px;
    line-height: 1.2;
    margin-bottom: 20px;
}

.bubble__body p {
    font-size: 15px;
    line-height: 1.8;
    color: var(--body-color);
    margin-bottom: 14px;
}

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

@media (max-width: 640px) {
    .bubble {
        gap: 12px;
    }
    .bubble__avatar {
        width: 44px;
        height: 44px;
    }
    .bubble__content {
        padding: 20px;
        border-radius: 4px 12px 12px 12px;
    }
    .bubble__content::before {
        left: -6px;
        top: 14px;
        width: 12px;
        height: 12px;
    }
    .bubble__title {
        font-size: 18px;
    }
}

/* === Speaker Cards === */
.speakers {
    padding: 48px 0 80px;
}

.speaker-card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 40px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-blue) 0px 30px 45px -30px, var(--shadow-black) 0px 18px 36px -18px;
    transition: box-shadow 0.25s ease, transform 0.15s ease;
}

.speaker-card:hover {
    box-shadow: var(--shadow-blue) 0px 40px 55px -25px, var(--shadow-black) 0px 24px 42px -14px;
    transform: translateY(-2px);
}

.speaker-card--host {
    border: 2px solid var(--purple);
    background: linear-gradient(135deg, var(--white) 0%, var(--purple-light) 100%);
}

.speaker-card__header {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 24px;
}

.speaker-card__avatar {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--border);
    flex-shrink: 0;
}

.speaker-card--host .speaker-card__avatar {
    border-color: var(--purple);
}

.speaker-card__day {
    display: inline-block;
    font-size: 11px;
    font-weight: 600;
    color: var(--purple);
    text-transform: uppercase;
    letter-spacing: 1.2px;
    background: var(--purple-light);
    padding: 3px 10px;
    border-radius: var(--radius-sm);
    margin-bottom: 4px;
}

.speaker-card--host .speaker-card__day {
    background: var(--purple);
    color: var(--white);
}

.speaker-card__name {
    font-size: 22px;
    font-weight: 500;
    color: var(--navy);
    letter-spacing: -0.22px;
    line-height: 1.2;
}

.speaker-card__role {
    font-size: 13px;
    color: var(--body-color);
    margin-top: 2px;
}

.speaker-card__session {
    font-size: 16px;
    font-weight: 500;
    color: var(--label-color);
    margin-bottom: 12px;
    padding-left: 12px;
    border-left: 3px solid var(--purple);
}

.speaker-card__bio {
    font-size: 15px;
    line-height: 1.7;
    color: var(--body-color);
    margin-bottom: 24px;
}

.speaker-card__links {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.speaker-card__dm {
    margin-top: 16px;
    font-size: 14px;
    color: var(--label-color);
    padding: 12px 16px;
    background: var(--bg);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--purple);
}

.speaker-card__dm a {
    color: var(--purple);
    font-weight: 500;
}

@media (max-width: 640px) {
    .speaker-card {
        padding: 24px;
    }
    .speaker-card__header {
        gap: 14px;
    }
    .speaker-card__avatar {
        width: 56px;
        height: 56px;
    }
    .speaker-card__name {
        font-size: 18px;
    }
    .speaker-card__links {
        flex-direction: column;
    }
}

/* === Buttons === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 20px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    line-height: 1;
    text-decoration: none;
    transition: all 0.2s ease;
    white-space: nowrap;
    cursor: pointer;
    gap: 6px;
}

.btn--primary {
    background: var(--purple);
    color: var(--white);
    box-shadow: 0 4px 12px rgba(83, 58, 253, 0.3);
}

.btn--primary:hover {
    background: var(--purple-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(83, 58, 253, 0.4);
}

.btn--primary:active {
    transform: translateY(0);
    box-shadow: 0 2px 6px rgba(83, 58, 253, 0.3);
}

.btn--primary::before {
    content: "→";
    font-size: 13px;
    opacity: 0.7;
}

.btn--accent {
    background: linear-gradient(135deg, var(--navy) 0%, #1a3a5c 100%);
    color: var(--white);
    box-shadow: 0 4px 12px rgba(6, 27, 49, 0.3);
}

.btn--accent:hover {
    background: linear-gradient(135deg, #0a2e4f 0%, #1e4670 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(6, 27, 49, 0.4);
}

.btn--accent:active {
    transform: translateY(0);
}

.btn--accent::before {
    content: "→";
    font-size: 13px;
    opacity: 0.7;
}

.btn--outline {
    background: var(--white);
    color: var(--purple);
    border: 1px solid var(--border-purple);
    box-shadow: 0 1px 3px var(--shadow-soft);
}

.btn--outline:hover {
    background: var(--purple-light);
    border-color: var(--purple);
    transform: translateY(-1px);
    box-shadow: 0 4px 8px var(--shadow-soft);
}

.btn--outline:active {
    transform: translateY(0);
}

/* === Footer === */
.footer {
    background: var(--white);
    border-top: 1px solid var(--border);
    padding: 32px 0;
    text-align: center;
}

.footer p {
    font-size: 13px;
    color: var(--body-color);
}